System of gauging a camera suitable for equipping a vehicle

• US 8,659,659 B2
• Filed: 10/28/2010
• Issued: 02/25/2014
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Valeo Vision (Valeo SE)
• Original Assignee: Valeo Vision (Valeo SE)
• Inventors: Bradai, Benazouz, Moizard, Julien, Rebut, Julien
• Primary Examiner(s): Rao, Andy
• Assistant Examiner(s): WALKER, JARED T
• Application Number:
  US12/914,068
• Publication Number:
  US 20110102592A1
• Time in Patent Office: 1,216 Days
• Field of Search: 348/148, 382/104
• US Class Current: 348/148
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
• CPC Class Codes: H04N 17/002 for television cameras

Abstract

A system and process of gauging a camera suitable for equipping a vehicle. The system and process determines at least one value of at least one geometrical parameter of the camera, at least in accordance with an item of information that represents a parameter associated with an object detected by the camera, compares the determined value to a value of reference (θpitching_ref, θrolling_ref, θtwisting_ref) of the geometrical parameter of the camera, and controls the geometrical parameter of the camera in accordance with the comparison, particularly by modifying the value of reference in such a way as to gauge the camera.

Claims

1. A system of gauging a camera suitable for equipping a vehicle, said system being set up in order to:

determine at least one value of at least one geometrical parameter of the camera, in accordance with at least one item of information that represents a parameter associated with an object detected by the camera;

compare the determined value to a value of reference (θ

pitching_ref, θ

rolling_ref, θ

twisting_ref) of said at least one geometrical parameter of the camera; and

control said at least one geometrical parameter of the camera in accordance with said comparison by modifying the value of reference in such a way as to gauge the camera, wherein said control of said at least one geometrical parameter occurs when said vehicle is in motion;

wherein said object detected by the camera is a detected vehicle, other than the vehicle on which the camera is fitted, and said parameter associated with this detected vehicle is preferably dependant on a position of a certain zone of the detected vehicle;

said parameter associated with the detected vehicle corresponds to at least one of the following;

a distance (D), measured according to a longitudinal (X) axis of the vehicle on which the camera is arranged, between this camera and the rear of the detected vehicle;

a height (Hlp) of the rear lamps of the detected vehicle;

a center of gravity (Glp_g, Glp_d) of each of the rear lamps of the detected vehicle;

a center of gravity (Gv) of the detected vehicle;

or

at least one of a position or center of gravity of a registration plate of the vehicle;

wherein said system is set up so that, when a discrepancy (Epitching, Erolling, Etwisting) resulting from the comparison between the value of reference of the geometrical parameter of the camera and the determined value presents a value above a pre-determined threshold value (Epitching_s, Erolling_s, Etwisting_s), it can modify the value of reference significantly by the determined value;

wherein said system is set up to control the geometrical parameter of the camera only when distance (D) between the camera and the rear of a detected vehicle is included within an interval of pre-determined values;

wherein these values are determined over a pre-determined period, or for a pre-determined number of detected objects (Nv);

wherein the geometrical parameter of the camera corresponds to at least one of the following;

pitching, which is a movement of rotation around a transversal (Y) axis of the vehicle, also known as the axis of pitching;

rolling, which is a movement of rotation around a longitudinal (X) axis of the vehicle, known as the axis of rolling; and

twisting, which is a movement of rotation around a vertical (Z) axis of the vehicle, known as the axis of twisting.

2. The system according to claim 1, wherein said system is set up so that, when a discrepancy (Epitching, Erolling, Etwisting) resulting from the comparison between the value of reference of the geometrical parameter of the camera and the determined value presents a value above a pre-determined threshold value (Epitching_s, Erolling_s, Etwisting_s), it can modify the value of reference significantly by the determined value.

3. The system according to claim 1, wherein said system is set up to control the geometrical parameter of the camera only when distance (D) between the camera and the rear of a detected vehicle is included within an interval of pre-determined values.

4. The system according to claim 1, wherein said system is set up to detect several objects in succession in order to determine several values of a geometrical parameter of the camera, store each determined value, and determine a final value (θ

pitching_f, θ

rolling_f, θ

twisting_f) that represents this geometrical parameter.

5. The system according to claim 4, wherein these values are determined over a pre-determined period, or for a pre-determined number of detected objects (Nv).

6. The system according to claim 1, wherein the geometrical parameter of the camera corresponds to at least one of the following:

pitching, which is a movement of rotation around a transversal (Y) axis of the vehicle, also known as the axis of pitching;

rolling, which is a movement of rotation around a longitudinal (X) axis of the vehicle, known as the axis of rolling; and

twisting, which is a movement of rotation around a vertical (Z) axis of the vehicle, known as the axis of twisting.

7. The system according to claim 1, wherein the determined value and the value of reference of the geometrical parameter of the camera are angular values (θ

pitching, θ

rolling, θ

twisting).

8. The system according to claim 1, wherein said system is set up to acquire at least one item of information that represents a parameter (θ

as, θ

anv) associated with the vehicle on which the camera is arranged, particularly the structure and angle at the steering wheel of the vehicle.

9. The system according to claim 8, wherein said system is set up to control the geometrical parameter of the camera only when the information that represents the parameter associated with the vehicle on which the camera is situated is included within an interval of pre-determined values.

10. A process for gauging or calibrating a camera suitable for equipping a vehicle, said process comprising the following stages:

determining at least one value of at least one geometrical parameter of the camera, at least in accordance with an item of information that represents a parameter associated with an object detected by the camera;

comparing the determined value to a value of reference (θ

pitching_ref, θ

rolling_ref, θ

twisting_ref) of said at least one geometrical parameter of the camera; and

controlling said at least one geometrical parameter of the camera in accordance with said comparison particularly by modifying the value of reference in such a way as to gauge the camera, wherein said control of said at least one geometrical parameter occurs when said vehicle is in motion;

wherein said object detected by the camera is a detected vehicle, other than the vehicle on which the camera is fitted, and the parameter associated with this detected vehicle is preferably dependant on a position of a certain zone of the detected vehicle;

said parameter associated with the detected vehicle corresponds to at least one of the following;

a distance (D), measured according to a longitudinal (X) axis of the vehicle on which the camera is arranged, between this camera and the rear of the detected vehicle;

a height (Hlp) of the rear lamps of the detected vehicle;

a center of gravity (Glp_g, Glp_d) of each of the rear lamps of the detected vehicle;

a center of gravity (Gv) of the detected vehicle;

or

at least one of a position or center of gravity of a registration plate of the vehicle

wherein said system is set up so that, when a discrepancy (Epitching, Erolling, Etwisting) resulting from the comparison between the value of reference of the geometrical parameter of the camera and the determined value presents a value above a pre-determined threshold value (Epitching_s, Erolling_s, Etwisting_s), it can modify the value of reference significantly by the determined value;

wherein said system is set up to control the geometrical parameter of the camera only when distance (D) between the camera and the rear of a detected vehicle is included within an interval of e-determined values;

wherein these values are determined over a pre-determined period, or for a pre-determined number of detected objects (Nv);

wherein the geometrical parameter of the camera corresponds to a least one of the following;

pitching, which is a movement of rotation around a transversal (Y) axis of the vehicle, also known as the axis of pitching;

rolling, which is a movement of rotation around a longitudinal (X) axis of the vehicle, known as the axis of rolling; and

twisting, which is a movement of rotation around a vertical (Z) axis of the vehicle, known as the axis of twisting.

11. The process according to claim 10, wherein said process further comprises the step of:

modifying the value of reference of the geometrical parameter when a discrepancy (Epitching, Erolling, Etwisting) resulting from the comparison between the value of reference of the geometrical parameter of the camera and the determined value presents a value above a pre-determined threshold value (Epitching_s, Erolling_s, Etwisting_s).

12. The process according to claim 10, wherein said process further comprises the step of:

controlling the geometrical parameter of the camera only when distance (D) between the camera and the rear of the detected vehicle is included within an interval of pre-determined values.

13. The process according to claim 10, wherein said process further comprises the step of:

detecting several objects in succession in order to determine several values of a geometrical parameter of the camera, store each determined value, and determine a final value (θ

pitching_f, θ

rolling_f, θ

twisting_f) that represents this geometrical parameter.

14. The process according to claim 13, wherein said process further comprises the step of:

determining said values over a pre-determined period, or for a pre-determined number of detected objects (Nv).

15. The process according to claim 10, wherein said geometrical parameter of the camera corresponds to at least one of the following:

pitching, which is a movement of rotation around a transversal (Y) axis of the vehicle, also known as the axis of pitching;

rolling, which is a movement of rotation around a longitudinal (X) axis of the vehicle, known as the axis of rolling; and

twisting, which is a movement of rotation around a vertical (Z) axis of the vehicle, known as the axis of twisting.

16. The process according to claim 10, wherein the determined value and the value of reference of the geometrical parameter of the camera are angular values (θ

pitching, θ

rolling, θ

twisting).

17. The process according to claim 10, wherein said process is set up to acquire at least one item of information that represents a parameter (θ

as, θ

anv) associated with the vehicle on which the camera is arranged, particularly the structure and angle at the steering wheel of the vehicle.

18. The process according to claim 17, wherein said system is set up to control the geometrical parameter of the camera is controlled only when the information that represents the parameter associated with the vehicle on which the camera is situated is included within an interval of pre-determined values.