Developing a physical emulator for a flexible manufacturing system

In order to develop, test, and validate system control software for managing flexible manufacturing systems, most laboratories have constructed an experimental testbed using actual manufacturing equipment. These experimental systems typically occupy a large amount of lab space, cost hundreds of thousands of dollars to construct, and require considerable human expertise to operate. In addition, given their experimental nature, there is little or no opportunity to recapture the costs through the manufacturing of commercial products. We propose an alternative solution for providing the essential testbed. Using dedicated micro-controllers (programmable logic controllers), we have developed a physical emulator for a flexible manufacturing cell which faithfully replicates the operating characteristics of an ensemble of physical equipment that would typically comprise a flexible manufacturing system. The proposed system has several unique advantages over the traditional testbeds. First, it is inexpensive and can easily be replicated at other laboratories. Second, it can be easily reconfigured to consider alternative manufacturing scenarios. Third, it can consider an emulated environment that is far more complex than those that are typically addressed by testbeds using actual equipment. Finally, it is totally reliable and safe, and it requires minimal expertise to operate. The paper discusses the design and operational characteristics of the developed emulator along with its anticipated uses and current limitations.