2020 年 20 巻 1 号 p. 45-54
The λ type enforcement braking device (EBD) is a kind of an equipment designed to halt a vehicle, and in turn, prevent a potential traffic accident. The employment of EBD may considerably increase the safety protection of drivers and workers in any road construction region. For the performance improvement of EBD on the collision safety and reliability, it is necessary to evaluate the braking characteristics and optimize the structure of the device. This paper concerns the influence of the ‘arm’ which is an important EBD component on the device’s performance. In particular, the effect of the arm-shape and -length on braking characteristics is investigated by model collision test and respective theoretical calculations. The collisions with three different velocities were carried out using model of automobile and EBD with straight and bend arm shape. A general analysis of a braking distance was derived based on the conservation energy principle. In the model collision test, both straight and bend arm EBD brought us to the same braking distance result, which suggests the negligible effect of the arm shape on the braking. The output of our research was in good agreement with theoretical results. This paper demonstrates the theoretical prediction of the pertinent parameters of a collision behavior. Furthermore, the use of the long arm in the λ type EBD is effective for the shortening of the braking distance, given a proper arm structure optimization. This approach allows us to carry out the braking independent of an automobile driving system.
