Crash tests remain indispensable even in the age of computer simulations, and maintain the high level of occupant and road user protection provided by vehicles from Mercedes-Benz – Prof. Dr.-Ing. Rodolfo Schöneburg, Head of Vehicle Safety, Durability and Corrosion Protection at Mercedes-Benz Cars, talks about the new technology centre for vehicle safety (TFS).
Professor Schöneburg, the old crash hall in Sindelfingen has been in operation for over 40 years. Will the new TFS be up-to-date for a similar time?
Schöneburg (smiling): Well, that's rather difficult to predict of course. But naturally we made every effort not only to cover current legal and rating requirements, but also to be equipped for the future. This applies both to future crash test configurations and to new vehicles with alternative drive systems or innovative assistance systems, for example. We are also able to minutely analyse what happens in the pre-accident phase, so that we can make our PRE-SAFE® and assistance systems even more effective.
How is it that despite computer simulation, the number of crash tests conducted by Mercedes-Benz has increased further in recent years?
This is due firstly to the broad Mercedes-Benz product portfolio, which has grown considerably, and secondly to the fact that we always go beyond the number and scope of the legally prescribed tests in our crash test programme. Thanks to simulation, tests can now be conducted much more purposefully and efficiently.
What crash programme does a new model have to complete?
The current development programme for a new, production-mature model comprises around 15,000 realistic crash test simulations and over 150 crash tests. These include not just the approximately 40 different impact configurations required for ratings and worldwide vehicle homologation, but also especially exacting crash tests such as the roof-drop test that are additionally carried out by the company.
If so many crash tests need to be conducted, this surely means that the capacity of the crash test hall must be optimally managed?
Yes, one of the aims when designing the new hall was to make crash test operations as efficient as possible. Numerous new facilities help to achieve this. For example, the two crash blocks that are preconfigured with a different barrier on each side save valuable reconfiguration time. Vehicle measurement is also more efficient now, as it has been semi-automated by moving the vehicle across the laser scanner on a turntable.
And another new feature is that for the first time, vehicles can now be driven against a crash block or into another vehicle under their own power?
Correct, the conventional method being to accelerate the vehicle along the crash track using a draw cable. Previously this meant that vehicles could only travel in a straight line before the impact. The key feature in the TFS is that in the foreseeable future, we will for the first time be able to actuate the vehicle's accelerator, steering and brakes directly, allowing cornering and more complex driving manoeuvres. This will mean that we can also analyse the pre-accident phase in tests, for example the reaction of assistance systems or the effectiveness of our PRE-SAFE® measures.
The TFS is also designed for crash tests with large commercial vehicles. Is this aspect networked with passenger car safety development?
Of course, the advantage held by Daimler AG vehicles in the safety field is no accident. Trucks, vans, buses and also cars are closely networked with each other and with our central research activities. It means that each business unit benefits from the developments and experience of the others. One such example of technology transfer is ESP®: Introduced in the S-Class as a world first in spring 1995, the system became a feature in trucks, vans and buses only a few years later.
Let's hazard a look into the future: will autonomously driving cars also have to complete the crash tests?
The great advantage of automating driving functions is that the driver will less often be the cause of accidents in the future. Automation will however not be available on all roads, and drivers will be able to decide for themselves whether and when they use it or if they prefer to control the vehicle manually. There are also other factors that can lead to an accident. Other road users who are not in automated vehicles and cause an accident are just one example. For me this means that while a safe vehicle uses all possible means of avoiding accidents, it is always prepared for the eventuality of an accident. Accordingly our vehicles, including automated vehicles, must also meet our high crash safety requirements in the future.
If accident prevention is so important, and modern cars are nowadays equipped with numerous assistance systems that maintain their awareness even on junctions or in stop-and-go traffic: is passive safety, i.e. protection during an accident not losing its relative importance?
No, with the comprehensive approach of our safety philosophy, the principal goal is to prevent accidents. Where this proves unsuccessful, the aim is to mitigate the consequences of an accident. This is where passive safety continues to be important, maintaining an intact passenger compartment and giving the best possible occupant protection with restraint systems. It may be that owing to the great advances in assistance systems in recent years, there is an impression that nothing really new is to be expected in the field of passive safety. This is a false impression, however – examples include recent innovations such as the beltbag or PRE-SAFE® Impulse Side. Both of these are incidentally innovations from the ESF 2009 Experimental Safety Vehicle, and they entered series production in the S-Class and E-Class a few years later.
Prof. Rodolfo Schöneburg was born on 30 October 1959, studied aerospace engineering and obtained his doctorate at the Technical University of Berlin. He holds an honorary professorship at the College of Technology and Business Economics (HTW) in Dresden. He has been Head of Vehicle Safety, Durability and Corrosion Protection at Mercedes-Benz since April 1999. It was under his aegis that the preventive occupant protection system PRE-SAFE® entered series production in 2002, ushering in a new era in vehicle safety for the car industry.