抄録
An optimal logical structure is developed for a multichannel safety monitoring system. Each channel monitors a plant state, e.g., temperature or pressure. When a state becomes abnormal, the corresponding channel sets off an alarm signal and activates protective actions. Each channel consists of one or more sensors that are exposed to two contradictory failures; one is “failed-dangerous” and the other is “failed-safe”. The problem is to obtain the optimal coherent logical structure of sensors for each channel minimizing expected damage. The optimal channel structure is proven to be the k-out-of-n: G system, and the problem is formulated in nonlinear integer programming (NLIP). The NLIP problem is then solved by the extended Lawler & Bell method. An illustrative example is given.
