Patent ID: 7395144
Filing Date: 2008-07-01
Classification: B60T

Abstract:
1. A brake control system for a vehicle comprising: a braking device for applying braking force to respective vehicle wheels; a distance detecting device mounted in a vehicle for detecting a vehicle distance between the vehicle and a front obstacle; and an electronic control unit for controlling a braking operation by the braking device for the vehicle in accordance with input signals from various kinds of sensors, including the distance detecting device, wherein the electronic control unit comprises: a detecting portion for detecting a relative vehicle speed of the vehicle to the front obstacle; a first calculating portion for calculating an index for evaluating a change of the vehicle distance, the index indicating a condition of the vehicle distance to the front obstacle, the index being increased as the relative vehicle speed becomes larger, and the index having an increasing gradient which is increased as the vehicle distance to the front obstacle becomes shorter in each of the relative vehicle speed, a setting portion for setting a target value for the index, which is plotted on a line having an initial value corresponding to the index at a stating point of a braking operation carried out by a vehicle driver, the target value being increased as the vehicle distance to the front obstacle becomes shorter, with a constant gradient which is decided based on the index at the stating point of the braking operation; a second calculating portion for calculating a target value of a relative vehicle deceleration, based an actual current value of the relative vehicle speed and a target value of the relative vehicle speed, wherein the target value of the relative vehicle speed is calculated from the target value for the index; and a control portion for carrying out a brake assisting control to the braking force generated by the braking device such that an actual relative vehicle deceleration is controlled at the target value of the relative vehicle deceleration.