Application of object-oriented and qualitative modelling methodologies in the operation and control of a mobile structural press machine

Today, the use of computer-based systems for industrial process control is growing rapidly. The growing demand for efficient performance and flexibility in industrial systems makes control algorithm design an increasingly complex process. In this research work we address the problem of determining and establishing the most effective control of linear and concurrent processes in an industrial mobile press machine using a qualitative and simulation tool called QMTOOL in conjunction with other logical reasoning approaches. The main task presented here is to establish adequate control of a mobile press machine using an intelligent control algorithm, based on the construction and execution of machine's qualitative models. The overall behaviour of the system produced from model simulation, is derived from the behaviour of the system's individual components throughout the model's structure. That behavior is presented graphically as Cartesian plots of sequences of time-varying qualitative states. The above mentioned software environment enabled us to generate, test and redefine the qualitative models of control processes prior to their implementation, towards the achievement of the desired machine's control functionality. We were able to test and modify the structure of the control system algorithm at the design specification stage, without an in-depth requirement for programming skills, using qualitative approaches. Qualitative models of the machine processes were introduced at a high-level of abstraction, using relatively small amount of information, similar to human reasoning on studying complex system's behaviour. Key-Words: Qualitative modelling and simulation, linear and concurrent manufacturing processes, control