SAFETY SYSTEM FOR VEHICLES

摘要

The system comprising a controller fitted to a subject vehicle (16) and sensor means (20) operable to sense a distance of separation and relative velocity of a trailing vehicle (18). Also input to the controller is a velocity signal derived from a velocity sensing means (97) determining the ground speed of the subject vehicle using a doppler radar system. The controller calculates a safety envelope and activates a visible warning device attached to the rear of the subject vehicle if the trailing vehicle penetrates the safety envelope. An enhanced safety envelope determined by adverse road conditions is also established, any incursion into the enhanced envelope resulting generally in the visible warning being at a less prominent level. If however the closing speed of the trailing vehicle exceeds a predetermined threshold, penetration of the enhanced envelope results immediately in the full warning being displayed with full prominence to the driver of the trailing vehicle. The system has application to improving the safety of road vehicles.