Dynamic Analysis of Actuator System with the Coupling of Time-Varying Meshing Stiffness and Backlash

Aiming at the dynamic modeling and control of actuator system under the influence of nonlinear conditions such as clearance and friction, compared with the conventional nonlinear model, the variable stiffness and wear sliding characteristics of the transmission mechanism is considered. A dynamic modeling and control method of actuator system with time-varying meshing stiffness and backlash is proposed. The minimum circumferential backlash and the maximum circumferential backlash are obtained by the method of backlash deviation correction. The mechanism of grease film effect on time-varying backlash and meshing impact is studied, and the thermal lubrication behavior of grease film thickness change and backlash change is revealed. The analysis shows that the transmission mechanism of the autuator system is in the state of boundary lubrication. The dead zone model of continuous differentiable function approximating the backlash nonlinearity is designed, and the accurate compensation of backlash nonlinearity is realized. The simulation results verify the effectiveness of the proposed method.