Adaptive Robust Precision Motion Control of Linear Motors with Ripple Force Compensations: Theory and Experiments

This paper studies the high performance robust motion control of linear motors which are subjected to significant force ripple. Based on the structural property of linear motors, some simple models with unknown weights are used to approximate the force ripple as well as other reproducible nonlinearities, such as friction. The unknown weights are adjusted on-line via certain parameter adaptation law to achieve an improved model compensation. The model approximation error as well as lumped disturbance are handled via certain robust control law to achieve a guaranteed robust performance. Experimental results are obtained for the motion control of an iron core linear motor and verify the high performance of the proposed scheme. 1 Introduction Direct drive linear motor systems gain high-speed, highaccuracy potential by eliminating mechanical transmissions. However, they also lose the advantage of using mechanical transmissions -- gear reductions reduce the effect of model uncertainties. F..