Adaptive positioning control using adaptive velocity estimator

This paper considers an adaptive positioning control problem using adaptive velocity estimator. Previous adaptive control methods, the control strategy requires full-states measurements, such as position and velocity measurements. In the practical case, only the position is measured by using position sensors, therefore, we have to make a velocity signals. Making a velocity signal component, an approximate differentiator and first order filter are often applied. But, it may cause deterioration of the control performance for the high ultra precision positioning control problems. This paper deals with an adaptive friction compensation method that includes an adaptive differentiator which can estimate velocity signals without using approximated differentiator. Experimental results are given to show the effectiveness of the proposed method for the high ultra precision positioning control problems.