Development of Seat Belt Tension Control Equipment considering Relative Velocity between Lung and Rib

在汽车碰撞中，如果将乘员肺部的变形或脑与颅骨的相对位移控制在允许的范围内，则不会产生任何后遗症。为了实现这一目标，有必要开发一种主动冲击控制系统，通过反馈控制来实时调节安全带张力或头盔刚度。为此，从可行性出发，提出了一种不需要强力作动器的半主动冲击控制系统。在滑模控制的基础上推导了张力控制系统，并设计了基于摩擦装置的张力控制装置。并搭建了实验装置。然后，将两个连接有弹簧的滑车沿直线导轨从倾斜的上部落下，使其与塑料外壳发生碰撞，通过改变前滑车上的鱼线张力，使其相对位移几乎保持在恒定目标。验证了半主动冲击控制系统的有效性。在此基础上开发了主动安全带系统，并对普通成人轿车和典型乘用车进行了数值模拟。作为目标，乘员肺部的变形沿阶跃响应自然减小并保持在允许值内。结果证实了主动安全带的有效性。此外，利用直线电机建立了约1/10尺度的主动安全带模型，并对张力控制设备进行了改进，使其能够遵循约1ms的控制采样周期，产生几乎为零的张力。相对位移随目标减小，保持在目标的20%以内。结果表明了主动安全带的可行性。

In a car crash, if deformation of occupant lung or relative displacement between brain and skull is held to the allowable value, no aftereffect will remain. In order to realize this condition, it is necessary to develop an active shock control system which adjusts the seat belt tension or the helmet rigidity instantaneously by the feedback control. Therefore, a semi-active shock control system requiring no powerful actuator was proposed for the feasibility. The control system was derived based on the sliding mode control, and tension control equipment was developed using a friction device which expects the fast response. And, the experimental apparatus was set up. Then, two blocks connected with springs were fallen from the oblique upper part along the linear guide and made to collide with the plastic case, and the relative displacement was almost kept the constant target by changing the tension of fishing line put on the front block. As the result, the effectiveness of the semi-active shock control system was confirmed.The active seat belt system was developed on the basis of this result, and the numerical simulation was carried out using parameters for general adult and typical passenger car. The deformation of occupant lung was decreased naturally and kept to the allowable value along the step response as the target. As the result, the effectiveness of the active seat belt was confirmed.In addition, an active seat belt model of the about 1/10 scales using the linear motor was built, and the tension control equipment was improved in order to follow the control sampling period of about 1ms and generate the tension of almost zero. The relative displacement was decreased following to the target and kept within 20% of the target. As the result, it was shown the feasibility of the active seat belt.