Modeling of reconfigurable material handling system consisting of multiple mobile robots

The modelling of reconfigurable material handling system (RMHS) plays an important role in the planning and operation of a reconfigurable manufacturing system (RMS). The reconfigurable mobile robots have great advantages to perform RMS's material handling tasks in the volatile environment, where RMS layout will be frequently adjusted to fulfil the requirements of mutable production tasks. This paper proposes a new definition of RMHS, and presents a novel method based on graph theory and first-order logic calculus for configuration modelling of robot-based RMHS. The method is developed with full consideration of the reconfigurability of a single mobile robot at machine-level, and that of a system consisting of multiple mobile robots at system-level. The novel modelling method can facilitate selecting appropriate hardware and software modules to assemble a mobile robot, and also selecting appropriate mobile robots coupled with some cooperation strategy to construct a team for complex transportation task in the reconfiguration process of a RMHS.