Attitude control using active-mass-system in parallel two-wheel vehicle with underslung vehicle body

This paper is concerned with an advanced attitude control of the vehicle body in the parallel two-wheel vehicle with underslung vehicle body. Since the parallel two-wheel vehicle has large wheels with its diameter of 1.05m, and the battery, the actuators and the controller are placed on the lower position in the vehicle body, the gravity center of the vehicle body with a passenger can be assigned at the lower position than the wheel axis. Therefore, the vehicle has a pendular structure that enables the vehicle body with the passenger to always maintain the stable posture, even if the vehicle is in the power-off or control-off condition. In order to suppress the sway of the vehicle body on the pitch axis while driving the vehicle, the attitude control system using an active mass system is constructed into the vehicle body. However, the behavior of the vehicle body with the passenger differs depending on person. In this study, a design method for the attitude control system with applicability to various passengers is proposed. The behavior of the vehicle body is related strongly with the passenger´s properties. And, the control system using the active mass system is designed by a Backstepping Method. The robust control parameters for suppressing the behavior of the vehicle body associated with the passenger´s properties is clarified in this study. The effectiveness of the proposed attitude control system with the active mass system is verified by the experiments using the parallel two-wheel vehicle with underslung vehicle body.