Development of an In-Vehicle Meter ECU Hardware-in-the-Loop Automated Test Device Using NI LabVIEW and PXI Hardware

Author(s):

カルソニックカンセイ株式会社　 開発本部 開発信頼性統括グループ　実験技術開発チーム - 西田 尚史氏
Hisafumi Nishida - CalsonicKansei Corporation

Automotive computerization is advancing quickly and has become indispensable to the technology that improves safety and reduces carbon dioxide and nitrogen oxide emissions. The development of an ECU equipped with a microcontroller, which is basic for computerization, can even determine automobile performance and riding comfort.

The in-vehicle network also follows the course of this evolution, and communications technologies such as local interconnect network (LIN), controller area network (CAN), and FlexRay are attracting attention as the technology that will replace mechanical transmission mechanisms with electrical controlling known as "X-by-Wire."

At CalsonicKansei, we established test, research, and development centers in Saitama, Japan, and expanded our experimental facilities to Sano, Japan. We also partnered with Peritec Inc., a company with a strong background in ECU testing, when we began developing our automated test device for an in-vehicle indicator ECU (hereinafter called a meter).

Five Main Challenges in Developing the In-Vehicle Meter ECU

Departing from Man-in-the-Loop Test

Because errors are more likely to occur in tests conducted by humans and visual observation (man-in-the-loop test), the test loop needed to be automated. However, a meter is a display unit, which does not usually provide feedback for testing.

Supporting Various Models

It is necessary to test meters of various models in the reliability assessment section. Every meter can vary in the position and presence of a needle, an indicator, and an LCD. To be used as a universal test device, we had to change the position to acquire a picture and the contents of the test for every product. Overcoming this issue was the greatest challenge.

High-Resolution Image Processing

To test the angle of a meter indicator and LCD display, we had to capture an image using a camera with a high frame rate and high resolution and then process the image.

Indicator Test and Buzzer Test

We had to test the indicator display and buzzer sound pattern in the meter.

Driving Scenario

We created a driving and user operation scenario and also conducted an actual vehicle movement simulation.

Solving Our Development Challenges

Building a Hardware-in-the-Loop System

We developed a PXI system using the NI PXI Reconfigurable Multifunction Module, PXI Digital Multimeter (DMM), PXI Waveform Generator, PXI CAN interface, general-purpose switch module, and PXI industrial digital I/O module as the basic hardware. To replace the visual observation test (man-in-the-loop test), we built a hardware-in-the-loop (HIL) auto test system looped with an image reader (camera) and an image processing and testing program developed with NI LabVIEW.

Supporting Multiple Models

To overcome the model-specific meter difference problem, we repeated the test after providing a stage that moves the position of the camera, conducted teaching and preliminary tests before the test begins, and created a settings file.

High-Resolution Image Processing

To test the angle of the meter indicator/LCD display, we captured a detailed image by moving the stage to the position that enables testing of the high-resolution camera. We acquired and processed the image using the LabVIEW image processing function.

Indicator Test and Buzzer Test

To perform the indicator test, we used a camera obscura with an installed meter. To conduct the buzzer test, we installed a microphone and an amplifier in the camera to record sound using the digitizer function of the DMM and to test the frequency and pattern.

Driving Scenario

In the driving and user operation scenario, we prepared the HIL standard function created by LabVIEW for every model by developing a sequence file of NI TestStand.

Results of Using an HIL Test System

Using the "XY stage control – moving the camera" concept of supporting multimodels, we resolved the issue. Furthermore, we built a system capable of conducting all tests by providing a camera and a microphone used for the indicator test in the camera. NI products including several measurement modules and customizable LabVIEW and NI TestStand software made up the essential basic building block for achieving our test. By completing this system, we can cut time and cost by at least half compared to a manual test.

The use of NI hardware and software was very effective for building the HIL system for testing products in the automotive industry. We are using the automatic testing system to develop meters for installation in vehicles manufactured by the major domestic Japanese automakers, who are our business partners.

As the developmental reliability management group, we boldly promote test automation to cope with the rapid computerization of automobiles. This includes HIL standard functions for ECU testing such as the battery voltage test and dark current test, and is applicable to other ECU tests as well. Also, we are considering the deployment of air conditioner ECUs or air bag ECUs. Moreover, we expect a provision of measurement solutions that are in-line with the auto industry.

Contact Information:

Hisafumi Nishida
CalsonicKansei Corporation
8 Sakae-Cho Sano-shi
Tochigi-ken, Japan 327-0816
Tel: 81-283-21-8007
E-mail: hisashi_nishida@ck-mail.com

Author Information:
カルソニックカンセイ株式会社　 開発本部 開発信頼性統括グループ　実験技術開発チーム
西田 尚史氏