Key technical terms

May 20, 2019

Active safety: Attributes and measures that help to prevent accidents. The distinction from →passive safety was formulated by the Mercedes-Benz engineers Hans Scherenberg and Béla Barényi in 1966.

Automated cars: Guided by the SAE J3016 standard, the Association of the German Automobile Industry (VDA) defines six stages of automated driving.

  • Stage 0: no automation. The driver performs all driving functions.
  • Stage 1: assisted - driving with assistance systems. The driver always has full control of the vehicle, but can call on support from driving assistance systems for longitudinal or lateral guidance, e.g. parking aids or proximity cruise control.
  • Stage 2: semi-automated. The driver always has full control of the vehicle, but can call on support from driving assistance systems for longitudinal and lateral guidance.
  • Stage 3: highly automated. The automated driving function takes over certain driving functions. A driver is however still necessary. The driver must be ready to take control at all times when prompted to do so by the vehicle.
  • Stage 4: fully automated. Under certain circumstances (e.g. selected roads, not in any weather) the vehicle can manage all traffic situations by itself.      
  • Stage 5: driverless. The vehicle can perform all driving functions by itself in all circumstances.  

This classification was developed by SAE International (formerly Society of Automotive Engineers), a non profit-making organisation for technology and science. The classification was adjusted for Germany by the Association of the German Automobile Industry (VDA), an association of more than 600 companies in the automobile industry with production in Germany.

Car-to-X communication: Extends the horizon of previous vehicle sensors by the exchange of information with other vehicles, and between vehicles and the traffic infrastructure. Car-to-X technology allows information about potential road traffic hazards to be passed on to drivers at an early stage, so that they are able to prepare for them and critical situations do not arise in the first place. The first generation entered series production in the 213-series E-Class - it was initially an option in combination with the Drive Kit Plus in the A-Class in 2013, and entered series production in the 213-series E-Class in 2016.

Belt slack: If the belt does not fit closely to the occupant's body, the latter can be moved forward during a collision before the belt can exert major restraining forces. This increases the risk of collision with areas of the vehicle interior. Moreover, the deceleration forces of the impact act on the passenger at a later stage, and therefore more severely.

Integral safety: The term used for a collective view of the two safety aspects, as well as rescue measures, with the aim of improving protection for all road users. In 1966 the two Mercedes-Benz safety experts Béla Barényi and Hans Scherenberg formulated the division into →active and →passive safety. Thanks to the integral safety concept of Mercedes-Benz, both areas now intermesh seamlessly. This is because a new era in vehicle safety began in der Mercedes-Benz S-Class with PRE-SAFE® in 2002: for the first time, the technology was able to recognise an impending accident in advance and prepare passengers for a possible collision. Moreover, Mercedes-Benz follows a philosophy of →Real Life Safety.

i-Size: Standard for child seats based on the EU safety directive R129. Key requirements:

  • Improved protection during a side or frontal impact, more protection for the head/neck area
  • Children aged up to 15 months must be facing the rear when driving
  • Use of the ISOFIX system is mandatory, reducing the risk of incorrect installation
  • i-Size child seats are compatible with all i-Size cars and almost all ISOFIX cars
  • Lengths indicated in centimetres simplify the choice of the right child seat, and replace the previous weight indications in kg. This is to counter a premature upgrade to the next seat size.

ISOFIX: internationally standardised attachment system for child seats acc. to ISO 13216. A rigid connection is made between the vehicle body and the child seat. The car is equipped with ISOFIX anchorages located between the seatback and seat cushion of the car seat. The ISOFIX connectors of the child seat or a base station are engaged in these. Additional protection is provided by Top Tether (upper restraining belt) and/or a supporting leg. The key advantages of ISOFIX are ease of installation, which lowers the risk of incorrect fitting, and the rigid connection to the vehicle.

Driver-fitness safety (or performance-enhancing comfort): A mentally and physically fit driver has more performance reserves to react quickly and correctly in critical traffic situations. As a development objective, driver-fitness safety covers many areas:

  • NVH configuration (noise, vibration and harshness) of the body, suspension and drive system
  • Dimensional concept of the interior
  • Easy, ergonomic operation,
  • All aspects of climatic and seating comfort
  • Intelligent assistance systems.

Lidar: Abbreviation for "Light Detection and Ranging". The only sensor able to measure in 3D with high precision (distance, position, height), measuring the time taken by a pulsed laser beam to be reflected. In the ESF, the lidar housings are also used to accommodate signal LEDs.

MBUX – Mercedes-Benz User Experience: stands for a new infotainment system that focusses on the user (UX: user experience). A unique feature of this system is its ability to learn thanks to artificial intelligence. MBUX celebrated its premiere in 2018, in the new A‑Class, and is constantly developed further.

Mercedes-Benz Emergency Call: dependable aid whose functions go beyond those of the legally prescribed eCall. Mercedes-Benz Emergency Call is activated either automatically or by the driver pressing the button in the interior. Manual activation serves to report an accident which the driver has observed or to call for help if an occupant of the vehicle is experiencing health problems. The emergency call function is triggered automatically after deployment of one of the pyrotechnic belt tensioners or an airbag in the car. The vehicle then establishes a voice connection with the Mercedes-Benz emergency call centre. If the emergency call centre does not receive a response, it will immediately alert the nearest rescue service.

Mercedes me: digital mobility and service brand. Mercedes me allows individualised access to the world of Mercedes-Benz. This goes well beyond the car itself, offering an integrated system of products, services and innovations.

Passive safety: Measures to mitigate the consequences of accidents. With the introduction of the preventive occupant protection system →PRE-SAFE® (2002), the distinction from →active safety became less clear, as PRE-SAFE® uses active safety elements to protect passengers.

PRE-SAFE®: preventive occupant protection system. PRE-SAFE® activates preventive occupant protection measures when signs of an impending accident are recognised, so that e.g. belts and airbags are best able to perform their protective function during a collision. This early accident recognition is possible because as a preventive occupant protection system, PRE-SAFE® is networked with active safety elements such as Brake Assist and the Electronic Stability Program ESP®, as well as with other driving assistance systems whose sensors recognise critical driving and traffic situations and are able to send corresponding information to the electronic control units within milliseconds. These extensive sensor data are also used by PRE-SAFE®.

Real life safety: This safety philosophy not only includes simulations and crash tests, legal requirements and published ratings. On the basis of what actually happens in accidents, it develops strict in-house safety regulations that in many cases go well beyond the legal requirements or rating requirements. The key is accident research: for 50 years, in-house experts have examined serious accidents involving current Mercedes-Benz vehicles. The aim is to learn from them, and incorporate the findings into the designs of new models.

Reboard child seat: rear-facing child seats. Especially in frontal collisions, these can give better protection to infants and small children by distributing the forces more evenly over a larger area of the child's body, which also reduces the loads on the head and neck.

Sensor fusion: The vehicle's surroundings are registered by sensors (ultrasound, radar, cameras, lidar). During sensor fusion, all the data are brought together, evaluated and adequately interpreted.