Managing Product Performance through Design Engineering: Condition Monitoring in Automated Organisations

Despite impressive advances in automated production technology, manufacturing industry is still heavily reliant on conventional processes, particularly in processes designed for materials removal in which controlled shearing of the work-piece occurs. Such processes typically involve the use of automated computer controlled machining centers, which, in principle, are capable of sustained periods of unattended operation. However, the quality of the finished product, in terms of its conformance to dimensional and surface finish requirements as specified in the design, is strongly dependent upon the condition of the cutting tools used. A number of tool life management systems have been designed and engineered and are employed in production environments today, but these are usually based on expired life criteria and are of limited applicability. Crucially, in the context of increasing product life cycles, the disguarding of tools earlier than may be necessary is wasteful, expensive and inconsiderate to the environment. More sophisticated designs do exist, typically based on advanced technologies, such as acoustic emission or spindle torque sensors, for dynamically sensing tool condition during operation. Such systems are potentially more useful but still only indicate that some aspect of the cutting process has changed and usually require human intervention. This paper thus addresses the need for better control of production processes with the objective of increased operating efficiency based on reducing waste and improving the product life cycle. The work reported here is primarily concerned with the design and application of prototype intelligent systems for automated tool management.