ERROR ACTUATED OUTPUT-FEEDBACK CONTROL-THEORY FOR DIFFERENTIAL LINEARREPETITIVE PROCESSES

Repetitive, or multipass, processes are a class of two-dimensional (2D ) systems characterized by a recursive action over a finite fixed dura tion-the pass length. On each sweep, or pass, through the dynamics an output-the pass profile-is produced which acts as a forcing function o n, and hence contributes to, the next pass profile. The basic unique c ontrol problem is that the output sequence can contain oscillations wh ich increase in amplitude from pass to pass. Differential processes ar e a sub-class which have well defined structural links with standard l inear systems. Previous work has used these links to develop computati onally feasible stability tests which can be implemented using only st andard linear systems tests. This paper reports the first significant results on the theoretical basis of output feedback based control sche mes. The major result is a return difference theory for these schemes.