Vacuum Gripper Mass Detection for Double Blank Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current automated systems for picking sheet metal workpieces from a stack often face inefficiencies due to the 'double blank' condition, where two workpieces stick together, causing damage to machinery and inefficiencies, and existing solutions like magnets and air knives are inconsistent or costly.
Innovation Solution
A system using a mount adaptor with an accelerometer and load cell connected to a manipulator, which measures acceleration and force to determine the mass of the workpiece in real-time, allowing for accurate detection of multiple workpieces and preventing double blanks without adding cost to the end-of-arm tool.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If magnets are used to prevent double blanks, then the top workpiece can be separated from the stack, but the system becomes limited to magnetic materials only and cannot handle non-magnetic materials like aluminum or plastic
Solution Approach 1:
The patent replaces the magnetic field-based separation mechanism with a vacuum suction-based mechanical attachment system. The vacuum cup creates a pressure differential that adheres to the workpiece surface regardless of material composition, enabling universal application across magnetic and non-magnetic materials while maintaining reliable double blank prevention
Solution Approach 2:
The system changes the operating parameter from magnetic field strength to vacuum pressure differential. By controlling the vacuum level and air pressure parameters, the system can adapt to different material surfaces and achieve consistent attachment and separation without being limited by material magnetic properties
2Reliability
If air knives are used to separate workpieces, then the bond between workpieces can be broken, but the application is not consistent and not always successful
Solution Approach 1:
The system incorporates sensors that detect the mass or weight of the picked workpiece and provide feedback to the control system. This feedback loop allows the system to adjust vacuum pressure, pickup force, and manipulation parameters in real-time to maintain consistent and reliable separation, preventing both single workpiece pickup failures and double blank conditions
3Difficulty of detecting and measuring
If electronic sensing devices are mounted on the end-of-arm tool to detect double blanks, then detection capability is provided, but additional costs are incurred and the sensor must be mounted within the end-of-arm tool
Solution Approach 1:
The system uses the existing vacuum cup and manipulator infrastructure to perform both the pickup function and the detection function. The vacuum cup serves dual purposes: adhering to the workpiece during pickup and enabling mass measurement through the vacuum pressure differential, eliminating the need for separate electronic sensors mounted on the end-of-arm tool
Solution Approach 2:
The system uses the workpiece's own mass to provide the detection signal. By measuring the mass of the picked workpiece through vacuum pressure differential or accelerometers, the system self-determines whether a single or multiple workpieces were picked without requiring external sensing devices mounted on the manipulator
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
This solution enables accurate and consistent detection of multiple workpieces during the lifting process, preventing double blanks and reducing machinery damage and inefficiencies, while maintaining system cost-effectiveness.
Implementation Method 1
measuring an acceleration value of the workpiece
Implementation Method 2
measuring a force value of the workpiece
Implementation Method 3
a vacuum suction cup which utilizes compressed air and a vacuum pump or venturi-type vacuum-generating device to create vacuum within the suction cup
Data Source
AI summary
An apparatus and method is provided for detecting multiple workpieces. The present invention provides a mount adaptor connected to a workpiece engaging device for engaging and manipulating a workpiece. A cell body is connected to the mount adaptor, and the cell body has an accelerometer disposed therein for measuring and signaling an acceleration value of the workpiece. A load cell is connected to the cell body and is connectable to a manipulator, wherein the load cell measures and signals a load value of the workpiece. A computer processor receives the acceleration value and the load value of the workpiece for determining the mass of the workpiece and determining whether there are multiple workpieces engaged by the workpiece-engaging device.