An indirect adaptive controller with a self-excitation capability

An indirect adaptive pole placement controller is presented which stabilizes and asymptotically regulates any discrete-time single-input, single-output linear time-invariant plant which is of known order n , is controllable, and observable, and has unknown parameters. To avoid singular points in the algorithm, the adaptive controller solves the pole-placement design equation asymptotically with time rather than trying to solve it exactly at each time instant. The stability of the adaptive control system and the asymptotic regulation of the plant output to zero are ensured by an additional self-excitation generated by the adaptive controller. A novel kind of an error signal to control the magnitude of the self-excitation is obtained by suitably filtering the self-exciting signal and monitoring changes of the controller parameters as they are generated by the adaptive algorithm