Design of a pedestrian protection airbag system using experiments

Abstract

The safety of vehicles has been studied in the past on the basis of the safety of passengers. Recently, pedestrian safety has also attracted attention. The pedestrian protection performance of vehicles has gradually improved but is still not sufficiently good. Devices such as the pop-up hood and the pedestrian protection airbag system are generally used to protect pedestrians. Since these devices are relatively newer than other parts of an automobile, a standard design process has not yet been rigorously established. There have been studies that demonstrated how to determine the design parameters of the devices using computer simulations. In this research, a novel design process for a pedestrian protection airbag is proposed, which utilizes the results of the experiments. Some parameters of the pedestrian protection airbag system, which cannot be determined by simulations, are selected and obtained using experiments. They are the folding method of the airbag, the height type of the airbag and the inflator type. The design results using simulations are incorporated in the initial design of the proposed process. The experimental facilities are prepared on the basis of a mid-sized passenger vehicle, and the headform tests are performed according to the protocol of the European New Car Assessment Programme test. The proposed design process selects the rolling and folding method, the small height type and the bottom spurt inflator type. The resultant design is evaluated and analysed using experiments, and it is found to be satisfactory.

An experimental comparison of the pedestrian safety performances of a spring actuator and a pyrotechnic actuator for deploying an active hood lift system

“…Recently, because of the increasing need for pedestrian safety and strict regulations, safety systems to prevent pedestrian accidents and to reduce pedestrian injuries have been greatly improved in vehicle systems. [1][2][3][4] So far, it has been reported that most pedestrian fatalities occur because of injuries to the head, which are normally caused from collision with hard structures beneath the vehicle's hood, such as the engine. 5 With regard to this issue, an advanced safety system protects pedestrians using an active hood lift system (AHLS) that lifts the hood of an automobile in a pedestrian accident.…”

Development of a new recline mechanism in order to reduce the “whiplash” effect using a virtual model

“…The head injury risk is assessed using head injury criteria (HIC) criteria on a time interval of 36 ms for the occupant, and 15 ms for the pedestrian. 18–20…”

“…The head injury risk is assessed using head injury criteria (HIC) criteria on a time interval of 36 ms for the occupant, and 15 ms for the pedestrian. [18][19][20] In this case study, there were two sled tests used: at the velocity of 10 km/h and at 16 km/h. Sled velocities represent the EES velocities.…”

Shock mitigation of pedestrians from sports utility vehicles impact using active pop-up and extended hood mechanisms: experimental work

“…Recently, due to the increasing requirement for pedestrian safety with strict regulations, various kinds of safety mechanisms which prevent pedestrian accidents or reduce pedestrian injuries have been extensively developed in vehicle systems. [1][2][3][4][5][6] Thus far, it has been concluded that most pedestrian fatalities are caused from injuries to the head, which are normally caused by collision with rigid structures beneath the vehicle hood or the front area of windshield. [7][8][9] In regard to this matter, one of the most advanced safety mechanisms to protect pedestrians is the pop-up hood mechanism that lifts the hood of the vehicle during collision accident.…”

“…9,34,35 Recently, Lim et al and Yang et al proposed the cowl airbag system to protect pedestrians from windshield front impact. 4,5 However, it has been reported that the deployment time of cowl airbags is close to 110 ms. Since the head impact time in the case of sedan collision is 130-140 ms, this is sufficient when applied to a low vehicle.…”