Tracking of a target vehicle using adaptive cruise control

• US 6,795,765 B2
• Filed: 03/22/2001
• Issued: 09/21/2004
• Est. Priority Date: 03/22/2001
• Status: Active Grant

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Miyahara, Shunji
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): To, Tuan C
• Application Number:
  US09/815,187
• Publication Number:
  US 20020138193A1
• Time in Patent Office: 1,279 Days
• Field of Search: 342/29, 342/104, 342/109, 342/70, 701/96, 701/301, 701/93, 701/205, 701/300, 340/902, 340/903, 340/435, 340/436, 340/444, 340/441, 340/465, 340/467, 180/170, 180/282, 180/169, 180/168, 180/167, 180/271
• US Class Current: 701/96
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/14 Yaw
• 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 2554/4041 Position
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

An adaptive cruise control system is provided for tracking a target vehicle through a curve. The adaptive cruise control system tests whether the target vehicle is traveling along the curve or whether the target vehicle is changing lanes. The test includes monitoring a change in travel directions between the target vehicle and the adaptive cruise control vehicle. In one embodiment, the test monitors a change relative velocity versus azimuth angle.

Claims

1. An adaptive cruise control system comprising a sensor determining a travel direction of a first vehicle and a travel direction of a second vehicle;

an electronic control unit operable to receive said determinations from said sensor and monitor an increasing change between said first vehicle travel direction and said second vehicle travel direction;

wherein said electronic control unit controls a speed of said first vehicle as a function of said monitoring; and

wherein said electronic control unit determines whether said change in travel directions continues to increase or begins to decrease after a test interval;

wherein said electronic control unit determines whether said second vehicle is traveling along a curve or is changing a lane, said curve travel decision occurring when a segment of said change in travel directions continues to increase after a test interval, said lane change decision occurring when said segment decreases after said test interval, wherein said electronic control unit adjusts a throttle to maintain a constant distance between said first and second vehicles when said curve travel decision occurs and said electronic control unit adjusts said throttle to maintain a preset speed when said lane change decision occurs.

2. The adaptive cruise control system according to claim 1, wherein said electronic control unit tests said determination repetitively for overlapping test intervals.

3. The adaptive cruise control system according to claim 1, wherein said electronic control unit tests said determination for a single test interval when said change in travel direction begins to increase.

4. The adaptive cruise control system according to claim 1, wherein said change in travel direction is a relative velocity.

5. The adaptive cruise control system according to claim 4, wherein said test interval is an azimuth angle.

6. The adaptive cruise control system according to claim 5, wherein said test interval is about 1.5°

.

7. The adaptive cruise control system according to claim 5, wherein said test interval is between 1°

and 2°

.

8. The adaptive cruise control system according to claim 7, wherein said electronic control unit tests said determination repetitively for overlapping test intervals.

9. The adaptive cruise control system according to claim 7, wherein said electronic control unit tests said determination for a single test interval when said change in travel direction begins to increase.

10. The adaptive cruise control system according to claim 5, wherein said test interval is between 1.3°

and 1.8°

.

11. A method for tracking a target vehicle through a curve comprising determining a travel direction of a tracking vehicle;

determining a travel direction of a target vehicle;

calculating a change in said travel directions;

testing said change in travel directions increases or decreases during a test interval, said test interval being an azimuth angle between 1° and

2°

; and

adjusting the speed of said tracking vehicle based on said testing, wherein said change in travel directions is a relative velocity, wherein said testing decides said target vehicle is traveling along a curve when said relative velocity is increasing after said azimuth angle test interval, wherein said testing decides said target vehicle is changing lanes when said relative velocity is decreasing after said azimuth angle test interval.

12. An adaptive cruise control system, comprising:

a sensor measuring a distance, relative velocity and azimuth angle of a preceding vehicle for an ACC vehicle;

instruments measuring the Yaw rate and/or steering angle and velocity of the ACC vehicle;

an electronic control unit receiving said measurements from said sensor and said measurements from said instruments, calculating a locus (phase chart) between the relative velocity and azimuth angle of said preceding vehicle, having already calculated the locus, comparing said locus with stored loci, selecting a most suitable locus among said stored loci, and controlling a throttle and/or transmission; and

said throttle and/or transmission being responsive to said electronic control unit, wherein said electronic control unit adjusts said throttle and/or transmission based on said selection.

13. The adaptive cruise control system according to claim 12, wherein said electronic control unit has stored loci corresponding to several lane changes, said preceding vehicle with various distances entering a curve with various curvature, said ACC vehicle and said preceding vehicle with various distances traveling in a curve with various curvature, and said preceding vehicle with various distances exiting a curve with various curvature;

said electronic control unit judging whether the preceding vehicle is entering a curve, changing a lane, traveling in the same curve with the ACC vehicle, or exiting a curve.

14. The adaptive cruise control system according to claim 13, wherein said sensor, instruments, said electronic control unit and throttle and/or transmission operate faster than 0.1 second.

15. The adaptive cruise control system according to claim 13, wherein said electronic control unit starts said selection after said azimuth angle becomes larger than 1.5 degrees, where the azimuth angle begins from almost zero.

16. The adaptive cruise control system according to claim 13, wherein said locus is recalculated after a change of the ACC vehicle'"'"'s velocity.

17. An adaptive cruise control system, comprising:

a sensor measuring a distance, relative velocity and azimuth angle of a preceding vehicle for an ACC vehicle;

instruments measuring the Yaw rate and/or steering and velocity of the ACC vehicle;

an electronic control unit receiving said measurements from said sensor and said measurements from said instruments, calculating a ratio between the relative velocity and azimuth angle of said preceding vehicle, comparing said ratio with thresholds, and controlling a throttle and/or transmission; and

said throttle and/or transmission being responsive to said electronic control unit, wherein said electronic control unit adjusts said throttle based on said comparison.

18. The adaptive cruise control system according to claim 17, wherein said thresholds correspond to driving straight and in curves of various curvature.

19. The adaptive cruise control system according to claim 17, wherein said sensor, instruments, said electronic control unit and throttle and/or transmission operable faster than 0.1 second.

20. The adaptive cruise control system according to claim 17, wherein said electronic control unit starts said comparison after said azimuth angle becomes larger than 1.5 degrees, where the azimuth angle begins from almost zero.

21. The adaptive cruise control system according to claim 17, wherein said electronic control unit makes said comparison on the basis of an average of angle change greater than 0.2 degrees.

22. The adaptive cruise control system according to claim 17, wherein said locus is recalculated after the change of the ACC vehicle'"'"'s velocity.