Summary: | 碩士 === 國立臺灣大學 === 電機工程學研究所 === 89 === This thesis describes works related to the system integration of a land vehicle simulator for hilly terrain driving. The system is based on a Stewart platform, and consists of motion, visual, force feedback, and audio components.
Though the Stewart platform is capable of carrying out motions with six degrees of freedom, it is constrained by a finite working space. Thus the motion sensation of vehicle driving has to be simulated by creating appropriate motion trajectory for the platform on which the pilot sits. It is necessary to develop a dynamic model for a vehicle moving on the hilly terrain, to analyze the specific forces acting on the pilot, and to apply washout algorithm and human motion sensation models. Besides, a computer graphical system generating scenes, a steering wheel delivering force feedback, and an audio system making sound effect have to be installed to give the pilot the visual, force, and audio cues, respectively. Following the pilot’s steering commands, the visual system creates interactive animation scenes of the environment, which are shown on a large screen in front of the pilot through an LCD projector. The feedback torque reflected on the steering wheel is determined by forces acting on the front wheels of the vehicle, which in turn depend on the geometry of the front wheel systems and vehicle motion conditions.
In this research, we also investigate how to compensate the nonlinear characteristics of the hydraulic actuator system of the Stewart platform, so that the chattering phenomenon of the platform can be suppressed. This allows the pilot to enjoy a more realistic motion sensation. Finally, the simulator is actually operated in order to test the overall system. Some experimental results are summarized and discussed.
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