Collision warning system and method for a motor vehicle
First Claim
1. A collision warning method for a vehicle, the vehicle having a device for measuring the distance from the vehicle to a second vehicle traveling ahead and a control unit programmed to generate a warning when a danger of collision of the vehicle and the second vehicle is determined, the method comprising the steps of:
- repetitively calculating in the control unit a deceleration rate for the vehicle sufficient to maintain a preselected distance between the vehicle and the second vehicle when the vehicle is decelerated subsequent to expiration of a braking reaction time of the driver of the vehicle, the calculation being based at least in part on a relative speed of the vehicle and the second vehicle, the distance between the vehicle and the second vehicle, a deceleration rate for the second vehicle and the preselected distance;
repetitively comparing the calculated deceleration rate for the vehicle against a deceleration rate associated with vehicle braking initiated by the driver of the vehicle; and
generating a collision warning signal when the calculated deceleration rate for the vehicle exceeds the deceleration rate associated with vehicle braking initiated by the driver of the vehicle;
wherein the deceleration rate for the vehicle “
asubject vehicle demand”
is calculated according to;
where;
dv1=the relative speed of the vehicle and the second vehicle at the expiration of the braking reaction time of the driver of the vehicle,dx1=the distance between the vehicle and the second vehicle at the expiration of the braking reaction time of the driver of the vehicle,dxremaining=the preselected distance between the vehicle and the second vehicle at the end of deceleration of the vehicle, andafront—
o=the deceleration rate for the second vehicle.
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Accused Products
Abstract
A collision warning system and method for a motor vehicle. A measuring device in the vehicle is provided for measuring the distance dx to a second vehicle traveling ahead, the distance signal being delivered to an evaluation device in the first vehicle. The evaluation device continuously calculates a deceleration asubject vehicle demand, which is applied by the vehicle after expiration of a driver reaction time Treaction in order that a remaining distance dxremaining to the second vehicle traveling ahead can be maintained. If asubject vehicle demand exceeds an instantaneous deceleration that can be achieved by an adaptive cruise control (“ACC”) system, a system limit warning is transmitted, prompting the vehicle driver to brake with additional appropriate force. If asubject vehicle demand exceeds an assumed vehicle deceleration that can be generated by braking on the part of the driver, a collision warning signal is transmitted independently of the ACC system.
26 Citations
22 Claims
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1. A collision warning method for a vehicle, the vehicle having a device for measuring the distance from the vehicle to a second vehicle traveling ahead and a control unit programmed to generate a warning when a danger of collision of the vehicle and the second vehicle is determined, the method comprising the steps of:
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repetitively calculating in the control unit a deceleration rate for the vehicle sufficient to maintain a preselected distance between the vehicle and the second vehicle when the vehicle is decelerated subsequent to expiration of a braking reaction time of the driver of the vehicle, the calculation being based at least in part on a relative speed of the vehicle and the second vehicle, the distance between the vehicle and the second vehicle, a deceleration rate for the second vehicle and the preselected distance; repetitively comparing the calculated deceleration rate for the vehicle against a deceleration rate associated with vehicle braking initiated by the driver of the vehicle; and generating a collision warning signal when the calculated deceleration rate for the vehicle exceeds the deceleration rate associated with vehicle braking initiated by the driver of the vehicle; wherein the deceleration rate for the vehicle “
asubject vehicle demand”
is calculated according to;
where;dv1=the relative speed of the vehicle and the second vehicle at the expiration of the braking reaction time of the driver of the vehicle, dx1=the distance between the vehicle and the second vehicle at the expiration of the braking reaction time of the driver of the vehicle, dxremaining=the preselected distance between the vehicle and the second vehicle at the end of deceleration of the vehicle, and afront — o=the deceleration rate for the second vehicle.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for warning the driver of a vehicle of an impending collision with a second vehicle traveling ahead, the system comprising:
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means for measuring a distance from the vehicle to the second vehicle traveling ahead; a control unit; means associated with the control unit for repetitively calculating a deceleration rate for the vehicle sufficient to maintain a preselected distance between the vehicle and the second vehicle when the vehicle is decelerated subsequent to expiration of a braking reaction time of the driver of the vehicle, the calculation being based at least in part on a relative speed of the vehicle and the second vehicle, the distance between the vehicle and the second vehicle, a deceleration rate for the second vehicle and the preselected distance; means for repetitively comparing the calculated deceleration rate for the vehicle against a deceleration rate associated with vehicle braking initiated by the driver of the vehicle; and means for generating a collision warning signal when the calculated deceleration rate for the vehicle exceeds the deceleration rate associated with vehicle braking initiated by the driver of the vehicle; wherein the means for calculating the deceleration rate for the vehicle “
asubject vehicle demand”
effects the formula;
where;dv1=the relative speed of the vehicle and the second vehicle at the expiration of the braking reaction time of the driver of the vehicle, dx1=the distance between the vehicle and the second vehicle at the expiration of the braking reaction time of the driver of the vehicle, dxremaining=the preselected distance between the vehicle and the second vehicle at the end of deceleration of the vehicle, and afront — o=the deceleration rate for the second vehicle.- View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification