Patent ID: 8073606

Claim:
A vehicle control system comprising: distance detecting means configured to detect a distance from a preceding object; relative speed detecting means configured to detect a relative speed relative to the preceding object; evaluation index calculating means configured to calculate an evaluation index of the subject vehicle as an index indicating an approach/separation condition relative to the preceding object as a function of a travel speed of the preceding object, the evaluation index being increased as the relative speed of approaching the preceding object becomes higher and a rate of increase thereof being increased as the distance becomes shorter; memory means configured to store each evaluation index calculated during travel of the subject vehicle together with the inter-vehicle distance detected at calculation of the evaluation index; maximum value determining means configured to determine a maximum value of the evaluation index stored in the memory means with respect to each distance; relational equation determination means configured to determine a relational equation based on the maximum value, the relational equation defining the distance from the preceding object and the maximum value of the evaluation index of each distance; threshold equation determining means configured to determine a threshold equation by correcting the relation equation, the threshold equation defining a relation between the distance from the preceding object and a threshold of the evaluation index of each distance and determining a value, which is greater than the evaluation index determined by the relational equation; threshold calculating means configured to calculate a deceleration threshold based on the threshold equation and the distance from the preceding object; and control means configured to start deceleration control of the subject vehicle when the evaluation index is greater than the deceleration threshold.