Linear motor motion control using fractional order sliding mode controller with friction compensation

This paper presents a fractional order sliding mode control for motion control of linear motor. Due to global memory characteristics and actual nature expression, fractional calculus is introduced into the design of sliding mode surface to achieve precision tracking of reference signals, and it is first to design a fractional order sliding mode controller for linear motor motion. LuGre model is employed to compensate sliding friction occurring between ball-bearing and liner guide to further improve tracking performance. Model uncertainty of linear motor is also taken into account in the controller design. Experimental results demonstrate that the proposed controller not only owns high precision tracking performance, but also has strong robustness to uncertainty and disturbance.