SPEED CONTROL DEVICE FOR VEHICLE

• US 20100082212A1
• Filed: 09/10/2009
• Published: 04/01/2010
• Est. Priority Date: 09/29/2008
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: KODAMA, Hiroyuki, KOTO, Hideaki, MARUYAMA, Masaki, MIYAJIMA, Takayuki, YASUI, Yoshiyuki
• Granted Patent: US 8,265,847 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60K 31/0066 responsive to vehicle path curvature
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 40/072 Curvature of the road
• CPC Class Codes: B60W 40/076 Slope angle of the road

Abstract

A speed control device includes: a reference point setting unit that sets, based on shape and position of a curve in advance of a vehicle, first and second reference points within the curve, the second reference point being nearer the curve exit than the first reference point; a distance calculating unit that calculates, based on the vehicle location and the reference points, first and second distances, between the vehicle and the first and second reference points, respectively; a target speed determination unit that determines, based on the curve shape and the first and second distances, the first and second target vehicle speeds to be maintained, respectively, before and after passing the first reference point; and a speed control unit that controls the speed of the vehicle based on the target speeds and the detected speed of the vehicle.

Claims

1. A speed control device for a vehicle, comprising:

a vehicle speed acquiring unit that acquires a speed of the vehicle;

a vehicle position acquiring unit that acquires a position of the vehicle;

a curve acquiring unit that acquires a shape and a position of a single curve located in front of the vehicle;

a reference point setting unit that sets, based on the curve shape and the curve position, a first reference point within the curve and a second reference point within the curve on the side nearer to the exit of the curve than the first reference point;

a distance calculating unit that calculates, based on the vehicle position and the first reference point, a first distance serving as a distance of an interval between the vehicle and the first reference point, and also calculates, based on the vehicle position and the second reference point, a second distance serving as a distance of an interval between the vehicle and the second reference point;

a target vehicle speed determination unit that determines a first target vehicle speed based on the curve shape and the first distance, and a second target vehicle speed based on the curve shape and the second distance, determines the first target vehicle speed as a target vehicle speed until the vehicle passes the first reference point, and determines the second target vehicle speed as the target vehicle speed after the vehicle passes the first reference point; and

a vehicle speed control unit that controls the speed of the vehicle based on the target vehicle speed and the speed of the vehicle.

2. The speed control device for a vehicle according to claim 1, wherein

the reference point setting unit is structured so as to determine an interval having a minimum radius of curvature within the curve based on the curve shape and the curve position, and to set the first reference point and the second reference point based on an end point of the interval.

3. The speed control device for a vehicle according to claim 1, wherein

the target vehicle speed determination unit is structured so as to determine the first target vehicle speed so as to decrease as the first distance decreases.

4. The speed control device for a vehicle according to claim 1, wherein

the target vehicle speed determination unit is structured so as to determine the second target vehicle speed so as to be constant at an appropriate vehicle speed required for the vehicle to appropriately pass through the curve, regardless of the second distance.

5. The speed control device for a vehicle according to claim 1, wherein:

the reference point setting unit is structured so as to set, based on the curve shape and the curve position, a third reference point within the curve on the side nearer to the exit of the curve than the second reference point;

the distance calculating unit is structured so as to calculate, based on the vehicle position and the third reference point, a third distance serving as a distance of an interval between the vehicle and the third reference point; and

the target vehicle speed determination unit is structured so as to determine a third target vehicle speed based on the curve shape and the third distance and to determine the third target vehicle speed as the target vehicle speed after the vehicle passes the second reference point.

6. The speed control device for a vehicle according to claim 5, wherein

the target vehicle speed determination unit is structured so as to determine the third target vehicle speed so as to increase as the third distance decreases.

7. The speed control device for a vehicle according to claim 1, further comprising:

an acceleration operating amount acquiring unit that acquires an operating amount of an acceleration operating member operated by a driver of the vehicle, wherein

the target vehicle speed determination unit includes an adjusting unit that adjusts, based on the operating amount, the target vehicle speed so as to be larger when the operating amount is greater than zero than the target vehicle speed when the operating amount is zero.

8. The speed control device for a vehicle according to claim 7, wherein

the target vehicle speed determination unit is structured so as to determine the target vehicle speed so that an increment from the target vehicle speed when the operating amount is zero does not exceed a predetermined upper limit.