Welding torch detector and welding robot system

Patent metadata

Field	Value
Publication number	US-10016834-B2
Application number	US-201514633754-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Feb 28, 2014
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A welding torch detector including an imaging unit capturing images of a welding torch and welding wire from a plurality of directions to acquire image signals, an image recognition unit recognizing welding wire images and welding torch images based on the image signals acquired, a setting unit setting a target point corresponding to a target position of the welding wire on the welding wire images recognized, a position detection unit detecting a position of the target point in a three-dimensional space based on the welding wire images recognized, and an inclination detection unit detecting an inclination of the welding torch in the three-dimensional space based on the welding torch images recognized.

First claim

The invention claimed is:

1. A welding torch detector, comprising:
a camera configured to capture images of a welding torch provided at an arm tip part of a welding robot and a welding wire fed from the welding torch from a plurality of directions, and acquire image signals of the welding torch and the welding wire;
an image recognition processor configured to recognize, based on the image signals acquired by the camera, a plurality of welding wire images representing the welding wire seen from the plurality of directions and a plurality of welding torch images representing the welding torch seen from the plurality of directions;
a setting processor configured to set a target point corresponding to a target position of the welding wire on the plurality of welding wire images recognized by the image recognition processor;
a position detection processor configured to detect, based on the plurality of welding wire images recognized by the image recognition processor, a position of the target point in a three-dimensional space;
an inclination detection processor configured to detect, based on the plurality of welding torch images recognized by the image recognition processor, an inclination of the welding torch in the three-dimensional space,
wherein the inclination of the welding torch is represented by a three-dimensional orthogonal coordinate system used for position control of the welding robot at the target point; and

a correction processor configured to, based on the inclination detected by the inclination detection processor, correct a command value for the inclination of the welding torch at the target point.

2. The welding torch detector according to claim 1 , wherein the setting processor is configured to set, as the target point, an intersection point between a circular arc having a predetermined radius around a tip of the welding torch image recognized by the image recognition processor and the welding wire image.

3. The welding torch detector according to claim 1 , wherein the setting processor is configured to set, as the target point, an intersection point between a virtual line away by a predetermined distance from a tip of the welding torch image recognized by the image recognition processor along a center line of the welding torch image and the welding wire image.

4. A welding robot system comprising:
a robot controller comprising the welding torch detector according to claim 1 ;
a robot configured to move the welding torch; and
a wire feeder configured to feed the welding wire from the welding torch;
wherein the robot controller is configured to control the robot, the wire feeder, and the camera, and
wherein the robot controller is configured to control the camera to capture images of the welding torch and the welding wire from a plurality of directions.

5. The welding robot system according to claim 4 , wherein
the welding torch detector further comprises a wire determination processor configured to determine whether the image recognition processor has recognized the welding wire image within a predetermined range, and
wherein the robot controller is configured to
control the wire feeder to feed the welding wire when the wire determination processor determines that the welding wire image within the predetermined range has not been recognized, and
control the camera to capture images of the welding torch and the welding wire after the wire feeder feeds the welding wire.

6. The welding robot system according to claim 4 , wherein
the welding torch detector further comprises a torch determination processor configured to determine whether the image recognition processor has recognized the welding torch image within a predetermined range,
wherein the robot controller is configured to
control the robot to move the welding torch toward an imaging region of the camera when the torch determination processor determines that the welding torch image within the predetermined range has not been recognized, and
control the camera to capture an image of the imaging region after the robot moves the welding torch.

7. The welding robot system according to claim 4 , wherein
the welding torch detector further comprises a correction processor configured to correct pre-instructed command values of a position and inclination of the target point by using the position detected by the position detection processor and the inclination detected by the inclination detection processor.

8. The welding robot system according to claim 7 , wherein,
the robot controller is configured to control the robot and the camera to move the welding torch to a predetermined position to acquire image signals of the welding torch and the welding wire at a first time point and a second time point after a predetermined time elapses from the first point time, and
when a position of the target point detected by the position detection processor and inclination of the welding torch detected by the inclination detection processor at the first time point are deviated from a position of the target point detected by the position detection processor and inclination of the welding torch detected by the inclination detection processor at the second time point, the correction processor is configured to correct the command values based on an amount of the deviation.

Assignees

• Fanuc Corp

Inventors

• Takayama Yuusuke

Classifications

• B23K9/32

  Accessories · CPC title

• B23K9/0956 Primary

  using sensing means, e.g. optical · CPC title

• B23K9/173 Primary

  and of a consumable electrode · CPC title