1. Conditions for the Sensing Width for
Deployable Systems
12 March 2019

2. Content
Background
Boundary Conditions
Proposal
Summary

3. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Background:
An agreement on the required sensing width to ensure adequate detection of pedestrians is sought after.
Different aspects for the determination of the Sensing Width need to be considered.
Limitations on impactors need to be taken into account.
Several proposals have been discussed so far.
There is a growing concern in some Contracting Parties of vehicle owners being exposed to false activation of deployable systems.
False activation needs to be avoided as it would result in a lower customer acceptance, based on higher cost of ownership.
In order to ensure due impact signal discrimination, sensing systems have a limitation in the minimum activation thresholds to work as intended in the field.

4. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Boundary Conditions:
A balanced proposal should be based on:
Benefit in real world accident scenarios
Technology neutrality
Relation to the vehicle front end contact zone
Technical feasibility
Robustness of the method for reproducibility in the execution by tests labs worldwide.
Stability against inappropriate design influence on the marking should be featured.
Glancing blow conditions of sensing as well as head impactors should be avoided.
Special conditions like a moveable bonnet top being more narrow than the front surface should be considered.

5. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Proposal:
To increase reproducibility it is recommended to use a known marking reference.
To reflect the leg as well as the head contact part of the impact, neither of the two test areas are appropriate to individually determine the adequate sensing width.
Therefore it is suggested to relate to the Corner Reference Point of the vehicle (CRP).
The CRP truly reflects the transition of the front to the side of the vehicle.
The CRP relates to the leg as well as the head contact part of the pedestrian impact.
However, some additional points need to be considered regarding robustness, reproducibility and narrow bonnets.

6. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Proposal:
A combination of the Corner Reference Point of the vehicle (CRP) and boundaries of the head impact zone are suggested. …
UN-R , E/ECE/324/Rev.2/Add.126/Rev.2-E/ECE/TRANS/505/Rev.2/Add.126/Rev.2

7. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Proposal:
The Sensing Width of the vehicle should be based on the Corner Reference Point, the required minimum being at each side 82.5 mm inside the reference points, projected in the transversal vertical plane on the vehicle.
In case of the deploying part (i.e. bonnet) being narrower than described above, at least the complete width of this respective part should be covered by the sensing system. However, to avoid glancing blows and to relate to the impact situation, the offset of half of the head impactor diameter should be considered.
CRP -82.5mm
projected in
the transverse
vertical plane
UN-R , E/ECE/324/Rev.2/Add.126/Rev.2-E/ECE/TRANS/505/Rev.2/Add.126/Rev.2

8. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Proposal:
If OEM specifies the sensing width to be narrower than CRP -82.5mm, tests in the head impact zone will be conducted on the un-deployed system for areas outside of this particular sensing zone.
The CRP should be measured in the non-deployed condition as this represents the state at the moment of the pedestrian impact.
As the CRP is subject to potential multi-contacts, CAD reference by OEMs is recommended.
CRP -82.5mm
projected in
the transverse
vertical plane
UN-R , E/ECE/324/Rev.2/Add.126/Rev.2-E/ECE/TRANS/505/Rev.2/Add.126/Rev.2

9. IWG-DPPS: Proposal
Conditions for the Sensing Width for Deployable Systems
Summary:
The proposal relates to an existing pedestrian marking reference.
The CRP is the best reference mark that truly reflects the transition of the front to the side of the vehicle and relates to the leg as well as the head contact part of the pedestrian impact.
Consideration of limitations (scope and feasibility) is given by the offset of 82.5mm to the CRP.
The concept reflects:
Benefit in real world accident scenarios
Technology neutrality
Relation to the vehicle front end contact zone
Technical feasibility
Robustness of the method
CRP -82.5mm
projected in
the transverse
vertical plane
UN-R , E/ECE/324/Rev.2/Add.126/Rev.2-E/ECE/TRANS/505/Rev.2/Add.126/Rev.2