Research On Feedback Linearization And Variable Structure Control Of Two-wheeled Self-balancing Vehicle

The two-wheeled self-balancing vehicle is a special kind of wheeled mobile robot with multi-variable, non-linear, strong coupling, time-varying, and parameters of uncertainty. The environment in which the vehicle moves is complicated, so is the control task that needs to finish balancing, path-planning and path-tracking at the same time. Therefore, the two-wheeled vehicle is an ideal platform for testing and learning various control methods. When we use VSC (Variable Structure Control) to control the system, it can bring good robustness, but the range of controlling is small, and it will inevitably produce buffeting. Therefore, as we design the VSC controller for the system, how to reduce buffeting will be focused on in this paper.There are two key points in this paper, one is the linearization of nonlinear model, and the other one is to design VSC controller with stronger ability of inhibiting buffeting. Specifically as follows:First, based on feedback linearization control theory and differential geometry method——Lie theory, we find that the nonlinear system model can not be precisely linearized, so we use partial feedback linearizing method to get the linearization. State feedback controllers are made for non-linear system, and we make comparison between partial feedback linearizing model and approximate model. The simulation results show that the former is closer to the original nonlinear system model. Second, we design the VSC based on feedback linearization. Conventional controllers are obtained according to rate reaching law. In order to enhance the ability of the system to suppress buffeting, the controllers are continually improved; What's more, we put forward a method of designing the dynamic sliding mode control for the system. At last, a comparative study of simulation is done among the control methods, the simulation results show that while the dynamic sliding mode controller has the apparent advantage on the control range and inhibiting buffeting, its capacity of resisting the external interference will diminish accordingly. Finally, we paticipant in designing and doing the experiments on the vehicle to make it balanced.