Vision-Based Robot Calibration Across Multiple Workstations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robotic systems in manufacturing face inaccuracies due to internal faults, leading to discrepancies between commanded movements in a virtual coordinate system and actual movements in real space, resulting in errors during operations.
Innovation Solution
A method involving hand-eye calibration and cross-station calibration between workstations, using a camera system and a controllable motion system to determine relationships between coordinate systems, allowing for precise control and movement of work objects across separate workstations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a robot is perfectly manufactured and maintained, then commanded movements in the motion coordinate system would perfectly replicate actual movements in real space, but real-world robots exhibit internal inaccuracies or faults that cause errors between commanded and actual movements
Solution Approach 1:
The patent performs preliminary calibration actions before actual manufacturing operations. A calibration object is positioned at multiple known locations, and the system captures images and records actual robot movements to establish correction transforms. This preliminary calibration data is then applied during subsequent operations to compensate for robot inaccuracies, ensuring consistent movement reliability.
Solution Approach 2:
The system implements feedback by comparing commanded movements with actual measured movements using vision systems. The calibration process captures feedback information about robot positioning errors at multiple locations, which is then used to generate correction transforms. This feedback loop allows the system to identify and compensate for internal inaccuracies in the robot's motion system.
2Productivity
If multiple workstations are used for manufacturing operations, then productivity increases, but coordinating accurate movements across separate workstations becomes more complex
Solution Approach 1:
The patent creates a universal calibration framework that works across multiple separate workstations. The same calibration methodology and transform coordination system are applied at each workstation, allowing the system to handle multiple stations with a unified approach. The calibration object and coordinate system relationships are made universal across all workstations, simplifying the coordination complexity.
Solution Approach 2:
The patent introduces an intermediary coordinate system and calibration framework that mediates between multiple workstations. By establishing a common calibration object and coordinate system relationships that span across workstations, the system creates an intermediary reference framework that simplifies the coordination of accurate movements between separate stations without requiring complex direct pairwise calibrations.
3Measurement precision
If hand-eye calibration is performed at each workstation, then local accuracy is improved, but the relationship between coordinate systems across different workstations remains uncoordinated
Solution Approach 1:
The patent merges the local hand-eye calibration at each workstation with a global cross-station calibration framework. Instead of treating each workstation's calibration independently, the system combines them by using a common calibration object and coordinate system relationships that link all workstations together. This merging ensures that local positioning accuracy at each station is maintained while also achieving cross-station accuracy through coordinated transform relationships.
Data Source
AI summary
A vision-based manipulations system can be configured for, and can be operated with methods including, performing hand-eye calibrations at multiple workstations of the system, performing a cross-station calibration for the system, and determining relationships between the hand-eye calibrations and the cross-station calibration. In some embodiments, the system can be used to move a work object between the workstations based on the cross-station calibration.