Adaptive friction compensation of electromechanical servo system based on LuGre model

摘要

Aerospace electromechanical servo system is a typical strongly nonlinear and coupling system, where the nonlinear friction is the main factor that impacts the performance. As the conventional closed loop controller can not meet the high performance requirements, an adaptive friction compensation method based on LuGre model is proposed in this paper. For the unknown dynamic friction parameters and load characteristics of the electromechanical servo system, the forming principle and characteristics of the friction is analyzed. After that, the method is designed through Lyapunov stability analysis, a dual-closed loop observer is constructed to estimate the friction state variables and the friction model parameters are identified online. The experiment results show that the proposed compensation method can effectively inhibit the adverse influence of the friction on the servo system, significantly improve the control precision of the system, and lay the foundation for the improvement of high dynamic tracking performance of the servo system.