FM RADAR VEHICLE CRASH ANTICIPATING DEVICE

摘要

A method and device for anticipating vehicle collisions are provided. The wave obtained by mixing the reflected wave from an object with a portion of the frequency-modulated transmitted wave is separated into Doppler signal component, a fundamental wave component and harmonic components. A time interval between a zero-crossing point of one of two components, which are selected from said components and different in phase, and a point at which said two components are equal in intensity is measured thereby detecting accurately a margin time before a collision takes place and anticipating a correct collision of the vehicle against the object. The relative velocity of the object with respect to the vehicle is detected from the Doppler signal component. The level of the reflected wave from the object is detected. The approaching and approaching angle of the object with respect to the vehicle are detected.