CRUISE CONTROL

• US 20080078600A1
• Filed: 09/18/2007
• Published: 04/03/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yamamura, Yoshinori, Uemura, Yoshitaka, Minegishi, Koki, Nakamura, Masahide, Nakajima, Hidekazu, Inoue, Takuya, Seto, Yoji
• Granted Patent: US 7,987,038 B2
• Time in Patent Office: Days
• US Class Current: 180/170
• CPC Class Codes: B60K 31/0066 responsive to vehicle path curvature
• CPC Class Codes: B60W 2050/0025 Transfer function weighting factor
• 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

Abstract

A cruise control for a vehicle that detects an inter-vehicle distance to a preceding vehicle. A first vehicle speed instruction value is computed based one the inter-vehicle distance. Curve information of a curve in the road ahead of the vehicle is detected, and a second vehicle speed instruction value is computed for traveling on the curve based on the curve information. A final target vehicle speed is set based on the vehicle speed instruction values. When the vehicle travels through the curve while the first vehicle speed instruction value is larger than the second vehicle speed instruction value, the final target vehicle speed is set to a vehicle speed higher than the second vehicle speed instruction value and lower than the first vehicle speed instruction value. The speed of the vehicle is controlled based on the final target vehicle speed.

Claims

1. A cruise control for a vehicle following a preceding vehicle, the vehicle including a preceding vehicle detector that detects an inter-vehicle distance to the preceding vehicle and a curve detector that detects curve information of a curve ahead of the vehicle, the cruise control comprising:

a first vehicle speed instruction value computing part adapted to compute a first vehicle speed instruction value based on the inter-vehicle distance;

a second vehicle speed instruction value computing part adapted to compute a second vehicle speed instruction value for traveling on the curve based on the curve information;

a target vehicle speed setting part adapted to set a final target vehicle speed higher than the second vehicle speed instruction value and lower than the first vehicle speed instruction value when the vehicle travels on the curve and while the first vehicle speed instruction value is larger than the second vehicle speed instruction value; and

a speed control part adapted to control a vehicle speed based on the final target vehicle speed.

2. The cruise control according to claim 1 wherein the target vehicle speed setting part is further adapted to compute the final target vehicle speed based on at least one of the inter-vehicle distance, the vehicle speed and the curve information.

3. The cruise control according to claim 1, further comprising:

a setting device configured to allow a driver to set at least one of a target inter-vehicle distance and a control mode for the inter-vehicle distance; and

wherein the target vehicle speed setting part is further adapted to compute the final target vehicle speed based on a setting of the setting device.

4. The cruise control according to claim 1 wherein the target vehicle speed setting part is further adapted to compute the final target vehicle speed based on the first vehicle speed instruction value, the second vehicle speed instruction value and weighting coefficients for the first and the second vehicle speed instruction values.

5. The cruise control according to claim 4 wherein the target vehicle speed setting part is further adapted to change the weighting coefficients based on at least one of the inter-vehicle distance, the vehicle speed and the curve information.

6. The cruise control according to claim 4, further comprising:

a setting device configured to allow a driver to set at least one of a target inter-vehicle distance and a control mode for the inter-vehicle distance; and

wherein the target vehicle speed setting part is further adapted to change the weighting coefficients based on a setting of the setting device.

7. The cruise control according to claim 4 wherein the target vehicle speed setting part is further adapted to maintain the weighting coefficients at values based on the setting of the setting device until the vehicle passes the curve.

8. The cruise control according claim 1 wherein the second vehicle speed instruction value computing part is adapted to preset the second vehicle speed instruction value ahead of the curve and to gradually lower the second vehicle speed instruction value by a first deceleration until a target turning vehicle speed is reached;

and

wherein the target vehicle speed setting part is further adapted to set a third vehicle speed instruction value as the final target vehicle speed, the third vehicle speed instruction value obtained by correcting at least one of the first deceleration and the target turning vehicle speed to a higher value.

9. The cruise control according to claim 8 wherein the target vehicle speed setting device changes the at least one of the first deceleration and the target turning vehicle speed based on at least one of the inter-vehicle distance, the vehicle speed and the curve information.

10. The cruise control according to claim 8, further comprising:

a setting device configured to allow a driver to set at least one of a target inter-vehicle distance and a control mode for the inter-vehicle distance; and

wherein the target vehicle speed setting part is further configured to change at least one of the first deceleration and the target turning vehicle speed based on a setting of the setting device.

11. The cruise control according to claim 8 wherein the first vehicle speed instruction value computing part is farther adapted to limit a variation in the first vehicle speed instruction value such that the first vehicle speed instruction value does not exceed a second deceleration higher than the first deceleration;

and

wherein the target vehicle speed setting part is further adapted to correct the first deceleration to the second deceleration.

12. The cruise control according to claim 1, further comprising:

a deceleration start predicting part adapted to compute at least one of a time and a distance until the second vehicle speed instruction value is reduced and deceleration with respect to the curve begins; and

wherein the target vehicle speed setting part is further adapted to set an acceleration limit value to make it more difficult to accelerate to the final target vehicle speed when the time or the distance becomes shorter.

13. A cruise control for a vehicle following a preceding vehicle, the vehicle including a preceding vehicle detector that detects an inter-vehicle distance to the preceding vehicle and a curve detector that detects curve information of a curve ahead of the vehicle, the cruise control comprising:

first computing means for computing a first vehicle speed instruction value based on the inter-vehicle distance;

second computing means for computing a second vehicle speed instruction value for traveling on the curve, the second vehicle speed instruction value based on the curve information;

target setting means for setting a final target vehicle speed higher than the second vehicle speed instruction value and lower than the first vehicle speed instruction value when the vehicle travels over the curve and while the first vehicle speed instruction value is larger than the second vehicle speed instruction value; and

speed controlling means for controlling the vehicle speed based on the final target vehicle speed.

14. A cruise control method for a vehicle following a preceding vehicle, the vehicle including a preceding vehicle detector that detects an inter-vehicle distance to a preceding vehicle and a curve detector that detects curve information of a curve ahead of the vehicle, the method comprising:

setting a first vehicle speed instruction value based on the inter-vehicle distance;

setting a second vehicle speed instruction value for traveling on the curve based on the curve information; and

setting a final target vehicle speed as a vehicle speed higher than the second vehicle speed instruction value and lower than the first vehicle speed instruction value for at least a portion of the curve when the vehicle travels on the curve and while the first vehicle speed instruction value is larger than the second vehicle speed instruction value.

15. The cruise control method according to claim 14 wherein setting the final target vehicle speed further comprises:

computing the final target vehicle speed based on at least one of the inter-vehicle distance, a vehicle speed and the curve information.

16. The cruise control method according to claim 14, further comprising:

setting at least one of a target inter-vehicle distance and a control mode for the inter-vehicle distance; and

wherein setting the final target vehicle speed further includes;

computing the final target vehicle speed based on the target inter-vehicle distance or the control mode.

17. The cruise control method according to claim 14, further comprising:

computing at least one of a time and a distance until the second vehicle speed instruction value is reduced and deceleration with respect to the curve begins; and

wherein setting the final target vehicle speed further comprises;

setting an acceleration limit value making it more difficult to accelerate to the final target vehicle speed when the time or the distance becomes shorter.

18. The cruise control method according to claim 14 wherein setting the final target vehicle speed further comprises:

computing the final target vehicle speed based on the first vehicle speed instruction value, the second vehicle speed instruction value and a weighting coefficient for the first and the second vehicle speed instruction values.

19. The cruise control method according to claim 18, farther comprising:

changing the weighting coefficient based on at least one of the inter-vehicle distance, the vehicle speed and the curve information.

20. The cruise control method according claim 14, further comprising:

setting the second vehicle speed instruction value ahead of the curve;

gradually lowering the second vehicle speed instruction value by a first deceleration until a target turning vehicle speed is reached; and

correcting at least one of the first deceleration and the target turning vehicle speed to a higher value to obtain a third vehicle speed instruction value; and

wherein setting the final target vehicle speed further includes setting the third vehicle speed instruction value as the final target vehicle speed.