Pedestrian impacts currently account for over 900 deaths and over 40,000 casualties each year in Britain. The chance of death or serious long-term disability increases greatly with impact speed. At 20mile/h (32km/h) the probability of killing or seriously injuring a child is 20%, but this rises to 80% at 40mile/h (64 km/h).
Advanced Active Adaptive Secondary Safety systems were studied, which comprised sensors to identify a pedestrian within the vicinity of a vehicle and determine the likelihood of an impact and airbags fitted to various parts of the vehicle front to protect the pedestrian in an impact. The research comprised modelling in MADYMO followed by impact testing. Sensor systems were investigated in parallel.
Impacts between a 50th percentile adult dummy and a saloon car and a Sports Utility Vehicle (SUV) were simulated in MADYMO at two impact velocities; 25mile/h (40km/h) and 30mile/h (48km/h). The vehicle models were modified, where possible, to ensure likely compliance with the proposed EEVC pedestrian protection limits. These models and the resulting potential injuries were used as the basis for comparison with the active systems. The simulation results for active systems showed that the potential for injury reduction was substantial. For example HIC was reduced from 1062 to 113 in an impact of 25mile/h (40km/h) with the saloon car. These results were used to select the system for experimental tests.
Testing consisted of impacts to an instrumented adult OPAT dummy and a child OPAT dummy with vehicles and conditions similar to those modelled and at the same velocities. Injury potential from the impacts was assessed. Results were similar to the simulation predictions and showed that a substantial reduction in lower limb and head injury may be possible with airbags mounted on the bumper and the bonnet. The paper describes the research including a brief resume of the sensor development.