DISCRETE-TIME ADAPTIVE-CONTROL OF SYSTEMS WITH MULTISEGMENT PIECEWISE-LINEAR NONLINEARITIES

Inverse schemes are constructed for multisegment piecewise-linear nonl inearities. Adaptive laws are proposed to update the inverse to cancel the effect of the unknown characteristic of such a nonlinearity which appears at the input of a linear part. Two adaptive control schemes u sing an adaptive inverse and a Linear controller structure are develop ed: one for the linear part known and the other for the Linear part un known, Different adaptive designs are given based on different a prior i nonlinearity know ledge necessary for the construction of an adaptiv e inverse. The adaptive inverse controllers ensure closed-loop signal boundedness and lead to significant improvements of system tracking pe rformance.