DETECTION AND DIAGNOSIS OF OSCILLATION IN CONTROL LOOPS

Previous work presented a real-time algorithm for the detection of osc illations in PI and PID feedback control loops. This paper examines fu rther opportunities for oscillation detection in the off-line analysis of ensembles of data from control loops. Its use with measurements fr om routine operations is emphasised. The paper presents operational si gnatures that indicate the cause of an oscillation. Typically, a full diagnosis requires a special test for which the loop is taken out of r outine operation. The signatures lead to recommendations about which s pecial test is most appropriate. They therefore reduce the time spent in trouble-shooting by guiding the choice of test. Copyright (C) 1997 Elsevier Science Ltd.