Safety device for motor vehicles altering direction - measures distance to following vehicle and uses RPM and acceleration to compute whether manoeuvre can be safety attempted

摘要

An optical laser or radar device mounted on a motor vehicle detects the distance between the vehicle and the following vehicle and provides a display (26) on the dashboard and near the rear view mirror to advise the driver whether a manoeuvre involving a change in direction can be executed without risk of collision with the following vehicle. An on board computer (2) compares the distance to the following vehicle as measured by the laser or radar device (1) against the vehicle engine speed (11) using a linear algorithm involving the maximum vehicle speed and a constant related to the acceleration capability of the vehicle. Two gates (18,20) and a comparator drive the display (26) from the output of the computer (2).