| 摘要 |
PURPOSE: To provide a novel collision detector by analyzing the electrical signals from transducers for detecting the stress waves propagating inside a waveguide tube in the inside of which the wave activity of stress is caused by the deformation of the waveguide tube due to collision, and by outputting the signal indicating the occurrence of a collision. CONSTITUTION: A collision detector 12 for a vehicle 10 comprises a waveguide tube 14 fitted to the vehicle body; and the waveguide tube 14 is made of a metallic member having a glass film 16, and the deformation of the metallic member causes a crack in the glass film 16 to produce stress waves propagating inside the waveguide tube 14. Transducers 20A, 20B acoustically coupled to the waveguide tube 14 are placed in different positions on the waveguide tube 14 to detect the stresswave activity propagating along the waveguide tube 14. The electrical signals from the transducers 20A, 20B are amplified by amplifiers 22A, 22B and a processor 24 compares the electrical signals from the transducers 20A, 20B, and when the difference or ratio is greater than a predetermined value, it is judged that a collision is caused, and an operating signal is sent to a valve 26 from a fluid supply source 28 to supply and expand the fluid bag 30. |
