In 1998, EEVC proposed the test procedure to assess the protection vehicle provide a lower extremity of a pedestrian during the collision, since then a rigid-bone type of Legform impactor is used to evaluate the pedestrian protection.
However, due to improve the biofidelity and repeatability of rigid-bone type. JAMA/JARI proposed a flexible type of Legform impactor which is biofidelic flexible design and it has been agreed and adopted as GTR model In 2009.
Since then, JASTI started development of flexible legform impactor in accordance with final GTR specification and design in 2013.
After the several evaluation and outside assessment of proto type JASTI developed. JASTI has completed the proto type stage and Flexible Legform Impactor was released to the market in 2016onward as commercial products of lower leg impactor.
This Flex-PLI has high biofidelity, especially to its center bone part which is molded with glass fiber reinforced plastic with thin wraps, that provides the flexibility and stiffness with high reliability, repeatability and durability. It is equipped four full bridge strain gages in Tibia and three full bridge strain gages in Femure with small power amplifiers on bone core to measure the bending moment in each.
The Knee part are composed of sharply machined aluminum condyles and jointed by steel cables and springs, which replicates the ligament in the real human knee.
Four sets of string potentiometers are located Inside of Knee condyle to measue LCL, MCL, ACL and PCL keeping the DAS space to be buit-in, whichh was designed to make the teat easier to handle in free flight motion.
| Description | Dimension(mm) w/o flesh system |
|---|---|
| Leg Length | 982.0 |
| Femur Length to Knee Joint | 433.0 |
| Tibia Length to Knee Joint | 495.0 |
| Knee Width | 118.0 |
| Leg Width | 84.0 |
| Knee Depth | 108.0 |
| Leg Depth | 90.0 |
| Femur Length from Top of Knee Assembly | 339.0 |
| Tibia Length from Bottom of Knee Assembly | 404.0 |
Assembly Weight: Total Weight:13.2kgs±0.7kgs
Standard Instrumentation:| Location | Description | Channels |
|---|---|---|
| Femur Bone | Load Cell (Strain gage) | Mx,3 Channels |
| Tibia Bone | Load Cell (Strain gage) | Mx,4 Channels |
| Knee | Displacement/String Potentiometer | D,MCL Ligament D,ACL Ligament D,PCL Ligament D,LCL Ligament |
| Lower Knee | Uniaxial Accelerometer | Ay |
Calibration Test：
Static Bent Test
Static Bent test are to apply the center of Tibia Bone, Femur Bon, and Knee block by Autograph.
The load is by the ratio of 400N、10-100mm/min applied onto Bone core which pass the requested corridors as Deflexion and Moment.
The left picture is to apply the load onto Tibia assembly by the Autograph.
Tibia Bone Bent Moment Calibration Test and Jig attachment
Knee Joint Static Calibration Test
The test has been done to eliminate the friction which cause the minor difference with special jigs as shown in left picture.
Neoplan sheet has been adopted as the real impact test. condition.
To measure Ligament (MCL/ACL/PCL/LCL) elongation.
Pendulum Impact Calibration Test
Pendulum Impact Calibration Test
The test has been done by free fall as shown left picture.
Dynamic Pendulum test is to release the Pendulum as free fall to measure inside the Tibia and Femur bones bending moment.
The each bones should meet the requested corridor (Nm). Knee Joint extention should be measured at the same time as Total Pendulum Impact Calibration test.
