Generalized Predictive Positioning Control for Linear Servo System Considering Nonlinear Friction Pre-compensation

Considering the issue that the traditional generalized predictive control strategy for linear servo systems fails to fully account for the impact of nonlinear friction on tracking accuracy, a generalized predictive positioning control approach for linear servo systems considering nonlinear friction pre-compensation is put forward. Firstly, a dynamic model of the linear servo system incorporating nonlinear friction disturbance terms is constructed. Subsequently, according to the system dynamics, a predictive model of the system is developed. Based on this predictive model, the position output of the linear servo system is predicted. Then, the optimal control increment sequence of the system is derived, enabling the implementation of linear generalized predictive control for the linear servo system. On this foundation, a simple nonlinear friction model is introduced. By means of this model, the nonlinear friction that the linear motor encounters during start-up and commutation is predicted and compensated. As a result, the displacement tracking error of the linear motor during start-up and commutation is decreased, and high-precision generalized predictive positioning control of the linear servo system is realized. Finally, the effectiveness and superiority of the proposed control method are validated through simulations and experiments.