Robot Picking Fingers Using Pressure Sensing for Count Accuracy
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Solution Overview
Problem
Conventional methods struggle to reliably detect and pick small or glossy workpieces due to difficulties in accurately determining their positions and postures, leading to failures in grasping and often requiring time-consuming re-detection before each picking operation.
Innovation Solution
A robot system with flexible fingers and pressure distribution sensors that adaptively adjust their position to ensure the correct number of workpieces is grasped, using learned models to recognize the number of workpieces based on pressure distribution and control the robot's movement to achieve accurate picking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If image sensors or depth sensors are used to detect workpiece positions and postures, then picking can be performed with automated control, but detection reliability deteriorates for small, metal, or glossy workpieces
Solution Approach 1:
The patent replaces optical detection systems (image sensors, depth sensors) with a mechanical detection system using pressure distribution sensors embedded in the fingers. This substitution allows reliable detection of workpiece presence and quantity through tactile feedback during grasping, overcoming the limitations of optical methods for small, metal, or glossy workpieces.
Solution Approach 2:
The picking system performs self-verification by using the pressure distribution sensors in the fingers to automatically detect and verify the number of workpieces grasped. The system compares detected values with target values and autonomously adjusts grasping operations without requiring external verification or manual intervention.
2Productivity
If the robot mechanism grasps workpieces without verifying the number, then picking speed is improved, but picking accuracy deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where pressure distribution sensors detect the actual number of workpieces grasped, this information is fed back to the control section, which then compares it with the target number and adjusts subsequent grasping operations accordingly. This closed-loop control ensures both speed and accuracy in picking operations.
Solution Approach 2:
The system performs preliminary detection of workpiece number and posture using the pressure distribution sensors before finalizing the grasping action. This preliminary verification allows the system to adjust its grasping strategy in advance, ensuring accurate picking without requiring slow, iterative adjustments during execution.
3Manufacturing precision
If the position and posture of workpieces are detected before each picking operation, then grasping accuracy is improved, but processing time increases
Solution Approach 1:
Instead of detecting workpiece position and posture before grasping, the patent inverts the sequence by performing detection during the grasping action itself using pressure distribution sensors. This reversal eliminates separate detection steps and integrates measurement into the execution phase, reducing time loss while maintaining accuracy.
Solution Approach 2:
The patent merges the detection function and grasping function into a single integrated operation. The pressure distribution sensors embedded in the fingers simultaneously perform grasping and detection, eliminating the need for separate detection phases and reducing overall processing time while maintaining grasping accuracy.
4Stability of the object's composition
If rigid fingers are used for grasping, then structural stability is improved, but adaptability to different workpiece shapes and numbers deteriorates
Solution Approach 1:
The patent employs flexible fingers with embedded pressure distribution sensors that can deform and adapt to different workpiece shapes and quantities. This flexibility allows the fingers to conform to various geometries while the embedded sensors maintain structural integrity and provide accurate detection feedback.
Solution Approach 2:
The system dynamically adjusts grasping parameters such as finger position, pressure distribution, and grasping force based on real-time feedback from pressure sensors. This parameter adjustment capability allows the same rigid-finger structure to adapt to different workpiece types, shapes, and numbers while maintaining structural stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable and efficient picking of workpieces without prior detection of their position and posture, ensuring high accuracy and adaptability in grasping the desired number of workpieces.
Implementation Method 1
the detecting section includes a pressure distribution sensor provided at a grasping surface of at least one finger and detecting a pressure distribution of the grasping surface that the workpiece contacts
Implementation Method 2
at least one of the plurality of fingers may be structured by an elastic member
Data Source
AI summary
Provided is a robot system comprising: a robot mechanism provided with fingers for grasping a workpiece; a detection unit that detects a grasping state of the workpiece by the fingers; a recognition unit that recognizes the number of workpieces being grasped by the fingers on the basis of a detection result from the detection unit; and a control unit that, after causing the robot mechanism to perform a motion of grasping the workpieces from a placing area where a plurality of workpieces are placed, if the number of the workpieces recognized by the recognition unit is different from a specified number specified in advance, controls the motion of the robot mechanism such that the number of the grasped workpieces is equal to the specified number.