Marker detection apparatus and robot teaching system

A marker detection apparatus comprising:

• an image generation unit that superimposes point group data, acquired by a 3D camera and photographed from a viewpoint substantially the same as a viewpoint of a 2D camera, on image data acquired by the 2D camera, thereby generating a combined image;
• a marker position calculation unit that detects a marker and calculates a position of the marker on a basis of the image data of the combined image;
• a plane detection unit that detects a plane on a basis of the point group data of the combined image;
• a marker plane determination unit that determines a marker plane on which the marker exists on a basis of point group data included in a region of the marker detected from the position of the marker calculated by the marker position calculation unit and the plane detected by the plane detection unit, wherein the marker plane determination unit determines the plane, detected by the plane detection unit, as the marker plane when the marker is installed on a workpiece, and wherein the marker plane determination unit determines an imaginary plane constituted by the point group data in the region of the marker, detected in the combined image, as the marker plane when the marker is installed on a manipulator;
• and
• a marker position correction unit that projects the position of the marker, calculated by the marker position calculation unit, onto the marker plane, thereby correcting the position of the marker.