Robust friction compensation based on Karnopp model

An essential problem concerning friction compensation is over-compensation or under-compensation. In model-based compensation for friction, these events are due to over-estimation or under-estimation of the model parameters. While generally under estimation results in steady state errors, over estimation may produce oscillations and instability. In this paper, a simple servo-mechanism where the friction part is modeled by Karnopp model is treated. A controller able to cope with these problems is proposed. Using describing function analysis the new design is studied.