High Precision Position Control Using an Adaptive Friction Compensation Approach

The presented work concerns the development of a trajectory tracking controller which is able to improve clearly the dynamical performance of a high precision positioning stage. Experiments in the pre-rolling and rolling friction regimes are conducted and a hybrid parameter estimation algorithm is used to fit the parameters of a simple dynamic friction model based on experimental data. Further experiments show that the identified model does not represent the system behavior over the whole operating range of 200 mm. To solve this problem the linear model parameters are adjusted online to ensure precise dynamic friction compensation. Finally, the extended friction model is utilized in a feed-forward controller in combination with a standard feedback controller to compensate for the effects of the friction force and other disturbances while moving.