How to enhance robustness testing with waveform parameterisation
Published on 22nd August 2017
Posted in in Automotive, LVTGO-VBS
Vehicles are harsh environments for electronics. Not only must electronics in vehicles function over a wide temperature range, but the supply voltages can also vary, such as when components like the starter motor are operated.
Noise signals are often used to test the capability of the electronics present, but often, using standard test waveforms does not uncover enough faults, if any at all. This is because standard waveforms are only one of many differing noise signals that an ECU or a network may encounter. Only specific instances may cause an ECU to fail, depending on how the vehicle is operated.
The alternative to using standard waveforms for test is to perform waveform parameterisation. This comprises breaking down a standard waveform into its component parts, and then randomly varying the voltage and time parameters of these parts. Through automating and repeating this process, engineers are able to to uncover the exact parameters that cause faults, resulting in:
- More robust electrical systems
- Compliance with automotive standards
- Uncovering faults that standard test waveforms cannot detect
Breaking down a test waveform
Our LVTGO-VBS system facilitates the parameterisation of waveforms. The waveform (pictured, right), is a crank waveform, and simulates how the battery supply voltage might vary when a driver starts an engine, or how voltage varies in a start/stop environment. As seen in the image, variables have been applied to each significant voltage value (U0 – U7), and time values (T0-T9). Each of these parameters can then be assigned a maximum and minimum value, as well as a step size.
Generating random test waveforms
Once the variables have been assigned through the LV-Test GUI, the LVTGO-VBS will assign values to them through a pseudo-randomisation sequence, making the values truly random and also repeatable.
The benefits
By running thousands of tests over hours or days with the LVTGO randomly varying each voltage waveform parameter, engineers can perform exhaustive and reliable tests of ECUs, networks or entire vehicles. With waveform parameterisation, devices under test will experience 99% of supply voltage conditions that they would encounter in the field. As well as this, production costs are significantly reduced due to test engineers finding faults at the yellowboard stage, before prototype.
…
add2 is represented in the United States by Spes Development Co, who take credit for this article. Its representatives will be pleased to chat with you to discuss your low voltage EMC testing requirements.
If you’d like more information on our other products, why not create an account for free? Members gain access to a range of documentation including brochures, manuals and software updates.
More information on the LVTGO-VBS is available here.