Model reduction and the design of reduced‐order control laws

Abstract

Abstract This paper is concerned with the problem of designing satisfactory loworder (incomplete state feedback) controllers starting with a high‐order, state‐space model. Two design approaches are considered: the control law reduction technique, recently developed by the authors (Wilson et al., 1973), and the well‐known model reduction approach. These two design techniques are used to develop a variety of low‐order controllers for a double‐effect evaporator starting with a 10th‐order model. Experimental and simulated response data from the computer‐controlled evaporator demonstrate the superiority of the control law reduction approach in this application. It is also shown that several of the previously published modal approaches to model reduction are basically equivalent since they yield identical reduced‐order models.