Vehicle-in-the-Loop speeds automotive design cycles
At their Open House customer meeting, simulation expert company IPG (Karlsruhe, Germany), showed how simulation of multiple driving situations by software can complement actual driving tests with strong benefits for the entire development process. Since simulation can be used to verify interim design goals, it supports the agile development approach and thus brings the cars faster from the drawing board to the road.
Future development trends in car design such as the connected car, sensor fusion, partly or full autonomous driving actually make the number of tests required to ensure proper functionality explode, said IPG general manager Steffen Schmidt. The same holds true for the „hybridization“ of the powertrain, with a broad range of variations from mild hybrid to completely electric systems. „The ESP as one of the first electronic systems for the car has been verified completely with real testing“, Schmidt remembers. This is no longer possible. „In autonomous driving, the electronic systems have to master an infinite number of traffic situations and driving maneuvers. Real tests would take years and cost a fortune“, Schmidt said.
To solve this problem, IPG has developed an approach it calls Vehicle-in-the-Loop (ViL) which combines real and virtual tests. The vehicle with its electronic systems in this case is real, the traffic and the environment is generated by additional software and hardware; the surroundings can even be displayed as augmented reality in a kind of eyeglass with integrated display for the driver. Such scenarios allow testing of driver assistance systems, for example the driver can test if the vehicle’s parking assistant correctly maneuvers the car into a virtual parking spot, generated by the simulator. Traffic situations can be set according to the requirements and, if necessary, be reproduced precisely.
Not only the new technological approaches like (semi)autonomous driving increase the necessity for more, and more thorough testing. Also the continuous exacerbation of US and European NCAP (New Car Assessment Program) criteria drive the demand for virtual vehicle tests, Schmidt explained. The reason: NCAP increasingly extends the range of features to be included into the assessment. Years ago, a newly designed vehicle could achieve the best rating of five stars if the passengers were protected well enough in the case of an accident. Today and in the future, to reach this rating NCAP expects that the vehicles have accident-avoiding techniques in place such as emergency brake assist or pedestrian detection. „With our simulations we already can predict if a car will get the five-star rating“, Schmidt said.
But why is this relevant? „NCAP ratings are clearly driving the end customer’s buying decisions“, Schmidt explains. Therefore, more or less all OEMs today tend to simulate the behaviour of their ADAS in virtual traffic situations.