US 4,862,381 AGranted

Position control method in which a cartesian point is transformed through two cartesian coordinate systems

AssigneeFanuc Corporation

InventorTomoatsu Shibata

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Abstract

When NC data inputted from an NC data supply unit (1) are data (G68) indicative of a coordinate transformation, a discriminating unit (2a) applies rotational axis vectors, the coordinates of centers of rotation and the angles of rotation, all of which are commanded following the data G68, to a transformation matrix generator (2b) and instructs the latter to generate transformation matrices. In response, the transformation matrix generator (2b) generates coordinate transformation matrices [M.sub.1 ], [M.sub.2 ] using the given data. When the NC data are path data, on the other hand, the discriminating unit inputs these data to a coordinate transformation unit (2c), which proceeds to subject the positional coordinates contained in the path data to a coordinate transformation using the transformation matrices [M.sub.1 ], [M.sub.2 ] and apply the results to an axis controller (3). The axis controller (3) performs machining by moving a tool along a path obtained by rotations through angles .theta., .phi. about first and second rotational axes, respectively, based on the position data obtained by the coordinate transformation.

Claims3

Dependent claims

A position control method for performing pulse distribution processing based on position data coordinates (x, y, z) in a three-dimensional program coordinate system, and controlling the position of a movable element on the basis of data obtained by said pulse distribution processing, comprising:

a first step of obtaining, in the program coordinate system, a central axis vector (i.sub.o, j.sub.o, k.sub.o) of a first rotational axis, coordinates (x.sub.co, y.sub.co, z.sub.co) of a rotational center point on said first rotational axis, and an angle of rotation .theta., and defining a central axis vector (i.sub.1, j.sub.1, k.sub.1) of a second rotational axis in a new three-dimensional coordinate system determined by rotation of the program coordinate system through .theta., coordinates (x.sub.c1, y.sub.c1, z.sub.c1) of a rotational center point on said second rotational axis, and an angle of rotation .phi.;
a second step of calculating a transformation matrix [M.sub.1 ] using the central axis vector (i.sub.o, j.sub.o, k.sub.o) of the first rotational axis and .theta., wherein coordinates (x.sub.1, y.sub.1, z.sub.1) in the new three-dimensional coordinate system are obtained, when coordinates (x, y, z) in the program coordinate system are rotated by .theta. about the first rotational axis, in accordance with the following equation:
##EQU8## and calculating a transformation matrix [M.sub.2 ] using the central axis vector (i.sub.1, j.sub.1, k.sub.1) and .phi., wherein coordinates (x.sub.2, y.sub.2, z.sub.2) are obtained, when the new three-dimensional coordinate system is rotated by .phi. about the second rotational axis, in accordance with the following equation:
##EQU9## a third step of transforming the position data coordinates (x, y, z) in accordance with the following equation:
##EQU10## and a fourth step of moving a movable element along a path based on the transformed position data (x', y', z').

2 more elements

Dependencies are inferred from the claim text.