Lack of master-slave relationships and absence of a centralized supervisor in heterarchical manufacturing systems prohibits the use of centralized scheduling. A fully distributed scheduling method for these systems is described in this paper. Entities in the system continually generate tentative local schedules in real time using a cooperative scheduling heuristic and select the beast schedule for execution. Tentative schedules are evaluated in time-scaled, distributed simulations using software that is a replica of the real system software. The state of the real system is copied into this virtual system at the beginning of each simulation, eliminating cumulative uncertainties and immediately incorporating equipment failures and other unexpected events into schedule evaluation. Experimental results illustrate the real-time distributed scheduling method and its response to faults.
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Hardware and Architecture
- Industrial and Manufacturing Engineering