Pole placement in discrete plants with unstable zeros with extensions to adaptive control

Presents an adaptive pole and zero placement controller for the control of time-varying plants with unstable zeros. The main novelty of the controller is that the plant unstable zeros are not required to be included as zeros of the reference model. This objective is achieved by including a feedforward compensator between the control signal and the plant output which is incorporated to the usual controllers consisting in a precompensator and a feedback compensator. The basic developed controller gives model-following for the plant output plus the feedforward compensator output. Then, the design is extended to allow the plant to follow the reference model very closely. The adaptive control of time-varying plants is achieved by using the recursive-least squares algorithm with exponential forgetting and resetting of the covariance matrix.