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On-Line Monitoring and Fault Detection of Control System Performance.

pdf icon On-Line Monitoring and Fault Detection of Control System Performance. (1506 K)
Seem, J. E.; House, J. M.; Monroe, R. H.

CLIMA 2000 Conference, Proceedings. August 30-September 2, 1997, Brussels, Belgium, 1-20 pp, 1997.


monitors; control loops; control system performance; heating; ventilation; air conditioning; equations; fault detection


This paper presents a new method for monitoring the performance of control loops. The method determines performance indices using recursive relationships. The recursive formulation gives the method two desirable characteristics, namely, it is computationally efficient, and the memory requirements are small because only previous values of the performance indices are stored. Consequently, the method can be implemented in low-cost digital controllers, thereby reducing traffic on the communication network. Building operators can use the performance indices to quickly assess the performance of a large number of controllers. Performance indices may be used to quantify information about the amount of travel of an actuator, the difference between the desired process output and the actual output, saturation of a controller, etc. This paper presents laboratory and field test results demonstrating the utility of the performance indices for performance monitoring and fault detection in variable-air-volume air-handling units with pressure-independent variable-air-volume boxes.