25 years ago, the automotive world was in turmoil: the new A-Class, which had only recently been presented, tipped over spectacularly during a test by the Swedish magazine “Teknikens Värld” on October 21, 1997. Rather involuntarily, the compact car helped the Electronic Stability System ESP® to achieve a breakthrough with the “elk test”, which was only known to the Scandanavian public at the time. Two years earlier, Mercedes-Benz had introduced this system as standard worldwide for the first time in the S-Class coupé (C140 series). After the manoeuvre with the A-Class, the company reacted immediately: from February 1998, the A-Class was fitted with ESP® as standard, and the 18,000 vehicles already delivered were retrofitted free of charge.
Historical photo of the former first A-Class (W168) in the so-called moose test of a Swedish trade journal. Equipped with ESP®, the A-Class completed the maneuver.
From 1999, Mercedes-Benz successfully equipped all model series with the system as standard, which stabilises vehicles through targeted and lightning-fast braking interventions on individual wheels. Overnight, ESP® becomes a symbol for an innovative, active safety system in the car – regardless of the car class. Today, 25 years later, it is part of the standard equipment: it has been a legal requirement for all new passenger car registrations in Europe since November 2011. In addition, ESP® is regarded as a pioneer of current driving assistance systems.
In fact, brake control systems have developed rapidly since the “moose test” - even if they have gone largely unnoticed by the public. They are now networked with more than 100 vehicle functions, which leads to active improvements in safety, efficiency and comfort in many driving situations – from the integrated brake controller and active rear-axle steering, to off-road functions, recuperation for electric drives, hill start assistants and trailer stabilisation, to support for automated vehicle driving and numerous assistance systems.
The milestones in development include the regenerative braking system for hybrid and electric vehicles introduced by Mercedes-Benz in 2010. The electric motor switches to generator operation when braking. The wheels transfer the kinetic energy to the generator via the drive train. This rotates in turn and converts part of the kinetic energy into electrical energy. The braking torque of the electric motor, which is generated during energy generation, decelerates the vehicle. In addition, the wheel brake is used to decelerate if more braking power is required. The brake control system always has the distribution between the generator and the braking system and the stability of the vehicle under control.
The TwoBox system, which went into series production in 2020, stands out from the more recent innovations. The combination of ESP® and an electromechanical brake booster is indispensable for electric cars in particular: Because the vacuum otherwise generated by the combustion engine, which is then routed to the conventional brake booster, is missing here. The system's rapid build-up of brake pressure enables, among other things, a short braking distance in the event of automatic emergency braking.
Another innovation is the combination of brake control system and rear-axle steering, which also went into series production in 2020. This new approach to control technology enables the active representation of the desired driving behaviour in the normal range, and the stabilisation of the vehicle in the limit range. The modular use of different actuators gives a good view of even further potential in the future.
The introduction of PRE-SAFE® 20 years ago attracted the same attention as the moose test. Because Mercedes-Benz presented a groundbreaking innovation in 2002: For the first time, active elements helped to support passive protective measures to reduce the consequences of accidents. This includes, for example, closing the windows and sunroof in critical driving situations before an imminent collision, pretensioning the belts with the belt tensioners, which are reversible for the first time, or moving the front passenger seat to a more upright position if it is equipped with a memory function. The company is thus implementing the central idea of its holistic concept of "integral safety".
However, this is by no means the end of the evolution. The Mercedes-Benz Group AG is committed to further improving road safety. After all, according to estimates by the World Health Organization (WHO) in the 2018 Road Safety Report, around 1.3 million people worldwide still die in road accidents every year. According to the WHO, between 20 and 50 million people suffer serious injuries. With its safety and assistance systems, Mercedes-Benz is therefore working resolutely to help achieve the goals of "Vision Zero". In concrete terms, this means zero road deaths by 2050 and a halving of the number of road deaths and serious injuries by 2030 compared to 2020.
Among other things, the focus is on guaranteeing comparable protection regardless of the drive system – whether it is a combustion, hybrid or electric drive. For example, to avoid electric shocks and high-energy short circuits in electric cars, a multi-stage high-voltage safety concept was developed that offers a high level of safety when driving, charging, and both during and after a crash. In addition, Mercedes-Benz, together with the City of London, is researching how anonymously-processed data from vehicles with the star can make the roads even safer in the future.