Pedestrian protection sensors
For the pedestrian protection system, the following versions are described with regard to the number and function of the pedestrian protection sensors:
- Pedestrian protection with 1 pedestrian protection sensor (optical fibre)
- Pedestrian protection with 3 pedestrian protection sensors (acceleration sensors)
- Pedestrian protection with 2 pedestrian protection sensors (optical fibre and acceleration sensor)
- Pedestrian protection with 2 pedestrian protection sensors (pressure hose and pressure sensors)
Pedestrian protection with 1 pedestrian protection sensor (optical fibre)
An optical fibre is integrated in the bumper. The optical fibre is a constituent part of the pedestrian protection sensor. Through the sensor, the light in the optical fibre is sent out at one side of the bumper to the other end of the bumper and back to the sensor again via a loop.
A force acting on the optical fibre alters this in its structure. This causes the light in the optical fibre to be attenuated. The acting force is proportional to the light attenuation. A characteristic signal is thus generated by the differing light attenuation in dependence on the mass and rigidity of the colliding object. This signal is recorded in the evaluation electronics of the sensor and transmitted via a data line to the Crash Safety Module (ACSM).
| Item | Explanation |
|---|---|
| 1 | Pedestrian protection sensor with optical fibre |
| 2 | Loop |
| 3 | Electronic component |
Pedestrian protection sensor with 3 pedestrian protection sensors (acceleration sensors)
A number of pedestrian protection sensors are installed in the bumper. The right pedestrian protection sensor is supplemented by the center pedestrian protection sensor and the left pedestrian protection sensor. All sensors are common parts.
The pedestrian protection sensor is an acceleration sensor. The acceleration values picked up by the micro-mechanical acceleration sensor are converted into digital signals and sent cyclically to the crash safety module (ACSM).
| Item | Explanation |
|---|---|
| 1 | Pedestrian protection sensor, right |
| 2 | Pedestrian protection sensor, center |
| 3 | Pedestrian protection sensor, left |
| 4 | Pedestrian protection sensor |
| 5 | two-pin plug connection |
Pedestrian protection with 2 pedestrian protection sensors (optical fibre and acceleration sensor)
One optical fibre and one acceleration sensor are installed in the bumper. The acceleration sensor is installed in the center at the bumper.
| Item | Explanation |
|---|---|
| 1 | Pedestrian protection sensor with optical fibre |
| 2 | Loop |
| 3 | two-pin plug connection |
| 4 | Pedestrian protection sensor (acceleration sensor) |
| 5 | Electronic component |
Pedestrian protection with 2 pedestrian protection sensors (pressure hose and pressure sensors)
There are 2 pressure sensors installed in the bumper; the pressure sensors are connected to each other via a pressure hose. The pressure hose is a constituent part of the pedestrian protection sensor.
A force acting on the pressure hose alters this in its structure. The displaced air volume causes an increase in pressure at both pressure sensors.
Each pressure sensor transmits the pressure signal, which is dependent on the mass and rigidity of the impacting object, via a data line to the Crash Safety Module (ACSM). The characteristics of the signal is analyzed in the Crash Safety Module (ACSM) and a decision is made as to whether to trigger, if necessary.
| Item | Explanation |
|---|---|
| 1 | Pressure hose |
| 2 | Pedestrian protection sensor, left |
| 3 | Pedestrian protection sensor, right |
| 4 | Pedestrian protection sensor (pressure sensor) |
| 5 | two-pin plug connection |