Design And Analysis Of Controller For Two Types Of Wheeled Mobile Robot With Input Delay

Robotic control is a research hotspot in control theory and control engineering.The wheeled mobile robot has become an important object of robotic research because of its simple structure,flexibility and convenience.Since the wheeled mobile robot is a nonlinear system,its motion control is a research difficulty and hotspot of mobile robot control.In the control process of mobile robot,actuator delay is often unavoidable,which leads to poor control performance of system.Therefore,the design and research of controller for the wheeled mobile robot with input delay is of great theoretical and practical significance.In this paper,the wheeled mobile robot is taken as the research object.The controller design and stability analysis of two kinds of wheeled mobile robots with input delay are studied.A new prediction method is proposed for linear time-invariant systems with input delay.The main results include:(1)A new asymptotic prediction scheme is proposed for linear time-invariant systems with input delay and external disturbance.The prediction scheme can asymptotically converge the error between the actual value of the system state and the predicted value of the system state to zero.The sliding mode controller design and finite spectrum configuration design based on the asymptotic prediction scheme are studied.(2)For the self-balancing mobile robot system with input delay,the predictor-based state feedback control scheme is proposed.The linear model is obtained by linearizing the dynamic model of the self-balancing robot at the equilibrium point.By using the finite spectrum configuration,predictor-based state feedback controllers are designed to realize the balance control of the self-balancing mobile robot.Finally,the effectiveness of the designed controller is verified by numerical simulation.(3)For the nonholonomic wheeled mobile robot system with input delay,the predictor-based finite time trajectory tracking control scheme is proposed.(i)Consider the influence of external disturbance on the system,a finite time observer is designed to observe the external disturbance,and the system state is predicted based on the observation of disturbance.Then the finite time full state feedback controller is designed based on the predicted value of state,so as to ensure the tracking error of the mobile robot converges to zero in a finite time.(ii)When the angular velocity is unmeasurable,a finite-time observer is designed to observe the angular velocity,and the system state is predicted based on the observation of angular velocity.Then the finite time partial state feedback controller is designed based on the predicted value of state,so that the mobile robot can track the reference trajectory in a finite time.(iii)When both angular velocity and linear velocity are unmeasurable,two finite-time observers are designed to observer the angular velocity and linear velocity respectively,and the system state is predicted based on the observations of the velocity signal.Then the finite-time output feedback controller is designed based on the predicted value of state and realize the output signal tracking the reference signal in a finite time.Finally,the effectiveness of the designed controller is verified by numerical simulation.