Robust model-based delay timer alarm for non-linear processes

We consider the problem of robust alarm design for chemical processes represented by stochastic state-space models (SSMs). Alarm design for such complex processes faces three important challenges: 1) processes exhibit highly non-linear behavior; 2) state variables are not precisely known (modeling error) and often unmeasured (hidden); and 3) process signals are not necessarily Gaussian, stationary or uncorrelated. We propose the design of a delay timer alarm for monitoring unmeasured latent variables. The proposed design reduces the false and missed alarm rates. To deal with non-stationary process behavior in normal and abnormal operations, we propose an average-case delay timer alarm design. The efficacy of the proposed robust alarm design is illustrated on a non-stationary chemical reactor.