Fault diagnosis and fault-tolerant estimation of a rail traction system via fuzzy observers

Abstract

This paper studies the fault diagnosis and fault-tolerant estimation problems of a rail traction system. The main idea is to use a bank of fuzzy observers to detect faults and to isolate failed sensors. Once the failed sensor is isolated, the fuzzy observer driven by healthy sensors provides reliable torque and flux estimates which are used for the control purpose. The concept and design procedures for fuzzy observers are presented in this paper. A fuzzy observer is able to produce accurate state estimations and generate robust residuals for non-linear dynamic systems such as a rail traction system. The fault diagnosis and fault-tolerant estimation scheme proposed for the rail traction system is demonstrated using simulations.