Metal Detection Sensor With Meandering Coils
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional metal detectors face limitations in detection range and sensitivity due to small overlapping areas between transmitter and receiver coils, leading to unsymmetrical and near-field errors, which restrict their effectiveness in industrial applications.
Innovation Solution
A sensor design featuring meandering loop sections in both transmitting and receiving coils, allowing for increased overlapping areas and rotationally symmetrical detection properties, with coils arranged to optimize field cancellation and reduce mechanical influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the coils are overlapped to cancel magnetic field, then detection sensitivity is improved, but the overlapping area is small leading to large coil systems
Solution Approach 1:
The coil windings are segmented into meandering loop sections that are distributed around the circumference. These sections are arranged to create multiple overlapping regions between transmitter and receiver coils, effectively segmenting the detection area to achieve both high sensitivity and compact size.
Solution Approach 2:
The coil sections are arranged in a two-dimensional circular pattern around the circumference rather than simple linear overlap. This dimensional arrangement creates multiple overlapping regions simultaneously, increasing the effective overlapping area without proportionally increasing the overall coil system area.
2Measurement precision
If the coils are overlapped to cancel magnetic field, then detection sensitivity is improved, but the detection properties become unsymmetrical
Solution Approach 1:
The meandering loop sections are arranged with specific angular offsets and asymmetric patterns around the circumference. This controlled asymmetry in the arrangement of transmitting and receiving coil sections creates multiple overlapping regions that collectively achieve rotationally symmetrical detection properties, canceling out directional biases.
Solution Approach 2:
Multiple meandering loop sections from different angular positions are merged to form the complete transmitter and receiver coils. The combined effect of these distributed sections creates both magnetic field cancellation and rotationally symmetrical detection characteristics.
3Measurement precision
If the coils are arranged to increase overlapping area, then detection range is improved, but mechanical deformations cause offset errors
Solution Approach 1:
The meandering loop sections are designed with flexible pathways that can accommodate mechanical deformations. The distributed circular arrangement allows the coil structure to deform dynamically without significantly changing the overlapping area between transmitter and receiver sections, maintaining measurement stability.
Solution Approach 2:
The geometric parameters of the meandering loop sections (such as loop depth and spacing) are optimized to maintain stable overlapping characteristics across a range of mechanical deformations. This parameter optimization ensures that detection range is maximized while immunity to mechanical-induced offset errors is enhanced.
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
The design enhances detection sensitivity and range while minimizing near-field errors, providing consistent object detection regardless of direction and allowing for integration into conventional industrial housings with improved sensitivity and reduced mechanical influences.
Implementation Method 1
a coil to emit an electromagnetic pulse that generates an eddy current in the metal part to be detected. This eddy current is usually received with a second coil
Implementation Method 2
generates an eddy current in the metal part to be detected
Implementation Method 3
The coils are overlapped in such a way that the emitted magnetic field is canceled out in the receiving coil without the influence of metal
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A sensor for locating metal objects has coils or coil parts which form at least one transmitting coil (5.1) and at least one receiving coil (7.1) which are inductively coupled to one another and are arranged such that said coils partially overlap for the purpose of interaction decoupling, wherein optimum cancellation of the interaction can be achieved. Sensor electronics are provided for energizing the transmitting coil and for evaluating a reception signal (10.6) from the receiving coil. As a result of the fact that the transmitting coil (5.1) and the receiving coil (7.1) substantially have an identical coil shape and are arranged such that said coils are rotated and/or offset with respect to one another, wherein a plurality of symmetrically arranged, overlapping regions (8.4) are formed, a sensor which provides a greater range and extended possibilities for installation in conventional industrial sensor housings is provided.