Modeling, Identification, and Compensation of Stick-Slip Friction

The paper presents a novel approach for stick-slip friction modeling. The adaptive friction compensator, which uses this modified model guarantees the convergence of the tracking error to a small residual set and at the same time the algorithm can easily be implemented on standard industrial controller architectures. The model clearly distinguishes the low and the high-velocity regimes. Accordingly, at low velocities the adaptive laws in the friction compensator tune only the parameters which characterizes the low-speed friction behavior (Striebeck friction) and at the high-speed regime the adaptive laws modify only the parameters which characterize the high-speed friction behavior (Coulomb and viscous friction terms). An off-line identification method for the friction model parameters is also presented. Experimental results are provided to show the performances of the proposed friction modeling and compensation method.