An improved on-line monitoring procedure for multiloop control systems

In this paper, an improved relay-based monitoring procedure is presented to on-line identify the maximum closed loop log modulus, L-c,L-max, for multi loop control systems. The proposed method addresses two potential problems inherent in previous methods: (a) too many relay tests are required; (b) th e monitoring information fails to be exploited to redesign the controller w hen there is incentive to do so. Simulation results demonstrate the success ful applications of the proposed on-line monitoring procedure as well as it s utility in the redesign of the controllers. (C) 2001 Elsevier Science B.V . All rights reserved.