Indirect predictive monitoring in flexible manufacturing systems

In this paper, a new method of monitoring of failures in flexible manufactu ring systems (FMS) is developed. The main objective is to manage progressiv e failures in order to avoid breakdown state for FMS. To achieve these requ irements an indirect predictive monitoring approach is proposed. The main i deas of this approach are first to follow the state evolution of the resour ces indirectly by the perturbations on the manufactured products. The param eter used is the production flow for which a drift rate indicator is define d for each of the family. Detection and diagnostic methods based on the on- line exploitation of the drift rates are presented in this paper. Another i dea developed is the necessity to integrate different approaches of monitor ing to obtain a global management of failures. For this purpose a functiona l framework of integrated monitoring in the control command of an FMS is pr oposed. (C) 2000 Elsevier Science Ltd. All rights reserved.