It is important for the tool changer to be able to detect factors that would reduce part quality. For this unit there are two specific areas that would significantly improve its diagnosability:

a) Tool location – This is the machine’s knowledge of which tool is in which place in the storage carousel.

b) Tool wear – This is the machine’s knowledge of the working condition of each tool.

Currently the operator has to enter which tool is housed in which slot in the carousel manually. If the unit had an automatic method of detecting this, it would speed up reconfiguration time and hence production. Solutions to this will be researched as the project continues.

Tool wear has a more direct effect on the quality of the products produced. Therefore it would be a great advantage to the system if the tool changer had an automatic method of detecting the condition of the tools it houses. A large amount of research has gone into this important field, realising significant savings for manufacturers [18], [19]. Many methods are currently available to detect the condition of machine tools accurately; and modern laser techniques are even able to detect tool condition through a stream of coolant [20], [21].Such solutions will be added to the tool changer to give it a tool monitoring capacity.

6.CONCLUSION

Reconfigurable manufacturing systems research is ongoing, and many aspects of these types of systems have been examined. Owing to the modular requirement of these systems,modules that offer machines a selection of tools and that automatically adjust to reconfigurations of the system need to be developed.

One such module is currently being developed by the Mechatronics and Robotics Research Group of the University of KwaZulu-Natal. The main structure and functioning of the unit has been constructed. It was able to implement a simulated tool change within 30 seconds.The tool changer was able to house 8 BT 40 tool holders, and was an autonomous unit that required no other structures for support.

Technologies that aid the automatic calibration of the tool changer are still to be implemented. These enhancements will be used to enable the unit to interact with a 5-axis modular reconfigurable machine.

7.REFERENCES

[1] Koren, Y., Heisel, U., Jovane, F., Moriwaki, T., Pritschow, G., Ulsoy, G. & Van Brussel, H. 1999.Reconfigurable manufacturing systems, Annals of the CIRP 48(2), pp. 527-540.

[2] Daschenko, A. (ed.) 2006. Reconfigurable manufacturing systems and transformable factories,Springer.

[3] Padayachee, J., Masekamela, I., Bright, G., Tlale, N.S. & Kumile, C.M. 2008. Modular reconfigurable machines incorporating modular open architecture control, 15th International Conference on Mechatronics and Machine Vision in Practice. Auckland, New Zealand, pp. 127-132.

[4] Bi, Z.M., Lang, S.Y.T., Verner, M. & Orban, P. 2008. Development of reconfigurable machines,International Journal of Advanced Manufacturing Technology, 39(11-12), pp. 1227-1251.

[5] Ahuett, H., Aca, J. & Molina, A. 2005. A directed evolution modularity framework for design of reconfigurable machine tools, Cooperative Design, Visualization, and Engineering, Lecture notes in Computer Science, 3675, pp. 243-252.

[6] Chowdhury, S., Olivier, J., Rodger, M. & Stephen, W. 2009. Modular tool-changing unit for reconfigurable manufacturing machines, UKZN internal publication.

[7] Estment, W., Gorlach, I. & Wiens, G. 2010. Design of sub-systems of a reconfigurable machine tool, Proceedings of the 25th International Conference of CAD/CAM, Robotics and Factories of the Future.

[8] Mehrabi, M.G., Ulsoy, A.G. & Koren, Y. 2000. Reconfigurable manufacturing systems: Key to future manufacturing, Journal of Intelligent Manufacturing, 11(4), pp. 403-419.

[9] ElMaraghy, H.A. 2006. Flexible and reconfigurable manufacturing systems paradigms,International Journal of Flexible Manufacturing Systems, 17(4), pp. 261-276. 自动换刀在可重构制造系统英文文献和中文翻译(7):http://www.youerw.com/fanyi/lunwen_44923.html