1、Open Controller Architecture-Past, Present and Future Gunter Pritschow (Co-ordinator), Yusuf Altintas, Francesco Jovane, Yoram Koren, Mamoru Mitsuishi, Shozo Takata, Hendrik van Brussel, Manfred Weck, Kazuo Yamazaki Abstract Open Control Systems arethe key enabler for the realization of modular and
2、re-configurable manufacturing systems.Thelarge numberof special purpose machines and the high level of automation have led toanincreasing importance of open control systems based on vendor neutral standards. This paper gives an overview on the past, present and future of Open Controller Architecture
3、. After reflecting onthe different criteria, categories and characteristics of open controllers in general, the CNC products in the market are evaluated and an overview on the world-wide research activities in Europe, North America and Japan is given. Subsequently the efforts to harmonize the differ
4、ent results are described in order to establish acommon world-wide standard in the future. Due to the “mix-and-match nature of open controllers concentrated attention must be paid to testing mechanisms in the form of conformance and interoperability tests. Keywords: Open architecture control, CNC, M
5、achine tool 1 INTRODUCTION Open Architecture Control (OAC) is a well known term inthe field of machine control. Since the early nineties several initiatives world-wide have worked on concepts for enabling control vendors, machine tool builders and end-users to benefit more from flexible and agile pr
6、oduction facilities. Themain aim was the easyimplementation and integration of customer-specific controlsby meansofopen interfacesand configurationmethods in a vendor-neutral, standardized environment 1319. The availability and broad acceptance of such systems result in reduced costs and increased f
7、lexibility. Software can be reused and user-specific algorithms orapplications can be integrated. Users can design their controls according to a given configuration. This trend was forced both by the increasing number of special purpose machines with a high level of automation and the increasing dev
8、elopment costs for software (Figure 1). Figure 1: CNC Hardware and software -Actual trend existing In the past the CNC market was dominated byheterogeneous, device-oriented systems with proprietaryhardware and software components. The tight coupling of application software, system software and hardw
9、are led to very complex and inflexible systems. Great effortswere made to maintain and further develop the productsaccording to new market requirements. Modern CNC approaches, which comprise extensive functionality to achieve a high quality and flexibility of machining results combined with a reduce
10、d processing time, favor PC- based solutions with a homogenous, standardized environment (Figure 2). The structure is software- oriented and configurable due to defined interfaces and software platforms. Open control interfaces are necessary for continuously integrating new advanced functionality in
11、to control systems and are important forcreating re-configurable manufacturing units 17. Unbundling hardware and software allows profiting from the short innovation cycles of the semiconductor industry and information technology. With the possibility forreusing software components, the performance o
12、f the overall system increases simply by upgrading the hardware platform. Figure 2: PC-based, software-oriented Control Systems There are a lot of benefits for suppliers and users of open control systems (Figure 3) 7. CNC designers and academics benefit from a high degree of opennesscovering also th
13、e internal interfaces of the CNC. For CNC users the external openness is much more important. It provides the methods and utilities for integrating user-specific applications into existing controls and for adapting to user-specific requirements,e.g. adaptable user interfaces or collection of machine
14、 and production data. The external openness is mainly based on the internal openness but has functional or performance Iimitations. 2 STATE OF THE ART 2.1 Control Systems and their interfaces Controls are highly sophisticated systems due to very strict requirements regarding real-time and reliabilit
15、y.For controlling the complexity of these systems hardware and software interfacesare an essential means.The interfaces of control systems can bedivided into two groups-external and internal interfaces (Figure4). External Interfaces These interfaces connect the control system to superior units, to s
16、ubordinate units and to the user. They can be divided into programming interfaces and communication interfaces. NC and PLC programming interfaces are harmonized by national or international standards, such as RS-274, DIN 66025 or IEC 61131-3. Communication interfaces are also strongly influenced by standards. Fieldbus systems like SERCOS, Profibusor DeviceNet are used as the interface to drives and 110s. LAN (Local Area Network) networks mainly based on Ethernet and TCP/lP do reflect the interfaces to superior systems. InternalInterfaces
