Vehicle curvature determination

• US 10,202,144 B2
• Filed: 12/08/2015
• Issued: 02/12/2019
• Est. Priority Date: 12/08/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Brown, Andrew, Lauffer, Scott J., Joyce, John P., El Aile, Steven R., Pallett, Tobias John, Elwart, Shane, Williams, Wayne
• Primary Examiner(s): Nguyen, Cuong H
• Application Number:
  US14/962,265
• Publication Number:
  US 20170158225A1
• Time in Patent Office: 1,162 Days
• Field of Search: 701 22, 701 28, 701 305, 701 314, 340438, 340439, 340441
• CPC Class Codes: B62D 15/021 Determination of steering angle
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: B62D 5/0457 characterised by control features of the drive means as such
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/0231 using optical position detecting means position-fixing by using electromagnetic waves other than radio waves, e.g. optical position detecting means G01S5/16
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93

Abstract

A current state of a vehicle is identified. Vehicle path curvature limits are determined. A curvature performance profile to follow is determined based at least in part the vehicle path curvature limits. A direction of the vehicle is controlled based at least in part the curvature performance profile.

Claims

1. A system, comprising a computer having a processor and a memory, the memory storing instructions executable by the processor such that the computer is programmed to:

identify a current state of a ground vehicle, the current state including one or more quantities related to operation of the ground vehicle;

determine vehicle path curvature limits;

determine a curvature performance profile to follow based at least in part the vehicle path curvature limits; and

control a direction of the ground vehicle based at least in part the curvature performance profile.

2. The system of claim 1, wherein the current state of the ground vehicle includes at least one of an internal vehicle state and an environmental condition.

3. The system of claim 2, wherein the computer is further programmed to determine the internal vehicle state of the ground vehicle from in part one or more of a steering wheel angle, a wheel speed sensor, an inertial sensor, an active controller status, a componentry status, a controller area network (CAN) bus status, a power supply level, a current vehicle speed and a tire saturation.

4. The system of claim 2, wherein the computer is further programmed to determine the environmental condition from at least in part one or more of a road grade, a bank, a surface mu and a temperature.

5. The system of claim 1, wherein the computer is further programmed to determine the vehicle path curvature limits from at least in part one or more of the current state of the ground vehicle, a steering system capability model and a vehicle dynamic capability model.

6. The system of claim 5, wherein the current state of the ground vehicle further includes at least one of a lateral acceleration value, a road wheel angle, a steering wheel angle, a yaw rate and a path radius.

7. The system of claim 5, wherein the steering system capability model includes at least one of an asymmetric left to right change value, a maximum rate of change of curvature and data from a vehicle sensor.

8. The system of claim 5, wherein the vehicle dynamic capability model includes at least a suspension geometry and data from a suspension sensor.

9. The system of claim 8, wherein the computer is further programmed to determine a suspension geometry from at least one of a reaction load at steer axle, a bank, a surface mu, a CAN signal loss, a CAN signal corruption, a power supply level and a tire saturation.

10. The system of claim 1, wherein the computer is further programmed to determine the curvature performance profile from at least one of a map stored in the memory, a desired route to follow, the maximum curvature capability of the ground vehicle, a communication from a second vehicle, a communication from an external road infrastructure system and an obstacle detection sensor.

11. The system of claim 10, wherein the obstacle detection sensor includes at least one of a LIDAR sensor, a SONAR sensor and an optical range determination system.

12. The system of claim 1, wherein the computer is further programmed to select an at least one discrete value of the maximum curvature capability;

send the at least one discrete value to a second computer; and

regenerate the vehicle path curvature limits by interpolating using the at least one discrete value of the vehicle path curvature limits.

13. The system of claim 1, wherein the vehicle path curvature limits are expressed as a profile that one of (a) includes first series of curvatures for left turns and a second series of curvatures for right turns, (b) includes each of a curvature that is a limit for both left and right turns, a left turn path curvature rate, and a right turn path curvature rate, and (c) includes a combination of a series of left and right path curvatures and curvature rates.

14. A method, comprising:

identifying a current state of a ground vehicle, the current state including one or more quantities related to operation of the ground vehicle;

identifying an environmental condition;

determining vehicle path curvature limits;

determining a curvature performance profile to follow based at least in part the vehicle path curvature limits; and

controlling a direction of the ground vehicle based at least in part the curvature performance profile.

15. The method of claim 14, further comprising determining the current state of a vehicle from at least a steering wheel angle, a curvature of vehicle, a wheel speed sensor, an inertial sensor, an active controller status, a componentry status, a controller area network (CAN) bus status, a power supply level, a current vehicle speed and a tire saturation.

16. The method of claim 14, further comprising determining the vehicle path curvature limits from at least in part one or more of the current state of the ground vehicle, a steering system capability model and a vehicle dynamic capability model.

17. The method of claim 16, wherein the current state of the ground vehicle further includes at least one of a lateral acceleration value, a road wheel angle, a steering wheel angle, a yaw rate and a path radius.

18. The method of claim 16, wherein the steering system capability model includes at least one of an asymmetric left to right change value, a maximum rate of change of curvature and a vehicle sensor.

19. The method of claim 16, wherein the vehicle dynamic capability model includes at least one of a reaction load at steer axle value, a bank, a surface mu, a CAN signal loss, a CAN signal corruption, a power supply level and a tire saturation.

20. The method of claim 14, further comprising:

selecting an at least one discrete value of the vehicle path curvature limits;

sending the at least one discrete value to a second computer; and

regenerating the vehicle path curvature limits by interpolating using the at least one discrete value of the vehicle path curvature limits.