A scheduling model for multirobot assembly cells

The authors propose a mixed 0-1 linear programming model for repetitive scheduling of multirobot assembly and machining cells. The approach adopted is monolithic as opposed to hierarchical to avoid system suboptimization. The model permits any number of alternative ways (or modes) to perform each operation. A mode of an operation is determined by the required resources (facilities) and the duration of their use. The model incorporates facility changeover times. Robot collisions are avoided. Several objective functions are formulated to support different purposes. The scheduling problem of a multirobot assembly cell is formulated and solved by using commerically available mathematical programming software. Solutions under four different objective functions are reported. Acknowledging the complexity and considerable size of the formulation required, the authors prescribe and illustrate specific methods to achieve size reduction. Finally, for successful use of the present model, an information processing schema is offered as a general guidance to help data management needed by the model.