Energy reduction in cyclic flow shop plants through on-off control of robots

This paper addresses the design of an on-off control strategy for operating robots in a cyclic flow shop plant. The main goal is to properly switch off and on the robots to save energy consumption without any reduction of the plant desired throughput. To fulfill this goal, first mathematical conditions, which characterize movement of parts in the plant and the on-off control for robots, are presented. Then a mathematical model which measures energy reduction in robots is introduced. Constrained to the conditions, a mixed integer linear programming model with the energy monitor as the objective function is developed. Solving this model, the set points for decision parameters are obtained to reduce energy consumption in idle robots. This model is applied to a case study and the related results are presented and discussed.