CONTROLLER DEGREE BOUND FOR H infinity -OPTIMAL CONTROL PROBLEMS OF THE SECOND KIND.

Further results are presented on the cancellation phenomena which occur in H infinity -optimal control problems which may be embedded in a particular generalized regulator configuration illustrated. The emphasis is on problems of the second kind which are characterized by the assumption that one of two off-diagonal blocks P//1//2 (s) and P//2//1 (s) is nonsquare. It is assumed that P//2 //1 (s) is square while P//1//2 (s) is tall, and also that P//1//2 (j omega and P//2 //1 (j omega ) have full rank for all omega .