| 摘要 |
Method and apparatus relating to a system for sensing crash for a vehicle. The system is mounted on the vehicle and determines the time-to-impact for approaching obstacles that are within a limited distance for the host vehicle. The system comprises a main control unit (100) and at least, and preferably several, rangefinder units (200). Each rangefinder unit comprises a pulse transmitter (10), a pulse receiver (20), a signal conditioner (30), a threshold discriminator (40), a clock (50), a counter (60) and an averager (70). Each rangefinder (200) measures the distance to objects in its sensing direction through the measurement of the time-of-flight of a short infrared pulse. Each transmitter (10) projects a narrow beam infrared and each receiver unit (20) detects or receives reflected return pulses and provides initial amplification. A time-to-impact is determined based on the time-of-flight and it is determined whether a crash will occur based on the time-to-impact information. |
