An Improved Nonlinear Cross-Coupled Control Strategy for Dual-Motor System Based on CM/DM Separation

In dual-motor system, uncertain disturbance, parameter differences, and mechanical issues deteriorate the synchronization. Moreover, motor collision problem arises in rigidly connected systems because of poor synchronization and transient large impact. Considering these factors, this article proposes a nonlinear cross-coupled control strategy based on common mode differential mode (CM/DM) separation to achieve position synchronization for dual-motor system under speed control. By utilizing the CM/DM separation method in cross-coupled control, the objectives of position synchronization control and speed tracking control is decoupled. Taking into account the collision model, mechanical clearance, disturbance, and real-time status of the dual-motor system, a nonlinear controller is designed to achieve high-accuracy synchronization and collision recovery. The stability of the dual-motor system is proved by analysis of frequency domain and nonlinear differential equations, and the tuning method for the proposed controller is provided. By comparison with the traditional cross-coupled control method, the effectiveness of the proposed control strategy is validated by experimental results.