Robot-Mounted Mobile Positioning With Visual Error Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems with robot-mounted mobile devices face accuracy issues due to positioning errors exceeding the movable range of the robot's acting part, leading to system shutdowns and reduced availability.
Innovation Solution
A robot-mounted mobile device with a camera and controller system that captures images of identification figures on machine tools to estimate positional errors, allowing for precise compensation of the robot's operating poses to avoid singularities and improve positioning accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the automatic guided vehicle moves to the operation position, then the robot can perform operations with respect to multiple machine tools, but the positioning accuracy becomes insufficient due to wheel-based movement
Solution Approach 1:
The patent replaces the mechanical wheel-based positioning system with an optical measurement system. A camera captures images of identification figures (markers) on the machine tool, and the control unit calculates the actual operation position based on image processing, substituting mechanical positioning with optical measurement for higher precision.
Solution Approach 2:
The system implements feedback by capturing the actual position through camera imaging of identification figures, comparing it with the target position, and compensating the robot's operating pose based on the calculated positioning error. This closed-loop feedback ensures accurate positioning despite AGV movement errors.
2Measurement precision
If the positioning error of the automatic guided vehicle is compensated by adjusting the robot's operating pose, then the positioning accuracy is improved, but the robot cannot compensate when the error exceeds the movable range of the acting part
Solution Approach 1:
The patent performs preliminary action by pre-calculating the relationship between AGV position errors and required robot compensation poses during the teaching phase. The system stores multiple operating poses that can be selected based on the magnitude and direction of positioning errors, enabling compensation before the error becomes critical.
Solution Approach 2:
The system dynamically adjusts the robot's operating pose based on the calculated positioning error. Instead of a fixed compensation method, the control unit selects and applies appropriate compensation strategies from multiple pre-programmed poses, allowing adaptive response to varying error conditions and preventing system shutdowns.
3Measurement precision
If a visual target with two calibration markers is used for position compensation, then the relative positional relation can be measured, but the compensation is limited by the robot's singularity constraints
Solution Approach 1:
The patent segments the identification figure into multiple distinguishable features (patterns, colors, shapes) that can be independently recognized by the camera. This segmentation allows the system to calculate both position and orientation information from a single visual target, expanding the compensation capability beyond simple positional adjustment.
Solution Approach 2:
The system transitions from two-dimensional marker recognition to three-dimensional pose estimation by analyzing the spatial relationship between multiple features on the identification figure. This dimensional enhancement enables comprehensive compensation of both positional and orientational errors, overcoming robot singularity limitations.
Data Source
AI summary
Based on a second identification position as a position of an identification figure when an image of the identification figure is captured by a camera (31) at a second device position different from a first device position, when the second identification position is within a predetermined range from the second device position, the position of a hand unit (29) is adjusted, and when the second identification position is out of the predetermined range from the second device position, the position of a moving unit (35) is adjusted by moving the moving unit (35).