The Research Of Control For A Two-wheeled Pendular Suspension Vehicle Based On Decoupling And Terminal Sliding Mode

The two-wheeled pendular suspension vehicle is a kind of two wheels robot, which center of gravity is located the wheel axis below, so it is a stable system in nature. The two-wheeled vehicle with the advantages of small size, activity, and the small range, and it has been applied in many fields. But the two-wheeled vehicle system has the problem, e.g. the underactuation, coupling, nonholonomic constraint, etc. So we should consider these complex factors when we design the controller system, and the two-wheeled pendular suspension vehicle achieve control target is challenging.First, we need design the physical model of two-wheeled pendular suspension vehicle based on the deep analysis of the structure of two-wheeled vehicle. Design the structure of two-wheeled pendular suspension vehicle which pendulum under the wheel axis for the system would be able to meet its stability requirements. At the same time understand the kinetic mechanism on the basis of the physical structure. After that, we also need set the parameter of the system, in order that use the Euler-lagrange method for the dynamics model of two-wheeled pendular suspension vehicle dynamics model.Second, based on the established system dynamic model, we can use the decoupling algorithm to design the subsystem controller for the stable operation of vehicle. In order to design of the controller, the coupling problems of dynamic model should be uncoupled first, so that the decoupling algorithm is introduced to make the system transformed into the ideal system which without coupling. After decoupling, the system can be divided into the forward subsystem and the steering subsystem, and design controllers of simulation analysis.Third, the application of terminal sliding mode control theory, the tracking error of two-wheeled pendular suspension vehicle could converge quickly in finite time. And the two-wheeled pendular suspension vehicle could keep running smoothly, in order to further control the trajectory tracking, the theory of terminal sliding mode control should be introduced and apply this theory in the trajectory tracking control of two-wheeled vehicles, so according to the system need to design its convergence time. At the same time, we use the algorithm of Lyapunov function method directly and fast terminal sliding mode to design the trajectory tracking controller respectively. Then carry on simulation analysis of the two kinds of controller and verify the controllability of the terminal sliding mode control theory for convergence time.Finally, apply the double closed-loop control structure to control system of two-wheeled pendular suspension vehicle which based on the self-adaptive control algorithm. With the self-adaptive control to design the controller can improve the robustness and anti-interference of the two-wheeled pendular suspension vehicle system. The double closed-loop control structure of the two-wheeled vehicle consist of outer loop and inner loop, which the outer loop used for the trajectory tracking control and the inner loop is the main implementation that realize the forward and steering of the two-wheeled pendular suspension vehicle system. And then let the two-wheeled vehicle keep running smoothly with the collaboration of inner and outer loop controllers. After that, we need carry on the Matlab simulation to verify the effectiveness of the designed control system.