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A method for programming of a robot application comprising an industrial robot having a robot coordinate system, a tool having a tool coordinate system and a work object ( 3 ) to be processed by the tool. The application is programmed by means of a position-measuring unit ( 15 ) adapted for measurin

A method for programming of a robot application comprising an industrial robot having a robot coordinate system, a tool having a tool coordinate system and a work object ( 3 ) to be processed by the tool. The application is programmed by means of a position-measuring unit ( 15 ) adapted for measuring positions relative a measuring coordinate system (db). The programming method comprises: selecting an object reference structure ( 25 ) on the object, defining a mathematical model for the object reference structure, defining an object coordinate system (o 2 ), providing measurements by the position-measuring unit on the surface of the object reference structure, determining the object coordinate system in relation to the measuring coordinate system (db) by best fit between said measurements and said mathematical model of the object reference structure.

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1. A method for programming of an industrial robot having a robot coordinate system, for an application comprising a tool having a tool coordinate system and a work object to be processed by the tool, wherein the application is programmed by means of a position-measuring unit adapted for measuring p

1. A method for programming of an industrial robot having a robot coordinate system, for an application comprising a tool having a tool coordinate system and a work object to be processed by the tool, wherein the application is programmed by means of a position-measuring unit adapted for measuring positions relative a measuring coordinate system, wherein the method comprises:selecting an object reference structure on or in a fixed relation to the object, the object reference structure having at least one surface,defining a mathematical model for the object reference structure,defining an object coordinate system in a fixed relation to the object reference structure,providing measurements on said at least one surface of the object reference structure, the measurements being performed by the position-measuring unit and are provided relative to the measuring coordinate system,determining the object coordinate system in relation to the measuring coordinate system, by means of best fit between said measurements performed by the position-measuring unit and said mathematical model of the object reference structure,measuring a plurality of positions on a desired robot path on the object by means of the position-measuring unit,determining the positions of the robot path in the object coordinate system, based on said measured positions of the robot path and said determined object coordinate system,determining the relation between the object coordinate system and the robot coordinate system,determining the relation between the tool coordinate system and the robot coordinate system, andprogramming the robot path based on said positions of the robot path in the object coordinate system, said relation between the object coordinate system and the robot coordinate system, and said relation between the tool coordinate system and the robot coordinate system. 2. A method according to claim 1, wherein said object reference structure is three-dimensional and has at least three non-parallel surfaces and measurements are provided on said at least three surfaces of the object reference structure. 3. A method according to claim 1, wherein said object reference structure is any of a cube, a cone or a cylinder. 4. A method according to claim 1, wherein said selected object reference structure is positioned in the vicinity of said robot path. 5. A method according to claim 1, wherein the robot comprises a base and said robot coordinate system is attached to the base of the robot. 6. A method according to claim 1, wherein the relation between the object coordinate system and the robot coordinate system comprises performing measurements on at least one surface of the object reference structure, or of a reference structure on or in a fixed relation to the robot, wherein the measurements are performed by means of an elongated probe and the inclination of the probe relative to the surface during the measurements are essentially the same as the inclination of the tool in relation to the object in the robot path. 7. A method according claim 1, wherein the determining of the relation between the object coordinate system and the robot coordinate system comprises:performing measurements on said surface of the object reference structure, the measurements being performed by the robot and are provided relative to the robot coordinate system, anddetermining the object coordinate system in relation to the robot coordinate system, by means of best fit between said measurements performed by the robot and said mathematical model of the object reference structure. 8. A method according to claim 7, wherein a robot program, for performing said measurements on the object reference structure by the robot, is automatically generated based on said measurements on the object reference structure performed by the position-measuring unit. 9. A method according to claim 7, wherein the direction of the normal of said surface of the object reference structure is calculated, based on s aid measurements on the object reference structure performed by the position-measuring unit, and the robot is moved along said calculated direction towards the surface when performing said measurements. 10. A method according to claim 1, wherein the determining of the relation between the object coordinate system and the robot coordinate system comprises:selecting a robot reference structure on or in a fixed relation to the robot, the robot reference structure having at least one surface,defining a mathematical model for the robot reference structure,defining a second robot coordinate system in a fixed relation to the robot reference structure,performing measurements on said at least one surface of the robot reference structure,determining the object coordinate system in relation to said first mentioned robot coordinate system, by means of best fit between said measurements of the robot reference structure and said mathematical model of the robot reference structure. 11. A method according to claim 10, wherein it comprises:providing a measuring probe in a fixed known position relative to the robot,performing measurements on the surface of the robot reference structure, the measurements being made by said measuring probe,performing measurements on the surface of the object reference structure, the measurements being made by said measuring probe,determining the relation between the object coordinate system and the second robot coordinate system, based on said measurements of the robot reference structure and said measurements of the object reference structure made by said measuring probe. 12. A method according to claim 10, wherein said measurements on said surface of the robot reference structure are made by the position-measuring unit and relative to the measuring coordinate system, and said relation between the object coordinate system and the robot coordinate system are determined, based on said object coordinate system relative to the measuring coordinate system. 13. A method according to claim 10, wherein the robot comprises a tool holder and said robot reference structure is selected on or in a close vicinity of the tool holder of the robot. 14. A method according to claim 10, wherein the robot is provided with a tool having an inner end connected to the robot and an outer end, and said robot reference structure is positioned on or in a close vicinity of the outer end of the tool. 15. A method according to claim 1, wherein the method further comprises:selecting a second object reference structure on or in a fixed relation to the object, the second object reference structure having at least one surface,defining a second object coordinate system on or in a fixed relation to the object reference structure,providing measurements on said at least one surface of the second object reference structure, the measurements being performed by the position-measuring unit and are provided relative to the measuring coordinate system, anddetermining the second object coordinate system in relation to the measuring coordinate system, by means of best fit between said measurements on the second object reference structure and said mathematical model of the object reference structure,determining the relation between the second object coordinate system and the robot coordinate system,the robot path positions are determined and programmed based on either the first or the second coordinate system according to a chosen condition. 16. A method according to claim 15, wherein a robot path position is determined and programmed based on which of the first and second coordinate systems is closest to the robot path position. 17. A method according to claim 15, wherein a robot path position is determined and programmed based on which of the first and second coordinate systems has about the same orientation, as the desired tool orientation in the robot path position. 18. A method according to claim 15, wherein a robot path position is determined and progra mmed based on which of the first and second coordinate systems has about the same torque direction on the robot axis, as the path position. 19. A method according to claim 1, wherein said object reference structure is at least a plane. 20. A method according to claim 1, wherein the tool comprises a tool base for attaching the tool to the robot, and determining the relation between the tool coordinate system and the robot coordinate system comprises:defining an reference coordinate system on or in a fixed relation to the tool base, the relation between the reference tool coordinate system and the robot coordinate system being known,selecting a first tool reference structure on or in a fixed relation to the reference coordinate system, the first tool reference structure having at least one surface,defining a mathematical model for the first tool reference structure,selecting a second tool reference structure in a fixed relation to the tool coordinate system, and at a distance from the first tool reference structure, the second tool reference structure having at least one surface,defining a mathematical model for the second tool reference structure,providing measurements on said at least one surface of the first tool reference structure,providing measurements on said at least one surface of the second tool reference structure,determining the relation between the tool coordinate system and the reference coordinate system, by means of best fit between said measurements on the first and the second tool reference structures, and said mathematical models of the object reference structures. 21. A computer program product for programming of an industrial robot having a robot coordinate system for an application comprising a tool having a tool coordinate system and a work object to be processed by the tool, wherein the application is programmed by means of a position-measuring unit adapted for measuring positions relative a measuring coordinate system, and the computer program product comprises program instructions which, when loaded into a computer, causes the computer to perform:receiving measurements from at least one surface of an object reference structure on or in a fixed relation to the object, the measurements being provided relative to the measuring coordinate system,determining an object coordinate system, defined in a fixed relation to the object reference structure in relation to the measuring coordinate system, by means of best fit between said measurements performed by the position-measuring unit and a mathematical model of the object reference structure,receiving a plurality of positions on a desired robot path,determining the positions of the robot path in the object coordinate system, based on said measured positions of the robot path and said determined object coordinate system,determining the relation between the object coordinate system and the robot coordinate system,determining the relation between the tool coordinate system and the robot coordinate system, andprogramming the robot path based on said positions of the robot path in the object coordinate system, said relation between the object coordinate system and the robot coordinate system, and said relation between the tool coordinate system and the robot coordinate system. 22. A computer readable medium having a program recorded thereon, where the program is to make a computer perform the steps of claim 21, when said program is run on the computer.