Banknote Foreign Object Detection via Pressure Sensing Array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies for detecting foreign objects in a stack of banknotes, such as staples or rubber bands, are inadequate as they may damage banknote-handling elements in automated teller machines and fail to accurately identify non-metallic objects like rubber bands or plastic paper clips.
Innovation Solution
A system with a housing, opposing clamping surfaces, and an array of pressure sensors that apply and measure pressure across the banknotes, calculating pressure gradients to detect high-pressure areas and generate signals for foreign object presence, effectively identifying objects like staples, paper clips, or rubber bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If metal detectors are used to detect foreign objects, then metallic objects can be detected, but non-metallic objects like rubber bands or plastic paper clips cannot be detected
Solution Approach 1:
The patent replaces electromagnetic detection (metal detector) with a mechanical pressure sensing system. An array of pressure sensors measures pressure distribution across the banknote stack surface when clamped, allowing detection of both metallic and non-metallic foreign objects through their mechanical impact on pressure distribution.
Solution Approach 2:
The system changes the detection parameter from electromagnetic properties (metal detector) to mechanical pressure distribution. By measuring pressure gradients and high-pressure areas across the banknote surface, the system can detect objects regardless of their material composition, achieving universal detection capability.
2Measurement precision
If X-ray imaging technology is used to detect foreign objects, then accurate detection can be achieved, but the cost becomes prohibitively expensive
Solution Approach 1:
The patent uses inexpensive pressure sensors instead of expensive X-ray imaging equipment. The pressure sensing array provides sufficient detection capability at a fraction of the cost of X-ray systems, making the solution economically viable for automated teller machines.
Solution Approach 2:
The system replaces complex X-ray imaging hardware with a simple mechanical pressure sensing array. This substitution dramatically reduces system cost while maintaining effective foreign object detection capability through pressure gradient analysis.
3Measurement precision
If pressure is applied to detect foreign objects, then detection capability is improved, but foreign objects may be damaged
Solution Approach 1:
The system applies pressure locally through multiple clamping surfaces and measures pressure distribution across an array of sensors. By analyzing pressure gradients and high-pressure areas, the system can detect foreign objects without requiring uniform high pressure that would cause damage.
Solution Approach 2:
The patent applies sufficient pressure to generate detectable pressure gradients and high-pressure areas, but not excessive pressure that would damage foreign objects. The pressure level is optimized to achieve detection sensitivity while preserving the integrity of detected objects.
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 improves detection accuracy by identifying foreign objects without damaging them, prompting users to remove them, and avoids the limitations of metal detectors and expensive X-ray imaging technologies.
Implementation Method 1
an array of pressure sensors positioned on at least one of the pair of opposing clamping surfaces and configured to measure the applied pressure across a surface area of the stack of banknotes
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An automated teller machine can use an array of pressure sensors, such as piezo-resistive sensors, to detect the presence of foreign objects, such as staples, paper clips, or rubber bands, in a stack of banknotes. A user can insert a stack of banknotes into an automated teller machine. A pair of opposing clamping surfaces can apply pressure to the stack of banknotes. An array of pressure sensors can sense non-uniformities in pressure over the area of the array. If circuitry coupled to the pressures sensors senses a presence of a high pressure area in the surface area of the banknotes, then the circuitry can generate a signal indicating that one or more foreign objects has been detected. The automated teller machine can then prompt the user to remove the stack of banknotes and remove the foreign object from the stack of banknotes.