Gallery
Figure 1: Full HIL test system used to intelligently find faults in embedded software.
"By combining TestWeaver with NI VeriStand, we could quickly validate ECUs when performing HIL testing, and we were able to find problems that were not covered by our standard testing procedures."
- Dr. Thomas Neubert,
Hydrive Engineering GmbH
The Challenge:
Improving embedded software quality in engine control units (ECUs) by expanding test coverage to find problems that traditional testing strategies miss.
The Solution:
Automating test-case generation and monitoring with QTronic TestWeaver and NI VeriStand to autonomously drive hundreds of simulation scenarios during hardware-in-the-loop (HIL) testing, which significantly increases the test coverage with many scenarios and can reveal problems that are not discovered using predefined test scripts alone.
Author(s):
Dr. Thomas Neubert -
Hydrive Engineering GmbH
Dr. Mugur Tatar -
QTronic GmbH
Hydrive and QTronic Test Background
Hydrive Engineering provides machine drive and construction machine control; farm equipment; and naval system design and test engineering services. It performs hardware-in-the-loop (HIL) testing to efficiently improve integrated control system reliability and safety. Using NI HIL test platform modularity and flexibility, Hydrive Engineering can even offer overnight software tests to support short-term customer projects.
QTronic provides engineering software and services for model-based development. QTronic tools are used by developers at Mercedes-Benz, AMG, BMW, ZF, IAV, and Continental to improve the software validation process. QTronic developed the Silver and TestWeaver software tools. These tools support integration and system test to identify design problems faster and with lower costs than ever before.
Using TestWeaver to Drive the NI VeriStand Setup
A company contracted Hydrive Engineering to analyze a closed-loop control system for an electrohydraulically driven excavator to find the source of unexpected error codes reported while the excavator was deployed in the field. We built an HIL test system based on NI VeriStand software, as well as NI PXI and NI reconfigurable I/O (RIO) hardware, to test the machine. We created a wide range of test scripts to reproduce the error. However, after three months of testing, we could not determine the root cause of the error codes observed in the field.
We began using TestWeaver, a test-case generation tool created by QTronic that is designed to find errors in embedded software, to automate test-case generation. Because NI VeriStand is built on an open framework, we were able to create an application to integrate TestWeaver with NI VeriStand and configure it to stimulate control signals such as bucket load, ground slope, boom angle, and travel speed. TestWeaver dynamically changed stimulus signals based on system responses during each simulation to maximize test coverage. At the end of each scenario, TestWeaver read and cleared ECU error codes and generated a test report. These comprehensive reports helped us observe the current test state.
Finding a Critical Scenario
We ran TestWeaver and NI VeriStand continuously for nearly four days. In that time, TestWeaver generated more than 2,700 independent test cases. TestWeaver adapts test cases based on results, so it can intelligently seek out potential software faults. Using this functionality, we could find a scenario that reproduced the ECU error code. We easily repeated this scenario and reliably reproduced the conditions under which the error code appeared. By reproducing the error, we could perform in-depth fault-condition analysis and report back to the customer.
Running an Autonomous, Intelligent Test in a Fraction of the Time
NI VeriStand out-of-the box functionality and native support for a wide variety of I/O devices helped us quickly create an HIL test system that met our testing needs. Using the open architecture, we integrated TestWeaver into our HIL test system, which significantly expanded the number of test cases that we could run for a given time period. Intelligent TestWeaver test-case generation algorithms let us run our test system autonomously and create test cases that identified the problem in a fraction of the time it would have taken had we written our own test scripts.
Author Information:
Dr. Thomas Neubert
Hydrive Engineering GmbH
Dr Mugur Tatar
QTronic GmbH
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