Smart machine tools
Improved manufacturing methods have become crucial factors in retaining global competitiveness for a wide range of products. This has led to the development of new automatic supervision techniques for use in smart machine tools. These are necessary because it is not possible to design and manufacture machine tool structures and systems with work zone areas of sufficient accuracy and repeatability to meet the improved performance requirements demanded by many modern manufacturing companies. The principal areas for automatic supervision of the machine tool are the tooling, appropriate machine elements and the overall machine system. Thermal effects have been shown to be the largest source of dimensional errors and apparent non-repeatability of machines. Therefore, for the highest precision machines on-line temperature monitoring and control is of paramount importance. This paper describes the application of automatic supervision techniques applied to the NION diamond turning and grinding machine, developed by Cranfield Precision Engineering Limited, which is the most accurate machine tool, of its size, currently available, as well as an ultra precision five-axis grinding machine, built in Japan by the Toyoda Machine Works Limited. In addition, following a project at Cranfield University, the benefits of on-line measuring techniques are discussed in obtaining new cost effective manufacturing methods for producing aero-engine turbine blades. Further examples are given, including major projects at Liverpool John Moores University and Eindhoven University of Technology, where significant improvements in accuracy capabilities were obtained for a standard cylindrical grinding machine and a five-axis vertical milling machine.