Extended state observer-based optimal control method for multi-motor drive system

In the multi-motor drive systems, the backlash nonlinearity and the external disturbances should be taken into their modeling, which is essential to design the safer and more efficient load tracking and motor synchronization control strategies. An extended state observer-based optimal control method for the multi-motor drive system is proposed in this paper. The average deviation coupling control structure is introduced to decouple the performance indexes because of the measurable states in the multi-motor drive system. The extended state and disturbance observers are adopted to estimate the unknown state and disturbance of the system. The tracking controller and synchronous controller are designed by the combination of the backward and optimal control methods. The stability of the system is analyzed by the Lyapunov functions. With the comparison of experiments, the results show that the proposed control method has the better performance. The optimal tracking controller can obtain the load position tracking, and the optimal synchronous controller achieves fast convergence to the average value for all motors.