October 20, 2022 – Safety is an essential part of Mercedes-Benz’s DNA and one of the central responsibilities the company has assumed – towards all road users. The priority of the brand with the star is to prevent accidents and improve the outcomes of accidents.
Twenty-five years ago, the automotive world was in an uproar when, on 21 October 1997, the new Mercedes-Benz A-Class (W 168 series) rolled spectacularly in a test conducted by the Swedish magazine “Teknikens Värld”. In this way, the compact car and the so-called ‘moose test’, only known to the Scandinavian public at the time, helped the Electronic Stability Program ESP® to achieve a breakthrough, admittedly involuntarily. It was only two years hence that Mercedes-Benz had for the first time introduced the system as standard worldwide in the S-Class Coupé (C 140 series). The company reacted immediately to the A-Class incident, upgrading all 18,000 vehicles already delivered at no cost to customers. And from February 1998, the system was a standard feature in the A-Class. This made Mercedes-Benz a pioneer in the industry, successively outfitting all model series with ESP® as a standard feature starting in 1999. Overnight, ESP® became a symbol for an innovative and active in-car safety system – regardless of vehicle class. Today, 25 years later, ESP® is standard equipment in all Mercedes-Benz passenger cars. And in November 2011, it even became a legal requirement for all new car registrations in Europe. ESP® is also considered to have paved the way for the other active driver assistance systems available today.
Brake control systems involved in more than 100 vehicle functions
ESP® stabilises the vehicle through targeted and lightning-fast braking intervention on individual wheels. Largely ignored by the public until now, brake control systems have continued to make rapid strides in development since the moose test incident. Today, these systems work in tandem with more than 100 vehicle functions to actively improve safety, efficiency and comfort in many driving situations, ranging from the integrated brakes controller and active rear axle steering to off-road functions, recuperation for electric drives, hill start assist and trailer stabilisation to the support of automated driving and numerous assistance systems.
Development milestones along the way include the regenerative braking system for hybrid and electric vehicles, which Mercedes-Benz introduced back in 2010. When braking, the electric motor switches to generator mode. The wheels transfer the kinetic energy to the generator via the drive train. The generator rotates, converting part of the kinetic energy into electrical energy. The braking torque that the electric motor generates when producing electrical energy slows down the vehicle. If more braking power is needed, additional deceleration is provided by the wheel brakes. The distribution between the generator and the braking system as well as vehicle stability, even in phases of high recuperation, is always managed by the brake control system.
TwoBox system for electric vehicles
One of the more significant recent innovations is the TwoBox system, which went into series production in 2020. The system, which is a combination of ESP® and an electromechanical brake booster, a crucial component for electric cars in particular, foregoes the negative pressure generated by a combustion engine that is then fed to a conventional brake booster. The system’s rapid build-up of brake pressure enables, among other things, short braking distances during automatic emergency braking.
In the plug-in hybrids of the new GLC as well as the S-Class, Mercedes-Benz uses the next generation of regenerative braking systems with a vacuum-independent, electromechanical brake booster. These systems automatically and flexibly switch between hydraulic braking and recuperation on a situation-by-situation basis for optimum energy recovery at all times. The upshot: the car achieves maximum recuperation power more frequently than with a conventional, purely hydraulic braking system.
Another innovation is the combination of brake control system and rear axle steering, which also went into series production in 2020. This novel control technology can actively adapt handling to the desired profile in the normal range as well as stabilise the car in the threshold range, while various modular actuators can accurately predict upcoming dynamics.
More than 40 active driver assistance systems ensure safety
Today, many components already work in tandem reliably to provide a high level of safety through more than 40 active driver assistance systems:
- Active Distance Assist DISTRONIC is an adaptive cruise control system that automatically maintains a preselected distance to vehicles in front on all road types.
- Active Steering Assist helps the driver stay in their lane. It can only be activated together with DISTRONIC.
- Active Lane Keeping Assist uses a camera to detect when road markings or road edges are crossed, helping the driver to avoid leaving the driving lane unintentionally.
- Active Blind Spot Assist monitors poorly visible areas and can help avoid accidents through braking intervention and warnings. Additionally, when the car is standing still, the Exit Warning function alerts occupants to the presence of road users such as passing cyclists. The ambient lighting in the door signals danger and can help to avoid a collision.
- Active Lane Change Assist cooperatively assists the driver when changing to an adjacent lane. A lane change to the right or left is only assisted if the sensors detect that the adjacent lane is separated from the present lane by interrupted lane markings, and no other vehicles are recognised in the relevant danger zone.
- Active Emergency Stop Assist brakes the vehicle to a standstill in its own lane if it recognises that the driver is no longer responding to the traffic situation for a longer period.
- Active Brake Assist uses the on-board sensors to register whether there is a risk of collision with vehicles travelling ahead, crossing or oncoming. The system can give the driver a visual and audible warning if a collision appears imminent. If the driver’s braking response is too weak, the system can also assist by increasing the brake pressure as the situation demands, and also initiate autonomous emergency braking if the driver fails to respond.
Improving the outcomes of accidents with PRE-SAFE® for 20 years
The introduction of PRE-SAFE® 20 years ago attracted similar attention to the moose test incident that took place 25 years ago. When Mercedes-Benz introduced the system in 2002, it was a disruptive innovation: the system marked the first time that active elements helped support passive protective measures in order to improve outcomes in the event of an accident. Examples include automatic closing of the windows and the sunroof in critical driving situations before an imminent collision, preventive tensioning of the front seat belts with the first reversible belt tensioners or adjusting the front passenger seat to a more upright position (if the seat features a memory function).
- In 2005, PRE-SAFE® was combined with Brake Assist PLUS (predecessor of today’s Active Brake Assist) to enable automatic closing of the side windows and inflation of side bolsters on multicontour front seats.
- This was followed in 2006 by the activation of other functions using radar technology. With the introduction of the third Driving Assistance package – featuring extensive sensor technology in the front and rear – imminent rear-end collisions can also be detected. In the event of an imminent rear end collision, PRE-SAFE® PLUS warns the traffic following behind by means of rapidly flashing warning lights.
- Introduced in 2016, PRE-SAFE® Impulse Side lifts the driver or front passenger inwards out of the danger zone just before a side impact.
- PRE-SAFE® Sound marked another addition in 2016: protection against hearing loss. In rare cases, the loud noise of a car accident can lead to impaired hearing over time. PRE-SAFE® Sound can trigger a reflex in the inner ear that acts like biomechanical hearing protection. In certain dangerous situations just before a possible collision, the system causes the vehicle’s speakers to emit a rushing sound (pink noise). The aim is to cause a tiny muscle in the inner ear to contract (acoustic reflex), which affects the coupling of the eardrum, preparing hearing for high sound pressures.
Central software as a new development focus
Mercedes-Benz is currently looking at one exciting innovation: a central software based on the future MB.OS platform will replace the current architecture with its many control units and lines. This will minimise possible sources of error and provide the basis for control systems to respond to sensor signals even faster. When the various actuators centrally coordinate the car’s driving dynamics, this brings new possibilities for fine-tuning the driving experience from highly comfortable to sporty and dynamic.
Clear goal for the future: Accident-free driving by 2050
The evolution of automotive technology is far from over. That is why Mercedes-Benz Group AG is taking on the responsibility of further improving road safety. After all, according to estimates by the World Health Organization (WHO) in its 2018 Road Safety Report, around 1.3 million people worldwide still die in road accidents every year. At the same time, the WHO reports that between 20 and 50 million people suffer serious injuries. Mercedes-Benz is working tirelessly toward its goal of “Vision Zero” through its safety and assistance systems. The goal is the clear vision of zero traffic fatalities by 2050 and reducing the number of traffic fatalities and serious injuries by 2030 compared to 2020 by half. The German Federal Government has incorporated this vision in its coalition agreement, while the WHO, along with the United Nations Regional Commissions, is equally committed. To achieve “Vision Zero”, many different disciplines and institutions will have to work hand in hand, from transport and urban planners to road authorities and legislators. A safe infrastructure is just as much a part of the approach as are universal rules. But Mercedes-Benz is going above and beyond this ambitious goal by committing itself to a “vision of accident-free driving” by 2050.
At Mercedes-Benz, we are pursuing our vision of accident-free driving. In other words: no more accidents involving a Mercedes vehicle. We are continuing to work toward this goal at full speed. Highly automated and autonomous driving will be a decisive contributor to its success. After all, vehicle safety has always been at the core of the Mercedes-Benz brand – and we want to continue to expand this claim in the future.
Maximum safety for electric cars too
When it comes to its high safety standards, Mercedes-Benz does not differentiate between different drive systems. Whether combustion, hybrid or electric drives – in all cases, the development team ensures that appropriate technology ensures a comparable degree of protection. This has been proven by tests conducted by independent organisations. Euro NCAP (European New Car Assessment Programme) has distinguished the Mercedes EQS twice, awarding the car “Best in Class” in 2021 in the categories “Premium Class” and “Pure Electric”. And the Mercedes EQE also received top ratings twice: The maximum rating of five stars in the Euro NCAP safety rating and the overall rating of “very good” with the optional assistance package in the special rating for assistance systems. In addition to protection in the event of an accident, Euro NCAP also evaluates child safety, pedestrian protection and assistance systems.