Robot control method for processing a workpiece on a processing line

• US 10,152,034 B2
• Filed: 03/26/2015
• Issued: 12/11/2018
• Est. Priority Date: 03/27/2014
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Komatsu, Takamichi, Yoshima, Kazumasa, Ikeda, Tatsuya
• Primary Examiner(s): Lee, Adam
• Application Number:
  US15/126,881
• Publication Number:
  US 20170090431A1
• Time in Patent Office: 1,356 Days
• CPC Class Codes: B23K 9/1274 Using non-contact, optical means, e.g. laser means
• CPC Class Codes: B25J 9/1684 Tracking a line or surface by means of sensors
• CPC Class Codes: G05B 13/0265 the criterion being a learning criterion
• CPC Class Codes: G05B 19/406 characterised by monitoring or safety G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/36415 Adjust path and attitude tool by detecting path, line with a photosensor, laser
• CPC Class Codes: G05B 2219/36433 Position assisted teaching
• CPC Class Codes: G05B 2219/40385 Compare offline teached point with online teached point, modify rest as function of error
• CPC Class Codes: G05B 2219/45135 Welding
• CPC Class Codes: G05B 2219/4701 Edge detector, project line, inclined camera detects discontinuity
• CPC Class Codes: G05B 2219/4705 Detect edge during machining, welding, sewing
• CPC Class Codes: G05B 2219/4719 Line detector with laser beam, adjustable optical axis

Abstract

A robot control method includes a teaching step, first processing step, modifying step, second processing step, and third processing step. In the modifying step, a third teaching point is changed to a second modified point, a fourth teaching point to a third modified point, and a fifth teaching point to a fourth modified point, based on a difference between a second teaching point and a first modified point. A profile modifying control to change the position of a work tool is applied, using a sensor mounted on the processing advancing direction side of the work tool, in the first processing step and the third processing step. An attitude of the work tool is changed during the second processing step.

Claims

1. A robot control method for performing processing on a workpiece on a processing line using a work tool and a sensor mounted on the processing line in advance of the work tool, the processing line including a plurality of teaching points for the workpiece, the robot control method comprising:

setting, in advance of the processing of the workpiece, a first teaching point, a second teaching point, a third teaching point, a fourth teaching point, and a fifth teaching point on the processing line for the workpiece, each of the first teaching point, the second teaching point, the third teaching point, the fourth teaching point, and the fifth teaching point corresponding to a position of the work tool during the processing of the workpiece in a process advancing direction on the processing line, the third teaching point corresponding to a turning point of the work tool on the processing line;

a first processing of performing the processing on the workpiece using the work tool from the first teaching point to the second teaching point on the processing line and applying a profile modifying control to change the position of the work tool with respect to the processing line based on a shape of the workpiece detected by the sensor;

changing, based on a difference between the second teaching point and a first modified point, the third teaching point to a second modified point, the fourth teaching point to a third modified point, and the fifth teaching point to a fourth modified point, wherein the first modified point is a point reached by the profile modifying control in the first processing based on the shape of the workpiece detected by the sensor and corresponding to the second teaching point;

a second processing of performing the processing on the workpiece using the work tool from the first modified point through the second modified point, and then to the third modified point; and

a third processing of performing the processing on the workpiece using the work tool from the third modified point to the fourth modified point and applying the profile modifying control to change the position of the work tool with respect to the processing line based on the shape of the workpiece detected by the sensor, wherein an angle of the work tool with respect to the processing line is changed during the second processing of the workpiece.

2. The robot control method of claim 1, wherein the profile modifying control is not applied during the second processing.

3. The robot control method of claim 1, wherein a distance between the second teaching point and the third teaching point is shorter than a distance between the work tool and the sensor.

4. The robot control method of claim 1, wherein the work tool is an arc welding torch, the sensor is a laser sensor, and the processing line is a welding line.

5. The robot control method of claim 1, wherein the work tool is a laser head for laser welding, the sensor is a laser sensor, and the processing line is a welding line.

6. The robot control method of claim 1, wherein the angle of the work tool with respect to the processing line is fixed during the first processing.

7. The robot control method of claim 1, wherein the angle of the work tool with respect to the processing line is fixed during the third processing.