Control method for a robot with sensor

• US 5,582,750 A
• Filed: 01/10/1995
• Issued: 12/10/1996
• Est. Priority Date: 05/10/1993
• Status: Expired due to Term

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Makihata, Yuuki, Hamura, Masayuki
• Primary Examiner(s): Shaw, Clifford C.
• Application Number:
  US08/367,147
• Time in Patent Office: 700 Days
• Field of Search: 219/124.34, 219/125.1, 219/125.12, 318/574, 901/42
• US Class Current: 219/124.34
• 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 2219/36417 Programmed coarse position, fine position by alignment, follow line, path adaptive
• CPC Class Codes: G05B 2219/49384 Control of oscillatory movement like filling a weld, weaving

Abstract

A control means for an industrial robot having a sensor for detecting the position of an operation line, in which the position of the robot is corrected by utilizing signals detected by the sensor in executing weaving welding, overlap welding, or other operation by the robot. In effecting weaving welding or the like with a taught track (P1→ . . . →Pn) as a reference, the robot control is carried out in a sensing/correcting operation mode (Q1 to Q1-10; . . . ) where the robot position is corrected in accordance with the signals detected by the sensor as the robot moves, and in a designated-shape track operation mode where the robot starts at an end point (Q1-10, Q1-20, . . . ) of one robot track section determined during a sensing/correcting operation mode to trace a track ([B0]1-1, [B0]1-2, . . . ) of a previously designated shape, alternately. Overlap welding can be executed by utilizing the correction data obtained by executing the operation in the sensing/correcting operation mode.

Claims

1. A method for controlling a robot having sensor means, said method comprising the steps of:

(a) detecting a position of an operation line on a workpiece by said sensor means to produce detected operation line position data and correcting a previously taught track based on the detected operation line position data, and operating said robot in a sensing/correcting operation mode in which a tool supported on the robot moves along the corrected track; and

(b) operating the robot in a designated-shape track operation mode in which said tool traces another track of a predetermined shape,

wherein the operation of the robot in the designated-shape track operation mode is started at an end point of one section of the track corrected in said step (a) by intermittently switching the sensing/correction operation mode to the designated-shape track operation mode when said tool is moved to the end point, so that said steps (a) and (b) being repeatedly and alternately executed.

2. The control method for a robot with sensor means according to claim 1, wherein said tool comprises a welding torch, and weaving welding is effected by executing said steps (a) and (b).

3. The control method for a robot with sensor means according to claim 1, further comprising the step of (c) preparing a plurality of types of said tracks of predetermined shapes for said step (b), and said step (b) including a step of selecting a track shape to be realized, in accordance with a previously set program, from among said plurality of types of track shapes prepared in said step (c).

4. The control method for a robot with sensor means according to claim 3, wherein said tool comprises a welding torch, and weaving welding is effected by executing said steps (a), (b) and (c).

5. The method for controlling a robot having sensor means, said method comprising steps of:

(a) detecting a position of an operation line on a workpiece by said sensor means to produce operation line position data, in a sensing/correcting operation mode;

(b) obtaining data for position correction based on the operation line position data detected in said step (a) and position data for a previously taught track in the sensing/correcting operation mode;

(c) storing the position correction data obtained in said step (b) in memory means, in the sensing/correcting operation mode; and

(d) correcting said previously taught track in accordance with the position correction data stored in said memory means and operating the robot so that said tool moves along the corrected track, in the sensing/correcting operation mode; and

(e) operating the robot in a designated-shape track operation in which said tool traces another track of a predetermined shape,

wherein the operation of the robot in the designated-shape track operation mode is started at an end point of one section of the track corrected in said step (a) by intermittently switching the sensing/correction mode to the designated-shape track operation mode when said tool is moved to the end point, so that said steps (a-d) and step (e) are repeatedly and alternately executed.

6. The control method for a robot with sensor means according to claim 5, wherein said tool comprises a welding torch, and overlap welding is effected by executing said steps (a), (b), (c), and (d).

7. The control method for a robot with sensor means according to claim 5, wherein said step (d) includes a step of adding a shift amount to the position correction data stored in said memory means, thereby correcting said previously taught track.