Apparatus and method for recognizing irradiation-enabled area of beam irradiating device and for establishing a moving path of the device

Patent metadata

Field	Value
Publication number	US-9050687-B2
Application number	US-79000407-A
Country	US
Kind code	B2
Filing date	Apr 23, 2007
Priority date	Apr 24, 2006
Publication date	Jun 9, 2015
Grant date	Jun 9, 2015

Abstract

An apparatus that can change an irradiating direction of the beam and a method of recognizing an irradiation-enabled area with respect to a processing course for a work piece. The method establishes an irradiation-enabled area at a focal length that corresponds to one point along the processing course, even when the beam irradiating device is moved away from the one point along the processing course of the work piece. The method further recognizes the irradiation-enabled area with respect to the one point along the processing course.

First claim

The invention claimed is:

1. A method of positioning a beam irradiating device configured to change an irradiating direction of a beam of a laser welding robot by determining an irradiation-enabled area of the beam irradiating device in which the beam irradiating device can be positioned to irradiate a plurality of points along a processing course of a work piece, comprising:
establishing a cone-shaped region based on a minimum focal length and a maximum focal length of the beam and a maximum angle range from one point along a processing course of a work piece, the minimum focal length and the maximum focal length of the beam defined by the bounds of the movement of a condensing lens of the beam irradiating device, and the maximum angle range defined by the bounds of the movement of a reflecting mirror of the beam irradiating device, the cone-shaped region including a plane on a bottom surface thereof and a vertex coinciding with the one point along the processing course, wherein the height of the cone-shaped region equals the focal length;
determining the bounds of the irradiation-enabled area of the beam within the bottom surface of the cone-shaped region based on the focal length and the angle range from which the one point can be irradiated even when the beam irradiating device is moved within the irradiation-enabled area;
forming a plurality of the irradiation-enabled areas based on a plurality of points spaced apart from each other by a resolution distance along the processing course;
combining the irradiation-enabled areas into a combined irradiation-enabled area with respect to the entire processing course; and
positioning the beam irradiating device along an optimum moving path in the combined irradiation-enabled area, without requiring that the moving path track the processing course, such that all points in the processing course are processed in a minimum amount of time or with a minimum amount of movement of the beam irradiating device.

2. The method of claim 1 , further comprising:
establishing two bottom surfaces corresponding to the maximum and the minimum focal lengths of the beam, wherein each irradiation-enabled area comprises a portion of cone-shaped region disposed between the bottom surfaces.

3. The method of claim 2 , wherein one or both of the bottom surfaces of each irradiation-enabled area comprises a polygon inscribed therein in a bottom surface of a cone obtained based on the focal length and the angle range configured to irradiate the top point even when the beam irradiating device is moved.

4. The method of claim 1 , further comprising excluding an irradiation-unable range from each of the irradiation-enabled areas in which the beam cannot be irradiated due to an obstacle.

5. An apparatus for determining an irradiation-enabled area of a beam irradiated from a beam irradiating device of a laser welding robot, the beam irradiating device being configured to change an irradiating direction of the beam, comprising:
an input means for inputting a minimum focal length and a maximum focal length of the beam defined by bounds of the movement of a condensing lens of the beam irradiating device and a characteristic dimension of the irradiation-enabled area; and
a computing means for:
establishing the irradiation-enabled area located at a distance of the focal length from one point along a processing course of a work piece and based on the inputted minimum and maximum focal lengths, the characteristic dimension of the irradiation-enabled area, and a maximum angle range defined by the bounds of the movement of a reflecting mirror of the beam irradiating device, from which the one point can be irradiated even when the beam irradiating device is moved within the irradiation-enabled area;
forming a plurality of the irradiation-enabled areas based on points spaced apart from each other by a resolution distance along the processing course;
combining the irradiation-enabled areas into a combined irradiation-enabled area with respect to the entire processing course; and
establishing an optimum moving path of the beam irradiating device within the combined irradiation-enabled area, without requiring that the moving path track the processing course, such that all points in the processing course are processed in a minimum amount of time or with a minimum amount of movement of the beam irradiating device.

6. The apparatus of claim 5 , wherein the computing means extracts a portion of the combined irradiation-enabled areas disposed between the maximum and minimum focal lengths to thereby determine a combined irradiation-enabled area with respect to the entire processing course.

7. The apparatus of claim 6 , wherein the input means further inputs an area in which the beam is blocked by an obstacle, and wherein the computing means extracts the area in which the beam is blocked by the obstacle from the combined irradiation-enabled area and determines the combined irradiation-enabled area configured to substantially irradiate the entire processing course while excluding the area in which the beam is blocked by the obstacle.

8. The apparatus of claim 5 , wherein the computing means establishes the irradiation-enabled area as a plane on the bottom surface of a cone-shaped region, wherein a vertex of the cone-shaped region is the one point along the processing course and a height of the cone-shaped region is the focal length.

9. A method of determining a moving path of a beam irradiating device of a laser welding robot when processing a work piece, the beam irradiating device being capable of changing an irradiating direction of a beam, the beam having a minimum focal length and a maximum focal length defined by bounds of the movement of a condensing lens of the beam irradiating device, the method comprising:
establishing the bounds of an irradiation-enabled area corresponding to the minimum focal length and the maximum focal length of the beam and a maximum angle ranged defined by the bounds of the movement of a reflecting mirror of the beam irradiating device such that when the beam irradiating device is located anywhere within the irradiation-enabled area the beam can irradiate the one point along a processing course, wherein the work piece is processed at one point by the beam irradiated from the beam irradiating device;
forming a plurality of the irradiation-enabled areas based on points spaced apart from each other by a resolution distance along the processing course;
combining the irradiation-enabled areas into a combined irradiation-enabled area with respect to the entire processing course; and
establishing an optimum moving path of the beam irradiating device within the combined irradiation-enabled area, without requiring that the moving path track the processing course, such that all points in the processing course are processed in a minimum amount of time or with a minimum amount of movement of the beam irradiating device.

10. The method of claim 9 , further comprising excluding an irradiation-unable range from each of the irradiation-enabled areas in which the processing beam cannot be irradiated due to an obstacle.

11. The method of claim 9 , wherein a shape of the processing course includes at least one of a successive straight line, a curve, a combination of successive straight line and curve, and any opened or closed shape.

12. The method of claim 9 , wherein the beam irradiating device is configured to change the focal length of the beam outputted from an oscillator of the beam irradiating device within a desired range from the minimum focal length to the maximum focal length, the method further comprising:
establishing each irradiation-enabled area as a por

Assignees

• Tanaka Daisuke
• Nissan Motor

Inventors

• Tanaka Daisuke

Classifications

• G05B2219/40416

  Planning for variable length tool, laser beam as tool · CPC title

• G05B2219/40523

  Path motion planning, path in space followed by tip of robot · CPC title

• B23K26/0884 Primary

  in at least three axial directions, e.g. manipulators, robots · CPC title

• B25J9/1664

  characterised by motion, path, trajectory planning · CPC title

• B23K26/032

  using optical means · CPC title