INTEGRATING SAFETY IN MANUFACTURING SYSTEMS

An integrated safety and manufacturing system (ISM) was developed. With this ISM system, a communication method between the safety system and the manufacturing system by means of a hybrid control strategy was introduced. The hybrid control strategy combined the hierarchical and heterarchical control in order to take advantage of both. Thus, a safety system can have the same weight as that of a manufacturing system, and is no longer an auxiliary part of a system. The safety approach, which was proposed for developing the safety system in ISM system, started by applying open-loop safety controls and closed-loop safety controls to machines. Applying a safety training program and personal protection equipment to humans followed. Then, a user-coded safety module was developed for users who want to integrate the safety concept into their simulation system. Finally, a simulated application example illustrated the compatibility of the safety module and the differences of a system cell before and after integration with the safety system. The simulation results, from throughput, utilization, and safety aspects, are discussed. (C) 1995 John Wiley and Sons, Inc.