Predefined time trajectory tracking control of wheeled-mobile robot

In the existing trajectory tracking control, the convergence time of the tracking error is usually related to the initial value of the error, and there are few results on the predetermined time trajectory tracking of nonholonomic system. To solve the above problems, a control method that ensures the nonholonomic wheeled mobile robot system to track a reference trajectory at a predetermined time is proposed. First, through coordinate transformation, the tracking error system is transformed into a first-order subsystem composed of angular errors and a second-order subsystem composed of position errors. Then the angular velocity and the speed of the robot are designed for the angle error system and the position error system respectively, which can force the angle error and position error converge to zero within a predetermined time. Finally, the Lyapunov method is used to prove the effectiveness of the designed control law. Numerical simulation shows that the proposed control method can make the robot track the reference trajectory at a predefined time, the real time for the robot to track the reference and the calculated convergence time is equal, and the convergence time is more accurate than that in existing control method.