Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Proceedings of the International Congress on Sound and Vibration  

This paper proposes a method to derive the contribution of frame vibration to panel vibration, with the aim of deriving design parameters based on vibrational energy propagation in the car body. The various frame deformations are classified into two types: global deformations and cross-sectional deformations. These deformation quantities are defined using vector geometry, and a FEM model is proposed to derive them. Based on the FRF Based Substructuring (FBS), the contribution of each type of frame deformation to the panel vibration was determined by calculating the panel vibration using the deformation vectors between the frame panels output from the analysis. Based on these results, the factors that cause changes in the energy transmission coefficient and panel vibration due to the structural changes described in the 1st. paper are discussed from the viewpoint of material mechanics. Possibility of reducing energy transmission coefficient and panel vibration by extracting design parameters intended to suppress frame deformation from the contribution of each deformation form is indicated.

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Proceedings of the International Congress on Sound and Vibration  

This paper aims at modeling the vibration energy propagation of flat plates with non-uniform parts and clarifies the influence of non-uniform parts on the coupling loss factor (CLF) of the Statistical Energy Analysis (SEA) method. The CLF variation due to non-uniform parts is discussed from the equation for calculating the CLF using the power injection method, and numerical validation is carried out on a structure with some thickness changes. The results show that the CLF varies with the rate of change of the ratio of the subsystem energy of the non-uniform part to the subsystem energy of the uniform part. As an application example, it has been shown that the CLF of a structure consisting of a frame and panels simulating a part of a car can be reduced by changing the structure of the frame and that the response of the panels can be reduced.

Scopus

Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Automotive Engineers  

Spring-mass systems are commonly used in the design of vehicles considering crash worthiness for occupant protection. On the other hand, if the crash is considered as the absorption of the vehicle’s kinetic energy in the crushable zone, it can be regarded as a damper-mass system. In this paper, an impact model using damper-mass system is compared with a spring-mass system, assuming a situation where the front frame of the vehicle is crushed by the impact. As a result, it can be said that it is reasonable to use the damper mass system as an impact model.

DOI： 10.11351/jsaeronbun.54.1170

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

<p>In automotive development, it is important to balance various phenomena with a simplified vehicle body model in the initial design phase. Additionally, idling vibration, engine shake, and road noise are phenomena that affect vehicle ride comfort. Since they have different exciting components and target frequencies, each simplified vehicle model examined in the past report is different. Therefore, it is necessary to represent of each phenomenon in a single vehicle model. Therefore, in recent years, much research has been done in initial design techniques called Model Based Development (MBD) and 1D CAE. We have studied using the Statistical Energy Analysis (SEA) for the initial design. Especially an energy transmissibility parameter of SEA which is called by coupling loss factor (CLF) is focused on describing the phenomenon for various kinds of vibration and noise problem. In this paper, a fundamental study is conducted to examine the balance of multiple phenomena in the initial design phase by the energy transmissibility. At first, a simplified vehicle model that represents each phenomenon is constructed. Next, the energy transmissibility is used to represent each phenomenon, and vibration reduction guidelines are obtained and verified through balance design. The obtained guidelines are then applied numerically to the actual vehicle to confirm vibration reduction.</p>

DOI： 10.1299/transjsme.23-00025

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

<p>This study focuses on the energy transmissibility, which is called coupling loss factor (CLF) in Statistical Energy Analysis (SEA) framework, for two degree of freedom vibration system. The aim of this study is to obtain a new interpretation of the energy transfer viewpoint of the phenomena represented by the two-degree-of-freedom vibration system and to utilize it for vibration control and structural design. In this paper, the energy transfer characteristics of one-degree-of-freedom and two-degree-of-freedom vibration systems are explicitly derived from the equations of motion under broadband excitation through the energy (power) equilibrium and the frequency average concept. And then it is shown that the derived energy transmissibility can be described by a mathematical equation and is a single value. The transmissibility is determined by three parameters, which are the properties concerning each two uncoupled one degree of freedom vibration system, the uncoupled natural angular frequencies, the damping and the coupling properties. Then the energy transmissibility can be easily used for understanding phenomena described by the two degree of freedom systems and for control and design them. Furthermore, as an example of vibration control based on the energy transmissibility, the reduction of engine shake in automobiles is presented, and its effectiveness is compared and discussed with the results in the reference.</p>

DOI： 10.1299/transjsme.22-00315

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

<p>Vibration measures can be taken at three main locations: the vibration source, the propagating part, and the radiating part. However, measures at the vibration source are often difficult to implement, and countermeasures at the radiating part are inefficient. Therefore, measures at the propagation part are expected. For measures at the propagation part, the technique of structural intensity (SI) is used, which is effective in understanding the propagation path. Then, we attempt to reduce the vibration by a viscous damper layout based on the SI distribution. In this paper, the most effective layout for vibration reduction is presented for 2 and 3 DOF systems. As a result, it was found that adding a damper on the response side is effective. For beam system, the relationship between the ratio of change of SI and the velocity was also discussed. Based on these findings, a method for identifying the damper location by SI is newly proposed, and its effectiveness is verified.</p>

DOI： 10.1299/transjsme.22-00330

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Automotive Engineers  

This paper proposes a new method for analyzing the impact performance of vehicle bodies in the early stages of design. The method is called Impact Statistical Energy Analysis (ISEA), which is based on the propagation of energy and considers the conversion of kinetic energy of the structure into internal energy in the deformed parts of the structure during a crash. The paper discusses the effectiveness of ISEA in comparison with damper mass models and FEM models for one- and two-member structures.

DOI： 10.11351/jsaeronbun.54.1067

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

<p>Overhead cranes are widely used to transport heavy loads, and their efficient operation requires fast and accurate positioning. However, residual vibration which prevents positioning accuracy generally tends to be induced by fast transportation. In previous paper, we proposed a control method which is based on the characteristic that the residual vibration is completely suppressed in a linear undamped system when excited by an external force which does not contain the natural frequency component of the system. To apply this characteristic to nonlinear damped systems, we defined the apparent external force which includes the influence of system nonlinearity and damping. It was confirmed that the residual vibration of a double pendulum type system model of crane can be suppressed by eliminating two natural frequency components from each the apparent external forces. In this paper, in addition, to improve the robustness for a double pendulum type system against the estimation error, new conditions are added to reduce the component around the natural frequencies from each of the two apparent external forces. The effectiveness of these conditions for robustness is verified through numerical simulations. Furthermore, changes in the robustness are examined when the position of the mass point near the support point of the double pendulum is changed. The results showed that the robustness can be improved in many cases except when the control time is short and the mass point is close to the support point.</p>

DOI： 10.1299/transjsme.22-00331

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Automotive Engineers  

This paper presents a method using energy transmissibility to discuss the vibration frequency-averaged response of a 2-DOF system. First, it is shown that the response of a simple 2-DOF vibration system composed of two masses and two springs can be simply predicted from the formula of the energy transmissibility. Next, previous studies on engine shake reduction are presented and the measures to reduce the shake response are reviewed, which measures are considering the coupling of bouncing and pitching motions and the employment of the hydraulic engine mount which are equivalent to dynamic dampers. It is then shown that these measures can also be derived in terms of the energy transmissibility. Finally, we argue that the energy transmissibility is useful for understanding vibration phenomena, designing vibration response, and enhancing new ideas for vibration response reduction.

DOI： 10.11351/jsaeronbun.54.144

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Automotive Engineers  

This paper describes the vibration phenomenon on vehicle motion from the perspective of energy propagation based on a two-degree-of-freedom vibration system. The energy transmissibility between the yaw and roll motions is analytically formulated by using their uncoupled natural angular frequencies, damping, and coupling characteristics. It is shown that the neutral steering character can be expressed by zero-energy transfer between the yaw and roll motion. The transmissibility is also useful to express the transient performance of the vehicle with under/over steering characteristics and the stable limit speed and so on. Finally, it is demonstrated that the transmissibility is useful to understand the transient performance under changing the roll stiffness and damping coefficient as examples.

DOI： 10.11351/jsaeronbun.54.56

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Automotive Engineers  

In automobile industry, the welding is usually employed to connect metal and metal parts. However, recently, adhesives with large internal damping are used to join structures instead of welding. Therefore, we formulate the sensitivity of subsystem energy to internal loss factor in SEA. We considered the perturbation of the loss factor in the SEA fundamental power balance equation. We can deduce a guideline for reducing the subsystem energy by adding the damping to appropriate subsystem. The guideline is shown that the damping addition is more effective on the subsystem in the path from the excitation subsystem to the response subsystem.

DOI： 10.11351/jsaeronbun.53.516

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ASME  

A systematic approach is developed for determining a control input for the point-to-point control of an overhead crane that exhibits temporal variation of rope length in addition to damping and nonlinearity, without inducing residual vibration. Complete suppression of the residual vibration is achieved by eliminating the natural frequency component of the cargo from the apparent external force, which is defined to include the effects of damping, nonlinearity, and parameter variation.

DOI： 10.1115/1.4051138

Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

本研究では，オープンループ制御における台車軌道の設計手法に固有振動数成分除去法を提案している．本報では，固有振動数の推定誤差に対する残留振動抑制のロバスト性向上を目指して台車軌道の設計に新たな条件を加える．条件としては複数の振動数成分を除去する条件と振動数成分の微分係数を零にする条件の2種類を用い，ロバスト性や適用可能範囲について，その有効性を数値シミュレーションによって検証し両者の比較を行う．

DOI： 10.1299/transjsme.18-00274

Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

本研究では，オープンループ制御による天井走行クレーンの残留振動抑制を目的として，台車軌道の設計手法に固有振動数成分除去法を提案している．固有振動数成分除去法とは，不減衰線形系に関して外力が系の固有振動数の成分を持たなければ残留振動は生じない，という性質を利用したものである．本報では，本手法を減衰非線形系の残留振動抑制に適用した際の有効性を数値シミュレーションによって検証する．

DOI： 10.1299/transjsme.17-00477

Event date： 2023.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋市  

自動車車体や各種機器の筐体の振動を低減するために，対象物のどこに減衰を付与することがより有効で，その見通しのよい設計としてどのようなものがあるか．効果的な振動低減のために，減衰付与位置についてSEA に基づき検討した．

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Event date： 2023.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Chiba-shi   Country：Japan  

Originally, the ray tracing method does not take frequency response into account, but in this study, the ray tracing method is modified so that frequency response can be calculated in order to apply the ray tracing method to general sound field analysis other than buildings. For this purpose, the propagation distance of each sound ray and the phase change due to reflection are considered, and the interference of each sound ray at the receiver is calculated.

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Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Yokohama   Country：Japan  

著者らはエネルギー伝達に基づく衝突性能の設計に関する研究を行っており，その一環としてダンパマス系を用いた衝突モデルについて検討している．本報では，同じ部材をバネまたはダンパでモデル化し，数値シミュレーションを用いて，ダンパマス系を用いた衝突モデルの特徴をバネマス系と比較してまとめる．

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Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Qingdao (Online)   Country：China  

In this paper, statistical energy analysis (SEA) method was used to analyse the acoustics of a straight pipe and a bent pipe. SEA was applied to the acoustic analysis by calculating the acoustic pressure loss in the pipe from the acoustic energy loss. In addition, for the internal acoustics of an automobile exhaust pipe, we used analytical SEA to optimize the structure to maximize the loss.

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Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Yurihonjo city   Country：Japan  

著者らは先行研究にて固有振動数成分除去法を提案し，その有効性を示した．本報では，フックの質量を考慮した二重振子型のクレーンモデルに対し，固有振動数の同定誤差に対するロバスト性向上を図った．その結果，非線形性や減衰を外力として考慮した2個のみなし外力からそれぞれに対応する固有振動数の成分を除去し，さらにその周りの成分も低減することでロバスト性を向上させられることを確認できた．

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Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Japan  

本報では，統計的エネルギー解析法（SEA）を用いて，直管と曲げ管を組み合わせた管路内の音響解析を行った．SEAはエネルギー伝達を要素毎の損失と要素間の伝達率を用いて表す手法であり，音響のエネルギー損失から管路内における損失を算出することで音響解析にSEAを適用した．さらに，損失が最大になるような管内径の組み合わせについて検討し，FEMによる検証を行った．

Event date： 2021.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Japan  

著者らは先行研究にて，固有振動数成分除去法を提案し，その有効性を数値シミュレーションによって示した．また，固有振動数の推定誤差に対してロバスト性を向上させる手法も提案している．本報では，直線のレール上を駆動される天井走行クレーンを模した実験装置を用い，本手法を適用した実験を行った．その結果，固有振動数に誤差がある場合でも，吊り荷の残留振動が抑制されており，本手法の有効性が実験によって示された．

Event date： 2019.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Sydney   Country：Australia  

In a previous report, numerical simulations showed that residual vibrations can be suppressed in nonlinear damped systems by eliminating the natural frequency component from the apparent external force. This paper employs two methods to improve the robustness to the estimation error for the natural frequency. Numerical simulations demonstrated the effectiveness of these methods for reducing residual vibration in overhead crane operation, showing that they exhibit similar robustness.

Event date： 2019.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka-shi   Country：Japan  

著者らは先行研究にて，固有振動数成分除去法を提案し，その有効性を示した．本報では，吊り荷のロープ長が搬送中に変化する場合について，台車軌道およびロープ長を表す関数に冗長性を持たせて最適化することで軌道の改善を図る．台車軌道とロープ長に関する目的関数をそれぞれ用意し，それらを線形結合した関数に最適化を行った結果，軌道の改善が可能であることが明らかとなった．

Event date： 2018.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

本研究では，オープンループ制御による天井走行クレーンの残留振動抑制を目的として，台車軌道の設計手法に固有振動数成分除去法を提案している．本報では，本手法を減衰非線形系の残留振動抑制に適用した際の有効性を数値シミュレーションによって検証
する．

Event date： 2018.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Koganei-shi   Country：Japan  

著者らは先行研究にて，天井走行クレーンに現れる非線形性や減衰の影響をも考慮して吊り荷の残留振動を抑制する手法（固有振動数成分除去法）を提案し，その有効性を示した．本報では，台車と吊り荷をつなぐロープ上にフック等がある系に対して，連成振動を考慮した残留振動の抑制を図った．その結果，非線形性や減衰を外力として考慮した2個のみなし外力からそれぞれに対応する固有振動数の成分を除去することで，残留振動が抑制されることを確認できた．

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka-shi   Country：Japan  

著者らは先行研究にて，天井走行クレーンに現れる非線形性や減衰の影響をも考慮して吊り荷の残留振動を抑制する手法（固有振動数成分除去法）を提案し，その有効性を数値シミュレーションによって示した．本報では，直線のレール上を駆動される台車と台車にロープで連結された吊り荷からなる天井走行クレーンを模した実験装置を用い，本手法を適用した実験を行った．その結果，吊り荷の残留振動が抑制されており，本手法の有効性が実験によって示された．

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Nanjing, P R China   Country：China  

The authors have developed an efficient method to derive an adequate trajectory of the trolley which prevents the residual vibration. This paper proposes an optimization method to design the trajectory of the trolley to minimize the angular displacement of the cargo using orthogonal polynomials for basis functions representing trolley trajectory.

Event date： 2017.8 - 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Toyohashi-shi   Country：Japan  

著者らは先行研究にて固有振動数成分除去法を提案し，その有効性を示した．本手法で残留振動を抑えるにはクレーンの正確な固有振動数を要するが，同定誤差は避けられない．本報では同定誤差のある場合にも外力の持つ固有振動数成分を低減することでロバスト性向上を図り，数値シミュレーションで検証した．その結果，誤差の無い場合に固有振動数成分の推定誤差に対する変化率が零となる条件を加えることで，ロバスト性の向上が確認できた．

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Saga-shi   Country：Japan  

著者らは先行研究にて，固有振動数成分除去法を提案し，その有効性を示した．本報では，固有振動数に推定誤差がある場合に残留振動を抑制することができないという問題について，外力の満たすべき条件を追加することで，推定誤差に対するロバスト性の向上を図った．数値シミュレーションによる検証を行った結果，外力の持つ固有振動数付近の振動数成分を低減させることで，推定誤差がある場合においても残留振動の低減が確認できた．

Event date： 2016.8 - 2023.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Ube-shi   Country：Japan  

天井走行クレーンに固有振動数成分除去法を用いることで，残留振動を抑制する台車軌道を求められる．その軌道について，任意の目的関数の最小値をとる軌道を求め，運搬中の吊り荷の揺れを低減する．

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Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎市   Country：Japan  

本研究では，天井走行クレーンの台車制御に固有振動数成分除去法を適用し，吊り荷の残留振動を抑制する．本報では，台車を高速で動かしたときに問題とされていた運搬中に吊り荷が大きく振れることについて，台車の軌道を改善することにより対策を図った． 数値シミュレーションを用いて検証を行った結果，台車の目標軌道に条件の数以上の項を有する式を与えることで運搬中の吊り荷の振れ角の減少が見られ，軌道の改善に有効であることが確認できた．