Supervision and Coordination of Parameter-Adaptive Controllers

Adaptive controllers have proven to work well as long as all theoretical pre-conditions are fulfilled and the free design parameters are chosen property. However in practice these pre-conditions may be violated and/or some free design parameters are not chosen properly. Both result in a lowering of the control performance. Therefore a supervision and coordination level is introduced, monitoring the adaptive controller and taking appropriate actions if malfunctions are detected. The introduced supervision and coordination level exists altogether of two parts, named start-up part and run-time part. The start-up part involves tasks for the configuration and the implementation of adaptive controllers and the run-time part involves tasks for the supervision and coordination of the adaptive controller in closed-loop operation. A sensible start-up procedure is recommended and an eigenvalue analysis is shown in order to monitor the parameter estimation. To track time-varying process parameters an eigenvalue controlled forgettig factor. is introduced. Simulation and experimental results for an a.c. motor are shown, indicating an improvement of the overall control performance.