|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. In order to achieve this goal, GMPTG is participating in several government sponsored OMAC development projects to provide user requirements, ensure project progress is aligned with GMPTG OMAC direction, and validate technologies being developed by these projects.
The government sponsored, OMAC related projects include:
1) Department of Energy (DOE), Technologies Enabling Agile Manufacturing (TEAM) Project, Intelligent Closed Loop Processing (ICLP) Thrust Area
One of the critical elements in the development of an open, modular architecture controller with the highest level of openness is a set of standard API specifications. There are two approaches with which API specifications can be achieved. The bottom-up approach is that a vendor develops an OMAC with his own set of API’s and then makes the API’s available to anyone who is interested in adopting them. If the product becomes accepted by the marketplace, then the API specifications will become a ‘de facto’ standard. The top-down approach is to define a set of strawman API specifications by a knowledgeable working group, and then ask the controls community to participate in the refinement of the standard.
The TEAM project is addressing technical issues in the total product realization process from initial customer requirements to product manufacturing. The ICLP Thrust Area addresses manufacturing control issues, and OMAC is one of the technical topics. One key task of the TEAM ICLP project is to develop a set of strawman common API’s. A group of government researchers are in the process of accomplishing this task. An important advantage of having this group of researchers define the common API’s is that they do not have particular product interests that they have to protect, and a more objective, general set of specifications can be accomplished. The intention is to make the strawman documents available to all control vendors for review and comments so that an acceptable set of standard API’s can then be realized.
Other aspects of the TEAM ICLP project include sensor integration for closed loop machining, in-process inspection, closed loop stamping, etc.
2) Department of Energy, ICON Manufacturing Operating System Project
Another critical issue for OMAC is the real time performance of the Microsoft Windows operating system. Because the current design of the Microsoft Windows operating systems is not suitable for time critical industrial controls applications, one of the tasks of the ICON project is to develop a real time operating system infrastructure, called the Manufacturing Operating System (MOS), that also supports MS Windows for OMAC. One of the deliverables of this project is an OMAC running under MOS.
3) Department of Commerce (DOC), National Institute of Standards and Technology (NIST) – Enhanced Machine Controller (EMC) Project
NIST has been working on technical issues related to control architecture for many years, and the objective of the EMC project is to implement a PC-based CNC controller based on the knowledge that has been developed within NIST. One important accomplishment of the EMC project is development of a software wrapper for various commercial motion control cards. The software wrapper is technically an API that can be incorporated into the common API standard set. The wrapper also allows the capability of ‘Plug and Play’ of a number of commercial motion control cards.
4) Department of Defense (DOD) – Title III Project for Open Architecture Machine Tool Controller
The objective of the Title III project for open architecture machine tool controller is to establish an open architecture for a world class, domestically built machine tool controller and evaluate the benefits of the open system concept at different test sites. The goal is the commercialization of an open architecture machine tool controller, for both defense and commercial applications.
5) National Center of Manufacturing Sciences (NCMS), Next Generation Inspection System II (NGIS) Project
The main focus of the NGIS project is to develop standard sensor interfaces for OMAC and the integration of sensors for in-process gauging. It is not a controller development task but does address one of the standard interfaces that may be needed for an OMAC system and using OMAC for inspection applications.
The OMAC document is a common thread through all these development projects because it provides a consistent set of requirements to guide the technology development efforts. GMPTG participation in these projects has already resulted in an important accomplishment; all these controller development projects have agreed to adopt the common API specifications being developed by the TEAM ICLP program. It certainly is a significant step toward achieving an acceptable common API standard by the controls community.
GMPTG OMAC Pilot Program
The Advanced Manufacturing Department of GM Powertrain and the Manufacturing Controls Department of the GM North American Operations (NAO) Manufacturing Center have several active OMAC pilot projects. These projects are being done either as a part of the validation process or to support the government sponsored development efforts. Following are brief descriptions of selected OMAC pilot projects:
1) Kearney and Trecker 800 Machine Retrofit at GMPTG Headquarters
This machine is used to support the DOE TEAM, NIST EMC, and NCMS NGIS projects. The original controller was replaced by a NIST EMC controller, and sensors are being incorporated to help develop solutions for intelligent closed loop processing, in-process inspection, and sensor integration issues.
2) Kearney and Trecker 600 Machine Retrofit at Shreveport, LA
A K&T 600 was shipped to ICON in Shreveport, LA. to be retrofitted with an OMAC controller based on the real time Manufacturing Operating System. It will be used as the pilot machine to validate not only the operating system technology but also issues related to the integration of the SERCOS interface and DeviceNet CANbus I/O systems.
3) Kearney and Trecker 600 Machine Retrofit at GMPTG Headquarters
Another K&T 600 machine was retrofitted with a Delta Tau PMAC-NC controller with Wizdom Paradym 31 discrete logic solving and Honeywell Microswitch SDS CANbus I/O to control tool change operations. The purpose of this pilot system is to validate the integration of multiple vendor products in a common Windows environment.
The machine will also be used as the testbed for the Title III project in the later part of 1996.
4) Vickers A2100 Controller Evaluation at GMPTG Headquarters
GMPTG has received a Cincinnati Milacron machine with Vickers’ new A2100 PC-based controller on consignment, and the capability and functions of the controller will be validated.
5) HES 2-Axis Lathe at GM NAO-MC Laboratory
A HES lathe was retrofitted with a PC-based controller running the Windows NT operating system and the ASIC-100 product from Automation Systems and Products (ASAP) for evaluation. The main purpose of this pilot project is to validate the performance and examine the limitations of using Windows NT operating system for industrial control applications.
6) 3-Axis Table Top Mill with SERCOS drives and motors at GM NAO-MC Laboratory
This table top mill is used to validate the compatibility of CNC controllers with a SERCOS interface.
7) OKUMA Lathe Retrofit at GMPTG Headquarters
One of the problems with retrofitting older machines with OMAC CNC controllers is that these machines do not truly represent the ones being used in current manufacturing operations. A retrofit project was initiated with Okuma to retrofit a lathe which is similar to the ones being used in production at GMPTG, with an OMAC-based CNC controller. The intent is to perform an objective engineering comparison of the performance between the existing controller and an OMAC controller. The lathe will then be relocated to a production facility, and a comparison of an OMAC-based machine with a regular production machine in a production environment will be conducted. Data will be gathered to analyze the benefits of and issues related to the implementation of the OMAC-based controller.
8) LeBlond Makino J55 Machine Retrofit at GMPTG Headquarters
A LeBlond Makino J55 machine will be retrofitted with an OMAC-based CNC so that GMPTG engineers can perform engineering and business analyses similar to the ones being done in the Okuma project, but for milling operations.
9) Voest-Apline 7-axis Millturn Machine Retrofit at GMPTG Headquarters
A Voest-Alpine 7-axis millturn machine will be retrofitted with a software based CNC from Software Algorithms, Incorporated (SAI). The controller runs on QNX real-time operating system and uses generic PC components and touch-screen operator interface console. This retrofit provides GMPTG engineers the opportunity to understand the benefits and difficulties associated with a software based controller and evaluate an alternative operating system platform for implementing OMAC systems.
10) THT Presses 100 Ton Vertical Clamp Indexing Press at GMPTG Saginaw
A THT 100 ton press was outfitted with a PC-based controller running the ControlSuite product from Arbor Coast Software. The Interbus-S I/O network from Phoenix Contact and the PMAC-Lite motion control board from Delta Tau were also utilized. This pilot will validate the development tools and runtime environment of the Arbor Coast software package, identify Interbus-S and PMAC integration issues with ControlSuite, and validate the PMAC for single axis hydraulic control applications .
GMPTG Development Strategies
GMPTG is taking an active role to accelerate the development of OMAC controllers and the strategies that are employed can be summarized in the following list:
strongly encourage technology developers and vendors to adopt available standards and interface specifications;
actively participate in and/or follow existing OMAC development activities;
effectively leverage government funding and coordinate government projects;
practically utilize government’s influence to define a set of strawman common API’s;
openly invite third party vendors to finalize and support the common API specifications;
frequently interact with international open architecture development activities to advance OMAC technologies.