Accounting for a stagnation of pedestrian fatality numbers alongside increasing injury severities, including lower extremities, the SENIORS project developed and evaluated a pedestrian torso surrogate for the lower legform impactor FlexPLI for incorporation in improved test and assessment procedures with focus on biofidelity and injury assessment ability. Based on APROSYS results, this next generation upper body mass (UBM) is attached via flexible rubber element to the FlexPLI, providing for time lag of the pedestrian’s torso and hip joint rotation observed during vehicle-to-pedestrian impacts.

While human injury risk functions were analyzed, human body model (HBM) and FlexPLI-UBM simulations were correlated for a femur transfer function. FlexPLI vs. FlexPLI-UBM correlation studies contributed to knee and tibia assessment. Performance limits were proposed for revised Euro NCAP assessment procedures within the framework of a new rating scheme. Experimental tests served for evaluation.

The UBM significantly improves the impactor biofidelity and lower legform test and assessment procedures, including vehicles with distinctively angled outboard areas and high frontends. FlexPLI-UBM tests confirm good correlations with the HBM. For the first time, pedestrian lower extremity injury assessment is based on one unique test, replacing the lower (or upper) legform to bumper test as well as the test with the upper legform impactor to wrap around distance line 775.