Test bench concept cuts changeover time

September 27, 2017 // By Norbert Witteczek, Smart Testsolutions
The strong increase in the number of electronic control units in vehicles is accompanied by an increase in testing effort. In order to keep the time for the test procedures to a minimum, the measurement technology specialist Smart Test Solutions and the automotive supplier ZF Friedrichshafen AG (ZF) have developed a new generation of test benches; the development focus was on maximum flexibility in use. The system described is used for ZFs captive supply.

Some of today's luxury cars are fitted with more than 100 electronic control units (ECUs). They communicate via data buses with one another and with the numerous sensors distributed throughout the vehicle. The increasing complexity of the components also makes greater demands on product testing.

Before it can be released, every ECU has to pass a comprehensive series of functional, electrical and mechanical tests. For example, the devices are subjected to thermal cycling and vibration in an endurance test lasting several months, as well as undergoing spray testing with salt and water. These environmental and life tests can only produce meaningful results if the test bench provides full simulation of the electrical and electronic environment of the control units in the vehicle. Simulation of all analog and digital signals is essential, as is the so-called residual bus simulation of messages from other control units in the vehicle network.

The problem is that no two vehicle environments are alike. Test bench changeover is not only required when control units are to be tested for different applications, but also if a particular unit is to be used in another vehicle model. The time needed for adapting the test systems has increased enormously in recent years on account of the ever more complex nature of vehicle electronics. The time frames available have however remained more or less the same. There is only one possible answer to this dilemma: Namely to shorten the test bench changeover times.

From eight months down to just a few weeks

This has been achieved by the Active & Passive Safety Technology division of tier one supplier in cooperation with Smart Testsolutions. Whereas the adaptation of test benches used to take up to eight months, it can now be completed in three to four weeks. The tremendous time saving was made possible by the development of a new generation of test benches offering the necessary flexibility and easy configuration thanks to the use of a lightweight scripting language (Lua) and special drivers.

Design category: