According to the Federal Statistical Office, almost 11,000 children suffered accidents as car passengers in Germany in 2017. With PRE-SAFE® Child in the ESF 2019, Mercedes-Benz now shows how child safety can be further improved. With this child seat with PRE-SAFE® functions, the seat belts are preventively tensioned before a crash and side impact protection elements are extended. Monitoring of seat installation and the child's vital signs are other functions integrated into the seat.
In 2002 Mercedes-Benz began a new era in vehicle safety with the preventive occupant protection system PRE-SAFE®, by integrating active and passive safety functions. PRE-SAFE® is able to activate preventive protection measures for car passengers. The aim is to prepare the occupants and the car for an impending impact, so that e.g. the seat belts and airbags can develop their best protective effect.
In the ESF 2019, small children now also benefit from PRE-SAFE® protection and side impact protection by elements integrated into the sides which extend automatically in a PRE-SAFE® situation.
The child seat is networked with the vehicle by radio. When the vehicle sensors recognise a manoeuvre relevant for PRE-SAFE® (for example a skid to the side), a signal is sent to the child seat which triggers the corresponding protective functions.
Within milliseconds the belts of the child seat are tensioned and the side impact protection element is extended by operating solenoid switches. A battery integrated into the child seat supplies the power.
The great advantage of this system is that thanks to the tensioned belt, the child is more firmly and accurately fixed in the seat while belt slack is reduced. The loads acting on the child during an impact are considerably reduced. The side impact protection elements also follow this approach.
The five-point belt system of the child seat is mechanically pretensioned. This is how this is done: the child seat can be rotated, so the child can be lifted in or out of the seat when facing the door. The subsequent 90° rotation to position the seat either in or against the direction of travel pretensions the system. The generated spring force is used to tension the seat-integrated belt as soon as the vehicle recognises a situation justifying PRE-SAFE® intervention. The reversible system is pretensioned again when the child seat is next used and rotated.
A similar principle is used for the side impact protection elements integrated into the sides of the seat, which extend automatically in a PRE-SAFE® situation. This always happens on the side next to the door, irrespective of whether the seat is facing forwards or backwards. The system is mechanically pretensioned by manually pressing the protective element into the seat. This also keeps them out of the way when not in use.
Installation monitoring: reduces the risk of incorrect operation
A study published by insurance company accident researchers (UDV) in October 2018 found that almost one in two child seats are not correctly installed in the car. 48 percent of the 1042 children examined were not correctly secured in their child seats. The main causes were seat installation errors and incorrect belt fastening.
The aim of the installation monitoring function in the networked child seat of the ESF 2019 is to prevent such mistakes. Eight symbols directly on the seat, and corresponding three-dimensional animations in the media display of MBUX, provide self-explanatory guidance through the individual installation steps and signal that they have been done correctly.
Monitoring vital signs: reduces the risk of distraction
i-Size is an improved standard for child seats. In line with the safety directive ECE R129, i-Size child seats can be attached to the Isofix anchorages in a rearward-facing position. This means that children up to the age of 15 months can be carried against the direction of travel. The advantage of these so-called reboard child seats is that during a frontal impact, the head and neck of a small child are subjected to lower loads than in a forward-facing child seat.
However, the rear-facing position of these seats also has the disadvantage that the child cannot be observed from the driver's seat. So that the driver is not distracted from the traffic situation to check how the child on the rear seat is faring, the networked child seat of the ESF 2019 monitors its temperature, pulse, breathing and state of wakefulness. During the journey, animations (e.g. "All OK" or "Child waking up") in the media display report the child's condition. The display is intuitive to understand, and the system requires no additional mirrors in the interior.
The child seat is additionally provided with a camera. When stationary, e.g. at traffic lights, it is possible to briefly switch over to a live video image in the media display. If required, and with the help of the Mercedes me App, all the vital signs can also be transferred to a smartphone during a journey, e.g. to inform the other parent about the child's condition.