Proposal from the EDR/DSSAD informal group to amend the text of their proposal for guidelines on EDR data elements for heavy vehicles.

Proposal from the EDR/DSSAD informal group to revise and clarify the acceleration data accuracy for the lateral and longitudinal acceleration data elements and introduce procedures to verify compliance of the acceleration data with the acceleration sensor accuracy specifications. The proposal is based on the following considerations:

1. There are multiple ways in which the acceleration data accuracy tolerance can be applied. This can potentially lead to different interpretations when applied by type-approval authorities. For clarity, the accuracy tolerance is specified as “+/- 10 per cent of the full range of the accelerometer used in the ECU containing the EDR function”.
2. The proposal enables a component test (including a time-shifting algorithm to address differences in sampling rates between an EDR and bench test) to address difficulties in verifying acceleration sensor accuracy under vehicle crash tests.
3. The proposal adds a footnote to clarify that the manufacturer has discretion (option) over the format for lateral acceleration data in rollover event because such data is not recorded using the lateral airbag deployment sensors.
4. The proposal adds Annex 6 on the verification procedure with an illustration of the tolerance corridor for lateral and longitudinal acceleration.