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Published on: September 21, 2017
Contact-Triggered Active Bonnet System for Pedestrian Head Injury Mitigation: Multibody Modelling and Experimental
Alexandru Ionut Radu1, Bogdan Adrian Tolea2, Horia Beles2
1Department of Automotive and Transport, Faculty of Mechanical Engineering, Transilvania University of Brașov, 500036 Brașov, Romania.
Sensors (Basel, Switzerland)
|August 13, 2026
Summary
Active bonnet systems reduce pedestrian head injuries in vehicle collisions by creating space during impact. Their effectiveness in mitigating head acceleration and injury severity depends on impact conditions and pedestrian trajectory.
Area of Science:
- Automotive Safety Engineering
- Biomechanics
- Computational Dynamics
Background:
- Vehicle-pedestrian collisions are a major cause of severe head injuries.
- Active bonnet systems aim to reduce injury severity by increasing clearance between the hood and engine.
- System effectiveness relies on rapid impact detection and timely deployment.
Purpose of the Study:
- To analyze pedestrian impact dynamics.
- To evaluate the performance of a contact-triggered active bonnet system.
- To assess the influence of impact configuration and pedestrian trajectory on head injury severity.
Main Methods:
- Developed a simulation model in MATLAB/Simulink and Simscape Multibody.
- Reproduced pedestrian-vehicle interaction using spatial contact force models.
- Validated the model with controlled pedestrian impact tests (17 km/h and 29 km/h).
Main Results:
- The active bonnet system demonstrated a reduction in peak head acceleration and Head Injury Criterion (HIC15) values.
- Simulations confirmed the system's protective effect under various impact conditions.
- Effectiveness was influenced by pedestrian positioning and head trajectory relative to the vehicle.
Conclusions:
- The contact-triggered active bonnet system can effectively mitigate pedestrian head injuries.
- Optimal protection is achieved when head impacts occur within the bonnet's deformable region.
- Further research should consider pedestrian kinematics and vehicle front-end geometry for enhanced system design.
