Abstract: In traffic accidents, pedestrians' heads hit hard spots under the engine canopy, causing many casualties. In view of this situation, the intelligent ejection device of the engine canopy designed by the system is composed of ultrasonic radar, engine canopy, front cover front rotating shaft, front axle switch lock, rear axle rotating shaft, rear axle switch lock, air spring and other parts. In the event of a pedestrian collision, the control system controls the rear axle switch lock to open, the front axle switch lock to close, and the air spring to bounce up the rear end of the engine canopy, which cushions the pedestrians from impacting, avoiding the pedestrian's head from hitting the hard point under the engine and reducing casualties. After the release of the air spring, it can be pressurized again, so that the engine canopy intelligent bounce device can be reused, the maintenance cost is low, the pedestrian distance is detected by ultrasonic radar, and the collision analysis is carried out in combination with the speed of the car, which can predict the collision in advance and play a more timely protection effect.

Key words: Ultrasonic radar; Pedestrian detection; Air springs; Predictive collisions; Pedestrian protection; Engine canopy; Intelligent bouncing

摘要： 交通事故中，行人头部撞击发动机舱盖下方硬点造成很多伤亡。针对这种情况，本系 统所设计的发动机舱盖智能弹起装置，由超声波雷达、发动机舱盖、舱盖前旋转轴、前轴开 关锁、舱盖后旋转轴、后轴开关锁、空气弹簧等部分组成。在发生行人碰撞时，控制系统控 制后轴开关锁打开，前轴开关锁关闭，空气弹簧弹起发动机舱盖后端，对行人起到撞击缓冲， 避免行人头部撞击发动机下方硬点，减少伤亡。空气弹簧释放后可以再次加压，使发动机舱 盖智能弹起装置可以重复使用，维护成本低，通过超声波雷达检测行人距离，结合汽车车速 进行碰撞分析，能提前预测碰撞，起到更加及时的保护效果。

关键词: 超声波雷达；行人检测；空气弹簧；预测碰撞；行人保护；发动机舱盖；智能弹起