As Featured on NI.com
Original Authors: Minsuk Ko, Hyundai Kefico
Edited by Cyth Systems
We needed to sustainably meet manufacturing test deadlines for increasingly complex powertrain electronic control units (ECU) with over 200 pins and 20,000 test steps; while ensuring test times comply with throughput needs and cost of tests is reduced to remain competitive in the market.
Using the NI test platform to build a standard architecture, we achieved flexible test system configurations of all powertrain ECU types and reusable test scripts and procedures that guarantee test coverage alignment from R&D to manufacturing, while allowing global, standard test deployment and operation.
Automotive technology is accelerating faster than ever before. Trends like powertrain electrification, wide adoption of advanced safety systems, and enhanced driving and comfort functionalities significantly increase the amount of software needed. As a result, electronic control units (ECUs) are more complex and in higher demand. One of the most important of these is the powertrain ECU. Beyond ensuring proper operation of the powertrain that moves the vehicle, these ECUs impact the environmental performance of the vehicle, its economy, and driving experience, which are factors buyers seriously consider.
Hyundai Kefico, a subsidiary company of Hyundai, has provided powertrain automotive electronics since 1972. Like other automotive suppliers that want to remain competitive on the market, our engineers at Hyundai Kefico faced increased test demands and tighter emission regulations while also managing budget and timeline challenges. When our powertrain ECUs reached 200 pins and the functional test needed to ensure quality stretched to 20,000 test steps for an increased variety of ECU types, it became clear that we could not use traditional test engineering approaches to keep up with the pace of vehicle electronics. We needed a change.
A New Approach
In the past, an ECU functional tester required that we design sensor/actuator emulators, vehicle communication modules, test execution engines and applications, test procedures, and test result management tools for each type of ECU. In other words, we developed a new tester for every new ECU, with minimum reuse of test engineering assets and a negative impact to the cost of test.
To solve this problem, we started with the development process and created the Common Platform Tester (CP-Tester), and the standardized ECU Functional Tester development process (Figure 1). We based the CP-Tester on standardized test assets called CP-Standard, which define sensor/actuator emulation, vehicle communication, test execution (test engine), operator interface (test application), and test result management.
The CP-Tester has a few key components that streamline the test development process. R&D or product engineers can use a test scripting modeling tool called CP-Editor to configure each test step and parameter by choosing from over 200 prebuilt functions to develop test sequences. They can map these test steps to the appropriate hardware I/O and reconfigure them for different ECU types. The CP-Server is another component that engineers can use to effectively manage test result data to improve upon new test requirements. Our engineers can realize these three benefits from the CP-Tester:
Shorter tester development times because of its adaptability to various types of powertrain ECUs
Efficient use of test engineering assets because it can reuse and reconfigure test steps from R&D to manufacturing
More value out of manufacturing test data due to data handling and traceability in standard format
We chose the NI PXI platform because it is better suited to deal with the complexity of our powertrain ECUs. Benefits of NI PXI solutions include:
High and flexible channel counts (over 200 pins) with different layouts
I/O configuration with source and measurement capabilities
Ability to connect dummy loads (resistance and inductance) to properly test ECUs
Wide variety of switching options and ease of use with NI-SWITCH to increase I/O flexibility
Ability to customize I/O through FPGA to implement special sensor communication protocols such as SENT (Single Edge Nibble Transmission and SAE J2716)
Most turnkey ECU testers on the market require 10–12 months to adopt new test plans for new products, and they still require significant interaction with the vendors and high costs. Given the importance of a short development time, we took advantage of NI’s automated test solutions to become independent and develop our own flexible standard tester within three months. This resulted in an 80 percent reduction of development time, while giving us the ability to add functionality like CAN with flexible data-rate in the future, as product requirements evolve.
At the company level, given the higher demands for ECUs, the NI PXI timing and synchronization features improved our test time by 15 percent and cut the test system cost by 30 percent, which has helped us be more competitive in the market. In addition, we can procure and assemble the CP-Tester at any of our manufacturing sites around the globe thanks to NI’s global presence.
For the first 17 CP-Testers, we achieved a 45 percent better project ROI and saved over $1M compared to our previous solution.
Minsuk Ko, Hyundai Kefico
Edited by Cyth Systems