DISCRETE-TIME ADAPTIVE-CONTROL OF SYSTEMS WITH UNKNOWN DEADZONES

An adaptive deadzone inverse approach is developed for control of disc rete-time systems with unknown deadzones at the input of linear dynami cs. The proposed controller consists of an adaptive deadzone inverse, whose para meters are updated to cancel the effect of the deadzone, an d a linear part, which is designed to achieve tracking of a reference signal by the system output. When the linear part of the system is kno wn, its parameters are used to specify the parameters of the linear pa rt of the controller. When the linear part of the plant is unknown, th e linear control parameters are adaptively estimated. The control erro r caused by the adaptive deadzone inverse is expressed as a linearly p arametrizable part plus a bounded disturbance. Adaptive laws which emp loy parameter projection are used to update the controller parameters. They are robust with respect to the bounded disturbance, and they res ult in parameter estimates needed to implement an adaptive deadzone in verse. We prove the closed-loop signal boundedness, and illustrate by simulations that the system tracking performance is significantly impr oved.