| Shinji Hokamoto | Last modified date：2024.04.09 |
Professor /
Flight Dynamics and Controls /
Department of Aeronautics and Astronautics /
Faculty of Engineering
Papers
| 1. | Soi Yamaguchi, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Mission Strategy to Await Comets by Leveraging Manifolds and Low Thrust, Proceedings of the 74th International Astronautical Congress, 2023.10. |
| 2. | Shodai Hirayama, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Optimal Trajectory Design by ADAM under Stochastic Disturbing Acceleration, Proceedings of the 74th International Astronautical Congress, 2023.10. |
| 3. | Ayumi Chikusa, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Guidance and Control Algorithm for Mars Aerocapture Considering Uncertainties, Proceedings of the 74th International Astronautical Congress, 2023.10. |
| 4. | Yuta Hayashi, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Attitude Control Using Iterative Learning Control Considering Orbital Motion of NRHO, Proceedings of the 74th International Astronautical Congress, 2023.10. |
| 5. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Analysis of Transfer Trajectories in Cislunar Space Using Sequences of Lobe Dynamics, Proceedings of the 74th International Astronautical Congress, 2023.10. |
| 6. | Zhengxu Pan, Mai Bando, Zhanxia Zhu, Shinji Hokamoto, A New Gravitational Wave Observatory Formation Configuration Design and Control Method, Proceedings of the 2023 SICE Annual Conference, 2023.09. |
| 7. | Naoki Hiraiwa, Isaia Nisoli, Yuzuru Sato, Mai Bando, Shinji Hokamoto, Transfer between Resonances via Lobe Dynamics in the Standard Map, Proceedings of 10th International Congress on Industrial and Applied Mathematics, 2023.08. |
| 8. | Saki Takeuchi, Mai Bando, Shinji Hokamoto, Optimization of Structural Configurations of Spacecraft for Efficient Attitude Change Utilizing Non-holonomic Features, Proceedings of the 34th International Symposium on Space Technology and Science, 2023.06. |
| 9. | Zhengxu Pan, Zhanxia Zhu, Mai Bando, Shinji Hokamoto, Orbital Configuration Control for Space-based Gravitational Wave Observatory in the Three-body Problem, Proceedings of the 34th International Symposium on Space Technology and Science, 2023.06. |
| 10. | Ayano Tsuruta, Mai Bando, Daniel Scheeres, Shinji Hokamoto, New Equilibria in Quadratic Optimal Control Systems, Proceedings of the 34th International Symposium on Space Technology and Science, 2023.06. |
| 11. | Shodai Hirayama, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Optimal Transfer by Stochastic Gradient Descent Algorithm ADAM, Proceedings of the 34th International Symposium on Space Technology and Science, 2023.06. |
| 12. | Yuta Hayashi, Mai Bando, Shinji Hokamoto, Discrete-Time Attitude Control for Spacecraft Using Iterative Learning, Proceedings of the 34th International Symposium on Space Technology and Science, 2023.06. |
| 13. | Taiga Kajikawa, Tatsuya Shiotsuka, Mai Bando, Shinji Hokamoto, Data-Driven Guidance and Control for Asteroid Landing Based on Real-Time Dynamic Mode Decomposition, IEEE Access, 10.1109/ACCESS.2023.3276754, 11, 52622-52635, 2023.05. |
| 14. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Halo-to-Halo Low-Thrust Transfer via Successive Convex Optimization with Intermediate Orbit Design, Journal of Journal of Evolving Space Activities, 10.57350/jesa.48, 1, 2023.06. |
| 15. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Trajectory Design in Irregular Gravitational Fields Based on Center Manifold Theory, Journal of Guidance, Control, and Dynamics. |
| 16. | Xi Chen, Mai Bando, Shinji Hokamoto, An Improved YOLO for Tiny Rocks Detection in Spacecraft Autonomous Landing, Proceedings of the 2022 Asia-Pacific International Symposium on Aerospace Technology (APISAT2022), 2022.10. |
| 17. | Kanta Ikeda, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Design of Satellites Tours Using Periapsis Poincaré Map in Multibody Dynamics of Jovian System, Proceedings of the 73rd International Astronautical Congress, 2022.09. |
| 18. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Design of Optimal Low-Thrust Orbit-to-Orbit Transfers via Convex Approach, Proceedings of the 73rd International Astronautical Congress, 2022.09. |
| 19. | Kyoshuke Sato, Mai Bando, Shinji Hokamoto, A Data-Driven Nonlinear Optimal Control Using Koopman Operator on Hamiltonian Flow, Proceedings of the 73rd International Astronautical Congress, 2022.09. |
| 20. | Taiga Kajikawa, Mai Bando, Shinji Hokamoto, Data-Driven Guidance for Asteroid Landing Based on Real-Time Dynamic Mode Decomposition, Proceedings of the 73rd International Astronautical Congress, 2022.09. |
| 21. | Hiromitsu Hiraiwa, Mai Bando, Shinji Hokamoto, Altitude Estimation by Wide-Field-Integration Optic Flow, Proceedings of the 33rd Congress of the International Council of the Aeronautical Sciences, 2022.09. |
| 22. | Yuke Huang, Mai Bando, Shinji Hokamoto, Influence of Overall Layout Design of Compound Multi-Rotor Vehicles on Flight Performance, Proceedings of the 33rd Congress of the International Council of the Aeronautical Sciences , 2022.09. |
| 23. | Komsun Tamanakijprasart, Mai Bando, Shinji Hokamoto, Data-Driven Orbital Control in Perturbed Environment, Proceedings of the 2022 SICE Annual Conference, 2022.09. |
| 24. | Mai Bando, Hamidreza Nemati, Yuki Akiyama, Shinji Hokamoto, Formation Flying Along Libration Point Orbits Using Chattering Attenuation Sliding Mode Control, Frontier in Space Technology, 2022.07. |
| 25. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Sparse Optimal Trajectory Design in Three-Body Problem, Journal of the Astronautical Sciences, 26, 829-856, 2022.05, [URL]. |
| 26. | Yuki Kayama, Kathleen Howell, Mai Bando, Shinji Hokamoto, Low-Thrust Trajectory Design with Convex Optimization for Libration Point Orbits, Journal of Guidance, Control, and Dynamics, 10.2514/1.G005916, 45, 4, 623-637, 2022.04, [URL], In space missions, numerical techniques for minimizing the fuel consumption of spacecraft using low-thrust propulsion are desirable. Among various nonlinear optimization methods, convex optimization has been attracting attention because it allows optimal solutions to emerge robustly and requires short computation times. In particular, trajectory design in the three-body problem near the Lagrange points involves instability and nonlinearity. Hence, this study considers the application of convex optimization to trajectory design with low-thrust propulsion in cislunar space and verifies that this technique performs well, even for sensitive and highly nonlinear dynamics. Specifically, the convex optimization scheme is applied in the transfer from a halo orbit to a near-rectilinear halo orbit where both are periodic as defined in the circular restricted three-body problem. As a further step, the transfer problem is transitioned to an ephemeris model. In addition, extensive investigations of the dependence on various parameters used in convex optimization are conducted, and a trajectory corrections maneuver method is constructed combined with the convex optimization process. This investigation provides valuable insight into the convex optimization technique in the three-body problem and facilitates the estimation of low-thrust trajectory designs for complex space missions.. |
| 27. | Yuke Huang,Tatsuya Watanabe, Mai Bando, Shinji Hokamoto, PSO algorithm parameter settings and optimal multi-rotor layout design, International Journal of Sustainable Aviation, 8, 2, 116-135, 2022.04. |
| 28. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Halo-to-Halo Low-Thrust Transfer via Successive Convex Optimization with Intermediate Orbit Design, Proceedings of the 33rd International Symposium on Space Technology and Science, 2022.03. |
| 29. | Kanta Ikeda, Mai Bando, Shinji Hokamoto, Design of Low Energy Transfer Trajectories from Earth to Europa with Ballistic Capture, Journal of Journal of Evolving Space Activities, 10.57350/jesa.35, 1, 1-10, 2023.04. |
| 30. | Kanta Ikeda, Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Design of low energy transfer trajectories from Earth to Europa with ballistic capture, Proceedings of the 33rd International Symposium on Space Technology and Science, 2022.03. |
| 31. | Mohamed Shouman, Mai Bando, Shinji Hokamoto, Controllability Analysis of Propellant-Free Satellite Formation Flight, Journal of Guidance, Control, and Dynamics, 10.2514/1.G006035, 44, 12, 2214-2224, 2021.12, [URL], This paper presents a comprehensive analysis of the controllability for the relative dynamics of satellites using space environment forces. First, the constraints of the space environment forces are illustrated for circular orbits, and the integration of space environment forces for achieving full controllability is considered. Two approaches are used to estimate the controllability of various configurations of space environment forces. The first approach relies on controllability theory for linear continuous and discrete systems, including a derivation of a new linear formulation for solar radiation pressure with lower constraints. The second approach exploits extensive numerical simulations for controllability analyses of nonlinear dynamics models. The linear quadratic regulator is designed for different dynamics models of the space environment forces and implemented numerically for nonlinear dynamics using an anti-windup scheme with bounded control inputs. The numerical simulations demonstrate that the Lorentz forces and the differential atmospheric drag are more effective control forces in the low Earth orbits than the solar radiation pressure.. |
| 32. | Xin Gao, Mai Bando, Shinji Hokamoto, Semantic Segmentation Technique to Identify Landing Area for Autonomous Spacecraft, Proceedings of the 2021 Asia-Pacific International Symposium on Aerospace Technology (APISAT2021), 2021.11. |
| 33. | Yuto Hirose, Mai Bando, Shinji Hokamoto, Spacecraft Trajectory Design Using Data-Driven Model Predictive Control, Proceedings of the 72nd International Astronautical Congress, 2021.10. |
| 34. | Yusei Sasaki, Tomohiro Ishizuka, Mai Bando, Shinji Hokamoto, Two-Input-Torque for Hopping Exploration Robot to Enhance Reachability under Microgravity, Transactions of Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 10.2322/tastj.19.719, 19, 5, 719-725, 2021.09. |
| 35. | Yoshiki Matsumura, Mai Bando, Shinji Hokamoto, Multirotor Vehicles Design Based on Dynamic Manipulability for Underactuated Flying Systems, Proceedings of the 32nd Congress of the International Council of the Aeronautical Sciences, 19, 5, 2021.09. |
| 36. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Analysis of Ballistic Escape Based on Lobe Dynamics, Proceedings of the 72nd International Astronautical Congress, 2021.10. |
| 37. | Taiki Urashi, Shinji Hokamoto, Mai Bando, Data-Driven Analysis of Chaotic Orbits in the Circular Restricted Three Body Problem, Proceedings of the 2021 AAS/AIAA Astrodynamics Specialist Conference, 2021.08. |
| 38. | Kyosuke Sato, Shinji Hokamoto, Mai Bando, A Data-Driven Nonlinear Optimal Control of Unstable Fixed Points, Proceedings of the 2021 AAS/AIAA Astrodynamics Specialist Conference, 2021.08. |
| 39. | Saki Takeuchi, Kanta Ikeda, Mai Bando, Shinji Hokamoto, Three-Dimensional Attitude Change of Variable Structured Spacecraft by Utilizing Non-holonomic Features, Proceedings of the 31st Workshop on JAXA Astrodynamics and Flight Mechanics 2021, 2021.08. |
| 40. | Yang Zhou, Mai Bando, Shinji Hokamoto, Panlong Wu, Orbit Maintenance for Quasi-Periodic Orbit in Earth-Moon System, Transactions of Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 10.2322/tastj.19.562, 19, 4, 562-569, 2021.07. |
| 41. | Naoto Kobayashi, Mai Bando, Shinji Hokamoto, Daisuke Kubo, Guidelines for practical navigation systems based on wide-field-integration of optic flow, Asian Journal of Control, 10.1002/asjc.2363, 2021.10, This paper shows some guidelines to improve the estimation accuracy of a navigation system, which is based on wide-field-integration (WFI) of optic flow. Optic flow is a vector field of relative velocities obtained by photoreceptors in image sensors, and WFI of optic flow enables motion estimation robust by integrating wide range of optic flow. Since the system has several attractive features (small size, light weight, and low computation), it is applicable to an autonomous control system of micro air vehicles. However, due to some restrictions of real systems, WFI of optic flow theory should be applied while considering sensor arrangement for better estimation. In this paper, first an adequate number and adequate optical-axes of image sensors are investigated. Then, a new estimation system combining a gyro sensor with WFI of optic flow is discussed by numerical simulations. Finally, the essential effect for the number of cameras are verified in experiments..  |
| 42. | Yuke Huang, Mai Bando, Shinji Hokamoto, Optimal Layout Design of Multi-Rotor Vehicle Based on PSO Algorithm, Proceedings of the International Symposium on Aircraft Technology 2021, 2021.06. |
| 43. | Saki Takeuchi, Kanta Ikeda, Mai Bando, Shinji Hokamoto, Effects of Rotational Joint Directions of Variable Structure on Non-holonomic Features, Proceedings of the 33rd International Symposium on Space Technology and Science, 2022.03. |
| 44. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Halo-to-Halo Low-Thrust Transfer via Successive Convex Optimization with Intermediate Orbit Design, Proceedings of the 33rd International Symposium on Space Technology and Science, 2022.03. |
| 45. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Sparse Optimal Control for Nonlinear Trajectory Design in Three-Body Problem, Transactions of Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 10.2322/tastj.19.545, 19, 4, 545-552, 2021.07. |
| 46. | Zhe Xu, Mai Bando, Hedeaki Ogawa, Shinji Hokamoto, Application of Halo Orbit on Extension for Launch Window Limited by Direct Earth-Mars Transfer, Advances in the Astronautical Sciences, 176, 55-74, 2021.02. |
| 47. | Xiaoxu Feng, Mai Bando, Shinji Hokamoto, Obstacle Shape Estimation by Wide-Field-Integration of Optic Flow, Proceedings of the International Symposium on Electric Aviation and Autonomous Systems 2020, 93-96, 2021.01. |
| 48. | Yusei Sasaki, Masato Matsumoto, Mai Bando, Shinji Hokamoto, Three-dimensional Attitude Control of Spacecraft by Three Thrusters, 71st International Astronautical Congress, IAC 2020
Proceedings of the International Astronautical Congress, IAC, 2020.10. |
| 49. | Takehiro Yasuda, Mai Bando, Shinji Hokamoto, Formation Control Using Differential Atmospheric Drag Considering Attitude Constraints, 71st International Astronautical Congress, IAC 2020 Proceedings of the International Astronautical Congress, IAC, 2020.10. |
| 50. | Keitaro Miyahara, Yuki Kayama, Mai Bando, Shinji Hokamoto, Cycler orbit design using low-thrust in the Sun-Earth-Moon system, 71st International Astronautical Congress, IAC 2020 Proceedings of the International Astronautical Congress, IAC, 2020.10. |
| 51. | Wataru Noma, Zhe Xu, Mai Bando, Shinji Hokamoto, Trajectory Design to Mars from Earth-Moon System with Three-Dimensional Transit Orbits, 71st International Astronautical Congress, IAC 2020 Proceedings of the International Astronautical Congress, IAC, 2020.10. |
| 52. | Motoki Yamane, Mai Bando, Shinji Hokamoto, Formation Flying Trajectory Design based on Attractive Sets of Tschauner-Hempel Equations, Journal of Guidance, Control, and Dynamics, 43, 10, 1943-1951, 2020.10, This paper proposes a new method of optimal trajectory design for formation flying along an elliptical orbit. If the system is linear and a quadratic performance index is assumed, the optimal cost is quadratic form of the initial state. Attractive sets of optimal control are defined as level sets of the optimal cost based on linear quadratic regulator theory. They describe a set of all initial states to reach a desired state by a given cost. By solving the optimal control problem for the Tschauner-Hempel equations, the optimal cost is characterized by a time-periodic solution to the Riccati differential equation. This paper defines the attractive set for optimal formation reconfiguration problem and develops the procedures to draw the attractive set. A novel method to depict the geometry of the attractive set of optimal control along a periodic orbit is proposed. Several applications to illustrate the theory are also given.. |
| 53. | Anviksha Sharma, Mai Bando, Shinji Hokamoto, Daniel J. Scheeres, Optimal Landing Problem for a Binary Asteroid System and its Error Sensitivity, Proceedings of the SICE Annual Conference 2020, 2020.09. |
| 54. | Mohamed Shouman, Mai Bando, Shinji Hokamoto, Performance Analysis of Low-Gain Feedback for Saturated Differential Drag in a High-precision Orbit Propagator, Transactions of the Japan Society for Aeronautical and Space Sciences, 10.2322/tjsass.63.243, 63, 5, 243-247, 2020.09. |
| 55. | Naoki Hiraiwa, Mai Bando, Shinji Hokamoto, Trajectory design in the vicinity of 65803 Didymos based on the center manifold theory, Proceedings of the 2020 AAS/AIAA Astrodynamics Specialist Conference, 2020.08. |
| 56. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Sparse Optimal Control for Nonlinear Trajectory Design in Three-Body Problem, Transactions of Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 17, 20, 10-17, 2020.06. |
| 57. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Minimum Fuel Trajectory Design Using Sparse Optimal Control in Three-Body Problem, Proceedings of the 2020 AIAA SciTech Forum, 2020.01. |
| 58. | Yang Zhou, Mai Bando, Shinji Hokamoto, Panlong Wu, Integrated orbit determination and maintenance in Earth-Moon unstable dynamics environment, Acta Astronautica, 10.1016/j.actaastro.2018.11.041, 163, 69-76, 2019.10, The hyperbolic instability of collinear libration point orbits dominates the distribution of orbit uncertainty, which is closely related with the unstable manifold of the local orbit. Exploiting the distribution of orbit uncertainty in an unstable orbital environment, an integrated orbit determination and maintenance approach is proposed. X-ray pulsar navigation embedded in the Kalman filtering architecture is adopted to determine the orbit of a spacecraft flying along the Earth-Moon L2 halo orbit. To keep the spacecraft in the vicinity of the nominal trajectory, the newly proposed orbit maintenance approach based on the covariance matrix is proposed to design the orbit maintenance maneuver. The numerical simulations show that the proposed approach has a good performance in orbit determination and maintenance.. |
| 59. | Yang Zhou, Mai Bando, Shinji Hokamoto, Panlong Wu, Manifold-based robust stationkeeping of libration-point orbit with navigational uncertainty, 70th International Astronautical Congress, IAC 2019 Proceedings of the International Astronautical Congress, IAC, 2019-October, 2019.10, This paper investigated the manifold-based robust stationkeeping approach for the halo orbit near the Earth-Moon L2 point in the ephemeris model. The well-known Hamiltonian structure-preserved (HSP) method is utilized to design the controller for stationkeeping. However, conventional HSP method is proposed under the ideal condition, where the equations of motion are constructed in the circular restricted three-body problem, and the navigational uncertainty is not considered as well. Actually, these uncertainties always exist and have significant influence on the performance of stationkeeping. To make the results more realistic, the dynamics in the ephemeris model is used to describe the motion of a spacecraft. A filtering structure-based navigation is incorporated in the stationkeeping, where the navigational uncertainty is introduced. In addition, the navigation filter is reformed to compensate for the control uncertainty. Simulation is performed to observe the influence of the control gain and the magnitude of the uncertainty on the stationkeeping performance.. |
| 60. | Yuke Huang, Mai Bando, Shinji Hokamoto, Optimal Layout Design of Multi-Rotor Vehicle Based on PSO Algorithm, Proceedings of the International Symposium on Aircraft Technology 2021, 2021.06. |
| 61. | Yuri Hachiya, Yuki Kayama, Mai Bando, Shinji Hokamoto, Manifold-to-manifold transfers using low-thrust acceleration, 70th International Astronautical Congress, IAC 2019 Proceedings of the International Astronautical Congress, IAC, 2019-October, 2019.10, This paper considers manifold-to-manifold transfers in the circular-restricted three-body problem enabled by low-thrust acceleration where an initial and target states lie on invariant manifolds associated to libration point orbits with different Jacobi constant. The basic idea is to utilize a family of stable and center manifolds that lie arbitrarily close to the target invariant manifold to reduce the cost of transfer. The linear quadratic regulator is used to design feedback control to transfer to the target manifold. Time invariant and time periodic controlleres are derived based on the linearized motion around the equilibrium point and periodic orbit respectively. The results show that the feedback controller can shape the linearized motion around manifold to be that around the equilibrium point or a periodic orbit. As a demonstration, transfer trajectories are designed to target the unstable manifold associated with an unstable Lyapunov orbit in the Earth-Moon system.. |
| 62. | Kyosuke Asaki, Mai Bando, Shinji Hokamoto, Riemannian optimization for spacecraft trajectory design, 70th International Astronautical Congress, IAC 2019 Proceedings of the International Astronautical Congress, IAC, 2019-October, 2019.10, Many of the equations of motion appearing in the aerospace field are nonlinear, and the problem of input optimization under this equation of motion is important. There are two methods for solving the nonlinear optimal control problem: direct method and indirect method. In the direct method, the equation of motion is discretized, and the problem is solved as a nonlinear programming problem with motion equations as constraints. In the direct method, it is possible to solve the problem by adding various constraints, but the solution becomes complicated and it is difficult to guarantee the convergence to the optimal solution. In this study, we consider a set of unknowns that satisfy constraints as Riemannian manifolds, and treat the problem as an unconstrained optimization problem on Riemannian manifolds. A simplified rocket trajectory optimization problem illustrates the proposed method.. |
| 63. | Mohamed Shouman, Mai Bando, Shinji Hokamoto, Output regulation control for satellite formation flying using differential drag, Journal of Guidance, Control, and Dynamics, 10.2514/1.G004219, 42, 10, 2220-2232, 2019.10, This paper proposes a new approach of using differentials in aerodynamic drag in combination with thrusters to control satellite formation flying in low Earth orbits. Parameterized output regulation theory for formation-flying missions with combined control action is developed based on the Schweighart–Sedwick relative dynamics equations. The theory is implemented to precisely track the different trajectories of reference relative motion and eliminates the effects of the J2 perturbations. The parametric Lyapunov algebraic equation is proposed to ensure the stability of the linear relative model subject to saturated inputs. The main goal of this study is to approve the viability of using the differentials in aerodynamic drag to precisely control different formation-flying missions. Numerical simulations using a high-fidelity relative dynamics model and a high-precision orbit propagator are implemented to validate and analyze the performance of the proposed control algorithm in comparison with the linear quadratic regulator algorithm based on actual satellite models.. |
| 64. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Station-keeping of Unstable Orbits Based on Sparse Optimal Control, Proceedings of the SICE Annual Conference 2019, 2019.09. |
| 65. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Periodic and quasi-periodic orbit design based on the center manifold theory, Acta Astronautica, 10.1016/j.actaastro.2019.02.029, 160, 672-682, 2019.07, This paper proposes a new numerical method for finding libration point orbits in the vicinity of collinear libration points in the circular restricted three-body problem. The main advantage of this method is that it requires neither an initial guess nor complex algebraic manipulations for finding both quasi-periodic and periodic orbits. The proposed method consists of two steps: center manifold design and differential correction. The first step provides a quasi-periodic orbit parametrized by a single parameter vector. In the second step, the parameter vector in the first step is used to obtain an exact periodic orbit. This method is applied to find periodic and quasi-periodic orbits in the Sun-Earth restricted three-body problem around the L1 and L2 libration points.. |
| 66. | Wataru Noma, Mai Bando, Shinji Hokamoto, Design of 3D Transit Orbits and Application to Mission Design, [第29回アストロダイナミクスシンポジウム講演後刷り集] = The 29th Workshop on JAXA Astrodynamics and Flight Mechanics, 2019.07, The 29th Workshop on JAXA Astrodynamics and Flight Mechanics 2019 (Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan. |
| 67. | Mohamed Shouman, Mai Bando, Shinji Hokamoto, Performance Analysis of Formation Flying Using Differential Aerodynamic Drag in High Precision Orbit Propagator, Proceedings of the 32nd International Symposium on Space Technology and Science, 2019-d-032, 2019.06. |
| 68. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Sparse Optimal Control for Nonlinear Trajectory Design in Three-Body Problem, Proceedings of the 32nd International Symposium on Space Technology and Science, 2019-d-003, 2019.06. |
| 69. | Yang Zhou, Mai Bando, Shinji Hokamoto, Penlong Wu, Orbit Maintenance for Quasi Periodic Orbits in Earth-Moon System, Proceedings of the 32nd International Symposium on Space Technology and Science, 2019-d-082, 2019.06. |
| 70. | Yusei Sasaki, Tomohiro Ishizuka, Mai Bando, Shinji Hokamoto, Reachability of Hopping Exploration Robot to a Destination Point Under Microgravity, Proceedings of the 32nd International Symposium on Space Technology and Science, 2019-k-34, 2019.06. |
| 71. | Mohamed Shouman, Mai Bando, Shinji Hokamoto, Controllability analysis of propellant-free satellite formation flight, 29th AAS/AIAA Space Flight Mechanics Meeting, 2019 Spaceflight Mechanics 2019, 3577-3596, 2019.01, This paper proposes the controllability analysis of relative motion using different configurations for hybrid control actions of space environmental forces. It tends to present a minimal configuration for the missions exploiting these forces. It illustrates the constraints in each space environmental force and analyzes the integration between these forces to achieve full controllability of the satellite formation flight for near-circular low earth orbits with different orbit configurations. The paper implements a Kalman decomposition approach to decompose the system into controllable and uncontrollable subspaces for linear time-invariant control actions. Numerical simulations are investigated to study the controllability analysis for nonlinear models and substantiate the success of the controllability study for all hybrid control actions with different orbit configurations.. |
| 72. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Sparse optimal trajectory design in three-body problem, 29th AAS/AIAA Space Flight Mechanics Meeting, 2019 Spaceflight Mechanics 2019, 2599-2618, 2019.01, A structure of the optimal trajectory for minimizing fuel consumption in an unstable dynamical environment such as the three-body problem is not well studied. Recently, it has been found that a sparse solution structure appears in the optimal control of a dynamical system. The concept of sparsity explains the property that the minimum fuel trajectory corresponds to the trajectory which minimizes the total thrusting time. In this paper, we propose a numerical method to obtain the minimum fuel sparse optimal trajectory in the unstable dynamical system. As an example, proposed methods are applied to the transfer in the Sun-Earth system.. |
| 73. | Yuki Oshima, Mai Bando, Shinji Hokamoto, Trajectory design in the circular restricted three-body problem using artificial invariant manifolds, 29th AAS/AIAA Space Flight Mechanics Meeting, 2019 Spaceflight Mechanics 2019, 1235-1254, 2019.01, This paper generalizes the invariant manifolds of unstable libration point orbits through the application of continuous thrust. Considering Jacobi constant of the end of invariant manifolds, an artificial periodic orbit around a libration point realizes heteroclinic connections between itself and an unforced periodic orbit with same Jacobi constant of the end of invariant manifolds. Heteroclinic connections between libration point orbits are constructed by detecting intersections of states of manifolds on the Poincaré map. We reveal low-energy spacecraft can transfer to some periodic orbits with different Jacobi constant. In addition, this paper defines New Jacobi constant of low-thrust spacecraft. By utilizing new Jacobi constant, we illustrate zero-velocity curves of low-thrust spacecraft and reveal that there is a crack of zero-velocity curves and spacecraft can pass the crack.. |
| 74. | Mohamed Shouman, Mai Bando, Shinji Hokamoto, Output regulation control for satellite formation flying using differential drag, 29th AAS/AIAA Space Flight Mechanics Meeting, 2019
Spaceflight Mechanics 2019, 3433-3452, 2019.01, This paper proposes a new hybrid control action of differentials aerodynamic drag and thrusters to control satellite formation flying in low Earth orbits. Parameterized output regulation algorithm for formation flying missions is developed based on the Schweighart-Sedwick relative dynamics equations. It is implemented to precisely track the different trajectories of reference relative motion and eliminates the effects of the J2 perturbations. Parametric Lyapunov algebraic equation is derived to ensure the stability of the linear relative model subject to saturated inputs. The main goal of this study is to approve the viability of using the differentials in aerodynamic drag to precisely control different formation flying missions. Numerical simulations using a high fidelity relative dynamics model are implemented to analyze the performance of the proposed control algorithm in comparison with the linear quadratic regulator algorithm for actual satellite parameters. The paper exploits a high-precision orbit propagator model to verify the robustness of the control algorithm.. |
| 75. | Motoki Yamane, Mai Bando, Shinji Hokamoto, Optimal Trajectory Design of Formation Flying based on Attractive Sets, TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 10.2322/tastj.17.96, 17, 1, 96-103, 2019.01, This paper presents a new method of optimal trajectory design for formation flying. Under linearized assumptions and a quadratic performance index, we introduce an attractive set of optimal control based on the linear quadratic regulator theory. The attractive set is defined as a set of all initial states to reach a desired state for a given cost. In particular, we consider attractive sets for two problems: a fixed final-state, fixed final-time problem and an infinite-time problem, and the optimal initial state is found based on the geometry of the attractive set. The optimal trajectories for two problems are evaluated in terms of L1-norm of control input and termination time.. |
| 76. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Station-keeping and formation flying based on nonlinear output regulation theory, Acta Astronautica, 10.1016/j.actaastro.2018.02.004, 153, 289-296, 2018.12, Station-keeping and formation flying along a libration point orbit in the circular restricted three-body problem are considered. In order to deal with the relative motion with respect to a reference trajectory, this paper extends our previous study which derives the station-keeping controller based on the output regulation theory. First the reference orbit of the chief satellite is represented as the output of an autonomous system called exosystem, assuming the reference orbit is given by a truncated Fourier series. For the formation flying, the relative trajectory of the deputy satellite with respect to the chief satellite is also represented by the output of an exosystem. Then the reference signal to be asymptotically tracked for the formation flying is obtained by the superposition of the two exosystems. The proposed controllers are applied and verified for the station-keeping and formation flying along a periodic orbit of the Sun-Earth L2 point.. |
| 77. | Wide-Field-Integration of optic flow for autonomous vehicles. |
| 78. | Satoshi Nagashima, Mai Bando, Shinji Hokamoto, Optimal trajectory design for safety rendezvous based on sparse modeling, 69th International Astronautical Congress: #InvolvingEveryone, IAC 2018 Proceedings of the International Astronautical Congress, IAC, 2018-October, 2018.10, In trajectory design of a spacecraft, reducing the fuel consumption is important factor. In order to find the minimum fuel trajectory, this paper considers the L 1 norm as the performance index. This paper discuss design parameters characterizing the L 1 optimal trajectory, such as sampling time, flight time and magnitude of thrust. Also, this paper compare with the conventional method from the viewpoint of fuel consumption. In addition, this paper consider the rendezvous problem considering safety.. |
| 79. | Takashi Matsuno, Yasuhiro Yoshimura, Shinji Hokamoto, Consideration of three-dimensional attitude and position control for a free-floating rigid body using three thrusters, International Journal of Aerospace Engineering, 10.1155/2018/2825681, 2018, 2018.10, The study examines the control algorithm of a three-dimensional attitude and position of a free-floating rigid body with three thruster forces in which the force directions are fixed with respect to the body. This study provides a theory to develop a control method of an underactuated satellite with the minimum thruster number. In the procedure, three switching controllers are used in conjunction with motion planning in the final angular-rate deceleration phase to individually control the six state variables to the target values. The switching controllers have a hierarchical structure by using invariant manifolds as switching surfaces. The state variables in higher class manifolds that include lower class ones are adjusted by repeatedly adding intentional disturbances while the lower class state variables are returned to the original values by using lower class invariant manifolds. This study describes methods to define the invariant manifolds and also the intentional disturbance for achieving the forementioned control strategy. Finally, the motion planning in the angular-rate deceleration phase from a remained single-axis rotation finalizes the six state values of the body to the target values. Numerical simulations verify the proposed method.. |
| 80. | Tomoya Sakamoto, Mai Bando, Shinji Hokamoto, Optimal control of spacecraft attitude motion using Port-Hamiltonian systems, 69th International Astronautical Congress: #InvolvingEveryone, IAC 2018 Proceedings of the International Astronautical Congress, IAC, 2018-October, 2018.10, In this study, a concept of optimality is introduced into Port-Hamilton systems for attitude control of spacecraft. Port-Hamiltonian systems make it possible to design asymptotically stable controllers in a uniform procedure for a wide variety of physical systems. By introducing optimality to Port-Hamilton system, conventional error systems of Port-Hamilton systems are expanded to minimize a quadratic form of evaluation function. In this study, as an optimal control method of Port-Hamiltonian system, Hamilton-Jacobi-Bellman (HJB) equation is considered. Since solving HJB equation is not easy, the equation is simplified through generalized canonical transformation, which is a unique conversion of Port-Hamiltonian system. Furthermore, by considering the minimum evaluation function as a Hamiltonian transformed through the generalized canonical transformation, the analytical solution of the HJB equation can be derived. This method can be used for a time-varying error system and applied for tracking control of spacecraft to specified trajectories. The optimality of the control input obtained from the proposed procedure is verified in numerical simulations.. |
| 81. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Extended state space approach for trajectory design in elliptic restricted three-body problem, 69th International Astronautical Congress: #InvolvingEveryone, IAC 2018 Proceedings of the International Astronautical Congress, IAC, 2018-October, 2018.10, This paper presents novel methods to provide libration point orbits (LPOs) and invariant manifolds (IMs) associated with libration point orbits in the elliptic restricted three-body problem (ERTBP). First, we introduce an extended autonomous system to describe the ERTBP. By introducing an autonomous system which generates a periodic function and integrating it with the ERTBP which is non-autonomous, we can obtain the extended autonomous system. Then, the center manifold design method which can uniquely provide an LPO in the circular restricted three-body problem is applied to the ERTBP. Next, we present a design method for IMs in the ERTBP by using the local stability characteristics obtained by the state transition matrix along LPOs of the extended system. The proposed design methods are applied and verified for the Earth-Moon L 1 ERTBP. We show various LPOs in the ERTBP by changing design parameters, and IMs associated with a libration point and an LPO.. |
| 82. | Yuki Kayama, Mai Bando, Shinji Hokamoto, Optimal Trajectory Design Using Attractive Set on Elliptical Orbit, [第28回アストロダイナミクスシンポジウム講演後刷り集] = The 28th Workshop on JAXA Astrodynamics and Flight Mechanics, 2018.07, The 28th Workshop on JAXA Astrodynamics and Flight Mechanics 2018 (July 30-31, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan. |
| 83. | Yusei Sasaki, Mai Bando, Shinji Hokamoto, Fuyuto Terui, Yuichi Tsuda, Dynamics of a Released Robot on an Asteroid with Small Gravity, [第28回アストロダイナミクスシンポジウム講演後刷り集] = The 28th Workshop on JAXA Astrodynamics and Flight Mechanics, 2018.07, The 28th Workshop on JAXA Astrodynamics and Flight Mechanics 2018 (July 30-31, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan. |
| 84. | Takayoshi Oba, Mai Bando, Shinji Hokamoto, Controller Performance for Quad-Rotor Vehicles Based on Sliding Mode Control, Journal of Robotics and Mechatronics, 10.20965/jrm.2018.p0397, 30, 3, 397-405, 2018.06, This study applies a sliding mode control (SMC) strategy for a robust controller of a quad-rotor vehicle. First, a controller combined with a nested control loop and an SMC is introduced, because a quad-rotor vehicle has only four control inputs although the vehicle has six degrees of freedom. The control performance for the feedback gains in the nested loop is investigated in numerical simulations. Subsequently, the effects of practical system limitations (control cycle and rotor dynamics) on the control performance are examined. Finally, the robust performance of the SMC strategy on a quad-rotor vehicle is discussed.. |
| 85. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Explicit form of station-keeping and formation flying controller for libration point orbits, Journal of Guidance, Control, and Dynamics, 10.2514/1.G002845, 41, 6, 1405-1413, 2018.07, A new station-keeping strategy based on nonlinear output regulation theory has been proposed for the periodic orbits in the circular restricted three-body problem. A Fourier series approximation was employed to generate the desired orbits, and then the output regulation theory for nonlinear systems was applied. The output regulation problem was solved in an analytical form. The proposed controller has been applied and verified in numerical simulations for the halo orbit of the sun–Earth L2 point. In the case that the reference orbit is the natural periodic orbit, the controller can approximate the optimal controller in the sense of minimizing the station-keeping cost. As an application of the proposed method, formation flying using circular orbits around the chief satellite has been worked out.. |
| 86. | Yang Zhou, Mai Bando, Shinji Hokamoto, Panlong Wu, Influence of unstable dynamics on orbit determination with x-ray pulsar navigation, 4th IAA Conference on Dynamics and Control of Space Systems, DYCOSS 2018 Dynamics and Control of Space Systems, 1827-1843, 2018.05, This paper explores the influence of unstable dynamics on orbit determination. A halo orbit about the Earth-Moon L2 is considered to be the nominal orbit and the dynamics model is constructed based on the Earth-Moon circular restricted three body problem. X-ray pulsar navigation method is introduced for orbit determination that is performed by Kalman filter. Simulation results show that unstable manifold of halo orbit dominates the growth of orbit-determination error and the corresponding uncertainty. However, when the orbit-determination measurements are incorporated in, the results change and are greatly influenced by the characteristic of the X-ray pulse measurements.. |
| 87. | Motion Estimation for Aerospace Vehicles Based on a Compound Eye System of Flying Insects. |
| 88. | Tsubasa Yamasaki, Mai Bando, Shinji Hokamoto, Tether cutting maneuver in swing-by trajectory, Acta Astronautica, 10.1016/j.actaastro.2017.11.002, 142, 212-220, 2018.01, The swing-by maneuver is known as a method to change the velocity of a spacecraft by using the gravity force of the celestial body. The powered swing-by has been studied to enhance the velocity change during the swing-by maneuver. This paper studies another way of the powered swing-by using tether cutting, which does not require additional propellant consumption, and shows that the proposed powered swing-by can increase the effect of the swing-by as same as using impulsive thrust. Moreover, it is discussed whether the system has possibility to realize both the powered swing-by of a mother satellite and the planetary capture of a subsatellite simultaneously.. |
| 89. | Tomoya Sakamoto, Yuki Akiyama, Mai Bando, Shinji Hokamoto, Considerations on design parameters for attitude control of spacecraft using port-controlled Hamiltonian systems, 56th Annual Conference of the Society of Instrument and Control Engineers of Japan, SICE 2017 2017 56th Annual Conference of the Society of Instrument and Control Engineers of Japan, SICE 2017, 10.23919/SICE.2017.8105722, 2017-November, 464-469, 2017.11, In previous research, a controller design procedure via generalized canonical transformations has been proposed to keep the passivity feature of Port-controlled Hamiltonian systems. The procedure has a general form and is applicable to spacecraft's attitude motion described with quaternion parameters. This paper investigates the roles of several design parameters in the generalized canonical transformations. Special attention is placed on the relation between the shape of Lyapunov functions and the convergence speed of the state variables. Furthermore, from the analysis utilizing the linearized form of the Port-controlled Hamiltonian system, the guideline to decide the preferable ratio between two parameters in the design procedure is proposed.. |
| 90. | Motoki Yamane, Mai Bando, Shinji Hokamoto, Formation flying along elliptical orbit using attractive sets of optimal control, 68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening Security, IAC 2017 68th International Astronautical Congress, IAC 2017 Unlocking Imagination, Fostering Innovation and Strengthening Security, 7186-7194, 2017.09, This paper proposes a new method of optimal trajectory design for formation flying along an elliptical orbit. Under linearized assumptions and a quadratic performance index, the optimal cost is quadratic in the initial state. Attractive sets of optimal control are defined as contours of the optimal cost based on linear quadratic regulator theory. It describes a set of all initial states to reach a desired state by a given cost. By solving the optimal control problem for TH equations, the optimal cost is obtained as a time-periodic function. This paper develops the attractive set for a time-periodic system and procedure to draw the attractive set is shown. The advantage of using attractive sets for optimal trajectory design is that it can determine the optimal initial state immediately. The various shape of the periodic orbit and the attractive sets are demonstrated by weight parameters of optimal control theory.. |
| 91. | Naoto Kobayashi, Mai Bando, Shinji Hokamoto, Optic flow-based navigation system for planetary rovers, 68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening Security, IAC 2017 68th International Astronautical Congress, IAC 2017 Unlocking Imagination, Fostering Innovation and Strengthening Security, 2839-2847, 2017.09, This paper proposes a novel optic flow-based navigation system for planetary rovers. Optic flow is a vector field of relative velocities between the camera mounted on a rover and environments, and it is often utilized for motion estimations or relative distance estimations. However, only either one of them can be estimated in general optic flow processing. The method proposed in this paper enables both of the estimations by utilizing an image segmentation technique in computer vision and applying Wide-Field-Integration (WFI) of optic flow for robust estimations. Thus, both obstacle avoidance and avoidance of getting stuck, which are key technologies for planetary exploration rovers, are realized in the method. Furthermore, since the estimation is accomplished in linear processing, a real-time estimation is possible by onboard computers. The effectiveness of the proposed method is examined through numerical simulations, considering sensor noises and the shape of obstacles.. |
| 92. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Quaternion based attitude stabilization in the circular restricted three-body problem, 68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening Security, IAC 2017 68th International Astronautical Congress, IAC 2017 Unlocking Imagination, Fostering Innovation and Strengthening Security, 750-762, 2017.09, This paper presents a novel method to realize station-keeping and control attitude motion simultaneously on a libration point orbit based on the nonlinear output regulation. First, the coupled orbit-attitude motion of a rigid spacecraft subject to three-body dynamics is formulated using the quaternion. Next, the reference orbit and attitude are represented as the output of an autonomous system called exosystem, assuming the reference orbit and attitude are given by a truncated Fourier series. Then the controller is derived by solving the output regulation problem. The derived controller has the explicit form and can achieve the asymptotically tracking for any reference orbit and attitude represented in the Fourier series. The proposed controllers are applied and verified for the Sun-pointing attitude control and station-keeping along Sun-Earth L2 Halo orbits.. |
| 93. | Nobuki Yamaguchi, Mai Bando, Shinji Hokamoto, Trajectory design to triangular libration points based on resonant orbits, 68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening Security, IAC 2017 68th International Astronautical Congress, IAC 2017 Unlocking Imagination, Fostering Innovation and Strengthening Security, 7507-7518, 2017.09, In this paper, we extend the flow function method for finding resonant orbits. The relation between flow function, resonance number and order of the resonant orbit are revealed. The resonant orbits design in the Sun-Earth CRTBP are demonstrated and the results show that the resonant orbits can be found globally and systematically by the flow function method. The flow function method can also be applied to obtain higher order resonant orbits. As an application, we propose a transfer trajectory to the L4/L5 SPOs by using various resonant orbits. Our results reveals that two types of insertion is possible for SPO insertion with small ΔV.. |
| 94. | Hamidreza Nemati, Mai Bando, Shinji Hokamoto, Chattering Attenuation Sliding Mode Approach for Nonlinear Systems, Asian Journal of Control, 10.1002/asjc.1477, 19, 4, 1519-1531, 2017.07, This study introduces a new robust nonlinear control scheme based on the theory of nonsingular terminal sliding mode control (NTSMC). Since conventional NTSMC utilizes a discontinuous switching function, a significant flaw called chattering can occur. The main purpose of this study is to design a new switching function based upon Lyapunov stability in order to alleviate this drawback over time. There are many approaches to mitigate the chattering drawback in SMC such as utilizing a smooth approximation of the switching element, or employing higher order sliding mode control (HOSMC) strategy. However, the use of a continuous approximation affects the system's performance and a finite reaching time to the sliding manifold, and in HOSMC the estimation of high-order derivatives of states is usually difficult and it still exhibits chattering in the presence of parasitic dynamics. In this study by employing a new sliding manifold including a time function, the chattering is attenuated as well as keeping the robustness. Finally, a second-order nonlinear dynamical system subject to disturbance is simulated to highlight the validity and applicability of the proposed method.. |
| 95. | Naoto Kobayashi, Mai Bando, Shinji Hokamoto, Improvement of Wide-Field-Integration of Optic Flow Considering Practical Sensor Restrictions, Journal of Mechanical Engineering and Automation, 10.5923, Vol.7, No.2, 53-62, 2017.05. |
| 96. | Yuki Akiyama, Mai Bando, Hamidreza Nemati, Shinji Hokamoto, Trajectory design using the center manifold theory in the circular restricted three-body problem, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, Vol. 14, Pd_151-Pd_158, 2016.12. |
| 97. | Sho Hayashida, Mai Bando, Shinji Hokamoto, Design of earth-moon cyclers using primer vector theory, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, Vol. 14, Pd_159-Pd_165, 2016.12. |
| 98. | Naoto Kobayashi, Masataka Oishi, Yutaka Kinjo, Shinji Hokamoto, Experimental Verification of Wide-Field-Integration of Optic Flow for State Estimation, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, Vol. 14, Pd63-Pd68, 2016.11. |
| 99. | Naoto Kobayashi, Ryusuke Nakata, Mai Bando, Shinji Hokamoto, A Novel Attitude Estimation Method Based on Wide-Field-Integration of Optic Flow for Autonomous Navigation, Proceedings of the 2016 Asia-Pacific International Symposium on Aerospace Technology (APISAT), Vol. 14, Pd63-Pd68, 2016.10. |
| 100. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Periodic Orbits Design based on the Center Manifold Theory in the Circular Restricted Three-Body Problem, Proceedings of the 67th International Astronautical Congress, 2016.09. |
| 101. | Tsubasa Yamasaki, Mai Bando, Shinji Hokamoto, Powered Swing-by Using Tether Cutting, Proceedings of the 67th International Astronautical Congress, 2016.09. |
| 102. | Kai Yun, Shinya Katoku, Yutaka Kinjo, Shinji Hokamoto, LRF Based Autonomous Navigation System Measuring on Moving Rover, Proceedings of the 13th International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS), 2016.06. |
| 103. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Global Trajectory Design for Position and Attitude Control of an Underactuated Satellite, Transactions of the Japan Society for Aeronautical and Space Sciences, 59, 3, 107-114, 2016.05. |
| 104. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, On the possibility of using small asteroids for deflecting near-Earth asteroids, Advances in Space Research, 10.1016/j.asr.2015.08.016, 57, 8, 1820-1831, 2016.04, This paper presents the trajectory design and analysis of the near-Earth asteroid (NEA) deflection mission enabled by a kinetic impact of an intermediate asteroid. The sequential transfer trajectory is designed by solving two Lambert's problems that yield a chain collision between a spacecraft and an intermediate asteroid, followed by a collision between the intermediate asteroid and an NEA. The characteristics of the low-cost trajectories are then identified with respect to the optimal collision point. We show that the feasibility of the mission depends on the existence of an intermediate asteroid with small minimum orbit interception distance (MOID) with the NEA. Moreover the selection strategy of an intermediate asteroid that makes the mission feasible is discussed. We show that several asteroids exist that allow a 10 ton spacecraft with limited ΔV to be launched and impact the NEA 99442 Apophis allowing a deflection given several years warning time.. |
| 105. | Environment recognition through laser-range-finder for small exploration rover. |
| 106. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Global trajectory design for position and attitude control of an underactuated satellite, Transactions of the Japan Society for Aeronautical and Space Sciences, 10.2322/tjsass.59.107, 59, 3, 107-114, 2016.01, Underactuated control offers fault-tolerance for satellite systems, which not only enables the position and attitude control of a satellite with fewer thrusters, but also can reduce the number of thrusters equipped on the satellite even when considering the need for backups. Due to having fewer thrusters, the coupling effect between the translational motion and rotational motion of the satellite cannot be avoided, and the coupled motion must be considered in control procedures. This paper presents a global trajectory design procedure required for the position and attitude control of an underactuated satellite. The satellite has four thrusters with constant thrust magnitudes on one plane of the satellite body. Then, an analytical solution for coupled motion between the rotation and translation of the satellite is obtained using three-step maneuvers of attitude control. The trajectory design based on the analytical solution is shown for the control of translational and rotational motion in three dimensions. Finally, a numerical simulation is performed to verify the effectiveness of the proposed design procedure.. |
| 107. | Mai Bando, Hamidreza Nemati, Shinji Hokamoto, Satellite formation-keeping about libration points in the presence of system uncertainties, Proceedings of the AAS/AIAA Astrodynamics Specialist Conference, ASC 2015, 785-804, 2016.01, This paper studies a control law to stabilize the orbital motion in the vicinity of an unstable equilibrium points and periodic orbits in the circular-restricted three-body problem. Utilizing the eigenstructure of the system, the fuel efficient formation flying controller via linear quadratic regulator (LQR) is developed. Then the chattering attenuation sliding mode controller (CASMC) is designed and analyzed for the in-plane motion of the circular circular-restricted three-body problem. Simulation studies are conducted for the Sun-Earth L2 point and a halo orbit around it. The total velocity change required to reach the halo orbit as well as to maintain the halo orbit is calculated. Simulation results show that the chattering attenuation sliding mode controller has good performance and robustness in the presence of unmodeled nonlinearity along the halo orbit with relatively small fuel consumption.. |
| 108. | Hamidreza Nemati, Mai Bando, Shinji Hokamoto, Design of Sliding Mode Controllers for Formation Flying along Unstable Periodic Orbits in CR3BP, Proceedings of the 66th International Astronautical Congress, 2015.10. |
| 109. | Yuki Akiyama, Mai Bando, Shinji Hokamoto, Station-keeping and formation flying for periodic orbit around Lagrangian points by Fourier series, Proceedings of the 25th International Symposium on Space Flight Dynamics, 2015.10. |
| 110. | Naoto Kobayashi, Masataka Oishi, Yutaka Kinjo, Daisuke Kubo, Shinji Hokamoto, Motion estimation of autonomous spacecraft near asteroid using wide-field-integration of optic flow, Proceedings of the 25th International Symposium on Space Flight Dynamics, 2015.10. |
| 111. | Mai Bando, Hamidreza Nemati, Shinji Hokamoto, Satellite Formation-Keeping about Libration Points in the Presence of System Uncertainties, Proceedings of the AAS/AIAA Astrodynamics Specialist Conference, 2015.08. |
| 112. | Kai Yun, Yutaka Kinjo, Shinji Hokamoto, Experimental Verification on Enabling Long Distance Travel for Planetary Rover Using Scanning LRF System, Proceedings of the 30th International Symposium on Space Technology and Science, 2015.07. |
| 113. | Hamidreza Nemati, Shinji Hokamoto, New Chattering Attenuation Sliding Mode Control of a Flexible Spacecraft, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology, 12, ists29, Pd_71-Pd_77, 2014.10. |
| 114. | Mai Bando, Naoki Date, Shinji Hokamoto, Estimation of mean orbital elements with unknown low-thrust acceleration, Proceedings of the 65th International Astronautical Congress, IAC-14.C1.2.8, pp. 1-11, 2014.09. |
| 115. | Shinji Hokamoto, Masataka Oishi, Naoto Kobayashi, Mai Bando, Wide-field-integration of optic flow for realistic estimation system for space probes, Proceedings of the 65th International Astronautical Congress, IAC-14.C1.7.11, pp. 1-9, 2014.09. |
| 116. | Hirofumi Sakamoto, Shinji Hokamoto, Attitude Angle Estimation of Space Probe through Wide-Field Integration of Optic Flow, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology, 12, ists29, Pd_41-Pd_46, 2014.06. |
| 117. | Kai Yun, Keita Sakurai, Shinji Hokamoto, Realistic terrain reconstruction method by using laser-range-finder, Proceedings of the 14th International Space Conference of Pacific-basin Societies,, 2014.05. |
| 118. | Yasuhiro Yoshimura, Shunsuke Tsuge, Shinji Hokamoto, Relative Position and Attitude Control of a Satellite with Unilateral Inputs, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology, 12, ists29, Pd_11-Pd_17, 2014.04. |
| 119. | Takashi Matsuno, Yasuhiro Yoshimura, Shinji Hokamoto, Geometric conditions of thrusters for 3D attitude control of a free-floating rigid spacecraft, Mathematics in Engineering, Science and Aerospace, 15, 1, 83-95, 2014.02. |
| 120. | Hamidreza Nemati, Shinji Hokamoto, Design Procedure of Chattering Attenuation Sliding Mode Attitude Control of a Satellite System, Advances in the Astronautical Sciences, 152, 3533-3541, 2014.01. |
| 121. | Mai Bando, Yuki Akiyama, Shinji Hokamoto, Robust deflection strategies of Near Earth asteroids under uncertainties, Proceedings of the 24th AAS/AIAA Space Flight Mechanics Meeting, 2014, 1165-1181, 2014.01, In this paper, an approach to optimize deflection mission of Near Earth asteroids under uncertainty is proposed based on control theoretical framework. By using the nonlinear mapping from initial deviation to the final deviation, the performance index J which is expressed as a function of the distance of the Earth in the Earth's closest approach time is minimized for the worst case initial condition. We also formulate the robust orbital transfer problem of kinetic impactor spacecraft where the initial state estimation error exists.. |
| 122. | Circular Restricted Three-body Problem as a Subject of Internship in the Field of Aeronautics and Astronautics. |
| 123. | Yasuhiro Yoshimura, Shunsuke Tsuge, Shinji Hokamoto, Relative Position and Attitude Control of a Satellite with Unilateral Inputs, Proceedings of the 29th International Symposium on Space Technology and Science, 2013-d-30, 2013.06. |
| 124. | Takashi Matsuno, Yasuhiro Yoshimura, Shinji Hokamoto, Attitude and position control for under actuated satellite by ON/OFF thrusters, Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C, 10.1299/kikaic.79.225, 79, 798, 225-235, 2013.05, This study proposes a new control method for under-actuated planar satellites having body-fixed thrusters that can generate unilateral and constant forces. The proposed method is applicable when the thrusters are not balanced, which means a rotational motion is inevitably induced whenever the thrusters are turned on. By applying the method, the position and attitude of any planar satellite can be controlled to arbitrary target states so long as a controllability condition is satisfied. The control logic is based on a switching control using plural manifolds. First, the satellite is transferred to an initial manifold, and then it moves to another manifold while decreasing its velocity and approaching the target states. The ON/OFF timing of the thrusters to transfer among the manifolds is explicitly specified in this paper. A numerical simulation validates the proposed control logic.. |
| 125. | Michael A. Shoemaker, Shinji Hokamoto, Comparison of integrated and nonintegrated wide-field optic flow for vehicle navigation, Journal of Guidance, Control, and Dynamics, 10.2514/1.59084, 36, 3, 710-720, 2013.05, Recent studies of vision-based navigation and guidance for robotic vehicles have been inspired by the biological systems found in flying insects. The wide-field integration of optic flow is one pre-existing method, in which the sensed optic flow is integrated along with sensitivity functions to mimic the action of directionally sensitive cells observed in some insects' visual systems. This study re-examines the wide-field integration method and reformulates the problem from a summation rather than an integral. This reformulation allows the wide-field integration measurement outputs to be directly compared with nonintegrated optic flow measurements. The method using nonintegrated optic flow measurements is shown to have some practical advantages, such as eliminating the need to define input sensitivity functions and having a measurement Jacobian that is easier to derive analytically. Also, the state estimates obtained with the nonintegrated method are proven to have minimum variance compared with those from the wide-field integration method. Numerical simulations of each method are shown for a vehicle maintaining level flight at constant altitude over a flat terrain.. |
| 126. | Hirofumi Sakamoto, Takumi Kanazawa, Shinji Hokamoto, State Estimation of Planetary Landing Vehicles with Wide-Field Integration of Optic Flow, Advances in the Astronautical Sciences, Vol. 146, pp.57-69, 2013.03. |
| 127. | Hamidreza Nemati, Shinji Hokamoto, Chattering attenuation sliding mode control of a satellite's attitude, 23rd AAS/AIAA Space Flight Mechanics Meeting, Spaceflight Mechanics 2013 Advances in the Astronautical Sciences, 148, 1369-1376, 2013.02, This paper develops a new robust nonlinear control algorithm based on the theory of sliding mode to control the attitude of a satellite. The system comprises a satellite with three pairs of thrusters on the satellite's principal axes. Since conventional sliding mode controllers include a discontinuous function, a significant problem called chattering can occur. The main purpose of this paper is to design a new switching function in order to alleviate this drawback. Moreover, for increasing the robustness of the proposed controller, a new slope-varying hyperbolic function is utilized. Simulation results highlight the effectiveness of the proposed method.. |
| 128. | Hirofumi Sakamoto, Takumi Kanazawa, Shinji Hokamoto, State estimation of planetary landing vehicles with wide-field integration of optic flow, 13th International Space Conference of Pacific-Basin Societies, ISCOPS 2012 Space for Our Future - Advances in the Astronautical Sciences: Proceedings of the 13th International Conference of Pacific-Basin Societies, ISCOPS 2012, 146, 57-69, 2013.01, In this paper, we apply Wide-Field integration (WFI) of optic flow for the state estimation of a planetary landing vehicle. This study utilizes nonlinear expressions for the Fourier coefficients of the optic flow instead of linearized expressions. By using the nonlinear expressions, it is shown that the vehicle's attitude angles can be estimated as well as its velocity components. First this paper deals with a two-dimensional model and explains how to estimate state variables. Then two three-dimensional models are discussed. Numerical simulation results are shown to evaluate the estimation accuracy.. |
| 129. | Michael A. Shoemaker, Shinji Hokamoto, Application of wide-field integration of optic flow to proximity operations and landing for space exploration missions, 2011 AAS/AIAA Astrodynamics Specialist Conference, ASTRODYNAMICS 2011 ASTRODYNAMICS 2011 - Advances in the Astronautical Sciences Proceedings of the AAS/AIAA Astrodynamics Specialist Conference, 23-36, 2012.12, New advances in vision-based navigation for micro air vehicles (MAVs) have been inspired by the biological systems of flying insects and the use of optic flow. These biologically-inspired optical sensor systems for MAVs are computationally efficient and have low mass and low power consumption, which makes them attractive for small spacecraft. This study explores the applicability of the wide-field integration (WFI) of optic flow to a spacecraft operating in close proximity to an asteroid. In contrast with past WFI work, this study uses an asteroid-relative reference trajectory and known a priori environment model such that the optimal sensitivity functions are recalculated onboard the vehicle at each time step. Numerical simulations with computer-generated images of the asteroid surface are used to estimate the vehicle's translational and angular velocities. Although the accuracy of these state estimates are reasonable considering the noise in the optic flow measurements, the onboard recalculation of the sensitivity functions for this time-varying scenario add computational burden which negates the main advantage of the WFI method. Hence, future applications to time-invariant scenarios for small-body missions are also discussed.. |
| 130. | Shunsuke Tsuge, Shinji Hokamoto, Relative Attitude and Orbital Control with a Fewer Thrusters for Rendezvous-Docking, Proceedings of the Asia-Pacific International Symposium on Aerospace Technology, 2012.11. |
| 131. | Shinji Nishikori, Shinji Hokamoto, Takashi Kubota, Study on a Reasonable Locomotion of a Multi-Legged Rover Using its Dynamic Motion, Proceedings of the International Symposium on Artificial Intelligence, Robotics and Automation in Space, 2012.09. |
| 132. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Satellite position and attitude control by on-off thrusters considering mass change, 2011 AAS/AIAA Astrodynamics Specialist Conference, ASTRODYNAMICS 2011 ASTRODYNAMICS 2011 - Advances in the Astronautical Sciences Proceedings of the AAS/AIAA Astrodynamics Specialist Conference, 142, 2953-2964, 2012.02, This paper deals with the two-dimensional position and attitude control of a satellite by on-off thrusters which are fixed to the satellite's body. Since the thrusters generate constant and unilateral forces, the equations of motion form nonholonomic constraint and cannot be integrated. Furthermore, the satellite's mass changes due to the fuel consumption. Utilizing Fresnel integrals and the partial integrals, we derive the approximate analytic solution considering the satellite's mass change to achieve a specified satellite's position and attitude. The accuracy of the proposed approximate technique is verified by applying it to a condition considered in SLIM project of JAXA.. |
| 133. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Position and attitude control of an underactuated satellite with constant thrust, Proceedings of the AIAA Guidance, Navigation, and Control Conference 2011, 2011.12, This paper discusses a position and attitude control problem of an underactuated satellite which uses on-off thruster mechanisms for control. Each thrusters has constant orientation relative to the satellite's body, and can generate only unilateral forces. The purpose of this paper is to clarify the control law for simultaneous position and attitude control for this type of satellite configuration. Considering the input constraints, we obtain the analytical solutions of the satellite's translational and rotational motion. Then the control procedure utilizing an invariant manifold is derived. Some numerical simulations are shown to verify the effectiveness of the proposed controller.. |
| 134. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Three dimensional attitude control of an underactuated satellite with thrusters, International Journal of Automation Technology, 10.20965/ijat.2011.p0892, 5, 6, 892-899, 2011.11, This paper deals with the three-dimensional attitude control of an underactuated satellite equipped with thrusters whose force directions are fixed to the satellite. First, the necessary number of thrusters for the satellite's attitude control is discussed utilizing the Minkowski-Farkas theorem. Then, using the wz parameters for a satellite's attitude expression, this paper proposes a non holonomic attitude controller which is effective for any satellite regardless of its moment of inertia. Numerical simulation demonstrates the effectiveness of the proposed controller. Furthermore, the efficiency of the controller for different thruster positions is also discussed.. |
| 135. | Position and Attitude Feedback Controller of a Planar Satellite with Two Thrusters. |
| 136. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, 3-D Attitude Control of an Underactuated Satellite with Constant Inputs, Proceedings of the 28th International Symposium on Space Technology and Science, 2011-d-16, 2011.06. |
| 137. | Shinji Hokamoto, Junko Murakami, Genetic-Algorithm-Based Rendezvous Trajectory Design for Multiple Active Debris Removal, Proceedings of the 28th International Symposium on Space Technology and Science, 2011-d-26, 2011.06. |
| 138. | Michael Shoemaker, Shinji Hokamoto, Relative Navigation Near Asteroid Using Wide-Field Integration of Optic Flow, Proceedings of the 28th International Symposium on Space Technology and Science, 2011-d-38, 2011.06. |
| 139. | Shinji Nishikori, Shinji Hokamoto, Takashi Kubota, Kinematic discussion and development of a multi-legged planetary exploration rover with an isotropic leg arrangement, Advanced Robotics, 10.1163/016918611X563300, 25, 6-7, 789-804, 2011.04, This study deals with a multi-legged planetary rover with a spherically isotropic leg arrangement. The legged rover is a reliable rover system for exploration on rough terrains, because it can continue walking even after overturning. Moreover, the legged rover can also show a rotational motion by utilizing its isotropic shape. This paper discusses the walking performance of two types of rover shapes: one has a six-leg arrangement based on a regular octahedron and the other has an eight-leg arrangement based on a regular hexahedron. The design procedure of the proposed rover is explained, and a test-bed system, which is developed to demonstrate the fundamental motions, is also presented.. |
| 140. | Junko Murakami, Shinji Hokamoto, Approach for Optimal Multi-Rendezvous Trajectory Design for Active Debris Removal, Proceedings of the 20th Workshop on JAXA Astrodynamics and Flight Mechanics, pp.147-152, 2011.03. |
| 141. | Hamidreza Nemati, Shinji Hokamoto, A Novel Chattering-Free Sliding Mode Controller for Attitude Control of a Microsatellite, Proceedings of the 22nd Workshop on JAXA Astrodynamics and Flight Mechanics, 249-254, 2011.03. |
| 142. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Position and attitude control of an underactuated satellite with constant thrust, Proceedings of the AIAA Guidance, Navigation, and Control Conference 2011, 10.2514/6.2011-6352, 2011.01, This paper discusses a position and attitude control problem of an underactuated satellite which uses on-off thruster mechanisms for control. Each thrusters has constant orientation relative to the satellite's body, and can generate only unilateral forces. The purpose of this paper is to clarify the control law for simultaneous position and attitude control for this type of satellite configuration. Considering the input constraints, we obtain the analytical solutions of the satellite's translational and rotational motion. Then the control procedure utilizing an invariant manifold is derived. Some numerical simulations are shown to verify the effectiveness of the proposed controller.. |
| 143. | Shinji Nishikori, Shinji Hokamoto, Evaluation on Efficient Attitude of a Multi-Legged Planetary Exploration Rover with Isotropic Leg Arrangement, Advances in the Astronautical Sciences, 138, pp.667-679, 2010.12. |
| 144. | Yasuhiro Yoshimura, Takashi Matsuno, Shinji Hokamoto, Three Dimensional Attitude Control of an Underactuated Satellite with Thrusters, Proceedings of the 4th Asia International Symposium on Mechatronics, pp.110-115, 2010.12. |
| 145. | Shinji Nishikori, Shinji Hokamoto, Evaluation of efficient attitude of a multi-legged planetary exploration rover with isotropic leg arrangement, 12th International Conference of Pacific-Basin Societies, ISCOPS Applications of Space Technology for Humanity - Advances in the Astronautical Sciences Proceedings of the 12th International Conference of Pacific-Basin Societies, ISCOPS, 667-679, 2010.12, This study deals with a multi-legged planetary rover with a spherically isotropic leg arrangement. This robot is a reliable system for the exploration on rough terrains, because the rover can continue walking even after overturning. Moreover, this rover can exhibit a rotational motion by utilizing its isotropic shape in addition to quadruped walking motion. This paper discusses two rotational motions; a quasi-static rotational motion and a dynamic rotational motion. This paper investigates reasonable attitudes for the quasi-static rotational motion from the view point of the energy consumption required for traveling. For the dynamic rotational motion, adequate attitudes to resist the shock for kicking and touchdown are discussed.. |
| 146. | Yutaro Ishida, Shinji Hokamoto, Interplanetary trajectory design of solar sail spacecraft utilizing an invariant manifold, Proceedings of the AIAA/AAS Astrodynamics Specialist Conference 2010, 10.2514/6.2010-8137, 2010.12, This paper deals with an in-plane trajectory design method for a solar sail spacecraft to rendezvous with a planet. In the interplanetary rendezvous problem, the spacecraft's velocity must coincide with the orbital velocity of the planet when it reaches the planet's orbit. This paper proposes a trajectory design procedure that utilizes an invariant manifold for a specified control profile to reach a target orbit. The proposed strategy allows a rendezvous to a planet in an elliptical orbit by adjusting the launch timing of the sailcraft when it starts from a circular orbit. Numerical simulations demonstrate the validity of the proposed procedure.. |
| 147. | Takashi Matsuno, Shinji Hokamoto, Position and attitude control of a planar satellite by two constant force thrusters, Proceedings of the AIAA/AAS Astrodynamics Specialist Conference 2010, 10.2514/6.2010-8393, 2010.12, This study deals with the in-plane motion of a free-floating planar satellite equipped with two thrusters having constant force magnitude and fixed direction with respect to the satellite. This paper discusses the motion of such a satellite, and proposes a simple trajectory design procedure for controlling both the satellite's position and attitude angle. First, this paper investigates the motion for constant force magnitude. A drift-less rotational maneuver forms an "invariant manifold", which can be used to design a trajectory for the target state. Then, the condition of the input profile for the drift-less motion is discussed. Furthermore, this paper explains an advantage of a rotational maneuver which intentionally generates drift velocity.. |
| 148. | Shinji Nishikori, Shinji Hokamoto, Takashi Kubota, Study on Efficient Attitude of a Multi-Legged Planetary Exploration Rover with Isotropic Leg Arrangement, Proceedings of the the 10th International Symposium on Artificial Intelligence, Robotics and Automation in Space, pp.237-243, 2010.08. |
| 149. | Shinji Nishikori, Shinji Hokamoto, Takashi Kubota, Study on Efficient Walking Attitude of Planetary Exploration Rover with Spherically Isotropic Leg Arrangement, Proceedings of the 19th Workshop on JAXA Astrodynamics and Flight Mechanics, 149-154, 2010.03. |
| 150. | Junko Murakami, Shinji Hokamoto, Approach for optimal multi-rendezvous trajectory design for active debris removal, Proceedings of the 61st International Astronautical Congress 2010, IAC 2010, 7, 6013-6018, 2010.10, This paper proposes a method for designing a rendezvous trajectory for active debris removal using Lambert's problem. For the active debris removal mission, it is preferable to remove multiple target debris in sequence during a single mission with a low required ΔV. The trajectory design process for the removal mission consists of the following three steps: selection of the removal target debris from among many candidates; specification of the rendezvous order for the chosen debris; and design of the rendezvous transfer orbits. Since Lambert's problem has multiple solutions, the design process requires a large number of computations. By limiting the debris removal mission to low-Earth orbit, this paper proposes a procedure to specify a unique solution for Lambert's problem. To demonstrate the feasibility of the proposed procedure, this paper deals with a simple rendezvous for three debris as an example, and applies a genetic algorithm to find a solution having a reasonable ΔV with low calculation cost. Numerical results show that the proposed design procedure can find a reasonable solution for the multiple rendezvous problem.. |
| 151. | Shinji Hokamoto, Masaoki Iwase, Position and Attitude Control of a Free-Floating Planar Satellite Controlled by Thrusters, TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 10.2322/tastj.8.Pd_1, 8, 27, Pd_1-Pd_7, 2011.01, This study deals with the in-plane motion of a free-floating satellite equipped with thrusters whose force directions are fixed to the satellite. The system's governing equations form nonintegrable second-order “nonholonomic” constraints due to the fixed force directions to the satellite. This paper treats a satellite with three thrusters, and at first assumes that the magnitudes of the thrusters can continuously be changed from zero to a specified positive value. Under the assumption, it is shown that the nonholonomic governing equations can be transformed into holonomic ones by a feedback of the rotational angular velocity. Then, this paper shows the procedures to control the satellite's position and attitude precisely. Finally, we restrict the magnitude of the thrusters to be constant, and discuss the control techniques for such systems.. |
| 152. | Takashi Matsuno, Shinji Hokamoto, Position and attitude feedback controller of a planar satellite with two thrusters, Proceedings of the ICROS-SICE International Joint Conference 2009, 4206-4211, 2009.12, This paper proposes a feedback control method for the in-plane motion of a satellite equipped with two thrusters, whose force directions are fixed to the satellite. The satellite's equations of motion have second-order nonholonomic constraints. This paper utilizes an invariant manifold and develops a feedback controller based on the Lyapunov's second method. The developed controller can control the satellite's state composed of six components for the position and attitude angle by two thruster systems. Furthermore, the controller has robustness for the system's modeling errors. Some simulations results are shown to demonstrate the effectiveness of the developed controller.. |
| 153. | Feedback Control for Satellite Orbit Transfer by a Tethered Satellite System. |
| 154. | Shinji Hokamoto, Masaoki Iwase, Position and Attitude Control of a Free-Floating Planar Satellite Controlled by Thrusters, Proceedings of the 27th International Symposium on Space Technology and Science, 2009.05. |
| 155. | Shinji Hokamoto, Masaoki Iwase, Junya Fujii, Non-holonomic Analysis and Control of a Thruster Driven Free-Floating Satellite, Proceedings of the 18th Workshop on JAXA Astrodynamics and Flight Mechanics, 189-194, 2009.03. |
| 156. | Shinji Hokamoto, Masaoki Iwase, Position and attitude control of a planar satellite by two thrusters, Proceedings of the AIAA Guidance, Navigation, and Control Conference and Exhibit, 10.2514/6.2009-6183, 2009.01, This study deals with the in-plane motion of a free-floating planar satellite equipped with two thrusters whose force directions are fixed with respect to the satellite. The system's governing equations form non-integrable second-order "nonholonomic" constraints due to the fixed force directions within the satellite. First, this paper shows the general expressions of the system's equations of motion, and shows that its translational and rotational motions can not be controlled independently. Next, by assuming an imaginary thruster controlled by a feedback law, we transform the nonholonomic constraints into holonomic ones. This concept is followed by a strategy to achieve a rotational motion without drift for a satellite system with two fixed thrusters. Afterwards, this paper shows a procedure for precise control of the position and attitude of the system. The validity of the proposed method is verified by numerical simulations. Finally, this paper discusses the special case when the magnitude of the thruster force is taken constant.. |
| 157. | Masaoki Iwase, Shinji Hokamoto, Roll Angular Momentum Enhancement of a Tethered Satellite System for Transfer in Different Orbit Plane, TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN, 10.2322/tstj.7.Pd_57, 7, 26, Pd_57-Pd_62, 2009.08, This paper discusses the in-planar and out-of-planar dynamics of a Tethered Satellite System (TSS), which aims to inject a satellite into a different orbit plane. The orbital transfer is achieved by only varying the tether length in a gravity gradient field. A previous work treating in-plane orbital transfer induces the system's pitch motion, and proposes a control procedure. For a transfer in a different orbit plane, the system's roll motion must be controlled as well as its pitch motion. First, this paper shows the system's governing equations of motion, and compares the features of the roll motion with its pitch motion. Then, a control method is proposed to increase the angular momentum of the roll motion. Finally, the effectiveness of the proposed method is demonstrated by numerical simulations.. |
| 158. | Shinji Hokamoto, Koji Sachimoto, Koki Fujita, Trajectory Design of Solar Sail Spacecraft for Interplanetary Rendezvous Missions, TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN, 10.2322/tstj.7.Pd_37, 7, 26, Pd_37-Pd_42, 2009.08, This paper deals with in-plane motion of a solar sail spacecraft to rendezvous with a planet. In the interplanetary rendezvous problem, the spacecraft's velocity must coincide with the orbital velocity of the planet when it reaches the planet's orbit. Thus, the spacecraft's radial and tangential velocities as well as its orbital radius are controlled by one control input, i.e. the spacecraft's pitch angle. In this paper, we propose a trajectory design method which can reduce the amount of computational iterations considerably. This is applied to a rendezvous mission to a planet in a circular orbit and is achieved by utilizing locally optimal control techniques. A hidden problem in the method is pointed out, and a countermeasure is proposed. Then, numerical results of the proposed method are shown and compared with the results obtained by a fully numerical iteration method. Finally, some mathematical properties of a sailcraft's governing equations are discussed in the framework of nonlinear control theory. We show analytically that a solar sail spacecraft can rendezvous with any planet in any elliptical orbit by using only pitch angle control.. |
| 159. | Shinji Nishikori, Shinji Hokamoto, Kinematic Discussion and Development of a Multi-Legged Planetary Exploration Rover with Isotropic Leg Arrangement, Proceedings of the 3rd Asia International Symposium on Mechatronics, 170-175, 2008.08. |
| 160. | Orbital Transfer of a Tethered Satellite System Using Pitching Motion Control through Tether Length Variation. |
| 161. | Shinji Hokamoto, Naritoyo Shibata, Tether Length Control for Orbital Transfer of Tethered Satellite, Proceedings of the 17th Workshop on JAXA Astrodynamics and Flight Mechanics, 261-266, 2008.03. |
| 162. | Koki Fujita, Shinji Hokamoto, A Consideration on Lander’s Motion Estimation from Range Image Sequence Utilizing LRF, Proceedings of the 17th Workshop on JAXA Astrodynamics and Flight Mechanics, 194-199, 2008.03. |
| 163. | Feedback Control of Orbital Parameters for a Rigid Satellite under Nonholonomic Constraint. |
| 164. | Koki Fujita, Shinji Hokamoto, Control Laws for Orbital Parameters of Rigid Satellite System Considering Nonholonomic Constraint, Proceedings of the Guidance, Navigation, and Control Conference, AIAA-2007-6849, 2007.08. |
| 165. | Shinji Hokamoto, Masaoki Iwase, Position and Attitude Control of a Planar Satellite by Two Thrusters, Proceedings of the Guidance, Navigation, and Control Conference, AIAA-2009-6183, 2007.08. |
| 166. | Feedback Control of a Planar Space Robot Using a Moving Manifold. |
| 167. | Koki Fujita, Shinji Hokamoto, Control laws for orbital parameters of rigid satellite system considering nonholonomic constraint, Proceedings of the AIAA Guidance, Navigation, and Control Conference 2007, 10.2514/6.2007-6849, 5073-5085, 2007.08, This study deals with orbital control of a rigid coplanar dumbbell-type satellite system. While most of the previous work for orbital transfer aim at changing just one parameter of the orbital elements, by applying a nonlinear method, this study proposes two control laws to change an orbit into a prescribed one defined by its orbital elements: semi-major axis (equivalent to semilatus rectum), eccentricity and argument of pericenter. First controller is developed from a two-step approach combining a solution for a chained formed system and numerical modification based on motion planning. Another is a feedback controller, which can compensate model uncertainty or disturbance. These two controllers can be combined to a complementary control technique. The effectiveness of the proposed control laws are demonstrated through a series of numerical simulations.. |
| 168. | A Study on Orbital Transfer of a Rigid Satellite System Using Its Nonholonomic Constraint. |
| 169. | Shinji Hokamoto, Toshirou Funasako, Considerations on a feedback control system for a space robot reorientation, Proceedings of the AIAA/AAS Astrodynamics Specialist Conference, 2006, 10.2514/6.2006-6519, 1205-1213, 2006.08, This study deals with feedback control of reorientation of a planar space robot. Mukherjee and Kamon propose to define 'a radially isometric orientation' and successfully establish a smooth time invariant control system. However the proposed controller suffers from slow rate of convergence for a desired configuration being placed on or near a zero-holonomy curve. They also propose two modified controllers for such configurations, but stability problem for the modified controllers remains future work and a criterion for choosing the original or modified controller is not discussed for general configurations. This paper proposes to adopt a 'moving desired configuration' for convergence to any desired configuration. The moving desired configuration is designed to move to a 'real' desired configuration with the system states close to an invariant manifold. The paper describes how to define the invariant manifold and how to move the moving desired point to the real one.. |
| 170. | Shinji Hokamoto, Orbital control of satellite systems using nonholonomic control theory, Proceedings of the AAS/AIAA Astrodynamics Conference 2005, 1533-1544, 2005.08, This study deals with orbital control of a rigid dumbbell-type satellite system. While most of the previous works for orbital transfer aim at changing just one parameter of the orbital element or the orbital energy, in this study the system is transferred by using its inner force into a prescribed orbit defined as a set of orbital elements: semilatus rectum, eccentricity, and argument of pericenter. By applying nonlinear control theories, it is shown that the satellite system is controllable except its pericenter and its apocenter in the elliptic orbit. Then, this paper transforms the nonlinear governing equations into a canonical system, called 'a chained system', and demonstrates that a specified orbit is accomplished by appropriately shaped time histories of control inputs.. |
| 171. | Considerations for Control of Planar Space Robot using Manifolds. |
| 172. | Shinji Hokamoto, Kazuo Setoyama, Orbital control of a tethered satellite system using tether-length variations, Proceedings of the 56th International Astronautical Congress 2005, 5, 3105-3111, 2005.10, This study deals with orbital transfer of a tethered satellite system into a specified orbit (defined in the equatorial plane as a set of semilatus rectum, eccentricity, and augment of pericenter,) by using tether-length variations. While in the 55th IAC conference the tethered satellite system was assumed as a rigid dumbbell type satellite, the tethered satellite system dealt in this paper is not rigid, and the system has only one control input: tether-length variation. By comparing the nature of the systems to that of rigid satellite systems, this paper points out that the timing of changing the tether length on its orbital motion is a key of orbital transfer. And controllability of the system is discussed numerically by examining the distribution of the control effect.. |
| 173. | Shinji Hokamoto, Considerations on control for a tethered satellite system through angular momentum conservation, Proceedings of the 55th International Astronautical Congress 2004, 2, 751-756, 2004.10, This study deals with orbital transfer of a tethered satellite system (TSS) on orbit. Dynamics of TSS is restricted to the angular momentum conservation law of the system around a planet. This constraint is not integrable (, that is called "nonholonomic constraint"), and the final state of TSS depends on a time history of the input. While previous works for orbital transfer mainly investigated dynamics of the system for specified time profiles of the tether-length, this study aims to make tether extension profiles to achieve some specified orbit. This paper, as a preliminary study, gives a brief overview of the previous works and investigates the fundamental property of the constraint based on the angular momentum conservation. Integrability and accessibility /controllability are analyzed and also numerically verified. For simplicity, TSS is modeled to a dumbbell-type satellite in this study.. |
| 174. | Koki Fujita, Shinji Hokamoto, An Autonomous Path Planning of a Rover Utilizing Multi-Image Shape from Shading, Proceedings of the AIAA/AAS Astrodynamics Specialist Conference, 2002.08. |
| 175. | Naoki Imamura, Shinji Hokamoto, Dynamical Interaction of a Tethered Space Robot, Proceedings of the 23rd International Symposium on Space Technology and Science, 2002.05. |
| 176. | Shinji Hokamoto, Masamitsu Kuwahara, Vinod Modi, Arun Misra, Formulation and Control of a Flexible Space-Based Robot with Slewing-Deployable Links, Acta Astronautica, 10.1016/S0094-5765(98)00040-X, 42, 9, 519-531, Vol.42, No.9, pp.519-531, 1998.05. |
| 177. | Shinji Hokamoto, Hajime Ohno, Path Planning for a Space Robot Using Surface Integral Map, Proceedings of the AIAA/AAS Astrodynamics Conference, 432-437, 1998.08. |
| 178. | Torque-Unit-Manipulator Driven by Control Moment Gyros. |
| 179. | Shinji Hokamoto, Manabu Ochi, Fundamental Abilities of Multi-Legged Rover with Isotropic Shape, Proceedings of the 22nd International Symposium on Space Technology and Science, 1627-1632, 2000.05. |
| 180. | Shinji Hokamoto, Manabu Ochi, Dynamic Behavior of a Multi-Legged Planetary Rover of Isotropic Shape, Proceedings of the 6th International Symposium on Artificial Intelligence, Robotics and Automation in Space, 2001.06. |
| 181. | Shinji Hokamoto, Naoki Imamura, V. J. Modi, Dynamics and Control of a Tethered Space Robot with Tension, Advances in the Astronautical Sciences, 109, 1587-1595, Vol. 109, pp.1587-1595, 2001.07. |
| 182. | Shinji Hokamoto, Torque Unit Manipulator Driven by Control Moment Gyro, Proceedings of the Seventh International Space Conference of Pacific-basin Societies, 1997.07. |
| 183. | Shinji Hokamoto, Masamitsu Kuwahara, Vinod Modi, Arun Misra, Control of a Flexible Space-Based Robot with Slewing-Deployable Links, Proceedings of the AIAA/AAS Astrodynamics Specialist Conference, 1996.07. |
| 184. | Shinji Hokamoto, Vinod Modi, Arun Misra, Dynamics and Control of Space Robots with Deployable Manipulators, Advances in the Astronautical Sciences, 90, 1996.01. |
| 185. | Shinji Hokamoto, Vinod Modi, Nonlinear Dynamics and Control of a Flexible Space-Based Robot with Slewing-Deployable Links, Proceeding of the International Symposium on Microsystems, Intelligent Materials and Robots, 1995.09. |
| 186. | Shinji Hokamoto, Vinod Modi, Arun Misra, Dynamics and Control of Mobile Flexible Manipulators with Slewing and Deployable, Proceedings of the AAS/AIAA Astrodynamics Specialist Conference, 1995.08. |
| 187. | Shinji Hokamoto, Norihiro Goto, LAC/HAC System with a Variable Feedback Gain for Flexible Space Structures, JSME International Journal, 37, 3, 431-435, 1994.09. |
| 188. | Shinji Hokamoto, Norihiro Goto, Modified LAC/HAC Technique for a Flexible Space Structure, Proceedings of the 18th International Symposium on Space Technology and Sciences, 961-966, 1992.05. |
| 189. | Shinji Hokamoto, Yoshinari Kawahara, A consideration on dynamic constraint of planar manipulators with free-joints, Proceedings of the AIAA Guidance, Navigation, and Control Conference and Exhibit 2002, 2002.08, It is known that the manipulators with free-joints are typical mechanical systems dominated by second-order nonholonomic constraints. This paper points out that only the second-order nonholonomic constraint at the first free-joint of the manipulator is integrable to first-order constraint, and that the integrated constraint has linear form of generalized velocities. This constraint implies that a planar manipulator whose first joint is replaced to a free-joint driven by a reaction wheel can be controlled using the same control strategy as that used for the original manipulator. Integrability of the resulting first-order constraint is also discussed for different planar manipulators with free-joints, and the usefulness of the first-order nonholo-nomic constraint is demonstrated numerically in a path-planning problem for a manipulator with two free-joints.. |
| 190. | Koki Fujita, Shinji Hokamoto, An autonomous path planning of a rover utilizing multi-image shape from shading, Proceedings of the AIAA/AAS Astrodynamics Specialist Conference and Exhibit 2002, 2002.01, For planetary exploration, path planning for a rover is one of the important missions. This paper deals with Shape from Shading (SfS) scheme for estimation of planet terrain. As a reliable reflectance model of a surface, the Hapke model is formed in the world of remote sensing. This paper proposes to utilize the Hapke model in the SfS algorithm for multiple camera images. Since the Hapke model has singularity when the gradient vector of a surface element is coincident with a certain direction, the model is modified not to show the singularity. As a result, the SfS algorithm is applicable to multiple camera images and valid regardless of the degree of albedo of the surface. Applying the proposed SfS algorithm for multiple images, an autonomous path planning based on Dynamic Programming is shown. The effectiveness of the proposed scheme is investigated in numerical simulations, and some discussion about the results is presented.. |
| 191. | Torque-Unit-Manipulator Driven by Control Moment Gyros. |
| 192. | Shinji Hokamoto, Masamitsu Kuwahara, Vinod Modi, Arun Misra, Formulation and control of space-based flexible robots with slewing-deployable links, Acta Astronautica, 10.1016/S0094-5765(98)00040-X, 42, 9, 519-531, 1998.01, The present study deals with a space-based variable geometry mobile manipulator with an arbitrary number of modules, each with two flexible links: one of them free to slew (revolute joint); and the other deployable (prismatic joint). The versatile manipulator has several attractive features: favorable obstacle avoidance, absence of singular configurations, reduced inertia coupling, relatively simpler inverse kinematics as well as governing equations of motion, to mention a few. To begin with, derivation of the governing equations of motion, using the Lagrangian procedure, is explained. As can be expected, the recursive equations are highly nonlinear, nonautonomous and coupled. This is followed by the development of a numerical algorithm leading to the solution for the inverse kinematics. Finally, some typical simulation results for trajectory control of the end-effector using the resolved acceleration approach are presented. They clearly emphasize importance of the control strategy based on the flexible manipulator model.. |
| 193. | Shinji Hokamoto, Torque Unit Manipulator Driven by Control Moment Gyros, Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C, 10.1299/kikaic.64.4292, 64, 627, 4292-4298, 1998.01, This paper deals with a space manipulator which is called Torque-Unit-Manipulator (TUM) : TUM separates its actuator called torque unit from its joints; i.e., torque unit is placed on an arbitrary place on a link, and each rotational joint is a free joint. The TUM proposed in the previous work, however, is driven by reaction wheels, and thus it has a problem to be solved : the angular velocity of the reaction wheel may saturate when external force disturbs the posture of the TUM repeatedly. The reason is that the reaction wheels accumulate angular momentum during the maneuver because of non-holonomic constraint for the free joints. Therefore, TUM driven by Control Moment Gyros (CMGs) is proposed in this paper. For the proposed TUM, an asymptotically stable controller can be designed through Lyapunov's approach, and besides the gimbal angular velocity of the CMG returns to zero after each maneuver. The dynamics of the proposed TUM is computed in numerical simulation, and the effectiveness of the designed controller is shown.. |
| 194. | Shinji Hokamoto, Torque unit manipulator driven by control moment gyros, Advances in the Astronautical Sciences, 96, 865-876, 1997.12, This paper deals with a space manipulator which is called Torque-Unit-Manipulator (TUM): TUM separates its actuator called torque unit from its joint: i.e., torque unit is placed on an arbitrary place on a link, and each rotational joint is a free joint. The TUM proposed in the previous work, however, is driven by reaction wheels, and thus it has a problem to be solved: the angular velocity of the reaction wheel may saturate when repeated external force disturbs the posture of the TUM. The reason is that the reaction wheels accumulate angular momentum during the maneuver because of non-holonomic constraint for the free joints. Therefore, TUM driven by Control Moment Gyros (CMGs) is proposed in this paper. For the proposed TUM, an asymptotically stable controller can be designed through Lyapunov's approach, and besides this the gimbal angular velocity of the CMG returns to zero after each maneuver. The dynamics of the proposed TUM is computed in numerical simulation, and the effectiveness of the designed controller is shown.. |
| 195. | Formulation and Dynamics of Flexible Space Robots with Deployable Links. |
| 196. | Shinji Hokamoto, Vinod J. Modi, Formulation and dynamics of flexible space robots with deployable links, Nippon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C, 10.1299/kikaic.62.1495, 62, 596, 1495-1502, 1996.01, This paper deals with a manipulator interconnected by an arbitrary number of modules, each with a flexible slewing link and a flexible deployable link. This manipulator has several inherent advantages compared to a manipulator connected by rotational joints. The two main ones are that integration of modules leads to a variable geometry manipulator with favorable obstacle avoidance and redundancy characteristics, and that there are no singular positions as in the revolute type manipulator. The equations of motion of the manipulator are derived from Lagrange's equations for the quasicoordinates using the elastic deformation modes orthogonal to the translational displacements. The total amount of calculation for the control torque is proportional to the number of links. Finally, to verify the validity of the derived equation and the computer program, the conservation of energy in a few dynamics problems is checked numerically.. |
| 197. | Shinji Hokamoto, Norihiro Goto, Lac/Hac System with a Variable Feedback Gain for Flexible Space Structures, jsme international journal. ser. c, dynamics, control, robotics, design and manufacturing, 10.1299/jsmec1993.37.431, 37, 3, 431-435, 1994.02, This paper proposes a new control technique, based on the low authority control/ high authority control (LAC/HAC) concept, to suppress the vibration of flexible space structures. The control system designed by the new control technique has a mechanism to adjust the HAC feedback gain between zero and one in such a manner as to enhance the effectiveness of control and to obtain global stability even when the magnitude of the LAC gain is not suitable. The paper first describes the theoretical mechanism of the new control technique and proposes a numerical method for determining the HAC feedback gain based on a neural network system. Then it shows the characteristic features of the new technique by computer simulation examples. The computer simulation shows that the new technique is quite effective in suppressing the spillover effects, and quite feasible for implementation.. |
| 198. | Shinji Hokamoto, Norihiro Goto, Proposal of a vibration control technique for a flexible structure, Proceedings of the 41st Japan Congress on Applied Mechanics _ NCTAM-41, 41, 15-20, 1992.12, In this paper a new control technique based on the LAC/HAC concept is proposed to suppress the vibration of flexible space structures. The new technique employs the mechanism to turn on or off the HAC part of the LAC/HAC system in such a manner as to suppress the spillover effects as quickly as possible. The control system designed by the new technique has global stability and is more effective than a pure LAC system, even when an ordinary LAC/HAC system results in failure because of spillover instability. To show the characteristics features of the new technique and how to implement the system, computer simulation examples are given. Finally, the technique is applied to the transversal vibration control of a cantilever beam to show its effectiveness and practicality.. |
| 199. | Shinji Hokamoto, Norihiro Goto, New control technique based on the LAC/HAC concept for flexible structures, Transactions of the Japan Society for Aeronautical and Space Sciences, 34, 106, 240-249, 1992.02, In this paper a new control technique based on the LAC/HAC concept is proposed to suppress the vibration of flexible space structures. The new technique employs the mechanism to turn on or off the HAC part of the LAC/HAC system in such a manner as to suppress the spillover effects as quickly as possible. The control system designed by the new technique has global stability and is more effective than a pure LAC system, even when an ordinary LAC/HAC system results in failure because of spillover instability. To show the characteristic features of the new technique and how to implement the system, computer simulation examples are given. Finally, the technique is applied to the transversal vibration control of a cantilever beam to show its effectiveness and practicality.. |
| 200. | Shinji Hokamoto, Norihiro Goto, Time Sharing LAC/HAC Technique for a Flexible Structure, Proceedings of the Second U.S./Japan Conference on Adaptive Structures, 280-296, 1991.11. |
| 201. | A New Control Technique Based on the LAC/HAC Concept for Flexible Structures.. |
| 202. | Shinji Hokamoto, Norihiro Goto, Spillover instability of a flexible structure equipped with a modal filter, Memoirs of the Kyushu University, Faculty of Engineering, 50, 4, 363-376, 1990.12, Modal instability due to spillover is investigated of a flexible vibration control system that employs a modal filter as the state estimator. First the characteristic equation of the closed-loop system containing actuators, sensors and a modal filter is derived in a determinantal form. Then it is shown that the characteristic equation can be expanded in a mathematically tractable form. By applying the perturbation technique to the expanded characteristic equation, a criterion is obtained that determines whether or not a residual mode is destabilized. Finally it is proved through the use of the criterion that the control system equipped with one actuator and one sensor always has unstable modes if they are non-colocated.. |
| 203. | Norihiro Goto, Shinji Hokamoto, ROOT LOCUS METHOD FOR ACTIVE CONTROL OF FLEXIBLE SYSTEMS., Transactions of the Japan Society for Aeronautical and Space Sciences, 30, 89, 150-161, 1987.11, Precise attitude and shape control of flexible spacecraft requires active control of flexural vibrations. This paper is concerned with the root locus method applied to active vibration control systems for a certain class of flexible bodies. A general characteristic equation is derived for a feedback system to control flexural vibrations with arbitrary numbers of sensors and actuators. Then it is shown, for the first time, that the characteristic equation in determinantal form may be reduced to a mathematically tractable form. It is also shown that under the condition of colocation of sensors and actuators the characteristic equation assumes a form in which the significance of this condition can be readily appreciated. Finally, the paper presents a numerical study to illustrate a practical procedure applying the root locus method to flexural vibration control systems.. |
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