Modeling and Compensation of Friction in Control Systems

The emphasis of this research project is on accurately modeling the friction characteristics so that its effect can be predicted in simulations. Friction has a significant influence on control systems since it limits their accuracy and speed, and may even induce tendency to instability, In addition to extending the reset integrator model, a new method of adaptive friction compensation is introduced. With this approach it is possible to estimate the coefficient of friction while the system is in operation, and to use this estimate to cancel out the friction component by an opposite term in control. The technique is verified by simulation, and the utility of adaptive compensation is validated experimentally via an apparatus designed and fabricated during the research period.*** //