Trajectory Tracking Control Of Wheeled Mobile Robot Based On Differential Flatness

With the rapid development of science and technology,wheeled mobile robots are playing an increasingly important role in the fields of industry,commerce,agriculture,national defense and security,and aerospace.This paper studies the trajectory tracking control of a wheeled mobile robot.First,according to a given desired trajectory,using differential flat technology,a feedforward control law that the wheeled mobile robot can run along the desired trajectory is obtained.Then,the sliding mode variable structure control method and the H_?control method based on the T-S fuzzy model are adopted to realize the trajectory tracking control of the wheeled mobile robot.Finally,a disturbance observer is designed to observe the disturbance in real time and compensate for the control law to suppress the disturbance in time.The main research content is divided into the following three aspects:(1)First,the differential flat technology is used to obtain the desired control value corresponding to the desired trajectory,and then the sliding mode variable structure control method is used to implement the trajectory tracking control problem of the wheeled mobile robot.When designing the tracking controller,firstly design a virtual sliding mode controller for the kinematics model to obtain the virtual control value,and then design the sliding mode controller again based on the dynamic model to obtain the control torque and realize the wheeled movement with actual physical parameters.The tracking control of the robot model to different desired trajectories.(2)The feedforward controller is designed by using the differential flatness method,and then a control method that combines the T-S fuzzy system and rolling optimization is proposed for the trajectory tracking control of the wheeled mobile robot.The error system is established by using the motion characteristics of the wheeled mobile robot,and the local error system is described in T-S to solve the conservative problem caused by the T-S description under the global error system.On this basis,the principle of rolling optimization is integrated,and the local error system is described.The error system rolls to realize the control from the local system to the global system.At the same time,a constrained H_?controller is designed on the T-S fuzzy subsystem to successfully realize the trajectory tracking control.The combination of these two methods solves the conservativeness of the T-S fuzzy description of the entire global system,and at the same time avoids the shortcomings of the large amount of calculation in the direct rolling optimization.(3)Based on the disturbance observer technology,the trajectory tracking of wheeled mobile robots with external disturbances is studied.In view of the limited anti-interference ability of sliding mode variable structure control and rolling T-S fuzzy control,a disturbance observer is added to the control system to estimate the external disturbance in these two control methods and compensate in the control law to solve the problem of wheeled The mobile robot cannot overcome the problem of large interference when tracking and controlling the desired trajectory,which improves the anti-interference ability of the entire control system.