Patent ID: 8577176

Claim:
A position and orientation calibration method for repeatedly correcting a stored position and orientation of an object, the method comprising: inputting a two-dimensional image of the object; detecting an image feature from the two-dimensional image; inputting three-dimensional coordinate information of a surface of the object; calculating a first difference between the detected image feature and a projected feature of a projected image acquired when projecting a stored three-dimensional model onto the two-dimensional image based on the stored position and orientation of the object; calculating a second difference between a three-dimensional feature of the three-dimensional coordinate information and a model feature of the three-dimensional model in the stored position and orientation; converting a dimension of the first difference and/or the second difference to cause the first difference and the second difference to have an equivalent dimension; and correcting the stored position and orientation based on the first difference and the second difference the dimension of at least one of the first difference and the second difference has been converted.