1. Japan Automobile Standards Internationalization Center (JASIC)
IWG-DPPS/3/04
Study of Application of Upper Legform to TRT/Lower Threshold Deployment Impactor Test
IWG-DPPS
3rd meeting, 10 Dec. 2018
Japan Automobile Standards Internationalization Center (JASIC)

2. Background
Regarding the verification performance test at the lower threshold speed using the Flex impactor, Japan is concerned that it would be difficult to do the test correctly at a speed lower than the speed specified in the regulation, i.e., 40 km/h.
With no data to verify PDI2 in Japan, we can not determine whether or not it can be adopted in regulation test. We think that verification is necessary to adopt PDI2 as a regulation testing tool. Hence, we consider that the early introduction of PDI2 into the GTR is difficult.
For the verification performance test , if contact forces or bumper deflections in vehicle-to-impactor impacts are equivalent to those in vehicle-to-pedestrian impacts, then the impactor test can simulate the pedestrian impact accidents.
When it comes to considering appropriate impactor other than Flex and PDI2, the upper legform impactor is also available, which is a verified tool in the regulation. In addition, since the upper legform impactor moves only in the slides guided rail, it should be possible to perform the test at speeds lower than the speed specified in the regulation.
To verify whether it is possible to use the upper legform impactor in the lower-speed verification performance test, we compared the contact forces and bumper deflections between vehicle-to-pedestrian impacts and impact tests using the upper legform impactor by numerical simulation.

3. Methodology
HBM: 5th Female and 6 YO (50th and 95th males need to be investigated in a future study)
Car: Actual car model representing a sedan
Impact speed: 25 km/h (estimated lower threshold of sensing)
Mass of upper legform: 9.5 kg (lower limit specified in user manual)
Sensing parameters: contact force, bumper deflection
5th Female
6 YO
Upper legform
Impact speed:
25 km/h
Impact speed:
25 km/h
Measuring point of bumper deflection (car center)

4. Contact Force – Small Sedan
Comparison between 5th Female and 6 YO
Comparison between Upper Legform and HTD
C6Y 25 km/h
Upper legform
10 km/h
20 km/h
C6Y 25 km/h
AF05 25 km/h
HTD: C6Y
Upper legform impact speed equivalent to HTD: km/h
HTD can be represented by upper legform impact at impact speed between km/h

5. Bumper Deflection – Small Sedan
Comparison between 5th Female and 6 YO
Comparison between Upper Legform and HTD
C6Y 25 km/h
AF05 25 km/h
AF05 25 km/h
Upper legform
10 km/h
20 km/h
HTD: 5th Female
Upper legform impact speed equivalent to HTD: km/h
HTD can be represented by upper legform impact at impact speed between km/h

6. Summary Results of CAE analysis Ongoing study
The range of impact speed in which HTD can be represented by upper legform was km/h for both sensing parameters (out of range of test apparatus).
Ongoing study
Add velocity change to sensing parameters
Other car models (SUV, mini-van, etc.)
Smaller interval of upper legform test speed
Consideration of procedure for impact below 20 km/h
Verification of feasibility of lower-speed test using the upper legform impactor