Method for Estimating the Roll Angle in a Travelling Vehicle

• US 20120281881A1
• Filed: 11/16/2010
• Published: 11/08/2012
• Est. Priority Date: 11/25/2009
• Status: Active Grant

• Current Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Original Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Inventors: Walter, Michael
• Granted Patent: US 8,824,741 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• CPC Class Codes: B60G 2400/0511 Roll angle
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 40/11 Pitch movement
• CPC Class Codes: B60W 40/112 Roll movement
• CPC Class Codes: B60W 40/114 Yaw movement

Abstract

The invention relates to a method for estimating the roll angle in a travelling vehicle (7), comprising the following steps. In step a), a camera (8) is used to record a sequence of images of the vehicle'"'"'s surroundings, in particular of the road (1) ahead. In step b), at least one signature (S1-S6) on the road surface is extracted from the camera images, i.e. said signature is determined and tracked. The changed position of the at least one signature (S1-S6) in one or more subsequent camera image(s) is used in step c) to determine in which direction the camera (8) is turned with regard to the roll angle.

The value of the roll angle is estimated in step d).

For this purpose, the roll angle is either directly estimated in step d1), taking into account the vehicle speed (v) and an imaging model of the camera (8), or the roll angle is iteratively increased or decreased by a defined correction angle in step d2) until the roll angle sufficiently compensates for the turning of the camera (8). On this basis, the estimated roll angle is obtained as an overall correction value.

Claims

1. A method for estimating the roll angle in a travelling vehicle (7) by means of a camera (8), comprising the following steps:

a) the camera (8) is used to record a sequence of images of the vehicle'"'"'s surroundings,

b) the camera images are used to determine and track at least one signature (S1-S6) on the road surface,

c) the changed position of the at least one signature (S1-S6) in one or more subsequent camera image(s) is used to determine in which roll angle direction the camera (8) is turned,

d) the value of the roll angle is

1) directly estimated, taking into account the vehicle'"'"'s speed (v) and an imaging model of the camera (8) or

2) iteratively corrected by a correction angle until the estimated roll angle sufficiently compensates for the turning of the camera (8).

2. A method according to claim 1, wherein the distance (d) of at least one signature (S1-S6) from the camera (8) in the vehicle'"'"'s longitudinal direction is determined in step d1), taking into account an imaging model of the camera (8).

3. A method according to claim 2, wherein the distance (d) of the signature (S1-S6) that has been determined and the vehicle'"'"'s speed (v) are used to predict a distance (d_est) of the signature (S1-S6) after a time Δ

t.

4. A method according to claim 3, wherein a subsequent image that has been recorded a time Δ

t after the first image is used to measure the distance (d_meas) of the same signature (S1-S6) from the camera (8) in the vehicle'"'"'s longitudinal direction by means of back-projection.

5. A method according to claim 4, wherein a deviation of the measured distance (d_meas) from the predicted distance (d_est) is used to estimate the roll angle, taking into account an imaging model of the camera (8).

6. A method according to claim 1, wherein

at least one first signature (S1-S3) in the left image half and, in the same or a subsequent image, a second signature (S4-S6) in the right image half are determined and tracked in step b), and, in addition, the vehicle'"'"'s speed (v) at the time each camera image is recorded is stored,

in step c), a separate prediction of the signature distance (d_est) is made for each signature (S1-S6), taking into account the relevant vehicle speed (v) and an imaging model of the camera (8), and the signature distance (d_meas) is measured in a subsequent image, and the turning direction of the camera (8) is determined by comparing the deviation of the predicted signature distance (d_est) with the signature distance (d_meas) that has been measured taking into account the currently estimated roll angle in both image halves, and

the roll angle is iteratively estimated according to step d2).

7. A method according to claim 1, wherein

in step b), at least one first signature (S1-S3) in the left and, in the same or a subsequent image, a second signature (S4-S6) in the right lower image quadrant are determined and tracked, and, in addition, the vehicle'"'"'s speed (v) at the time each camera image is recorded is stored,

in step c), the change in signature position in the image is related to the relevant vehicle speed (v) for each of the signatures (S1-S6), and the ratio obtained in this way is compared for both image halves, deducing that the camera (8) is turned in the direction of the image half where this ratio is larger, and

the roll angle is iteratively estimated according to step d2).

8. A device for estimating the roll angle in a travelling vehicle (7), comprising a camera (8) and an evaluation unit including means for estimating the roll angle according to the method of claim 1.