Abstract As a key technology in the field of advanced manufacturing, an open architecture controller is studied。 In order to develop an open architecture software-CNC system on personal computer (PC) according to open modular architecture controllers (OMAC)。 First, the software and hardware platform is chosen and software realization methodology for the CNC system is determined。 Second, static mod- eling methods of an open architecture controller inclusive of object-oriented (OO) programming technology, dynamic link library (DLL) technology and system modules partition are investigated。 Third, the dynamical behavioral modeling and the data flow representation of open architecture controller are discussed, which are both described in hierarchy finite state machine (FSM) model。 Fourth, a reusable software module model is established to develop software function module library。 Finally, a 3-axis milling machine tool test-bed, named for HIT-CNC, is successfully designed by means of the constructed software function module library and the system configuring method。 The experimental results show that, besides increasing the degree of reusability and openness, application of above-mentioned method- ology leads to significant decrease of development time as well as maintenance cost。76210

Keywords: open architecture controller; PC; software-CNC; behavioral model; OMAC; machine tool

1  Introduction

MOSAIC system developed by New York    Univer-Without a unified definition of open CNC  sys-sity  in  1998

。  Since  then,   ever-more-increasing

tem nowadays, openness is generally perceived as modularity, portability, extendibility, interoperabil- ity and scalability[1]。 In the 1980s, the design philosophy of open architecture controllers began to

efforts around the world have been made to intro-

duce open-architecture systems for industrial con- trols。 One of the most important achievements was achieved in 1992 within the frame of European  pro-

draw wide attention。 It made great progress over the

ject named OSACA

。 In 1994, in Japan, a   similar

last 20 years as the research on open architecture

project  named  OSEC  under  the  IROFA    Consor-

controllers became an important trend in the field of was  carried  out,  and  earlier  in  the  USA a

advanced manufacturing。 Provision of a realization basis for advanced manufacturing technology is the purpose of most studies on developing an open ar- chitecture CNC controller。

The  first  open  architecture controller  was the Foundation item: Key Development Program of Science and Technology of Heilongjiang Province, China (GB05A501)

number   of   American   researchers   acquired  out-

standing progresses in the realm of OMAC[5]。

There were a lot of Chinese experts who en- gaged in the study of open architecture controllers and thereby devised various controllers on the base of “software IC”[6], software component[7-8] etc。, which, however, proved to be defective in incom- patibility  and  lack  of  portability  as  well  as inter-

MA Xiong-bo et al。 / Chinese Journal of Aeronautics 20(2007) 272-281 · 273 ·

changeability。

Open architecture controllers are markedly dif- ferent from today’s vendor-specific, proprietary execution environments and their associated ven- dor-specific programming environments and inter- faces between control elements。 Most of today’s proprietary controllers allow neither plug-and-play interoperability, nor sufficient scalability to meet requirements in a broad scope of applications[9]。It is important to note that openness alone does not en- sure plug-and-play。 Vendor’s idea of openness var- ies from one to another。 As only one step towards plug-and-play, plug-and-play openness, in fact, is dependent on a standard。 In order to strike balance between the technology advancements and cost- effectiveness in the open market, open system must be built using “de facto” standards and commercial hardware and software components[10]。 Conse- quently, there has never been a genuine open archi- tecture controller that does not include elements associated with international standards。