Modelling and simulation in support of the design and construction of modular machine control system

Trends towards reduced life-time of products and globalised competition is placing increased pressure on world-class companies to be more responsive to changing needs of product markets. As a result advanced manufacturing systems are required which can handle greater product variety and volatility whilst maintaining high levels of productivity and efficiency. As a result new design and construction methods need to be conceived suitable for flexible manufacturing. The methods need to simultaneously facilitate improvements in manufacturing operations and improved responsiveness to change. Thus, either individually or as an interconnected group, computer-controlled machines must be capable of handling multiple jobs and parts and therefore of performing a number of different operations. Hence a new generation of machine control system is required capable of handling much increased complexity, including means of handling primary issues of concurrency and reconfigurability. In this research the requirement for more flexible and effective control systems for manufacturing machine systems is investigated and dimensioned which highlights a need for improved means of co-ordinating and monitoring production machinery and equipment used to transport material. MIMCA (Modular and Integrated Machine Control Architecture), which supports simulation based on machine modelling, was conceived by the author to address the requirements identified. Essentially MIMCA comprises an organised unification of selected architectural frameworks and modelling methods, which include: NIST RCS, UMC, CIMOSA, SADT and Coloured Tuned Petri nets (CTPN), and was enhanced by incorporating Object-Oriented Modular Petri nets (OMPN) and zonecontrol Timed Modular Petri nets (TMPN) concept. The unification has been achieved to support the design and implementation of hierarchical and modular control strategies which realised the concurrent operation of reusable and distributed machine control components, and the ability to handle growing complexity and support certain requirements of real-time control systems. Thus MlMCA enables mapping between 'what a machine should do' and 'how the machine does it' in a well-defined but flexible way designed to facilitate reconfiguration of machine systems. The research study involved proof-of-concept implementation, based on the integration of control formalisms and their use in application studies, by deploying MIMCA to design and construct laboratory-based computer-controlled machines. The approach proposed by the author could impact practice in two ways, viz.: by providing a means of decomposing complex manufacturing machines into reusable parts and therefore yielding scalable solutions; and enabling the rapid prototyping of machine systems, the performance of which can be analysed using the MIMCA modelling and simulation environment.