C. Michael Taylor, et al.
Authors : C. Michael Taylor director, GM Powertrain Manufacturing Engineering Controls Council Thomas J. Yager controls manager, manufacturing engineering - engines Raymond P.
Definition of OMAC Terms Illustration of the OMAC Concept Various Levels of Openness Other Factors Definition of OMAC Terms Definitions of key terms associated with the open, modular control systems described in the OMAC White paper are restated in the following table: Terms Definitions open allowing the integration of off-the-shelf hardware and software components into a 'de facto' standard environment modular permitting 'plug and play' of components scaleable enabling easy and efficient reconfiguration to meet specific application needs economical achieving low life cycle cost maintainable supporting robust plant floor operation (maximum uptime), expeditious repair (minimal downtime), and easy maintenance These definitions also accurately reflect the OMAC concept at GMPTG. Two important elements in the definition of 'open' are (1) the requirement of a 'de facto' standard environment, and (2) the availability of commercial control hardware and software components. GMPTG is not going to wait for an international standard for an open architecture control to be defined before it will start implementing OMAC systems.
Open, Modular Architecture Controls at GM Powertrain — Why Are OMAC Systems Needed in GM Powertrain?
GM Powertrain Organization GMPTG Math-Based Manufacturing Strategy GMPTG OMAC Implementation Strategies Why Are OMAC Systems Needed in GM Powertrain? GMPTG has always been known as a leader in advancing control technologies, notably for its involvement in the development of PLC's. GMPTG is once again leading the implementation of OMAC-based systems in its manufacturing facilities because it recognizes the need to have a new generation of manufacturing systems that are agile in order to produce products matching the demands of the fast changing market place. The OMAC effort has gained a great deal of recognition and momentum since the publishing of the OMAC White paper in August, 1994.
Open, Modular Architecture Controls at GM Powertrain — GMPTG PC-Based Control System Implementations
Spectrum of Control Applications at GMPTG Current Implementation of PC-Based Control Systems In order to execute the control strategies, GMPTG started to implement PC-based control systems on its factory floor. It needs to be clarified that a PC-based control system is only the first step toward the realization of the OMAC concept. The initial implementation of PC-based control systems enables an 'open' hardware platform to be used on the factory floor, even though there are still proprietary elements in the software environment.
Validation Process he current implementation of PC-based control systems is strictly in discrete logic control applications. The OMAC concept certainly is not limited to discrete control systems only. GMPTG is taking steps to migrate the OMAC direction into CNC and robotics control systems. Table 2 gives an overview of the control migration plan for GMPTG by application types.
GMPTG OMAC Pilot Projects GMPTG OMAC Development Strategies Many vendors in the controls community are developing products that satisfy some aspects of the OMAC requirements. GMPTG is not, and does not intend to be, in the control product development business. However, GMPTG is an end user of OMAC products and is interested in ensuring such OMAC products are available not only commercially but also expeditiously.
Operating Systems Hardware Platform Motion Control Open Device Level Networks User Interface Control Software Manufacturing Information System (MIS) Level Networks Application Programming Interfaces (API) It should be clear to the controls community that GMPTG is not trying to dictate the development of OMAC by specifying technical details for every aspect of OMAC. GMPTG is not going to lead the development of any new technology but will ride the technology wave! However, GMPTG engineers are not oblivious to the technical issues associated with OMAC systems. In this section, several OMAC technical areas will be examined.
Reliability of PC Hardware Integration of open control systems Liability of open control systems Support of open control system implementations Relationship between user and vendor Progression toward OMAC systems Globalization of the OMAC concept The OMAC concept has been presented to many control vendors, equipment builders, and end users, and the OMAC direction is being embraced by many companies. However, during the interactions with many companies about OMAC, many non-technical issues were raised concerning the feasibility of large-scale implementation of OMAC-based systems on the factory floor. Many similar concerns were voiced repeatedly, and perspectives from GM Powertrain are presented in this section to address these issues. Reliability of PC Hardware The GM Powertrain Windsor and Romulus plants have installed and are in the process of installing more than 500 PC based controllers.
Development Implementation A great deal of momentum has been generated toward the implementation of OMAC-based control systems. GMPTG is actively assisting the development of OMAC technologies and aggressively working with the suppliers to commercialize OMAC products. This document outlines the development and implementation strategies, and they are summarized here: Development adopt available standards and interface specifications; participate and/or follow existing development activities; leverage government funding and coordinate government projects to accelerate the development of OMAC; utilize government's influence to define strawman common API; invite third party vendors to finalize and support the common API specifications; interact with international open architecture development activities to advance OMAC technologies; Implementation expose OMAC direction to control system suppliers; integrate and validate commercial open controller products; resolve machine tool specific OMAC issues; cooperate with machine tool OEMs to implement OMACs; expose 'open' technologies to plant personnel; develop partners to support plant implementations. It should be clear that GMPTG is not taking a wait-and-see attitude in implementing OMAC technologies and is introducing OMAC systems in manufacturing operations with well defined approaches to minimize the risk. Active participation in efforts to accelerate the development of OMAC technologies is important and GMPTG is also defining the strategies to utilize diverse control products effectively.
Open, Modular Architecture Controls at GM Powertrain — Appendix A — Contacts for Government Sponsored Projects
DOE - TEAM Project Richard Neal, Program ManagerMartin Marietta Energy SystemsP.O. Box 2009Oak Ridge, TN 37831-8068 Phone: 423-574-1862Fax: 423-576-4663 DOE - ICON Project Bob BurlesonLawrence Livermore National LabP.O.Box 808Livermore, CA 94550 Phone: 510-423-1967Fax: 510-423-2419 NIST - Enhanced Machine Controller Project Fred ProctorNISTBuilding 220, Room B127Gaithersburg, MD. 20899 Phone: 301-975-3425Fax: 301-990-9688 DOD - Title III Open Architecture Machine Tool Controller Project Carroll FallsOasys Group, Inc.1300 Iroquois Avenue, Suite 160Naperville, IL.