Accident research: painstaking detective work and extensive collection of data

Oct 28, 2019

Mercedes-Benz Accident Research is a major component of the safety philosophy of "real-life safety" – taking guidance from what actually happens in accidents. The experts head out about 100 times each year to examine severe accidents involving current Mercedes-Benz or smart vehicles within a radius of around 200 kilometres of Sindelfingen. The insights from the painstaking detective work are incorporated into the improvement and construction of updated and new models.

Established in 1969, Mercedes-Benz Accident Research is one of the oldest departments of this kind in the global automotive industry. Since then, the teams have examined and reconstructed more than 4700 traffic accidents in all. Most assignments are within a radius of around 200 kilometres of Sindelfingen, but in some cases the distance can be much greater.

Thanks to cooperation with the interior ministry of Baden-Württemberg, the police report serious accidents involving a current Mercedes-Benz model that occur in the region. When the researchers head out in their service vehicle (details see next page), they usually start by examining the vehicle, which is often already in the workshop. How severely was the body shell deformed? Did the restraint systems trigger? Is there anything unusual or are there areas of contact in the interior of the Mercedes-Benz model involved in the accident? All of this is done on a voluntary basis and with the consent of the driver.

In the next step, the accident scene is visited to reconstruct the course of the accident, including single-car accidents where no other vehicle was involved. What position was the vehicle or were the vehicles in at the moment of impact? Are there tyre or skid marks? The researchers systematically find answers to these and many more questions. For a little over four years now, the accident researchers have been aided in this by a laser scanner that enables the accident scene to be scanned three-dimensionally as a point cloud and automatically measured.

The answers to the questions are structured and electronically stored on a tablet PC, along with photos and sketches. Once the researchers possess all of the information, they systematically reconstruct the collision.

Special software helps the researchers to do this. It converts the data and measured values from the scene into moving images. To this end, the computer combines for example the length of the tyre or skid marks with the design and dynamic driving data of the vehicle suffering the accident, and reconstructs what happened on this basis. The specialists are able to see on-screen how the vehicle moved before, during and after the collision.

Finally, the results are compared with the data from other accidents, so that over time, the automotive engineers get a precise picture of typical damage patterns and gain insights for the development of new, even more effective protection systems. With the help of a so-called prospective efficiency analysis, the accident researchers are also able to ascertain what the consequences of an accident would have been if a particular safety feature had been on board.

The feedback into the vehicle development takes places in various ways: in the case of isolated anomalies, the accident researchers bring it up directly with the responsible parties in the model series. Suggested systematic improvements are incorporated into the performance specifications of new model series. In addition, an annual report is compiled which presents the trends and developments in the area of traffic safety. It also explores in detail current issues such as, for example, the development of accidents involving electric bicycles.

In order not to jeopardise their impartiality as researchers, the accident research experts never prepare any expert opinions for parties involved in an accident or as expert witnesses for the judicial system.

Tools and camera always on board the service vehicle

The current service vehicle is a Mercedes-Benz V-Class sporting high-visibility car film. The accident researchers of Mercedes‑Benz have been heading out in it since 2017. A yellow light bar on the roof is switched on at the accident site to secure it. The equipment includes tools for a potential disassembly of components as part of the accident analysis. In addition, there is a jack, a measuring wheel as well as a 3D laser scanner with tripod for surveying the accident site. The researchers also carry a diagnostics tool for reading out the relevant control units of the damaged vehicle, a tablet computer for documenting the damages to the vehicle, safety vests, photo equipment complete with telescopic rods for overhead shots, as well as various measuring and testing devices for high-voltage vehicles.

With an international footprint and equipped with digital technology

With colleagues in India and China, Mercedes-Benz Accident Research has also operated internationally for some years now. The accident researchers in the Far East benefit from the expertise from Sindelfingen. With the help of AR goggles[1], they can compare notes with colleagues directly and in real time and thus conduct joint analyses even though the German accident research experts are not on site.

The user behaviour and accidents in European and Asian countries differ greatly in part. The aim of the accident research in Asia is also to develop approaches for reducing the significantly higher number of victims compared with Europe, for example.

Accident research also on commercial vehicles

Since 1972, Commercial Vehicle Accident Research at Daimler has studied accidents involving Mercedes-Benz trucks throughout Germany in order to derive measures for active and passive safety from them. The researchers always document all of the information about the circumstances of the accident, the vehicles involved and the damages. They also look for anomalies, for example, with regard to the frequency of types of accidents, the detectability of certain accident patterns or the injuries to the parties involved in the accidents. On the basis of this analysis, the accident researchers derive modification measures that culminate in future Mercedes-Benz requirements. This is how the idea for Sideguard Assist was born a few years ago, which is available ex-factory at Mercedes-Benz for many truck models on the market.

The innovative system, which helps to prevent accidents with pedestrians and cyclists, is just one of many examples of the decades-long pioneering role that Mercedes-Benz Trucks has had in the area of safety and assistance systems development. Numerous systems had been installed in the various model series long before they were mandated by law. This is true for the Anti-Lock Braking System (ABS) and Acceleration Skid Control (ASR) as well as for the Electronic Stability Program (ESP®) and Active Brake Assist, to name but a few examples.

"We deem our detailed investigations indispensable to be able to assess the behaviour of the vehicle in a real accident", emphasises Kay Morschheuser, Head of Commercial Vehicle Accident Analyses at Mercedes-Benz Trucks.  According to him, this is the only way to incorporate further improvements into the vehicle. Accident prevention is a key consideration in the truck development of Mercedes-Benz – for reasons relating to the great mass of a truck alone. However, the mitigation of the consequences of an accident also plays at least an equally important role. This makes crash tests indispensable, and Mercedes‑Benz Trucks has been systematically conducting these for years as well. This represents yet another crucial boost for the safety development of heavy-duty vehicles in particular.

Own accident research of Mercedes-Benz Vans

Research focusing on vans has also been around since the 1970s already. However, the various departments were initially assigned to different divisions. Vans Accident Research was given a new set-up in summer 2015 and has its headquarters in the Untertürkheim plant of Daimler AG. From here, the engineers investigate selected accidents involving vans from Mercedes-Benz. The results are directly incorporated into the vehicle development and thereby make Mercedes-Benz vans even safer.

Because the investigations routine includes a survey of the damaged vehicle and the accident site, Vans Accident Research has a Mercedes-Benz Vito Mixto as the service vehicle, which offers lots of space for the required equipment. The load compartment, separated from the seat rows by a partition, holds everything needed for the accident analysis, from a measuring wheel to safety vests and from a still camera to an inclinometer. If a trip by aeroplane is required in special cases, the shelved components can be removed as ready-to-go tool boxes and stacked to be checked in as luggage on the flight. In keeping with the "Mercedes-Benz Vans goes global" strategy, there are considerations to expand the analyses of the accident researchers to vehicle variants and model types of other markets in future – for example, to right-hand-drive vehicles or models of the North American market.

[1] AR = Augmented Reality, reality augmented with digital content