Controller Performance Monitoring
Process control performance is a cornerstone of operational excellence in a broad spectrum of industries such as refining, petrochemicals, pulp and paper, mineral processing, power systems, and wastewater treatment. Control performance assessment and monitoring applications have become mainstream in these industries and are changing the maintenance methodology surrounding control assets from predictive to condition based. The large numbers of these assets on most sites compared to the number of maintenance and control personnel have made monitoring and diagnosing control problems challenging. For this reason, automated controller performance monitoring technologies have been readily embraced by these industries.
This entry discusses the theory as well as practical application of controller performance monitoring tools as a requisite for monitoring and maintaining basic as well as advanced process control (APC) assets in the process industry. The section begins with the introduction to the theory of performance assessment as a technique for assessing the performance of the basic control loops in a plant. Performance assessment allows detection of performance degradation in the basic control loops in a plant by monitoring the variance in the process variable and comparing it to that of a minimum variance controller. Other metrics of controller performance are also reviewed. The resulting indices of performance give an indication of the level of performance of the controller and an indication of the action required to improve its performance; the diagnosis of poor performance may lead one to look at remediation alternatives such as retuning controller parameters or process reengineering to reduce delays or implementation of feed-forward control or attribute poor performance to faulty actuators or other process nonlinearities.
KeywordsTime series analysis; Minimum variance control; Control loop performance assessment; Performance monitoring; Fault detection and diagnosis
- Desborough L, Miller R (2002) Increasing customer value of industrial control performance monitoring: Honeywell’s experience. In: AIChE symposium series. American Institute of Chemical Engineers, New York, pp 169–189; 1998Google Scholar
- de Prada C (2014) Overview: control hierarchy of large processing plants. In: Encylopedia of systems and control. Springer, LondonGoogle Scholar
- Shah SL, Nohr M, Patwardhan R (2014) Success stories in control: controller performance monitoring. In: Samad T, Annaswamy AM (eds) The impact of control technology, 2nd edn. www.ieeecss.org
- Skogestad S (2014) Control structure selection and plantwide control. In: Encylopedia of systems and control. Springer, LondonGoogle Scholar
- Wolff F, Roth M, Nohr A, Kahrs O (2012) Software based control-optimization for the chemical industry. VDI, Tagungsband “Automation 2012”, 13/14.06 2012, Baden-BadenGoogle Scholar