Obstacle detection apparatus and a method therefor
An obstacle detection apparatus includes an image input unit inputting a image sequence captured by an image sensor, a velocity detector deriving velocity vectors representing motions of a to-be-detected point and a to-be-compared point on each image of the image sequence, a predictive velocity vector calculator calculating a predictive velocity vector of the to-be-detected point using a detected velocity vector of the to-be-compared point, an obstacle detector detecting the to-be-detected point as a point on the obstacle when a horizontal component of a detected velocity vector of the to-be-detected point is larger than a horizontal component of the predictive velocity vector by a given threshold, and an obstacle information output unit outputting information on the to-be-detected point detected as the obstacle.
1. An obstacle detection apparatus using an image sensor installed on a movable object, comprising:
an image input unit configured to input an image sequence captured by the image sensor;
a velocity detector to derive a plurality of velocity vectors representing motions of at least one to-be-detected point and at least one to-be-compared point on each picture of the image sequence;
a predictive velocity vector calculator to calculate a predictive velocity vector of the to-be-detected point using a detected velocity vector of the to-be-compared point;
an obstacle detector to detect the to-be-detected point as a point on an obstacle when a horizontal component of a detected velocity vector of the to-be-detected point is larger than a horizontal component of the predictive velocity vector by a given threshold; and
an obstacle information output unit to output information on the to-be-detected point detected as the point of the obstacle.
2. The apparatus according to claim 1 , wherein the velocity detector is configured to detect a velocity vector of a point of a movable obstacle that corresponds to the to-be-detected point and a velocity vector of a point of a non-movable object that corresponds to the to-be-compared point.
3. The apparatus according to claim 1 , wherein the movable object includes a vehicle running a road.
4. The apparatus according to claim 1 , which further comprises a predictive course calculator to calculate a predictive course of the movable object on the picture, and
the obstacle detector includes an obstacle point detector to detect the to-be-detected point as the point on the obstacle when the horizontal component of the to-be-detected velocity vector is larger than the horizontal component of the predictive velocity vector by the threshold in a direction approaching the predictive course from a position of the to-be-detected point.
5. The apparatus according to claim 4 , wherein the predictive velocity vector calculator is configured to calculate the predictive velocity vector, using the velocity vector of the to-be-compared point that is upward the to-be-detected point on the picture and has a horizontal position difference less than another threshold with respect to the to-be-detected point.
6. The apparatus according to claim 4 , wherein the predictive velocity vector calculator is configured to calculate the predictive velocity vector, using the velocity vector of the to-be-compared point that is on a side of the predictive course other than the to-be-detected point on the picture and has a vertical position difference less than a further threshold with respect to the to-be-detected point.
7. The apparatus according to claim 4 , wherein the velocity detector includes a pitching motion detector to detect a pitching motion of the movable object from the image sequence, and a pitching motion compensator to compensate affect of the pitching motion for each picture.
8. The apparatus according to claim 4 , wherein the velocity detector includes a detection region setting unit configured to set on the picture a detection region from which the to-be-detected point is selected, and a feature point deriving unit configured to derive a feature point in the detection region to determine the feature point as the to-be-detected point.
9. The apparatus according to claim 4 , wherein the predictive course calculator is configured to calculate another predictive course including time information of the movable object on a plane on which the movable object moves, and the obstacle information output unit includes means for calculating a position and a time that a distance between the movable object and the obstacle becomes not more than a threshold, using the velocity vector of the obstacle detected by the obstacle detector and the another predictive course.
10. The apparatus according to claim 4 , wherein the obstacle information output unit comprises a grouping unit configured to group to-be-detected points that are determined as the obstacle by using positions of the points and to-be-detected velocity vectors corresponding thereto, and means for calculating a position of the obstacle viewed from the movable object, using a geometric relation between the image sensor and a plane on which the movable object moves and a position of the to-be-detected point which is located at the lowest position on the picture in the to-be-detected points belonging to the same group.
11. The apparatus according to claim 4 , wherein the velocity detector is configured to detect a velocity vector of a point of a movable obstacle that corresponds to the to-be-detected point and a velocity vector of a point of a non-movable object that corresponds to the to-be-compared point.
12. The apparatus according to claim 4 , wherein the movable object includes a vehicle running a road.
13. An obstacle detection apparatus using an image sensor installed on a movable object, comprising:
an image input unit configured to input a image sequence captured by the image sensor;
a velocity detector to derive a plurality of velocity vectors representing motions of a plurality of to-be-detected points and a plurality of to-be-compared points on each picture of the image sequence;
a predictive velocity vector calculator to calculate a predictive velocity vector of each of the to-be-detected points using a detected velocity vector of each of the to-be-compared points;
an obstacle detector to detect each of the to-be-detected point as a point on a corresponding obstacle when a horizontal component of a detected velocity vector of each of the to-be-detected points is larger than a horizontal component of the predictive velocity vector by a given threshold; and
an obstacle information output unit to output information on the to-be-detected points each detected as the point of the corresponding obstacle.
14. The apparatus according to claim 13 , wherein the velocity detector is configured to detect a velocity vector of a point of a movable obstacle that corresponds to the to-be-detected point and a velocity vector of a given point of a non-movable object that corresponds to the to-be-compared point.
15. The apparatus according to claim 13 , which further comprises a predictive course calculator to calculate a predictive course of the movable object on the picture, and the obstacle detector includes an obstacle point detector to detect the to-be-detected point as the point on the obstacle when the horizontal component of each of the to-be-detected velocity vectors is larger than the horizontal component of the predictive velocity vector by the threshold in a direction approaching the predictive course from a position of the to-be-detected point.
16. The apparatus according to claim 13 , wherein the predictive velocity vector calculator is configured to calculate the predictive velocity vector, using the velocity vector of the to-be-compared point that is upward the to-be-detected point on the picture and has a horizontal position difference less than another threshold with respect to the to-be-detected point.