Autonomously Proficient CNC Controller forHigh-Performance

Autonomously Proficient CNC Controller for High-Performance Machine Tools Based on an Open Architecture Concept

Kazuo Yamazaki (2)l, Yoshimaro Hanakiz, Masahiko Mori3, Kazusaka Tezuka4 l IMS Mechatronics Laboratory, University of California, Davis, USA ZOkuma Corporation, Oguchicho, Niwagun, Aichi, Japan 3Mori Selki Co., Ltd., Yamatokoriyama, Nara, Japan jMitutoyo Corporation, Takatsuku, Kawasakishi, Kanagawa, Japan Received on January 6, 1997

Abstract

The paper deals with the new controller for the high performance CNC machine tools. The controller pro- posed is referred to as “TRUE-CNC.” “TRUE” means Transparent, Transportable and Transplantable, Re- vivable, User-reconfigurable, and Evolving. TRUE-CNC allows the operator to achieve the maximum pro- ductivity and highest possible quality of the machined parts in a given environment with autonomous cap- turing of the machining operation proficiency. The TRUE-CNC controller provides intelligent functions for less-skilled operator to run the high performance machine tools as if a skilled operator does. The concept

and design aspects of the system architecture and the algorithms for functions developed for the TRUE- CNC are described in the paper.

Keywords : Intelligent CNC, Open CNC, Automatic Machining

1. Introduction The recent evolution of CNC machine tool systems points to achieving simultaneously higher accuracy and higher productivity. The principle of the evolution is to realize the

light duty machining under the high speed motion of the mechanism with highly repeatable accuracy. [l] Recent research works have contributed to the enhancement of the component of technologies for the high speed machine tools. [2], [3] However, the operation of high speed ma- chine tool with full utilization of the performance in a given environment (an available set of operators, tools, jigs and fixtures, etc.) is a problem for the end user of the machine because the operation usually requires the specific know- how and skill which is different from those of the conven- tional machining method (ordinary speed with relatively heavy duty cutting). In order to solve the current problem, an autonomously proficient CNC controller and the control- centered infrastructure was proposed as a feasible solu- tion to enhance the utilization of the advanced CNC ma- chine tool systems. The whole architecture of the infra- structure is referred to as “TRUE-CNC”. In TRUE-CNC, the CNC controller plays an important role not only to in- telligently control the machine tool motion and the ma- chining process but also to actively acquire all kinds of useful information available in the control and related re- sources to circulate and reuse them in the infrastructure with an appropriate interpretation. Fortunately, the re- cently-proposed technology of “Open Architecture CNC Controller“ is suitable for implementing TRUE-CNC sys- tem. Although there were active research done with the focus on how to design and construct the Open Architec- ture Controller so far [4], few research results were pre- sented regarding to what kind of specific functions should be implemented into the Open Architecture Controller by machine tool builders and end-users. The paper de- scribes TRUE-CNC as a good example of what can be done on the Open Architecture Controller. 2. ConceDtual Architecture of the TRUE-CNC Con- troller TRUE-CNC is named after the following conceptual fea- tures: The system software should be “Transparent”, “Transportable”, and “Transplantable”. “Transparent” means that the system architecture is transparent to the machine tool builder or to the end- user. “lransportable” means that any part of the control software can be ported to any remote site’ such as a stand alone personal computer, etc.. “Transplantable” - means that the control software can

be implemented to the upgrade-compatible. The machine tool system with the outdated software and hardware should be “Revivable” by replacing a part of controller with newly emerging elements. The functions of the controller should be ‘‘User re- configurable” to autonomously customize the con- troller based on specific needs, and The overall system should always be “Evolving” during the system life.

Reauirements for the Svstem Desiun of TRUE-

- CNC

Active use of the caotured machinina know-how: The information stored in the machining know-how data- base should efficiently be utilized for future autono- mous machining operation. Active checkina and refreshina of the resource and caotured know-how: The information stored in the database should always be checked if the data