Robot Welding Teaching with Single-Marker Camera Calibration
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Solution Overview
Problem
Current robot teaching systems rely heavily on skilled operators to generate precise teaching data, especially for welding operations, which can be time-consuming and error-prone, and require the installation of multiple reference markers, limiting their efficiency and accuracy.
Innovation Solution
A robot teaching system that uses a camera to photograph both the welding target and a marker installed on the industrial robot's end effector to generate a working program, allowing for accurate detection and calibration of the welding position, enabling the system to set an appropriate operation path and reduce errors due to thermal distortion or workpiece alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple reference markers are installed for robot position recognition, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The invention extracts the calibration function from a multi-marker system and concentrates it into a single marker. The camera captures images of this single marker at multiple positions to obtain calibration data, eliminating the need for multiple reference markers while maintaining calibration accuracy.
Solution Approach 2:
The single marker serves multiple functions: it acts as both the reference marker for calibration and the target object for recognition. By moving this single marker to different positions, the system achieves what previously required multiple stationary markers, simplifying the overall device configuration.
2Manufacturing precision
If a skilled operator manually generates teaching data, then manufacturing precision is improved, but loss of time increases
Solution Approach 1:
The system enables automatic teaching data generation through self-service mechanisms. The camera automatically captures images of the marker at various positions, and the control device automatically processes these images to generate teaching data, eliminating the need for manual operator intervention while maintaining precision.
Solution Approach 2:
The invention replaces the manual mechanical operation of teaching pendant with an automated optical system. The camera-based image capture and automatic image processing substitute for the skilled operator's manual movements and judgments, achieving both time savings and consistent precision.
3Productivity
If camera photographs welding target and marker simultaneously, then productivity is improved, but measurement precision may worsen due to distance
Solution Approach 1:
The system employs dynamic positioning where the marker is moved to different positions relative to the welding target during the calibration process. This dynamic approach allows the camera to capture both the marker and target in the same field of view while ensuring the marker remains within the optimal recognition range, balancing productivity and precision.
Data Source
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AI summary
A robot teaching system includes: a photographing unit that photographs an image including a welding target and a marker installed on an industrial robot; a camera coordinate system setting unit that sets a camera coordinate system on a basis of the marker included in the image; an operation path setting unit that sets an operation path of the industrial robot on a basis of a welding position of the welding target included in the image in the camera coordinate system; and a program generation unit that generates a working program, while converting the set operation path from the camera coordinate system into a robot coordinate system set in a robot control apparatus on a basis of a position of the marker installed on the industrial robot. The robot teaching system generates a working program allowing appropriate welding at a welding position.