3D Workpiece Pickup Counting With Cavity-Aware Volume Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pick-and-place systems face challenges in accurately estimating the number of workpieces picked up, especially with small, thin, or adhesive workpieces, due to incorrect detection of cavities and multiple workpieces being picked up simultaneously, leading to increased complexity and cost with separate sensor usage.
Innovation Solution
A hand system that includes a three-dimensional information acquiring unit, workpiece shape information acquiring unit, and picking-up workpiece number calculating unit, which uses vision sensors to calculate the range of workpieces picked up, considering cavities in the loading region, to accurately estimate the number of workpieces picked up.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors (force sensor, electromagnetic induction type sensor, pressure sensor, or photoelectric sensor) are used to calculate the picking-up workpiece number, then the measurement accuracy is improved, but the device complexity and cost increase
Solution Approach 1:
The patent merges the workpiece number detection function into the existing vision sensor system by analyzing three-dimensional information from multiple viewpoints. Instead of adding separate sensors, the system combines imaging data from different angles to calculate the volume difference and determine the number of picked-up workpieces, thereby improving measurement accuracy without increasing device complexity
Solution Approach 2:
The vision sensor is made multi-functional by enabling it to perform both positioning and workpiece number detection tasks. The same vision sensor that captures workpiece positions is also used to calculate volume differences for determining picked-up workpiece numbers, eliminating the need for dedicated additional sensors and reducing overall system complexity
2Measurement precision
If additional sensors are used to measure the picking-up workpiece number, then the measurement precision is improved, but the cycle time increases
Solution Approach 1:
The system combines workpiece positioning and number detection into a single vision sensor measurement process. By capturing three-dimensional information from multiple viewpoints simultaneously and processing the volume difference in real-time, the system achieves accurate workpiece number detection without requiring sequential additional measurements, thus maintaining short cycle times
Solution Approach 2:
The system performs preliminary three-dimensional scanning of the workpiece pile from multiple viewpoints before the picking operation. This preliminary action captures the initial volume data, which is then compared with post-picking data to determine the number of workpieces removed, enabling rapid detection without adding time to the picking cycle
3Ease of manufacture
If the picking-up workpiece number is calculated by dividing the volume difference by the volume per workpiece, then the calculation process is simplified, but the measurement precision deteriorates due to undetected cavities
Solution Approach 1:
The system segments the workpiece pile into multiple regions by capturing images from multiple viewpoints and reconstructing three-dimensional information. This segmentation allows the system to identify and account for cavity regions separately, preventing misinterpretation of volume differences and improving the accuracy of workpiece number calculation while maintaining the simplicity of the volume division method
Solution Approach 2:
The patent introduces an intermediary analysis step that processes the three-dimensional information from multiple viewpoints to identify cavity regions. This intermediary process acts as a mediator between the simple volume difference calculation and the complex reality of irregular workpiece arrangements, correcting for cavities and improving measurement precision without significantly complicating the overall calculation process
4Device complexity
If a vision sensor is used to detect workpiece positions, then the system complexity is reduced, but the detection accuracy deteriorates for small, thin, or adhesive workpieces due to erroneous multiple workpiece pickup
Solution Approach 1:
The system transitions from two-dimensional image analysis to three-dimensional volume analysis by capturing images from multiple viewpoints and reconstructing three-dimensional information. This dimensional change allows accurate detection of workpiece volume differences, enabling precise determination of picked-up workpiece numbers even for small, thin, or adhesive workpieces that are difficult to detect with conventional vision systems
Data Source
AI summary
This workpiece retrieval count calculation device comprises: a three-dimensional information acquisition unit for acquiring three-dimensional information pertaining to a subject space in which a plurality of workpieces are loaded; a workpiece shape information acquisition unit for acquiring shape information pertaining to the workpieces; and a workpiece retrieval count calculation unit for calculating a range of workpiece retrieval counts, in consideration of cavities within a workpiece loading region, on the basis of the three-dimensional information pertaining to the subject space and the shape information pertaining to the workpieces from before and after retrieval of the workpieces.