To improve the frontal crash safety of occupants with different seat orientations in autonomous vehicles, an occupant protection strategy is proposed. Occupants with non-standard seat orientations are actively rotated to the standard seat orientation (0° direction) before a frontal collision occurs. By changing the force direction on the occupant, the protection strategy converts the frontal collision form into the standard frontal collision form, thereby reducing injuries by using airbags. Then, a simplified sled model with seat orientations of ±45° and ±90° was established based on a Honda Accord vehicle model. By comparing the kinematic responses and injury risks of occupants with and without the protection strategy, it can be concluded: 1) The traditional three-point seatbelt restraint system cannot effectively limit the occupant’s diagonal and lateral displacement, leading to a higher risk of “secondary collision” injuries. 2) Under the combined restraint of the leg baffle and seatbelt, the seat completes a rotational angle of ±45° within 200 ms and ±90° within 300 ms. In the simulation test, the occupants with protection strategy can be effectively restrained on the seat without any loss of control in their posture. The risk of “secondary collision” injury is minimal, and there is also a low risk of additional damage to the head, neck, and chest of occupants. Therefore, the effectiveness of the protection strategy of actively rotating seat orientation to face the airbag directly is verified.

为了提高自动驾驶汽车中不同座椅朝向乘员的正面碰撞安全性, 提出一种乘员保护策略, 在正面碰撞发生前, 主动将不同座椅朝向的乘员旋转至标准座椅朝向(0°方向), 通过改变乘员身体受力方向, 将非标准座椅朝向乘员的正面碰撞转化为标准朝向的正面碰撞形式, 从而利用安全气囊对乘员的保护来降低损伤。基于本田雅阁汽车模型, 建立±45°和±90°座椅朝向简化台车模型, 并进行有无应用该保护策略的对比试验, 得到如下结果: 1) 传统三点式安全带约束系统无法有效地限制乘员身体的斜向和侧向偏移, 发生“二次碰撞”损伤风险较大; 2) 在腿部挡板和安全带共同作用下, 200 ms内座椅旋转±45°和300 ms内座椅旋转±90°仿真试验中, 乘员均被有效地约束在座椅上, 姿态未发生失控现象, 发生“二次碰撞”损伤风险较小, 对乘员头部、颈部和胸部造成额外的损伤风险较小。由此验证了主动旋转座椅朝向至正对安全气囊保护策略的有效性。