System and method for hitch angle detection

• US 9,804,022 B2
• Filed: 03/24/2015
• Issued: 10/31/2017
• Est. Priority Date: 03/24/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Kyrtsos, Christos, Pilutti, Thomas Edward, Lavoie, Erick Michael
• Primary Examiner(s): McCall, Eric S
• Application Number:
  US14/666,491
• Publication Number:
  US 20160280261A1
• Time in Patent Office: 952 Days
• Field of Search: 7311701, 7311702
• CPC Class Codes: B60D 1/245 for facilitating push back or parking of trailers
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B62D 13/00 Steering specially adapted for trailers combined traction and steering hitches B60D
• CPC Class Codes: G01B 17/00 Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
• CPC Class Codes: G01B 21/24 for testing alignment of axes
• CPC Class Codes: G01H 17/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00

Abstract

A hitch angle detection system is provided herein. Ultrasonic transducers are disposed on a rear vehicle structure and are configured to transmit ultrasonic waves in a rearward vehicle direction. An ultrasonic reflector is disposed on a trailer and is configured to reflect incident ultrasonic waves back toward the corresponding ultrasonic transducers. A processor is configured to derive distance measurements between the ultrasonic transducers and the ultrasonic reflector and determine a hitch angle based on the derived distance measurements.

Claims

1. A hitch angle detection system comprising:

ultrasonic transducers disposed on a rear vehicle structure and configured to transmit ultrasonic waves in a rearward vehicle direction;

an ultrasonic reflector disposed on a trailer and configured to reflect incident ultrasonic waves back toward the corresponding ultrasonic transducers, the ultrasonic reflector comprising a trihedral reflector having a resonating cavity configured to amplify each reflected ultrasonic wave; and

a processor configured to derive distance measurements between the ultrasonic transducers and the ultrasonic reflector and determine a hitch angle based on the derived distance measurements.

2. The system of claim 1, wherein the hitch angle is among a range of determinable hitch angles, the range of determinable hitch angles comprising −

60 degrees to 60 degrees.

3. The hitch angle detection system of claim 1, wherein the ultrasonic reflector comprises a trihedral reflector having a resonating cavity for amplifying incident ultrasonic waves reflected back to the ultrasonic transducers.

4. The system of claim 1, wherein the ultrasonic transducers include first, second, third, and fourth ultrasonic transducers spaced along the rear vehicle structure such that the first and second ultrasonic transducers are located off to a first side of a longitudinal axis of the vehicle and the third and fourth ultrasonic transducers are located off to a second side of the longitudinal axis of the vehicle.

5. The system of claim 4, wherein the processor determines a negative hitch angle based on derived distance measurements between the ultrasonic reflector and each of the first and second ultrasonic transducers, a distance between the first and second ultrasonic transducers, a distance between the longitudinal axis and one of the first and second ultrasonic transducers, and a length of a vehicle hitch bar.

6. The system of claim 5, wherein the processor determines a positive hitch angle based on derived distance measurements between the ultrasonic reflector and each of the third and fourth ultrasonic transducers, a distance between the third and fourth ultrasonic transducers, a distance between the longitudinal axis and one of the third and fourth ultrasonic transducers, and the length of the vehicle hitch bar.

7. The system of claim 6, wherein the processor determines a zero hitch angle when each of the first, second, third, and fourth ultrasonic transducers receive reflected ultrasonic waves from the ultrasonic reflector.

8. A hitch angle detection system comprising:

ultrasonic transducers disposed on a rear vehicle structure and configured to transmit ultrasonic waves in a rearward vehicle direction;

an ultrasonic reflector disposed on a trailer and configured to amplify and reflect incident ultrasonic waves back toward the corresponding ultrasonic transducers; and

a processor configured to derive distance measurements between the ultrasonic reflector and at least two of the ultrasonic transducers and determine a hitch angle based on the derived distance measurements.

9. The system of claim 8, wherein the hitch angle is among a range of determinable hitch angles, the range of determinable hitch angles comprising −

60 degrees to 60 degrees.

10. The hitch angle detection system of claim 8, wherein the ultrasonic reflector comprises a trihedral reflector having a resonating cavity for amplifying incident ultrasonic waves reflected back to the ultrasonic transducers.

11. The system of claim 8, wherein the ultrasonic transducers include first, second, third, and fourth ultrasonic transducers spaced along the rear vehicle structure such that the first and second ultrasonic transducers are located off to a first side of a longitudinal axis of the vehicle and the third and fourth ultrasonic transducers are located off to a second side of the longitudinal axis of the vehicle.

12. The system of claim 11, wherein the processor determines a negative hitch angle based on derived distance measurements between the ultrasonic reflector and each of the first and second ultrasonic transducers, a distance between the first and second ultrasonic transducers, a distance between the longitudinal axis and one of the first and second ultrasonic transducers, and a length of a vehicle hitch bar.

13. The system of claim 12, wherein the processor determines a positive hitch angle based on derived distance measurements between the ultrasonic reflector and each of the third and fourth ultrasonic transducers, a distance between the third and fourth ultrasonic transducer, a distance between the longitudinal axis and one of the third and fourth ultrasonic transducers, and the length of the vehicle hitch bar.

14. The system of claim 13, wherein the processor determines a zero hitch angle when each of the first, second, third, and fourth ultrasonic transducers receive reflected ultrasonic waves from the ultrasonic reflector.

15. A hitch angle detection method comprising the steps of:

transmitting ultrasonic waves in a rearward vehicle direction with ultrasonic transducers disposed on a rear vehicle structure;

using an ultrasonic reflector on a trailer to amplify and reflect incident ultrasonic waves back toward the corresponding ultrasonic transducers;

using a processor to derive distance measurements between the ultrasonic transducers and the ultrasonic reflector; and

determining a hitch angle based on the derived distance measurements.

16. The method of claim 15, wherein the step of transmitting comprises spacing first, second, third, and fourth ultrasonic transducers along the rear vehicle structure such that the first and second ultrasonic transducers are located off to a first side of a longitudinal axis of the vehicle and the third and fourth ultrasonic transducers are located off to a second side of the longitudinal axis of the vehicle.

17. The method of claim 16, wherein the step of determining comprises determining a negative hitch angle based on derived distance measurements between the ultrasonic reflector and each of the first and second ultrasonic transducers, a distance between the first and second ultrasonic transducers, a distance between the longitudinal axis and one of the first and second ultrasonic transducers, and a length of a vehicle hitch bar.

18. The method of claim 17, wherein the step of determining further comprises determining a positive hitch angle based on derived distance measurements between the ultrasonic reflector and each of the third and fourth ultrasonic transducers, a distance between the third and fourth ultrasonic transducers, a distance between the longitudinal axis and one of the third and fourth ultrasonic transducers, and the length of the vehicle hitch bar.

19. The method of claim 18, wherein the step of determining further comprises determining a zero hitch angle when each of the first, second, third, and fourth ultrasonic transducers receive reflected ultrasonic waves from the ultrasonic reflector.