Abstract: Regarding the impact of uncertainty caused by internal and external disturbances on trajectory tracking accuracy of wheeled mobile industrial robots,a non-singular terminal sliding mode trajectory tracking control method was proposed. Firstly,the dynamic model and trajectory tracking error model of wheeled mobile industrial robot were established. Then,an extended state observer was designed to estimate the uncertainty in the system,and a non-singular terminal sliding mode control law was designed to suppress the influence of disturbances on the control system through real-time compensation of uncertainty,achieving high-precision control for the motion trajectory of wheeled mobile industrial robots. Finally,the stability analysis was conducted using Lyapunov theory. The simulation results show that the designed extended state observer can accurately estimate the uncertainty in the system,and the maximum errors of estimation are only 0.02 m/s and 0.03 rad/s separately. The designed non-singular terminal sliding mode control law has higher tracking accuracy and stronger robustness compared to the extended Kalman control method and the integral sliding surface control method,the maximum error of trajectory tracking is only 0.04 m. The test results verifiy that the proposed control method meets the design expectations,the maximum error of trajectory tracking is only 0.07 m,which can ensure that the wheeled mobile industrial robot can more accurately track the desired trajectory.

Key words: wheeled mobile industrial robot, trajectory tracking, internal and external disturbances, model error, expansion state observer, non-singular terminal sliding mode