A Cross-Coupled Control Strategy of Phase Difference for Electric Vibration Damping Actuator

The active vibration damping actuator uses dual-motors to drive two sets of eccentric wheels to achieve active vibration reduction, but the backlash nonlinearity and eccentric load will cause the load speed and load position to be out of synchronization, which will influence the system vibration reduction effect. The traditional parallel control strategy controls the dual motors separately without the consideration of internal coupling effect, leading to a poor synchronization performance. In order to solve these problems, a load position difference cross-coupled control strategy based on multiple-input and multiple-output (MIMO) is proposed in this paper. The minimum singular value of return difference matrix is used to analyze the stability margin of active vibration damping actuator system under the traditional parallel control strategy and the cross-coupled control strategy, and the analysis procedure has considered the influences of load disturbance and backlash nonlinearity. At the same time, the sensitivity comparison of the two strategies is conducted, and the results indicate that the system under cross-coupled control strategy has stronger relative stability and robustness. On this basis, a method for designing synchronization controller parameters is given. The stability region of parameters satisfying the requirement of stability margin is determined with the help of minimum singular value of return difference matrix. Then, the optimal value is found in the obtained parameter stability region according to the dynamic and steady-state performance. Finally, an experimental platform is set up to verify the effectiveness of cross-coupled control strategy and the rationality of parameter tuning.