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

Author(s):
Mathew Eurich - Wineman Technology

Industry:
Automotive

Products:
High-Precision DAQ, LabVIEW, Real-Time Module, PXI-4472

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 use separate programmable logic controllers (PLCs) for control, analog controls for servos, black boxes for special tests, and a separate data acquisition (DAQ) system.

The Solution:
Using a single system based on NI LabVIEW software that uses 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 to be used by Toyoda TRW.
The system needed to have the 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 analysis; configurable custom test sequences that users can save, load, and edit; live data display and system control from any remote operator terminals; the ability to recall, analyze, and print acquired data as a test runs; and a highly advanced, easy-to-use, and reliable system.

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 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 NI real-time embedded PXI controllers to deterministically control two pump test stands through a multicomputer interface system. Using a custom client-server application, we communicated between the systems using a TCP to send and receive high-priority configuration data. UDP data protocol provides live data updates to all remote terminals, and 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 RS232 link and acquires all low-speed data signals. We used the NI PXI-4472 high-speed DAQ module that features antialias filters and simultaneous sampling to capture all high-speed dynamic microphone, accelerometer, and pressure pulsation signals.

Integrating a Flexible Software 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 so operators can customize the available functionality at each of the remote stations. It also provides true redundancy because 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.

We developed a generic remote interface to control the system and interact with the real-time embedded controllers. This interface provided manual and automatic test control for the operator. Using the manual control screen, the operator can perform all of the operations 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 fast Fourier transform (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 provides the ability to run predefined test sequences and monitor all alarm conditions. Using the manual and automatic control screens, operators can control either pump test unit. From a single test station, the operator can view data or control units one and two individually or together. The only operator restriction is controlling a pump test stand with one remote terminal at a time. However, if another terminal has control of the unit, the live data of that unit 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

Because our system needed to run 16 standard, automatic tests and have the ability to generate custom tests, we developed a modular test editor to build custom and standard tests. With this test editor, users can manipulate basic building blocks to assemble a much larger sequence. These blocks include 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 to create larger performance or durability test sequences so 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

With our design approach and high level of integration, we completed all of the features in our module. By standardizing on NI components, we had a single source for technical support and used one programming language for development and debugging. With LabVIEW Real-Time, we simplified the system design, reduced cost, and delivered a test system that combines the features of a performance test stand with the capabilities of a durability test stand. Because we were not constrained by the communication protocols standard in PLCs or black-box equipment, our system configuration, synchronization, and communication successfully met the requirements of this application, which was extremely valuable in developing the test builder.

Using our test system, Toyoda TRW can use 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.

Author Information:
Mathew Eurich
Wineman Technology
1668 Champagne Drive North
Saginaw, MI 48604
United States
Tel: 989-771-3000
Fax: 989-771-3010
meurich@winemantech.com

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