Chemical Engineering Research & Design, Vol.122, 11-21, 2017
Design of multivariate alarm systems based on online calculation of variational directions
Alarm systems are critically important for safety and efficiency of industrial plants, but are severely suffering from alarm overloading. This paper proposes a method to design a multi-variate alarm system based on variational directions of involved process variables, in order to alleviate the severity of alarm overloading. By using adaptive time scales, time gradients of signals are extracted to calculate variational directions in an online manner. Adaptive time scales are determined from a function between time scales and volatilities of process variables. Alarms arise at the moment that a nominal relationship of variational directions among process variables is invalidated. Numerical and industrial examples illustrate the effectiveness of the proposed method. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.