The ESF 2009 is the first Experimental Safety Vehicle Mercedes-Benz has built since 1974. Like its historic predecessors, it attractively combines trailblazing innovations in the field of safety and makes the progress achieved visible. Integrating all the ideas and implementing them for a clear appreciation was an extraordinary challenge for the team in the test vehicle workshops.
The go-ahead for the ESF was given in October 2008, and the decision was received with great enthusiasm in the test workshop: “Making safety visible – I was quickly able to assemble a highly qualified team for this interesting project”, says Axel Wittig, the team leader for the entire workshop facility. “The complexity of this assignment was a welcome challenge, as we not only had to integrate the numerous innovations into an S 400 HYBRID, but also make them fully functioning in demonstration mode and provide a look behind the technical scenes by incorporating eight inspection windows in the bonnet, bumpers and doors.”
The core workshop team for the ESF 2009, headed by coordinator and facilitator Hans Peter Hiller, consisted of three model-builders and two electricians. The team was supported by Jürgen Arnold, who took care of the electrical engineering, and designer Matthias Rissmann, who e.g. prepared the body apertures for the inspection windows. It was only possible to keep to the ambitious time-plan because countless internal (from the upholstery specialists in Design to production engineering) and external suppliers gave rapid and unbureaucratic assistance. “The great enthusiasm for the core Mercedes expertise of safety could be felt at all times”, project manager Michael Fehring remembers: “The ‘Daimler spirit’ ensured rapid decisions without time-consuming consultation processes.” Sheer fascination for technology also played an important part. The chance to take a look into a radar sensor, which is normally only supplied as a ‘black box’ but was in this case integrated into the front bumper in a cutaway state, attracted many an engineer who was not involved in the project into the workshop bay for the ESF 2009.
The complexity of this project, which involved the integration of 13 safety innovations into the hybrid version of the S-Class that only existed as a prototype when the work started, is already shown by the fact that a completely new wiring harness had to be designed and produced. At the heart of the demonstration technology is a divided compressed air tank in the boot, with a compressor and external power supply, which provides the airbags and the air chambers for PRE-SAFE Pulse and Interseat Protection with air. The finishing touch for the ESF 2009 is a central remote control system for all the functioning demonstrations.
The result of all this work was two experimental vehicles in the special ESF paint finish, which includes black-painted chrome trim and reflective strips on the door seals and tyres: the actual ESF 2009 and its externally identical brother, which can be used for driving and photographic purposes.
Interview with Prof. Dr. Ing. Rodolfo Schöneburg, Head of Safety Development, Mercedes-Benz Cars.
Prof. Dr. Ing. 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 Technologyand Business Economics (HTW) in Dresden. He has been active as the head of the centre for safety/vehicle functions at Mercedes-Benz since April 1999. It was under his aegis that the preventive occupant protection system PRE-SAFE®entered series production in 2002, with which Mercedes-Benz started a new era in vehicle safety. Here are some of Prof. Schöneburg’s comments on the ESF 2009 experimental safety vehicle.
Question: Prof. Schöneburg, during the period from 1971 to 1974 Mercedes-Benz presented four Experimental Safety Vehicles (ESFs) to the public. Then there was silence. Why?
Prof. Schöneburg: At the end of the 60s, vehicle safety suddenly became a focus of public attention. In 1969 the Mercedes-Benz Safety Centerwas founded in Sindelfingen. Numerous developments were initiated, ranging from active safety with ABS and ESP® to fundamental improvements in vehicle structures and innovative restraint systems such as the airbag. All of these were tested and presented in our ESFs, and from the mid-70s more and more of these innovations reached series production maturity. Accordingly they were subsequently presented with the launch of new series production models.
Question: So why are you presenting another research vehicle now, the ESF 2009?
Prof. Schöneburg: Both in-house and externally, the large number of safety features that we already have in our series production cars has created the impression that we do not have much more to offer in this respect. This impression is quite wrong – we have a wealth of ideas on how safety might be improved still further. Some of these can be realised within a relatively short time, for example PRE-SAFE® for rear-end collisions. Other concepts like the inflatable metal sections in PRE-SAFE Structure lie well in the future. And with Interactive Vehicle Communication we are only just starting to develop a completely new field. The ESF 2009 comprehensively offers up all these perspectives. Moreover, our intention was to send out certain signals for the ESV Conference, which is being held in Stuttgart for the first time since 1971.
Question: What is particularly special about the ESF 2009?
Prof. Schöneburg: As with the ESFs of the 1970s, this is a comprehensive embodiment of our safety philosophy. The primary aim is to prevent accidents in the first place. Where this is not possible, the aim is to mitigate their effects. Moreover, we want to approach both of these goals without increasing the vehicle’s weight, restricting its practicality or compromising the autonomy of the driver. He or she bears the final responsibility – and the car should provide support in the process.
Question: What new ideas have been incorporated into the ESF 2009 to prevent accidents where possible?
Prof. Schöneburg: These start with the concept of “seeing and being seen”. The LED headlamps of the ESF2009 not only illuminate the road further and more efficiently, but also ensure that other detected road users are not dazzled in the process. The Spotlight function is something quite new: it precisely pinpoints obstacles or objects that have been recognised by the infrared Nightvision camera. Thanks to new reflective strips on the sides, which leave the body design unaffected during daytime, the ESF 2009 is also much more easily visible to other road users in the dark. One technology which we think has tremendous potential for the next few years and decades is car-to-car communication. This makes it possible to warn drivers of hazards on their route as the situation requires.
Question: In addition to highly developed restraint systems, Mercedes cars with PRE-SAFE ® have a preventive safety system that can recognise an impending accident and mitigate its effects with numerous actions right up to automatic emergency braking. Is it still possible to make significant improvements to this already high standard?
Prof. Schöneburg: Yes indeed. The basis for PRE-SAFE®is a network of onboard sensors and systems, and this is where we still have plenty of ideas for further developments. Take side impacts as an example: with the help of air chambers in the seats, it would be possible to move the passengers away from the danger zone to some extent. We have already spoken about improvements where rear-end collisions are concerned. And the Braking Bag is a completely new approach to scrubbing off energy before an impact occurs.
Question: At first glance this is a crazy idea – using an airbag under the car to force a high-friction coating against the road surface as an auxiliary brake…
Prof. Schöneburg: …certainly unusual, but by no means crazy. Initial trials of the principle have shown this idea to have considerable potential. In the next few years we intend to research and develop this potential further.