Fuzzy modeling of complex, multi-source, dynamic friction

The proposed modeling technique allows to model disturbances in motion control systems in case of multiple sources of friction. It may be used if the system demonstrates such phenomena as hysteresis, Dahl effect, `frictional memory´. The model will be useful for friction compensation in precise motion control problems, electric drive control, etc. The model will reconstruct accurately the steady-state friction curve, viscous friction, and will approximate complicated dynamics of multisource friction using one internal state variable. The model is based on the fuzzy approximation of the velocity-dependent coefficient influencing the internal state variable dynamics. The remaining parameters are tuned by error minimization. The presented experiments, performed with a real plant, prove the applicability and usefulness of the propose approach.