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

在车祸中，如果乘员肺部变形或大脑与头骨之间的相对位移保持在允许值，就不会留下后遗症。为了实现该条件，有必要开发一种主动冲击控制系统，该系统通过反馈控制瞬时地调节座椅安全带张力或头盔刚度。因此，半主动冲击控制系统不需要强大的致动器的可行性。基于滑模控制理论推导了控制系统，并设计了一种基于摩擦装置的张力控制装置，以实现快速响应。并搭建了实验装置。然后，两个连接有弹簧的滑块从倾斜的上部沿着直线导轨落下，并与塑料壳体碰撞，通过改变放置在前滑块上的钓鱼线的张力，使相对位移几乎保持恒定目标。在此基础上开发了主动式安全带系统，并以一般成人轿车和典型乘用车为例进行了参数仿真。乘员肺变形以阶跃响应为目标，沿着方向自然减小并保持在允许值。此外，建立了1/10比例的直线电机主动式安全带模型，并对张力控制装置进行了改进，使其能够跟踪约1 ms的控制采样周期，产生几乎为零的张力。相对位移随着目标值的降低而减小，并保持在目标值的20%以内。结果表明，主动式安全带是可行的。

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.