FAULT-DETECTION IN A CONTROL LOOP

This paper deals with a fault-detection method applied to a control lo op containing a non-linear actuator. In order to detect faults on the actuator, the sensor or the process itself, only three variables are a vailable : the set-point, the measurement and the controller output. W ith the use of a static and a dynamic model of the system it is nevert heless possible to detect failures. To improve the quality of detectio n, a fuzzy C-means algorithm is proposed to calculate the model parame ters. The proposed method has been applied to a flow control loop cont aining a pneumatic valve.