FRICTION MODELLING FOR CONTROL OF A LINEAR HIGH-PRECISION ACTUATOR

For control applications aiming accurate positioning and exact path tracking the compensation of friction can be very important, especially when working with small displacements as usual in nano technologies. The paper at hand describes the identification of pre-sliding motion in terms of elastic and plastic movements, and the utilization of these properties for fine positioning. A feed forward control based on the model together with a simple feedback controller is used for validation of the model. Furthermore the parameters for locations with differing friction force are outlined. The axis is a linear high-precision ball bearing guide driven by a voice coil actuator and using high-resolution position measurement equipment.