Xiong Zhenhua

Friction compensation design based on state observer and adaptive law for high-accuracy positioning system

Abstract Friction is one of the main factors that affect the positioning accuracy of motion system. Friction compensation based on friction model is usually adopted to eliminate the nonlinear effect of friction. This paper presents a proportional-plus-derivative (PD) feed back controller with a friction compensator based on LuGre friction model. We also design a state observer to observe the unknown state of LuGre friction model, and adopt a parameter adaptive law and off-line appromixation to estimate the parameters of LuGre friction model. Comparative experiments are carried out among our proposed controller, PD controller without friction compensation based on classical friction compensation model, and PD controller without friction compensation. Experimental results demonstrate that our proposed controller can achieve better performance, especially higher positioning accuracy.