APPARATUS AND METHOD FOR CALCULATING VEHICLE-DISTANCE

The present invention relates to an apparatus and method for calculating the distance between cars by setting physical limits so that it can recognize an error of the inter-vehicle distance caused by reasons such as a mounting location of a sensor, a vehicle type, and an unauthorized modification of a vehicle which may calculate the inter-vehicle distance more accurately. The inter-vehicle distance calculating apparatus according to the invention comprises an information obtaining unit which collects the inter-vehicle distance information from and to a preceding vehicle that has a temporal interval, an estimation unit which estimates the inter-vehicle distance from and to a preceding vehicle by using the information gathered from the information obtaining unit, a physical limit determining unit that determines whether the subtracted value from the inter-vehicle distance information collected from the information obtaining unit to the estimated inter-vehicle distance information from the estimation unit is within the per-set value of inter-vehicle distance or not, and a correcting unit in case if the pre-set inter-vehicle distance information is not within the range, it will recognize and decide the error of the obtained inter-vehicle distance information and so that it may correct the inter-vehicle distance information gathered from the information obtaining unit. [Reference numerals] (400) Calculating vehicle-distance appratus; (410) Information acquisition unit; (420) Determing unit of same vehicles; (430) Estimating unit; (440) Physical limit determining unit; (442) Vehicle distance fluctuation range determining unit; (444) Relative velocity fluctuation range determining unit; (446) Physical fluctuation range determining unit; (450) Correction unit; (460) Information transmission unit