Application of Robust Observer to Failure Diagnosis for D.C. Speed-controlled System

Abstract

The early failure diagnosis of a steel rolling plant has great economic benefit. Invited by a certain rolling mill, we have done the research of on-line supervision for steel rolling plants. Ihis paper is the report on the research of failure diagnosis for a D.C. speed-controlled system of a steel rolling. The D.C. speed-controlled system is a too fast system for many failure diagnosis methods, etc., to apply. Ve used detection observer method to monitor the changes of the system parameters. Simulation results show that detection observers may detect very small changes of system parameters in a few milliseconds. Because the failure modes of the D.C. speed-controlled system could not be output decoupled, we used robust detection observers to provide failure isolation information and used logic reasoning to make diagnosis decisions. The diagnosis system presented in this report would be a powerful subsystem of a large expert system for failure diagnosis of the steel rolling plant.