Control and Alarm Interplay and Robust State-Feedback Synthesis with an Alarm Performance Constraint

Abstract

In this paper, the effect of control systems, as a missing (but significant) actor, on the performance of alarm systems is studied. The interplay of control and alarm performance is justified, and it is shown that a state-feedback controller, which is designed to achieve a good quality of control (in terms of minimum output variance), has both desirable and undesirable consequences on the performance of alarm systems. To pave the path for finding a robust controller solution, a new alarm index is introduced and an analytical expression of the performance is derived for signals, known systems, and systems with parameter uncertainties. A set of linear matrix inequalities (LMIs) is proposed for the controller design to satisfy the required control and alarm performance. The effectiveness of the method is illustrated through a case study of a heat exchanger network, which is a frequently used plant in petrochemical industries.

A New Approach to Design Alarm Filters Using the Plant and Controller Knowledge

“…In addition to plant behavior, controller dynamics can also influence the overall performance of the alarm system. Considering this, some methods were proposed to design the controller and investigate the interplay of control and the alarm problem by incorporating the alarm performance requirements into the control problem. , However, they did not discuss the problem of alarm filter design. This motivated us to revisit the alarm filter design procedure, while taking into account the plant and controller dynamics.…”