Shinji Hokamoto | Last modified date：2022.11.08 |

Professor /
Flight Dynamics and Controls

Department of Aeronautics and Astronautics

Faculty of Engineering

Department of Aeronautics and Astronautics

Faculty of Engineering

Graduate School

Undergraduate School

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Homepage

##### https://kyushu-u.pure.elsevier.com/en/persons/shinji-hokamoto

Reseacher Profiling Tool Kyushu University Pure

Academic Degree

Kyushu University (Japan), Doctor of Engineering

Country of degree conferring institution (Overseas)

No

Field of Specialization

Aeronautics and Astronautics

Total Priod of education and research career in the foreign country

00years00months

Outline Activities

Research: Submittion of original research articles to Journals

Education: Lecture to students and supervisor of research

Education: Lecture to students and supervisor of research

Research

**Research Interests**

- Development of Autonomous Navigation Systems based on Insect Vision

keyword : Vision Guidance System, Optic Flow, Compound Eye System

2012.04Dynamics and Control of Planetary Rovers. - Control of Nonlinear Systems with Non-holonomic Constraints

keyword : Space, Non-holonomic, Tether

2000.01Dynamics and Control of Tethered Satellites. - Development of Autonomous Systems

keyword : Autonomous System, Path Plannning, Leg Locomotion, Vision Guidance System

2000.01Dynamics and Control of Planetary Rovers. - Dynamics and Control of Space Robots

keyword : Space, Robot, Non-holonomic, Path Planning

2000.01Dynamics and Control of Space Robots.

**Academic Activities**

**Papers**

1. | 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.. |

2. | 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. |

3. | 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.. |

4. | 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 attractiveset. 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.. |

5. | 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 L_{2} point.. |

6. | 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.. |

7. | 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.. |

8. | 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.. |

9. | Feedback Control of a Planar Space Robot Using a Moving Manifold. |

10. | A Study on Orbital Transfer of a Rigid Satellite System Using Its Nonholonomic Constraint. |

Educational

**Educational Activities**

Undergratuate Course:

Fundamentals of Guidance and Control I, Fundamentals of Guidance and Control II, Flight Control Systems

Graduate Course:

Advanced Guidance and Control I, Instrumentation, Guidance and Control Seminar I, Guidance and Control Seminar II, Guidance and Control Laboratory,

Advanced Guidance and Control

Fundamentals of Guidance and Control I, Fundamentals of Guidance and Control II, Flight Control Systems

Graduate Course:

Advanced Guidance and Control I, Instrumentation, Guidance and Control Seminar I, Guidance and Control Seminar II, Guidance and Control Laboratory,

Advanced Guidance and Control

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