Proportional plus integral output control and disturbance rejection for discrete linear repetitive processes

Repetitive processes are a distinct class of 2D systems (i.e. information propagation in two independent directions) of both systems theoretic and applications interest. They cannot be controlled by direct extension of existing techniques from either standard (termed 1D here) or 2D systems theory. Here we give further results on the relatively open problem of the design of control laws to achieve desired performance and disturbance decoupling in the sense defined in the body of the paper. The control laws are activated only by the process output and do not require access to state information.