METHOD AND APPARATUS FOR IDENTIFYING AND MEASURING THE DISTANCE BETWEEN VEHICLES

摘要

A method of measuring the distance between vehicles comprising the steps of: emitting light (14) from a first vehicle to define first and second light positions spaced apart a predetermined light distance (L), passing the emitted light through a lens (20) mounted on a second vehicle and having a focal length (f) to present an image (I) of the predetermined light distance (L) at the focal length (f) from the lens, sensing (22) the image (I) at the focal length, producing a signal representing the length of the image (I), storing a scale (28) on the second vehicle which is proportional to the predetermined light distance (L), comparing (26) the length of the image (I) with the scale to produce a signal representing the distance (D) between the vehicles. The method and apparatus is characterized by establishing the predetermined light distance (L) as a constant and fixed length from vehicle to vehicle by using the standard license plate or license plate holder on the first vehicle.