Patent ID: 6978193

Claim:
A positioning data calculating procedure for calculating relative rotation angles for first to sixth links arranged in series and included in an articulated manipulator including coaxial joints each connecting the adjacent ones of the first to the sixth link so that the adjacent links are able to turn about a rotation axis aligned with their axes, and diagonal joints each connecting the adjacent ones of the first to the sixth link so that the adjacent links are able to revolve about a rotation axis inclined to their axes, in which the sixth link is attached rotatably to a predetermined object, and a rotation axis about which the sixth link and the object turn, a rotation axis about which the fifth and the sixth link turn and a rotation axis about which the fourth and the fifth link turn intersect each other at a triaxial intersection point, said positioning data calculating procedure comprising: a data entering step of entering data on position and orientation of the object in a reference coordinate system with an x-axis, a y-axis and a z-axis orthogonally intersecting each other and fixed relative to the first link; a triaxial intersection point coordinate calculating step of calculating x-, y- and z-coordinate of the triaxial intersection point in the reference coordinate system on the basis of the entered data on the position and orientation of the object; a first-to-third rotation angle calculating step of calculating first to third rotation angles by solving coordinate expressions including an x-coordinate expression representing the x-coordinate of the triaxial intersection point, a yz addition coordinate expression representing the sum of the y- and the z-coordinate of the triaxial intersection point, and a yz subtraction coordinate expression representing the remainder of subtraction of the z-coordinate from the y-coordinate of the triaxial intersection point, and including a first rotation angle corresponding to a rotation angle through which the second link is turned relative to the first link, a second rotation angle corresponding to a rotation angle through which the third link is turned relative to the second link, and a third rotation angle corresponding to a rotation angle through which the fourth link is turned relative to the third link as variables; and a fourth-to-sixth angle calculating step of calculating a fourth rotation angle through which the fifth link is turned relative to the fourth link, a fifth rotation angle through which the sixth link is turned relative to the fifth link, and a sixth rotation angle through which the object is turned relative to the sixth link on the basis of the first to the third rotation angle and the orientation of the object.