Safety is an essential part of Mercedes-Benz’s DNA and one of the core responsibilities the company has assumed in regards to all road users. The priority of the brand with the star is to prevent and improve the outcome of accidents. Two anniversaries in active and passive safety serve the company as an opportunity to present its latest safety features.
Everything was set off by a car test in October exactly 25 years ago. In Sweden in 1997, the A-Class rolled over during the so-called ‘moose test’. This prompted the rapid and widespread introduction of the Electronic Stability Program ESP in all Mercedes-Benz models. The company immediately followed up with extensive development of driving assistance systems. Today, drivers of current Mercedes-Benz models enjoy many support systems.
The second anniversary: Twenty years ago, the anticipatory protection system PRE-SAFE, which has undergone continuous development ever since, was introduced. This was the first time that active elements helped support passive protective measures in order to improve outcomes of an accident. The company is pursuing a clear goal: to achieve accident-free driving by 2050. The ‘real-life safety’ philosophy guiding the company’s ambitious goal is based on real-world accidents. The Group’s own Accident Research unit, which Mercedes-Benz has been conducting for more than 50 years, forms an essential component. In recent years, research has been expanded to include locations in China and India.
Brake control systems involved in more than 100 vehicle functions
ESP stabilizes 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 develop rapidly since the moose test incident. Today, these systems work in tandem with multiple vehicle functions to actively improve safety, efficiency and comfort in many driving situations, ranging from the integrated brake controller and active rear axle steering to off-road functions, recuperation for electric drives 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 hybrid S-Class, Mercedes-Benz uses the next generation of regenerative braking systems with a vacuum-independent, electromechanical brake booster. These systems switch automatically and flexibly between hydraulic braking and recuperation on a case by case basis for optimum energy recovery at all times. The outcome: 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 optional 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 stabilize the car in the threshold range, while various modular actuators can accurately predict upcoming dynamics.
Mercedes-Benz and Mercedes-AMG have offered the integrated driving dynamics control and integrated traction control systems for some time now. They increase driving safety in the threshold range without taking away driving pleasure. Numerous sensors and parameters such as brake pressure, yaw torque, wheel slip and gas pedal position work in tandem to enable different driving experiences. Users can, depending on the selected driving program or individual settings, enjoy a different and completely unique driving experience without losing control of the vehicle.
Active driver assistance systems ensure safety for all road users today
Today, many components already work in tandem reliably to provide a high level of safety through many 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 detects 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 parked, the Exit Warning function alerts occupants 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 recognized in the relevant danger zone.
- Active Emergency Stop Assist brakes the vehicle to a standstill in its own lane if it recognizes that the driver is no longer responding to the traffic situation for a longer period.
- Active Brake Assist registers 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 as the moose test incident that took place 25 years ago. When Mercedes-Benz introduced the system in 2002, it was a disruptive innovation: this was the first time that active elements helped support passive protective measures in order to improve outcomes 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.
Focus on protection for back-seat passengers
In recent years, Mercedes-Benz was able to further increase the safety of back-seat passengers. Among other improvements, it is important to mention the belt tensioners for the rear seats, the side airbags, and the window bags. Introduced by Mercedes-Benz in the S-Class in 2020, the first frontal airbag for back-seat passengers reflects the frequent use of the car as a chauffeured vehicle: the feature increases safety for adult passengers while also taking into account concerns about child safety.
Integral Safety: A holistic philosophy from Mercedes-Benz
When it comes to vehicle development, Mercedes-Benz has been committed to its holistic philosophy of ‘Integral Safety’ for many years. As early as the late 1990s, the company first classified the support of its safety systems in four phases. This approach combines elements of active and passive safety in order to achieve the highest possible level of safety.
- Phase 1: Assistance while driving. This phase includes elements such as handling, good braking systems, precise steering, good visibility even at night as well as all systems necessary for maintaining driver-fitness safety such as air conditioning or comfortable seats. In addition, there are the extensive driver assistance systems and intelligent lighting equipment.
- Phase 2: Preparation for potential accidents. The systems involved in this phase are capable of recognizing more and more critical situations and initiating targeted actions that can prevent accidents or reduce their severity. Examples of involved systems include the driver assistance systems, emergency braking systems and PRE-SAFE equipment.
- Phase 3: Protection in the event of an accident. This phase encompasses all elements that improve accident outcomes, from the car body with its rigid passenger cell and crumple zones to the seat belts, belt tensioners and multiple airbags.
- Phase 4: Assistance after an accident. This phase pertains to measures taken after an accident occurs, which range from automatic emergency calls, switching on the hazard lights and unlocking the doors to quickly ventilating the interior after the airbag has been deployed.
Central software as a new development focus
Mercedes-Benz is currently looking at an 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 minimize 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 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,’ says Paul Dick, Head of Vehicle Safety at Mercedes-Benz Group AG.
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 –the development team ensures that appropriate technology ensures a comparable degree of protection. This has been proven by tests conducted by independent organizations. Euro NCAP (European New Car Assessment Program) has distinguished the Mercedes EQS twice, awarding the car ‘Best in Class’ in 2021 in the categories ‘Premium Class’ and ‘Pure Electric’. 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.
A multi-stage high-voltage safety concept
It goes without saying that we pay special attention to the live components in electric cars. To prevent the risk of electric shock and high-energy short circuits, we have developed a multi-stage high-voltage (HV) safety concept that comprises seven essential elements. In addition to the battery, HV components comprise all components with a voltage in excess of 60 volts. If a vehicle’s sensors detect a dangerous collision, the pyorofuse safety system automatically powers down the HV system.
This protection concept provides a high level of safety while driving and charging as well as during and after a crash. The battery housing and the vehicle structure are matched up to ensure that all internal Mercedes-Benz safety standards and legal requirements are met. The designers have also ensured that all HV elements are placed in crash-protected areas of the vehicle as far as possible. To this end, they were able to draw on 50 years’ worth of findings and data from thousands of real- world accidents collected through accident research.
Ongoing innovation through analysis of real-world accidents
The Group’s own Accident Research unit, which has scientifically analyzed and reconstructed more than 5,000 real-world accidents since its foundation in 1969, provides designers and developers with valuable findings. The goal: to understand how accidents occur, how collisions affect car occupants and how they could have been prevented. Since accident patterns are different all over the world, time and again Mercedes-Benz has to adapt. For example, the Accident Research unit has also set up teams in China and India that can use augmented reality to quickly exchange information with the teams in Sindelfingen. These teams are checking and evaluating the Group’s ‘real-life strategy’, i.e. in actual accidents, around the world. In many countries, there are more traffic fatalities outside than inside vehicles, so the developers at Mercedes-Benz are also looking at the question of how to increase protection for pedestrians, cyclists, motorcyclists, rickshaw drivers or e- scooter users in the future.
Saving lives with data and identifying potential high-risk locations
A new approach is helping Mercedes-Benz achieve its goals: the analysis of vehicle data that can save lives. As one of the first European cities, London is pairing with Mercedes-Benz to research how anonymized data from vehicles with the star can help make the city’s roads safer for everyone. The ‘Mercedes-Benz Road Safety Dashboard’ was developed for this purpose. The digital tool has the potential to identify higher risk urban locations prior to an incident taking place. Individual alerts at the exact GPS location are used to automatically identify potential collision spots, which are immediately analyzed using an intelligent algorithm. This only ever happens if the driver has given their consent to the processing of anonymized vehicle data.
The ‘Mercedes-Benz Road Safety Dashboard’ shows responsible local parties possible danger spots for collisions on a road map: easy to use, user-friendly and with lots of information for target- oriented action. The focus is primarily on the most vulnerable, unprotected road users: pedestrians and cyclists. Therefore, risky situations in zones around schools, nurseries and universities are prioritized in London.
A comparable project has also been launched in the Netherlands, surveying all motorways and rural country roads. The aim is to identify dangerous stretches of road and to make them safer through recommended construction measures. And a pilot project in the Limburg region even detects sudden black ice in winter, warning other vehicles and the traffic control centre.