多源干扰下谐波齿轮传动强抗扰控制

Harmonic drive systems can regulate the speed and torque. However, due to multiple disturbances such as kinematic errors, flexible stiffness, friction and hysteresis, it is difficult to achieve desired accuracy in precision motion control by ideally treating the harmonic drive system as a proportional link. For the problem of refined angular position control of harmonic drive systems under multiple disturbances, an enhanced anti-disturbance control (EADC) method combining the disturbance observer (DO) and the extended state observer (ESO) is proposed. The DO is used to estimate the hysteresis with partially known dynamics and the ESO is used to estimate the total disturbances except hysteresis. Through the composite control structure of “feedforward + feedback”, the simultaneous compensation and suppression of multiple disturbances can be achieved, ensuring the accuracy of the harmonic drive system. The convergence of the DO and the ESO, and the stability of the closed-loop system are analyzed. The reference tracking and disturbances rejection performances of the friction feedforward compensation control, active disturbance rejection control, disturbance observer based control, and the EADC method are compared via numerical simulation. The results show that EADC is superior to the other three control schemes, which verifies the effectiveness of the proposed method.