Implementing State-of-the-Art Test Systems for Toyoda TRW Automotive Pumps

Author(s):
Mathew Eurich - Wineman Technology

Industry:
Automotive

Products:
High-Precision DAQ, PXI/CompactPCI, LabVIEW

The Challenge:
Developing an innovative data acquisition and control system for a new power steering pump durability test stand that eliminates the complexities of traditional systems, which utilize separate PLCs for control, analog controls for servos, black-boxes for special tests, and a separate DAQ system.

The Solution:
Using a single National Instruments LabVIEW-based system that utilizes two PXI real-time systems and a network of computers, to consolidate the functions of traditional systems.

Established Design Goals
An OEM contracted Wineman Technology to provide a state-of-the-art data acquisition and control system for a new power steering pump durability test stand, for use by Toyoda TRW.
At the start of the project, we established the following design goals:

• Ability to perform independent deterministic control of multiple systems with a single reliable control system
• Integrated control and data acquisition
• Integrated dynamic signal acquisition and analysi
• Ability to run different tests simultaneously
• Configurable custom test sequences that users can save, load, and edit
• Live data display and system control from any remote operator terminals
• Ability to recall, analyze, and print acquired data while a test runs
• A highly-advanced, easy-to-use, and reliable systems

The mechanical design included a dual station system with each test stand capable of independent configuration and control. We provided universal fixturing, so TRW can mount a wide variety of pumps on the test stand at the correct in-vehicle orientation. We controlled speed from 0 to 10,000 RPM, pressure from 0 to 20 MPa, and flow could vary from 0 to 60 LPM. Accurate control over these ranges required several custom components and extensive cooperation with key vendors.

Controlling Two Pump Tests
We integrated National Instruments real-time embedded PXI controllers to deterministically control two pump test stands through a multicomputer interface system.Using a custom client-server application, we had communication between each of the system by use of a TCP to send and receive high-priority configuration data. UDP data protocol provides live data updates to all remote terminals. The PXI controller station performs deterministic, embedded, closed-loop control of pressure, temperature, torque, belt tension, speed, and flow for the two pump test units. It also controls a temperature chamber for atmospheric conditioning through an RS-232 link and acquires all low-speed data signals. The PXI high-speed data acquisition captures all high-speed dynamic microphone, accelerometer, and pressure pulsation signals though a PXI-4472 card that features anti-alias filters and simultaneous sampling.

Integrating a FlexibleSoftware Design
We developed the software as three separate LabVIEW applications - one for the real-time high-speed system, the second for the real-time low-speed control system, and the third for the remote terminal interface. We designed the remote terminal to deploy across multiple PCs while interacting with the two real-time systems. Because of this, operators can customize the functionality available to them at each of the remote stations. It also provides true redundancy, since users can configure any station to control either test unit.
The remote stations require only an Ethernet connection to the system, providing a flexible solution for relocation anywhere in the Toyoda TRW plant.

Continuing with the single application concept, we developed a generic remote interface to control the system and interact with the real-time embedded controllers. This interface provided both manual and automatic test control for the operator. Using the manual control screen, the operator can perform all of the operations available on previous generation pump test systems, including manually setting speed, pressures, hydraulic circuits, and circulation pumps.

In addition, operators have the convenience of a live data display for all acquired low-speed control and high-speed FFT signals, including maximum, minimum, and current value tracking. The manual control screen also provides the ability to freeze the data display, log data to file, and view all digital inputs. The automatic test control screen includes the same data display and tracking features as the manual control screen, and it provides the ability to run predefined test sequences and monitor all alarm conditions. Using both the manual and automatic control screens, operators control either pump test unit. From a single test station, the operator may control units one and two individually, together, or act solely as a data viewer. The only restriction on the operator is controlling a pump test stand with one remote terminal at a time. However, if another terminal has control of the unit, that unit’s live data is still available to all remote terminals. At any time, operators can transfer control from one remote terminal to the other and the real-time system continues to execute system control and data acquisition in a reliable and deterministic manner.

Generating Large Test Sequences
The system needed to run 16 standard, automatic tests and to have the ability to generate custom tests. To accomplish this, we developed a modular test editor to build not only custom tests, but the standard tests as well. Using this test editor, users can manipulate basic building blocks to assemble a much larger sequence. These blocks included modules to control data logging, speed, pressures, temperatures, hydraulic circuits, and operator intervention. By compiling the building blocks, the user can generate large test sequences. These test sequences can create larger performance or durability test sequences. Because of this, the operator can build a test that runs for seconds, minutes, hours, days, months, or years. Operators can save, load, and edit tests to create new ones.

Throughout acquisition and post acquisition, the system performs a battery of analysis, which includes alarm limit and system fault monitoring, data display of all acquired channels, real-time FFT analysis, order analysis of high-speed signals, order extraction, and sound pressure level calculation.

Providing a Powerful and Flexible Test System
Several of the features in this module would not have been possible without the high level of integration possible through our design approach. Standardizing on National Instruments components allows one source for technical support and enables us to use one programming language for development and debugging. With LabVIEW Real-Time, we simplified the system design, reducing cost, and providing a test system that combines the features of a performance test stand with the capabilities of a durability test stand. Since we were not constrained by the communication protocols standard in PLCs or black-box equipment, our system configuration, synchronization, and communication successfully meet the requirements of this application. This proved extremely valuable in developing the test builder. Our test system enables Toyoda TRW to utilize functions such as order analysis and the ability to combine high and low-speed data into reports. With the power and flexibility of the test builder module, Toyoda TRW can create and execute nearly a limitless amount of tests.

For more information, contact:

Matthew Eurich

Test Systems Director

1668 Champagne Drive

North Saginaw, MI 48604

Tel: 989-771-3000

Fax: 989-771-3010

E-mail: meurich@winemantech.com

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