Robot Path Correction Using Optical Reference Markings

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Solution Overview

Problem

Existing robot path creation methods, particularly for tasks like welding and cutting, require high expertise and multiple correction loops due to kinematic and dynamic limitations, leading to inaccuracies in following desired paths and maintaining constant speed.

Innovation Solution

A method and robot controller that detect a reference path marking, modify path points and speed/acceleration based on this marking, and generate additional points to improve path fidelity and reduce speed fluctuations, using contactless detection means like optical sensors and adaptable reference markings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual teaching method is used to program robot paths, then path creation can be performed with simple equipment, but path accuracy and speed consistency deteriorate due to kinematic and dynamic limitations

Engineering Contradiction:
Improvepath accuracyVSAvoidpath creation complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces manual mechanical teaching operations with an optical measurement system. A measurement device with optical sensors detects reference markings on the workpiece to automatically determine path points, substituting the mechanical manual teaching process with an optical measurement and calculation system that computes corrected path points based on detected positions and robot kinematics.

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

Solution Approach 2:

The system enables the robot to self-correct its path by automatically processing measurement data. The control device calculates corrected path points using the detected reference marking positions and robot kinematic parameters, allowing the robot to autonomously compensate for its own kinematic and dynamic limitations without requiring manual intervention for each correction.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If multiple correction loops are implemented to improve path accuracy, then path fidelity improves, but operating time and complexity increase

Engineering Contradiction:
Improvepath fidelityVSAvoidpath creation time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs path correction in advance by measuring reference markings before robot execution and pre-calculating all corrected path points. The control device computes the entire corrected path trajectory beforehand based on detected reference positions and robot kinematics, eliminating the need for multiple iterative correction loops during actual robot operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from optical measurement of reference markings to correct the robot path. The measurement device detects actual reference marking positions, the control device compares these with expected positions, and automatically calculates corrected path points that compensate for deviations, creating a closed-loop correction system that eliminates manual trial-and-error adjustments.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If high expertise is required for path creation, then path accuracy can be achieved, but ease of operation deteriorates

Engineering Contradiction:
Improvepath accuracyVSAvoidoperational simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent replaces expert manual teaching operations with an automated optical measurement and calculation system. The measurement device automatically detects reference markings and the control device automatically calculates corrected path points using robot kinematics, substituting the need for expert manual path creation with an automated system that requires minimal operator skill.

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

Solution Approach 2:

The system enables automatic path creation that serves itself by processing measurement data and calculating corrections without expert intervention. The control device automatically computes corrected path points based on detected reference markings and robot parameters, allowing operators without specialized path creation expertise to achieve accurate robot paths through simple operation of the automated system.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach simplifies and accelerates the creation of precise robot paths, reducing deviations and improving path accuracy, allowing for automated optimization and reduced expertise requirements in operating personnel.

Implementation Method 1

the reference path marking is detected contactlessly, in particular electromagnetically, in particular optically, by means of a detection means

Methodology Applied
Scientific EffectOptical detection: Light

Data Source

PatentEP3541586A1Method and robot control system for creating a path of a robot
Publication Date: 2019.09.25 KUKA DEUT GMBH

AI summary

The invention relates to a method for creating a path (B) of a robot (1) comprising the following steps: sensing (S30 - S60) a reference path marking (3; 3'); and modifying (S30, S50) at least one specified path point (P10, P20) and/or one specified path velocity and/or path acceleration of the robot path and/or generating (S50) at least one path point (P15) on the basis of the sensed reference path marking.