Robot Calibration Using Optical Reference Markers

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Solution Overview

Problem

Current robot calibration methods are prone to human error and are time-consuming, especially when determining the position and posture of calibration tools, leading to inaccuracies and increased complexity as the number of robots increases.

Innovation Solution

A control device that uses a robot system with a fixed camera and a mobile camera to capture reference markers, allowing for the acquisition of the posture of a reference surface based on images, reducing human intervention and improving accuracy by determining the posture in a non-contact state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a worker manually determines the contact state between the calibration tool and touch-up hand, then the position and posture of the calibration tool can be determined, but human error causes inaccuracies in determination

Engineering Contradiction:

Improveaccuracy of position and posture determinationVSAvoidmanual intervention in calibration

Core Design Contradiction:

Measurement precisionVSExtent of automation

Solution Approach 1:

The patent replaces the manual mechanical contact determination method with an optical imaging system. The imaging portion captures images of reference markers on the calibration tool, and the control device automatically calculates position and posture from these images, eliminating human error in contact state determination.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses reference markers that create optical copies/images of the calibration tool's position and posture. By capturing images of these markers and processing them computationally, the system obtains accurate position and posture data without manual measurement.

Inventive Principle:

Principle #26Copying

2Measurement precision

If a worker manually confirms the contact state to ensure accurate determination, then measurement accuracy improves, but the calibration process takes a long period of time

Engineering Contradiction:

Improveaccuracy of contact state determinationVSAvoidcalibration time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces time-consuming manual confirmation with automated optical imaging and computational processing. The imaging portion rapidly captures images of reference markers, and the control device automatically calculates position and posture, significantly reducing calibration time while maintaining or improving accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs self-calibration through automated image capture and processing. The control device automatically determines position and posture from captured images without requiring worker intervention, enabling the system to calibrate itself rapidly and accurately.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If the number of robots requiring calibration increases, then system capability improves, but the total calibration time increases significantly

Engineering Contradiction:

Improvenumber of robots that can be calibratedVSAvoidtotal calibration time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces manual calibration methods with automated optical imaging and computational processing. This automation enables rapid calibration of multiple robots sequentially or in parallel, as the system can quickly capture images and calculate position and posture data without worker intervention for each robot.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The imaging portion and control device enable continuous calibration processing. Once the imaging system is set up, multiple robots can be calibrated in sequence without interruption, as the automated system continuously captures images and processes position/posture calculations without requiring worker repositioning or manual confirmation for each robot.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS10201900B2Control device, robot, and robot system

Publication Date: 2019.02.12 SEIKO EPSON CORP

AI summary

A control device is capable of controlling each of a robot having a robot arm, and an imaging portion which is capable of capturing a first reference marker, a second reference marker, and a third reference marker, any one of the imaging portion, the first reference marker, the second reference marker, and the third reference marker is provided in the robot, and a posture of a reference surface parallel to a plane which passes through the first reference marker, the second reference marker, and the third reference marker, is acquired based on a first image in which the first reference marker is captured by the imaging portion, a second image in which the second reference marker is captured by the imaging portion, and a third image which captures the third reference marker by the imaging portion.