Three-dimensional vision sensor

A three-dimensional vision sensor comprising a stereo camera;

• a parameter calculation unit which extracts a plurality of characteristic points in a calibration pattern which is designed to enable extracting, therefrom, a plurality of characteristic points having certain positional relationship relationships thereamong, from a stereo image created through an image pickup on the calibration pattern by the stereo camera, and further calculates a parameter for three-dimensional measurement using the extracted characteristic points;
• a parameter storage unit in which the parameter for three-dimensional measurement is registered;
• a model creation unit which performs three-dimensional measurement processing using the parameter registered in the parameter storage unit on a stereo image created through an image pickup on a predetermined recognition-target object by the stereo camera for creating a three-dimensional model for the recognition-target object using a result of the measurement;
• a three-dimensional-model storage unit in which the created three-dimensional model is registered;
• and
• a three-dimensional recognition unit which performs three-dimensional measurement processing using the parameter registered in the parameter storage unit on a stereo image created by an image pickup for the recognition-target object by the stereo camera and, further, compares the result of the measurement with the three-dimensional model registered in the three-dimensional-model storage unit for recognizing a position and an attitude of the recognition-target object, the three-dimensional vision sensor further comprising:
• a coordinate acquisition unit which, in response to an image pickup performed on a plane provided with predetermined characteristic patterns by the stereo camera, performs three-dimensional measurement processing for at least three representative points in the predetermined characteristic patterns, using a stereo image created by the image pickup performed on the plane and the parameter calculated by the parameter calculation unit, for acquiring three-dimensional coordinates of respective of the representative points, and
• a determination unit Which, based on the three-dimensional coordinates of respective of the representative points which have been acquired by the coordinate acquisition unit, specifies a calculation equation expressing a plane including the acquired three-dimensional coordinates and determines a positional relationship between the plane expressed by the calculation equation and a plane recognized as having a height of zero through three-dimensional measurement processing using the parameter calculated by the parameter calculation unit, and
• wherein the model creation unit corrects the parameter registered in the parameter storage unit based on the positional relationship determined by the determination unit, further performs three-dimensional measurement processing using the corrected parameter, and creates the three-dimensional model using the three-dimensional coordinates each indicating a height of 0 or more, out of the three-dimensional coordinates obtained from the three-dimensional measurement processing using the corrected parameter.