Robot Teaching Position Correction via Displacement Calculation

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Solution Overview

Problem

Existing methods for correcting teaching positions in robot operation programs are time-consuming and lack precision, especially when posture changes are significant, and require manual touch-up operations or accurate visual setting of tool positions.

Innovation Solution

A teaching position correcting apparatus and method that calculates a position correction amount for each teaching point, allowing for automatic correction of multiple points based on a few accurately set positions, reducing the need for manual touch-ups and improving precision by recalculating correction amounts iteratively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual touch-up operations are performed at multiple teaching points, then correction precision can be improved, but correction time increases significantly

Engineering Contradiction:
Improvecorrection precisionVSAvoidcorrection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary automatic correction of teaching point positions based on displacement amounts calculated from workpiece image recognition, before manual touch-up operations are performed. This preliminary action reduces the magnitude of subsequent manual corrections needed, thereby improving overall correction precision while reducing total correction time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system introduces an intermediary automatic correction process that acts as a bridge between offline programming and manual touch-up operations. This intermediary step calculates displacement amounts from image recognition and applies automatic position corrections, reducing the burden on manual operations and improving overall system efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If accurate visual setting of tool positions is required, then correction precision is maintained, but operation complexity increases

Engineering Contradiction:
Improvetool position precisionVSAvoidoperation complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system replaces manual visual setting and mechanical positioning with automatic image recognition and computational processing. The workpiece recognition unit captures images and calculates displacement amounts automatically, eliminating the need for operators to perform complex visual measurements and manual position calculations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs self-correction by automatically calculating displacement amounts from workpiece image recognition and applying position corrections to teaching points without requiring manual intervention for each teaching point. The robot controller autonomously processes the correction based on recognized workpiece positions.

Inventive Principle:
Principle #25Self-service

3Productivity

If offline programming is used to prepare operation programs, then programming efficiency is improved, but field correction becomes necessary when position changes occur

Engineering Contradiction:
Improveprogramming efficiencyVSAvoidfield correction necessity
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The system implements feedback by recognizing the actual workpiece position in the field, calculating displacement amounts between offline programming positions and actual positions, and using this feedback information to automatically correct teaching point positions. This closed-loop approach maintains the benefits of offline programming while adapting to field conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts teaching point positions based on actual workpiece positions detected in the field. Rather than using static offline programming data alone, the system continuously adapts positions based on real-time image recognition and displacement calculations, enabling flexible field correction.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP1834738B1Teaching position correcting apparatus and teaching position correction method
Publication Date: 2019.11.27 FANUC LTD
  • EP1834738B1 patent drawingFigure 1
  • EP1834738B1 patent drawingFigure 2
  • EP1834738B1 patent drawingFigure 3

AI summary

A teaching position correcting apparatus (1) corrects plural teaching point positions of a robot (2) in a robot operation program, by sequentially moving the robot (2) to each of the plural teaching points and by sequentially reading a current position of the robot (2) at each of the plural teaching points. The teaching position correcting apparatus (1) includes: a position correction amount calculating means (11a) that calculates a position correction amount (A), based on corrected teaching point positions and teaching point positions before correction; and a corrected-position calculating means (11b) that calculates corrected positions of teaching point positions before correction out of the plural teaching points, based on the position correction amount (A). At the time of moving the robot to uncorrected teaching points, a moving means (15) moves the robot to corrected positions of the teaching point positions before correction. Based on the above operation, even when a posture change of the robot is large, teaching point positions in the operation program can be corrected accurately in short time.