Testing solutions for autonomous driving
If you try a comparison of different test levels from the subfields of system testing, design verification, product validation, end-of-line testing and prototype testing, there are, from the author’s point of view, similar issues and therefore also similar solutions.
OPEN TESTING PLATFORM
Using National Instruments technology, WKS Informatik GmbH developed the RTStand platform for testing integrated ECUs throughout all test levels from prototyping to end-of-line tests. RTStand combines the functionality of a traditional HiL system with those of a real-time automated test equipment (ATE) and uses methods of data reduction, for example for the minimisation of log data. In addition to that, RTStand provides a powerful technique of data navigation, to examine relations between test result, test report and actual values measured in timing diagrams – with the emphasis on finding relations, instead of only searching.
THE NEED FOR ADAPTIVE LOGGING
In order to insure components reliability, OEMs have to fulfil various norms. The LV 124 (and its related norms VW 80000,ISO 16750-2 etc.) is one of the most important norms for automotive validation. Developed by the German OEMs, it describes various testing scenarios for car components and the way they must behave under specific circumstances.
Having the purpose of detecting even the slightest failures in a signal and requiering a sampling rate of 100 kHz for all tested signals, the LV 124 produces huge amounts of data that need to be analysed. Assuming that such big testing resources are available, finding the one short sporadic error of 1 ms will be a challenge.
This idea drove WKS Informatik to develop an adaptive logging process for analysing data on-the-fly and thus reducing the amount of data produced. This not only saves IT resources, but also enables a much faster data analysis, through much easier data navigation.
As shown in FIGURE 2, it is possible to determine expected values like limits or envelope curves for the signals to be tested. These curves are used at runtime in order to determine whether a signal behaves as expected under given conditions. In a good case, the signal will be logged with a reduced rate – the only interesting information here being the approximate signal trend-. In a failedcase, the signal will be logged with the highest rate (for example 100 kHz).
Let us take an example where 15 min of usual logging produce 71 GByte of data. Using adaptive logging, which will only use high-sampling during the 1 ms event and for example 1 Hz sampling at the rest of the time, only 10 kByte of data will be produced, reducing the amount of data by seven million times.
BIG DATA ANALYSIS
By combining this procedure and log viewing capabilites, a quick and simple navigation of the test data is ensured. RTStand integrates all this natively and through complementary products for validation: Tube Analyzer – as the measurement and analysis unit – and RTStand LV 124 – as a fully-automated testing solution.
INTEGRATION OF CLOUD SOLUTIONS
The connected car needs intensive data communication, as explained above. RTStand integrates plugins for various Industry 4.0 needs, such as data saving into and visualising from cloud technologies.
Comparing the efficiency between different test benches can be an important aspect while testing various car components. Each test bench can correspond to a specific component and through cloud communication their interaction can be observed and improved.
As much as we as humans rely on our senses to navigate through the daily city jungle, so do autonomous vehicles rely on the accuracy of their sensors. A vehicle must be able to react at speeds of even over 150 km/h. So vehicle sensors must work more accurately than human senses.
RTStand integrates radar target simulation solutions for both 24- and 77-GHz radars, characterisation and chirp analysis tools for radar, which are used extensively in hardware development and end-of-line testing,FIGURE 3.
ONE PLATFORM TO RULE THEM ALL
WKS Informatik integrates all the above solutions and concepts into its RTStand platform, providing one solution for testing from early prototyping, until the end-of-line. Because as an OEM you have the certainty that at all levels in your product development cycle, the same technology and the same reliability of testing results is guaranteed.
An open platform can bring both kind of manufacturers – automotive and non-automotive – on the same testing grounds, allowing them to concentrate less on interfaces and more on quality.
Autonomous driving is happening. Traditional manufacturers must step up to the challenges from the newest players on the market, such as Google, Tesla, even Apple and Amazon, and make the transition to being a mobility service provider in the connected world of the Internet of Things.
While producing a reliable and client-appealing car, OEMs must be sure that their products function safely under all circumstances. Recently Tesla announced that they will skip testing steps in order to boost production and reach deadlines , by ordering ready-to-use equipment. If this becomes a trend, there will be more pressure on the automotive suppliers to validate thoroughly and rely on better risk management strategies.