METHOD FOR CALIBRATING A ROAD MONITORING DEVICE, AND ROAD MONITORING SYSTEM
A method for calibrating a road monitoring device in which, for a predefined calibration period, the positions of detected objects in relation to the road monitoring device are recorded and an accumulated object residence map is formed therefrom. A world coordinate map of the lanes or lane centers for the monitoring region with their position in a predefined world coordinate system. A position and orientation are determined automatically with a predefined degree of correspondence by computer-based movement and/or rotation of the accumulated object residence map or an object residence map derived from it, in particular a filtered object residence map, and computer-based determination of a respective degree of correspondence to the world coordinate map. The actual position and actual orientation of the sensor are derived from this position, and the position of the objects is calibrated accordingly.
1 . A method of calibrating a road monitoring device, the method comprising:
for a predefined calibration period, recording positions of objects detected by the road monitoring device in relation to the road monitoring device;
generating an accumulated object residence map based on the positions of the objects in relation to the road monitoring device;
determining a position and orientation of the objects based on the accumulated object residence map and a world coordinate map of lanes or lane centers of the objects in a world coordinate system; and
determining a position and orientation of the road monitoring device from the position the orientation of the objects.
2 . The method as claimed in claim 1 , further comprising:
performing dilation and subsequently erosion on the accumulated object resistance map, wherein a degree of filtering during erosion is set to be greater by a predefined degree than a degree of filtering during; and
orienting the object residence map on the basis of the world coordinate map.
3 . The method as claimed in claim 1 , further comprising adjusting the accumulated object residence map from a predefined starting position and starting orientation in a predefined first movement increment and rotated in the respective position in a predefined first rotational increment.
4 . The method as claimed in claim 3 , further comprising adjusting the accumulated object residence map around the position and angular orientation determined in a predefined second movement increment that is finer than the first movement increment and/or rotated in a predefined second rotational increment that is finer than the first rotational increment.
5 . (canceled)
6 . The method as claimed in claim 1 , further comprising:
defining a rough target position and/or target orientation in relation to the world coordinate map to the road monitoring device; and
calibrating the road monitoring device starting from the rough target position and/or target orientation.
7 . The method as claimed in claim 1 , further comprising evaluating the objects with regard to object type classes and/or position change speed; and
including only those objects which correspond to predefined object type classes and/or the predefined range of the position change speed in the accumulated object residence map.
8 . The method as claimed in claim 1 , further comprising adjusting the calibration period to a quantity of detected objects in a variable manner over time, if a predefined quantity of objects could not be assigned to the accumulated object residence map.
9 - 10 . (canceled)