Pedestrian collision warning system
First Claim
1. A computerized method using a camera mountable in a motor vehicle, the method comprising:
- acquiring a plurality of image frames from the camera with a known time interval;
detecting an image patch in at least one of the image frames, wherein the image patch includes a candidate image of a pedestrian in the field of view of the camera;
responsive to the motor vehicle moving forward, tracking optical flow between the image frames of an image point of the pedestrian;
from horizontal image motion of the tracked point of the pedestrian relative to the horizontal image coordinate of the focus of expansion in an image space, computing physical lateral motion of the pedestrian responsive to longitudinal distance to the pedestrian in a physical space; and
estimating the lateral position of the pedestrian at a time-to-collision from the physical lateral motion of the pedestrian.
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Accused Products
Abstract
A method is provided for preventing a collision between a motor vehicle and a pedestrian. The method uses a camera and a processor mountable in the motor vehicle. A candidate image is detected. Based on a change of scale of the candidate image, it may be determined that the motor vehicle and the pedestrian are expected to collide, thereby producing a potential collision warning. Further information from the image frames may be used to validate the potential collision warning. The validation may include an analysis of the optical flow of the candidate image, that lane markings prediction of a straight road, a calculation of the lateral motion of the pedestrian, if the pedestrian is crossing a lane mark or curb and/or if the vehicle is changing lanes.
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Citations
16 Claims
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1. A computerized method using a camera mountable in a motor vehicle, the method comprising:
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acquiring a plurality of image frames from the camera with a known time interval; detecting an image patch in at least one of the image frames, wherein the image patch includes a candidate image of a pedestrian in the field of view of the camera; responsive to the motor vehicle moving forward, tracking optical flow between the image frames of an image point of the pedestrian; from horizontal image motion of the tracked point of the pedestrian relative to the horizontal image coordinate of the focus of expansion in an image space, computing physical lateral motion of the pedestrian responsive to longitudinal distance to the pedestrian in a physical space; and estimating the lateral position of the pedestrian at a time-to-collision from the physical lateral motion of the pedestrian. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system comprising:
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a camera mountable in a motor vehicle; and a processor mountable in the motor vehicle, wherein the processor is operably connectable to the camera; wherein the processor is configured to; acquire a plurality of image frames from the camera with a known time interval; detect an image patch in at least one of the image frames, wherein the image patch includes a candidate image of a pedestrian in the field of view of the camera; responsive to the forward motion of the motor vehicle, track optical flow between the image frames of an image point of the pedestrian; from horizontal image motion of the tracked point of the pedestrian relative to the horizontal image coordinate of the focus of expansion in an image space, compute physical lateral motion of the pedestrian responsive to longitudinal distance to the pedestrian in a physical space; and estimate the lateral position of the pedestrian at a time-to-collision from the physical lateral motion of the pedestrian. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification