Real-Time Support for Online Controller Supervision and Optimisation

This paper presents three methods for the supervision and optimisation of a controller by means of an exemplary application. The supervision is used for error recognition, analysis, and processing. The basic principle comprises the use of different controllers. A robust controller as a fail-safe device and a controller to be tested are implemented In the case of an error during the tests the system automatically switches to the robust controller. This mechanism is implemented by means of a finite-state machine. A precision supervision compares setpoints and measured values. The difference is weighted and transformed into discrete events which affect the switching between the different controllers. Through a spectrum analysis appropriate for real-time use, supervision is effected in the frequency domain. The results of the computation can be used directly for online optimisation. It is shown that in the case of real-time, a synchronous computation of the frequency spectrum is more useful than an asynchronous one. The results are presented with a current application from the domain of railway technology. This is a suspension/tilt-module testbed employed with the research project “Neue Bahntechnik Paderborn”.