An integrated feature-based dynamic control system for on-line machining, inspection and monitoring

Manufacturing companies dealing with high value, high accuracy and complex parts are facing increasing demand for higher quality and efficiency at lower costs and reduced lead times from their global customers. In real-life production such as the Numerical Control (NC) machining processes, there are continuous changes in machine tool performance, cutting tool conditions, workpiece deformation, cutting parameters, in addition to the changes in the geometry and properties of the parts being machined. Some changes are caused by 'predictable' factors such as cutting forces and machine tool deterioration over time, whilst others are caused by 'unpredictable' factors such as sudden breakdowns, uneven material property, vibration and machining chatter, or even human errors. These dynamic factors impose significant difficulties to ensuring machining accuracy effectively especially the controlling of unrecoverable over-cut errors normally causing part failures. This project aims to establish a set of integrated information models to address the dynamics of machining conditions based on the Dynamic Feature concept proposed by the authors, which are used as the basis for integrating machining, monitoring, and on-line inspection operations for optimized machining process control of high value complex parts. A prototype framework based on an open platform has been developed to enable the application of the proposed method. Industrial examples used to validate the prototype will be presented in this paper.