Loop pairing analysis

Abstract

Despite the availability of sophisticated methods for designing multivariable control systems, decentralized control remains dominant in industry applications, because of its simplicity in design and ease of implementation, tuning, and maintenance with less cost [29,30]: Hardware simplicity: The cost of implementation of a decentralized control system is significantly lower than that of a centralized controller. A centralized control system for an n ×n plant consists of n! individual single-input single-output transfer functions, which significantly increases the complexity of the controller hardware. Furthermore, if the controlled and/or manipulated variables are physically far apart, a full controller could require numerous expensive communication links. Design and tuning simplicity: Decentralized controllers involve far fewer parameters, resulting in a significant reduction in the time and cost of tuning. Flexibility in operation: A decentralized structure allows operating personnel to restructure the control system by bringing subsystems in and out of service individually, which allows the system to handle changing control objectives during different operating conditions. © 2008 Springer-Verlag Berlin Heidelberg.