著者

吉田 直人 家澤 雅宏 西脇 和弘 髙橋 正樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.862, pp.17-00583, 2018 (Released:2018-06-25)

参考文献数

13

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In recent years, an automatic collision avoidance system has been put into practical use by various automotive companies. In this study, we propose an automatic collision avoidance system for a four-wheel independent drive vehicle using the state-dependent Riccati equation. By designing the state-dependent weighting functions, a control gain is automatically determined, based on the relative relationship with a preceding vehicle and the system can properly perform automatic braking and automatic steering. Moreover, by updating the state-dependent linear representation obtained from a nonlinear vehicle model in each control cycle, we design a control system in consideration of a change in vehicle dynamics due to vehicle velocity. Therefore, this study verifies the effectiveness of the automatic collision avoidance system using the state-dependent Riccati equation. We compare the performance of the proposed method with constant weight cases. The simulation results show that the proposed method can automatically adjust the control gain and properly avoid a collision by braking and steering to change the relative relationship with a preceding vehicle.

著者

佐藤 峻介 髙橋 正樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.801, pp.1526-1539, 2013 (Released:2013-05-25)

参考文献数

14

被引用文献数

3 5

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Recent years, it has been required accurate and agile attitude control of satellites. For this purpose, the necessity of Control Moment Gyros (CMGs) has been increasing, which can generate much higher torque than Reaction Wheel which is used for a conventional spacecraft actuator. CMGs have singularity problem that they cannot output a desired torque. Several singularity avoidance methods have been proposed, but they can fail to output the desired torque through the mission because of their singularity avoidance action. In this paper, we focus on singularity and CMGs' angular momentum and propose a singularity avoidance method by planning path in angular momentum space. Because output torque from CMGs depends on path of angular momentum, we plan the angular momentum path that avoids singularity and its length is short as possible by application of A* algorithm. It is shown from the simulations that the proposed method can realize desired output torque and assured singularity avoidance.

著者

奥川 恭平 中西 正樹 満倉 靖恵 髙橋 正樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.80, no.813, pp.DR0125-DR0125, 2014 (Released:2014-05-25)

参考文献数

19

被引用文献数

1 4

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This paper describes the driving control system of a powered wheelchair using voluntary eye blinks. Recently, new human computer interfaces (HCIs) that take the place of a joystick have been developed for people with disabilities of the upper body. In this study, voluntary eye blinks are used as an HCI. However, the problem with this HCI is that the number of input directions and operations is smaller than that of a joystick, which causes inefficient movement. Therefore, assist systems are needed for efficient and safe wheelchair movement. This paper presents the system which is based on environment recognition and fuzzy theory. It can detect obstacles and passages in a real environment, and the velocity and direction are calculated automatically for obstacle avoidance or right/left turns. Simulations show the effectiveness and robustness for the driving position and position where an operation input is given. Furthermore, experiments were carried out and verified the effectiveness of the proposed method.