Adaptive Compensation of a Linearly-Parameterized GMS Friction Model with Parameter Projection

A new, linearly-parameterized dynamic friction model is proposed based upon the generalized Maxwell-slip (GMS) model. This model is capable of describing essential frictional characteristics, such as the Stribeck effect, hysteresis, stick-slip limit cycling, frictional lag, non-drifting properties, and non-local memory. It replaces the traditional, nonlinear Stribeck function with a new function that is linearly-parameterized, and simplifies the design of an adaptive friction compensator. The proposed compensator has a switching structure to accommodate for the hybrid nature of the GMS model, and the parameter projection method is used to guarantee a bound on parameter estimates and stability of the switching adaptive controller. The validity and effectiveness of the proposed, linearly-parameterized friction compensator is verified by simulations for the velocity control of an inertia system under the influence of dynamic friction