Model Predictive Control with Disturbance Compensation for Trajectory Tracking of Three-Degree-of-Freedom Spherical Joint Actuator

To address tracking errors and susceptibility to interference in the actual trajectory of the three-degree-of-freedom (3-DOF) spherical joint actuator, a model predictive tracking control scheme incorporating disturbance compensation is proposed. Firstly, the nonlinear dynamics model of the 3-DOF spherical joint actuator is linearized through the feedback linearization. Then, model predictive control is employed to manage the multivariate constraint problem and achieve online rolling optimization. On this basis, disturbance compensation is added to eliminate the influence of external disturbance and to control the 3-DOF spherical joint actuator more accurately. Finally, the simulation results demonstrated the effectiveness and precision of the proposed control algorithm. This strategy effectively ensures the stability of the system's closed-loop system. It maintains strong robustness in the presence of external disturbance, which allows the 3-DOF spherical joint actuator to reach the desired position steadily.