Calibration method and measurement system

A calibration method in which a computer calibrates, using a calibration jig, a measurement apparatus that measures a three-dimensional geometry of a measurement target and includes a plurality of imaging parts that capture the measurement target, the calibration method comprising:

• a first imaging step of imaging a first element to be measured among a plurality of elements to be measured having a predetermined shape with a first imaging part and imaging a second element to be measured, which is different from the first element to be measured, with a second imaging part, which is different from the first imaging part, the plurality of elements to be measured being included in the calibration jig;
• a second imaging step of imaging the first element to be measured with the first imaging part and imaging the second element to be measured with the second imaging part, after causing the calibration jig to be moved in a predetermined first direction after the first imaging step;
• a third imaging step of imaging the first element to be measured with the first imaging part and imaging the second element to be measured with the second imaging part, after causing the calibration jig to be moved in a predetermined second direction different from the first direction after the second imaging step;
• a fourth imaging step of imaging the first element to be measured with the first imaging part and imaging the second element to be measured with the second imaging part;
• a fifth imaging step of imaging the first element to be measured with the first imaging part and imaging the second element to be measured with the second imaging part, after rotating the calibration jig about an axis oriented in a predetermined third direction after the fourth imaging step;
• a sixth imaging step of imaging the first element to be measured with the first imaging part and imaging the second element to be measured with the second imaging part, after rotating the calibration jig about an axis oriented in a predetermined fourth direction different from the third direction after the fifth imaging step;
• identifying a first coordinate position indicating a position of the first element to be measured in a first coordinate system based on a field of view of the first imaging part in a plurality of captured images captured by the first imaging part, and a second coordinate position indicating a position of the second element to be measured in a second coordinate system based on a field of view of the second imaging part in a plurality of captured images captured by the second imaging part;
• identifying a first rotation matrix for rotating the first coordinate system to perform a coordinate transformation and a second rotation matrix for rotating the second coordinate system to perform a coordinate transformation such that a direction in which the first coordinate position is moved and a direction in which the second coordinate position is moved coincide with each other before and after moving of the calibration jig in the first direction and the second direction;
• and
• identifying a first translation vector for translating the first coordinate system and a second translation vector for translating the second coordinate system such that a distance between the first element to be measured and the second element to be measured is the same before and after rotating the calibration jig.