Adaptive Trajectory Tracking Control Of Wheeled Mobile Robot

With the continuous development of computer,microelectronics,sensors,automatic control and other technologies,robot has been widely used in various fields of production and life as a new type of production tools.Robot technology has also been used as a measure of a country's scientific research strength and industrial level.In this paper,the modeling uncertainty and external disturbance of nonholonomic wheeled mobile robot system are discussed.Combined with backstepping,adaptive control,sliding mode variable structure,low pass filter and Lyapunov stability theory,trajectory tracking of mobile robot is studied.The main contents are as follows:(1)The problem of trajectory tracking control based on kinematics model of wheeled mobile robot is studied.Firstly,the global finite time control law of mobile robot angular velocity is designed based on finite time control theory.Then,a finite time sliding mode controller with linear velocity is designed by sliding mode control.The stability of the whole closed loop system is proved by using cascade control theory.Finally,the effectiveness of the proposed algorithm is verified by computer simulation.(2)The problem of adaptive trajectory tracking control of wheeled mobile robot is studied.Aiming at the parameter uncertainty of tire radius and wheel spacing in robot motion,the real value of the parameter is approximated by on-line estimation,and an adaptive trajectory tracking controller is designed.At the same time,the asymptotic stability of the tracking error system is proved under the framework of Lyapunov stability.Finally,the effectiveness of the proposed algorithm is verified by computer simulation.(3)The adaptive sliding mode trajectory tracking control of wheeled mobile robot under un-known disturbance is studied.Firstly,a virtual speed controller is designed according to the kine-matics model of the robot,then the dynamic trajectory tracking controller is designed under the condition of unknown external disturbance and unknown system parameters,combined with adap-tive technology and sliding mode control.Thus,the actual speed of mobile robot can be tracked to virtual speed.Simulation results show that the controller can make the system track a given reference trajectory quickly and is robust to external disturbances.(4)The adaptive trajectory tracking control of wheeled mobile robot based on low pass filter is studied.Firstly,a virtual speed controller is designed based on robot kinematics model.Then considering the unknown external interference and system parameter change,to avoid the complexity of velocity derivation,a new control is introduced at the dynamics level through a first-order low-pass filter to replace?_cand?_c.Combined with adaptive technology,a trajectory tracking controller is designed.The asymptotic convergence of the error between the actual velocity of the mobile robot and the virtual velocity introduced into the filter is realized.Finally,the effectiveness of the proposed algorithm is verified by computer simulation.