Patent ID: 6405120
Filing Date: 2002-06-11
Classification: B60K,B60W,F16H

Abstract:
A vehicular velocity controlling apparatus, comprising:an inter-vehicle distance detector to detect an inter-vehicle distance from a host vehicle to a preceding vehicle which is running ahead of the host vehicle; a target vehicular velocity calculating section that calculates a target vehicular velocity to make a detected value of the inter-vehicle distance substantially equal to a target inter-vehicle distance; a vehicular velocity detector to detect a vehicular velocity of the host vehicle; a target vehicular driving force calculating section that calculates a target vehicular driving force to make a detected value of the vehicular velocity substantially equal to the target vehicular velocity; a road surface gradient detector to detect a gradient of a descending slope on which the host vehicle is running; and a vehicular velocity controlling section that controls a driving force exerted by a rotary driving force source and a gear position of a vehicular transmission and controls a brake force exerted by a vehicular brake system if the target vehicular driving force is negative, the vehicular velocity controlling section including a gear position shift limiter to place a limitation on a shift of the gear position of the vehicular transmission even under an establishment of a gear position shift condition in accordance with the road surface gradient detected by the road surface gradient detector, wherein the gear position shift limiter of the vehicular velocity controlling section includes: a deceleration force margin calculator to calculate a deceleration force margin FDM on the basis of the target vehicular driving force; a shift threshold value setting section that sets a shift threshold value with reference to which the shift of the gear position of the vehicular transmission is to be made in accordance with the magnitude of the detected gradient of the descending slope on which the host vehicle is running; and a gear shift position determining section to determine the gear position of the vehicular transmission to which the present gear position is shifted on the basis of the deceleration force margin and the shift threshold value.