Adaptive compensation for actuator imperfections

A general adaptive inverse scheme is developed for control of systems with actuator imperfections caused by unknown nonsmooth nonlinearities such as dead-zone, backlash and other piecewise-linearities at the input of a linear dynamics. The proposed controller structure consists of an adaptive inverse for cancelling the effect of an unknown nonlinearity and a linear feedback design such as model reference, PID, or pole placement for the linear dynamics. An adaptive law is developed to update the inverse parameters for improved tracking performance despite the presence of actuator imperfections