Maxwell Slip based adaptive friction compensation in high precision applications

In this work an adaptive approach for friction compensation based on the Generalized Maxwell Slip (GMS) Model is presented. The model is utilized in a feed-forward controller in combination with a standard feedback controller to improve the dynamical performance of a two dimensional high precision positioning stage with a working range of 200 mm. The GMS model is extended to be used as an inverse system model. The parameter identification shows, that the identified model does not represent the system behavior at every position. On this account the linear model parameters are adapted online to ensure precise friction compensation. Experiments show that this approach can improve the dynamical behavior of the system significantly. In combination with a feedback controller the adaptive GMS model based friction compensation is robust against disturbances and reduces the tracking error while moving over the whole operating range.