Method and apparatus for controlling tracking path of working point of industrial robot

A method for controlling the tracking path of a working element of an industrial robot so that the working element moves along a path having a predetermined positional relationship with a prescribed working object, wherein the relative positional relationship between the working element and the working object varies in accordance with the movement of plural individually movable at least one moving element each being operatively coupled with either the working element or the working object in a prescribed coupling condition, said method comprising the steps of:

• allotting individual coordinate systems each having a discriminator to said working element, said working object and said moving elements to provide the coordinate systems with the corresponding discriminators;
• setting as a coordinate system expressing the data for controlling the movement of said working element a first coordinate system selected from said coordinate systems;
• describing, using a second coordinate system selected from the coordinate systems, the data representing the positions of the working element corresponding to at least specific points on the tracking path along which said working element is to move on the basis of a prescribed working schedule to store the data together with the discriminator representative of the corresponding coordinate system;
• deciding prior to executing a real work if or not said first coordinate system and said second coordinate system are the same from their discriminators;
• if both coordinate systems are different coordinate systems, converting the position data of the working element corresponding to the specific point into the data expressed in the first cordinate system;
• and
• controlling the movement of said working element on the basis of the converted position data corresponding to said at least two specific points.

An apparatus for controlling a tracking path of a working point of an industrial robot so that the working point moves along a path having a predetermined positional relationship with a prescribed working object, wherein the relative positional relationship between the working element and the working object varies in accordance with the movement of individually movable at least one moving element, each being operatively coupled with either the working element or the working object in a prescribed coupling condition, said apparatus comprising discriminators for discriminating individual coordinate systems allotted to said working element, said working object and said plural moving elements;

• means for controlling the movement of said working point on the basis of data expressed by a first coordinate system selected from said coordinate systems;
• means for storing the discriminator selected as said first coordinate system;
• means for describing, using a second coordinate system selected from the coordinate systems, the data representing the positions of the working element corresponding to at least specific points on the tracking path along which said working element is to move on the basis of a prescribed working schedule to store the data together with the discriminator representative of the corresponding coordinate system;
• means for deciding, prior to executing actual work, if or not said first coordinate system and said second coordinate system are the same from their discriminators;
• means for converting, if both coordinate systems are different coordinate systems, the position data of the working element corresponding to the specific point into the data expressed in the first coordinate system;
• and
• means for supplying to said means for controlling the movement of said working point said converted position data of said working point corresponding to said at least two specific points.