Robot control apparatus

• US 5,949,683 A
• Filed: 12/19/1995
• Issued: 09/07/1999
• Est. Priority Date: 12/20/1994
• Status: Expired due to Fees

• Current Assignee: Tokico Limited (Hitachi, Ltd.)
• Original Assignee: Tokico Limited (Hitachi, Ltd.)
• Inventors: Saisaka, Noriaki, Rembutsu, Tatsuya, Akami, Yusuke
• Primary Examiner(s): Simmons, David A.
• Assistant Examiner(s): PADGETT, CALVIN F
• Application Number:
  US08/573,951
• Time in Patent Office: 1,358 Days
• Field of Search: 901/41, 901/43, 901/42, 901/47, 118/675, 118/712, 395/80, 395/99, 395/85, 395/92, 395/89, 395/88, 364/469.02
• US Class Current: 700/123
• CPC Class Codes: G05B 19/425 Teaching successive positions by numerical control, i.e. commands being entered to control the positioning servo of the tool head or end effector
• CPC Class Codes: G05B 2219/36401 Record play back, teach position and record it then play back
• CPC Class Codes: G05B 2219/36458 Teach only some points, for playback interpolation between points

Abstract

A robot control apparatus does not require an expert to perform programming, prepare teaching data or reprogram the motions of a work robot. The controller for the robot accepts the teaching point instructed by a beginner operator, and computes the start and end points in a track from the input teaching points. The controller also computes target start and end points in each of the passes in the track based on the current track points and the overspray width input by the operator and automatically allows for the overspray width. The control apparatus therefore facilitates operation of painting tasks which conventionally required a labor-intensive effort in reprogramming by an expert operator.

Claims

1. In a robot control apparatus for controlling a robot which performs work using a work tool on a workpiece disposed on a work platform, an improvement comprising:

memory means for storing a plurality of coordinate data for defining teaching points arranged within a capacity range of movement of said work tool;

track points data computation means for computing a plurality of track points based on said coordinate data surrounding a work range;

correction data computations means for computing values of distance corrections, when corrections in track point data are requested, by calculating a difference in distance between a current track point as computed by the track points data computation means and a target track point, and memorizing said difference as correction data in said memory means; and

target track point data computation means for computing target track point data by adding said correction data to current track point data.

2. A robot control apparatus as claimed in claim 1, wherein said work range has approximately a rectangular shape;

and when the four corners of the rectangular shape are taught to said robot control apparatus and a number of passes corresponding to a number of passes of said robot over said workpiece are input to said robot control apparatus, said plurality of teaching points are the four corners of the rectangular shape and the corners of rectangles formed by equally dividing the rectangular shape by said number of passes along a single direction.

3. A robot control apparatus as claimed in claim 1, wherein said correction data computation means store each of said correction data together with an identity number assigned to said target track point in memory means, and said target track point data computation means correct a track point specified by said identity number with correction data matching said identity number.

4. A robot control apparatus comprising:

teaching data generation means for generating teaching data for a robotic means;

memory means for storing said teaching data;

control means for controlling motions of said robotic means based on said teaching data;

instruction means for instructing corrections for said teaching data; and

teaching data correction means for correcting said teaching data stored in said memory means while said control means control motions of said robotic means based on instructions generated by said instruction means.

5. A robot control apparatus as claimed in claim 4, wherein said control means control said robotic means so that a specific component of said robotic means successively moves through a plurality of track defining points defined by coordinate points in a specified order;

said instruction means specifies a current track point and a target track point; and

said teaching data correction means alter coordinate data of said current track point to coordinate data of said target track point while said control means control motions of said robotic means.

6. A robot control apparatus as claimed in claim 4, wherein said instruction means specify a moving speed of a specific component of said robotic means, said teaching data correction means correct said moving speed based on instruction data generated by said instruction means while said control means control motions of said robotic means.

7. A robot control apparatus as claimed in claim 4, wherein said instruction means specify a quantity of a task performed by said robotic means, said teaching data correction means correct said quantity of said task based on said instruction data while said control means control motions of said robotic means.

8. A robot control apparatus as claimed in one of claims 5 to 7, wherein:

said teaching data comprise coordinate data for each of said track defining points, said moving speed when said specific component of said robotic means is passing said track defining point, and said quantity of a task when said specific component of said robotic means is passing said track defining point;

said instruction means specify at least one of (a) said plurality of track defining points, and corrected values of the coordinate data for each of said track defining points, (b) the moving speed at said track defining point, and (c) the quantity of a task at said track defining point; and

said teaching data correction means simultaneously alter (a) said coordinate data, (b) said moving speed or (c) said quantity of work to said corrected values specified by said instruction means for each of said plurality of track defining points.

9. In a robot control apparatus for controlling a robot which performs work using a work tool on a workpiece disposed on a work platform, an improvement comprising:

memory means for storing a plurality of coordinate data for defining teaching points arranged within a capacity range of movement of said work tool;

track points data computation means for computing a plurality of track points based on said coordinate data surrounding a work range;

correction data computation means for computing values of distance corrections, when corrections in track point data are requested, by calculating a difference in distance between a current track point as computed by the track points data computation means and a target track point, and memorizing said difference as correction data in said memory means; and

target track point data computation means for computing target track point data by subtracting said correction data from said current track point data.

10. A robot control apparatus as claimed in claim 9, wherein said work range has approximately a rectangular shape;

and when the four corners of the rectangular shape are taught to said robot control apparatus and a number of passes corresponding to a number of passes of said robot over said workpiece are input to said robot control apparatus, said plurality of teaching points are the four corners of the rectangular shape and the corners of rectangles formed by equally dividing the rectangular shape by said number of passes along a single direction.

11. An apparatus as in claim 9, wherein said correction data computation means store each of said correction data together with an identity number assigned to said target track point in said memory means, and said target track point data computation means correct a track point specified by said identity number with correction data matching said identity number.