POSITIONAL ERROR EVALUATION METHOD FOR MOBILE DEVICE AND MOVEMENT ACCURACY IMPROVING METHOD BASED ON THE EVALUATION RESULT

摘要

In a mobile device for moving a mobile body in mutually orthogonal two- or three-axis directions, a positional error of the mobile body with respect to a direction orthogonal to preset two-axis directions out of the above two- or three-axis directions is used to determine, by using a sequential two-point method, a straightness error curve representing a change status along one-axis direction out of the above two-axis directions; the straightness error curve determining is repeated for the other one-axis direction out of the above two-axis directions to determine a straightness error curve representing a change status along the other one-axis direction at the coordinate positions at the opposite ends of the determined straightness error curve group by using the positional error of the mobile body with respect to a direction orthogonal to the preset two-axis directions; with the straightness error curve at the coordinate positions at the opposite ends used as a boundary straightness error curve, the arrangement of the above straightness error curve group is corrected to determine an error curved surface; and the two-dimensional positional error of the mobile body on a plane including the above preset two axes and with respect to a direction orthogonal to the plane is evaluated based on the error curved surface.