Real-time deadlock-free control strategy for single multi-load automated guided vehicle on a job shop manufacturing system

An unmanned automated job shop manufacturing system with a single multi-loa d automated guided vehicle, which traverses around a single-loop guidepath, is considered in this work. This type of shop design is often used as an i ndependent sector of some complex AGV layouts, such as tandem, segmented bi -directional single-loop and divided configurations. The type of multi-load vehicle is a good alternative against using more single-load vehicles to s erve a higher transportation demand. To an unmanned automated manufacturing system, the management of finite system resources, e.g. finite input/outpu t queuing space and transporting carriers, plays a vital role in avoiding s ystem deadlocks and machine blockages. The proposed control strategy for a single multi-load vehicle uses global shop real-time information to achieve the objectives: avoid shop deadlocks caused by inappropriate job movement as well as satisfy the system transport requirement. The efficiency of the proposed vehicle control strategy and the other two expanded strategies und er various parameter designs are verified by computer simulation.