Trajectory tracking control of three-joint mechanical manipulators based on the disturbance rejection method

The auto-disturbance rejection control approach is used in this paper to solve the trajectory tracking control problem of three-joint mechanical manipulators. The three-joint manipulators is a system with nonlinear, uncertainty, strong coupling, and is a multivariable system that is closely related to the principle of kinematics and dynamics. In the adopted auto-disturbance rejection control technology. The tracking differentiator is able to solve the problem that the system output cannot track the jumping reference well due to system inertia. The nonlinear state error feedback control law improves the traditional PID control with linear combination of tracking errors. The extended state observer estimates in real-time and compensate the sum of inside and outside disturbance, and eliminates the influence of internal and external interference on the system. By using the decoupling control method in the auto-disturbance rejection control technique, three joint mechanical manipulator controller´s design is finally realized. Finally, an illustrative example is presented to show the effectiveness and superiority of the auto-disturbance control method.