9307545 Tao This proposal describes a project to explore a new area of adaptive control and to address open problems of urgent relevance to theory as well as applications: adaptive control of systems consisting of a linear part and a nonsmooth nonlinear input- output characteristic being in either an actuator or a sensor. Typical examples of such nonlinear characteristics are dead-zone, backlash and hysteresis. An adaptive inverse approach is proposed to control such systems to meet desired performance specifications, which exploits an adaptive inverse for an unknown nonlinearity and a linear controller structure nonadaptive/adaptive for a known/unknown linear part. Choices of nonlinear models, design of adaptive inverse control algorithms, stability, convergence and robustness analysis, and applications will be investigated. The results of this research will provide new tools to handle unknown nonsmooth nonlinearities which are common in practical control systems. ***
