Customer Solutions

Introduction
A division of Exxon Chemical Company (recently reorganized as Infineum U.S.A) conducts ongoing research into ATF formulations. These fluids must undergo extensive testing primarily to characterize frictional properties for application in automotive transmissions. EJC Systems develops custom equipment and tools to support the work of this laboratory.

We must accomplish development work within reasonable budgets and frequently as a retrofit to an older, outdated system. A common core design solution accommodates a wide variety of machines. These systems dynamically control test conditions such as temperature, motor speeds, and clutch forces. Measurement data is programmatically recorded during testing for clutch torque, machine conditions, as well as each controlled test parameter.

Design Objectives
For our system, we needed the following:
• Standard PC hardware
• Software with a current reliable operatin system and user interfaces
• Test output results that can interface easily with standard desktop applications
• Complete test scripts to perform tests
• Integrated tool set for handling system calibration and maintenance activities
• Machine controls with integrated monitoring and safety functions
• Test reporting tools with both standardized output formats as well as user configurable options
• Backward compatibility in testing methods to ensure applicability and enhance user acceptance
• Integrated LAN capabilities to monitor in-process testing and to distribute and share test data
• Flexible design features to accommodate changing laboratory needs and the challenges of a busy R&D facility

Hardware Design
The heart of our friction test system hardware design is an industrial grade PC fitted with National Instruments AT-MIO-16 multifunction I/O and AT-DIO-24 digital I/O boards. Measurement interfaces use 5B signal conditioning modules for isolation and level conversion. Other hardware includes RS-232 interfaced motor controllers and RS-232 temperature controllers. We also included pneumatic controls and transducers in the designs for force control and various machine actuations. Special safety circuits provide a power interlock function that detects and interrupts machine operation in the event of abnormal operating conditions.

Software Design
We chose National Instruments LabVIEW as the foundation of the system software for its advanced user interfaces, adaptability for changing requirements, and powerful data acquisition capabilities. We designed system and user interfaces in the LabVIEW environment, while we implemented lower level control and processing functions in C++. Because LabVIEW provides powerful yet simple techniques to interface with C/C++ code, an efficient and seamless system architecture results.

We developed separate application tools to handle the programming of test procedures. These scripts or methods specify test conditions, test duration, and data collection specifications. Users initiate test execution by using the test control application software and specifying the requested testing method. Test data and results are automatically transferred via the company’s LAN to a dedicated file server. We have also developed extensive software tools to handle evaluation of test results. Large amounts of test data are reduced to standardized tables and graphs for use within a Microsoft Office environment, permitting further analysis and distribution. Infineum users thereby have the benefit of working with test results using flexible and familiar desktop PC tools.

Modularity and Reuse
We have adapted the system design for use on various machine configurations and even several operating systems by using the appropriate DAQ hardware. With National Instruments products, we use a common design core across Windows NT/9x using ISA and PCI-based boards. National Instruments provides a common DAQ driver interface throughout these varied environments. A structured software design has assured good design maintainability as well as frequent reuse in derivative systems. By using a layered software design technique, the top-level programs are identical on all systems while differing machine characteristics and control operations are handled by machine-specific dynamic link libraries and program configuration (.INI) files.

Project Accomplishments
The approach we chose for the development of the friction laboratory systems has provided us numerous benefits over alternate techniques. We reduced development efforts significantly as compared to conventional programming languages. Design flexibility and adaptability has been stressed repeatedly with very good success. A variety of machines are controlled with essentially a common software design and present a standardized interface to users.

Conclusions
A strategic system design approach along with National Instruments hardware and software products has produced a powerful and efficient suite of computer-based tools to support the work of Infineum Friction and Wear laboratory. We are meeting all the project goals with these designs, and the systems are well prepared to meet future challenges.

For more information, contact:

 Edward J. Carafa,

EJC Systems Inc.,

2950 State Route 23 N

Newfoundland, NJ 07435

Tel: (973) 697-5311

Fax: (973) 697-2777

E-mail: carafa@ejcsys.com