Robot Picking Control with Image-Based Workpiece Displacement Tracking
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Solution Overview
Problem
The existing robot control systems face challenges in accurately picking up workpieces due to displacement between the coordinate measuring machine's measurement and the robot's task execution, as the measurement interval is too long, leading to potential failure in the picking task.
Innovation Solution
Incorporating an image capturing apparatus with shorter image capture intervals than the coordinate measuring machine's measurement intervals, allowing the control device to compute the workpiece's position and detect displacement using image capture results between measurements, ensuring accurate positioning and orientation for the robot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the coordinate measuring machine is used to measure the three-dimensional shape of the workpiece, then the robot can operate in accordance with the measured shape to hold the workpiece properly, but the measurement interval is too long causing the workpiece to be displaced before the robot performs the picking task
Solution Approach 1:
The system segments the measurement and monitoring functions into two separate devices: a coordinate measuring machine for precise three-dimensional shape measurement at lower frequency, and an image capturing apparatus for continuous position monitoring at higher frequency. This segmentation allows each device to operate optimally - the measuring machine provides accurate geometric data while the image apparatus continuously tracks workpiece position to detect displacement, thereby resolving the contradiction between measurement precision and task reliability.
Solution Approach 2:
The image capturing apparatus serves as an intermediary between the coordinate measuring machine and the robot. It continuously monitors workpiece position and provides real-time position information to the control device, which then adjusts robot operations accordingly. This intermediary role allows the system to maintain high picking success rates by detecting displacement early, while still relying on the coordinate measuring machine for accurate three-dimensional shape data.
2Device complexity
If the coordinate measuring machine conducts measurement at long intervals, then measurement time and system complexity are reduced, but the workpiece may be displaced in the period between measurement and robot task execution
Solution Approach 1:
The system divides the monitoring function into two segments with different purposes and frequencies: the coordinate measuring machine performs comprehensive three-dimensional shape measurement at longer intervals, while the image capturing apparatus performs continuous position monitoring at shorter intervals. This segmentation maintains system complexity at acceptable levels while ensuring workpiece position accuracy through the supplementary high-frequency image monitoring.
Solution Approach 2:
The image capturing apparatus serves multiple functions: it continuously monitors workpiece position to detect displacement, provides real-time position feedback to the control device, and supplements the coordinate measuring machine's data. This multi-functionality allows the system to maintain high reliability without significantly increasing overall complexity, as a single device performs multiple critical roles.
Data Source
AI summary
A robot control system according to one or more embodiments may include a robot that performs a task in relation to a workpiece, a coordinate measuring machine that measures a three-dimensional shape of the workpiece, a control device that controls the robot in accordance with a measurement result from the coordinate measuring machine, and an image capturing apparatus that captures an image of the workpiece. An image capture interval for the image capturing apparatus is shorter than a measurement interval for the coordinate measuring machine. In a period after the coordinate measuring machine conducts a measurement and until the robot performs the task, the control device is configured to compute a position of the workpiece by referring to an image capture result from the image capturing apparatus.