Inductive Sensor Coil Segmentation for Extended Switching Distance
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Solution Overview
Problem
Existing inductive sensor technologies face limitations in achieving increased sensitivity and switching distance while maintaining a compact design for detecting the position and material properties of test objects, particularly across different metals.
Innovation Solution
The method employs a configuration of at least two driver coils and two sensor coils, where one group is connected in the same direction and the other in opposite directions, allowing for enhanced sensitivity by canceling out initial voltages and amplifying changes induced by test objects, with specific sampling times used to differentiate between amplitude and phase shifts for accurate detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inductive sensor designs are used, then the sensor can detect test objects, but the switching distance is limited and sensitivity is reduced
Solution Approach 1:
The sensor is divided into multiple driver coils (at least two) and multiple sensor coils (at least two), with each coil pair contributing to the overall measurement. This segmentation allows for increased switching distance while maintaining sensitivity by distributing the detection function across multiple elements rather than relying on a single coil pair.
Solution Approach 2:
Multiple driver coils and sensor coils are combined in a coordinated manner, with their outputs integrated to produce the final measurement signal. This merging of multiple coil signals amplifies the overall effect, enabling detection at larger distances while maintaining the sensitivity required for accurate measurement.
2Length of stationary object
If the sensor is designed for increased switching distance, then detection range is improved, but sensitivity and detection accuracy deteriorate
Solution Approach 1:
By segmenting the sensor into multiple coil pairs, each operating at optimized parameters, the system maintains high detection accuracy across extended switching distances. Each coil pair can be tuned to contribute optimally to the measurement, preserving sensitivity even as the overall detection range increases.
Solution Approach 2:
The sensor system incorporates feedback mechanisms where the output signals from multiple sensor coils are processed and combined in a way that compensates for distance-related signal attenuation. This feedback processing ensures that detection accuracy is maintained across the extended switching distance range.
3Length of stationary object
If multiple driver coils and sensor coils are used to increase switching distance, then detection range is improved, but device complexity increases
Solution Approach 1:
The multiple coil system is segmented into modular driver coil groups and sensor coil groups that can be independently configured and optimized. This modular segmentation reduces the overall complexity by allowing each segment to be designed and adjusted separately rather than requiring complex optimization of the entire system at once.
Solution Approach 2:
The multiple driver coils and sensor coils are designed to perform multiple functions simultaneously - each coil pair contributes to both the extended switching distance and the overall measurement accuracy. This multi-functionality reduces the need for additional separate components, thereby managing device complexity while achieving the desired performance improvements.
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 configuration significantly increases the switching distance and achieves equal sensitivity for various metal types, enabling detection at larger distances with high accuracy and minimal external magnetic field interference.
Implementation Method 1
Two driver coils 12, 13, which are successively traversed by a current in time with a clock circuit 11, induce a voltage in two sensor coils 14, 15
Implementation Method 2
one of these groups of these coils being connected in the same direction and the other of these groups of these coils being connected in opposite directions, allowing for enhanced sensitivity by canceling out initial voltages and amplifying changes induced by test objects
Implementation Method 3
if the magnetic field between a driver coil and a sensor coil is influenced by a test object, the voltage induced at the sensor coil is changed in such a way that the presence and/or certain properties of the test object can be detected
Data Source
Figure 1a
Figure 1b
Figure 2~3
AI summary
The invention relates to a method and a sensor device for the inductive generation of an electrical measuring signal depending on a variable to be measured, at least two drive coils (12, 13) being provided and a current flowing successively through the coils at the rate of the clock circuit (11). The current induces a voltage in a plurality of sensor coils (14, 15), which voltage depends on the variable to be measured and is subdivided into associated voltage signals (S13) at the rate of the clock circuit (11) in the drive coils (12, 13), the voltage signals thereby obtained being evaluated to obtain the measuring signal. At least two sensor coils (14, 15) are associated with the at least two drive coils (12, 13), either the sensor coils (14, 15) or the drive coils (12, 13) being switched identically while the respective other coils are switched in opposite directions. The voltage signals of the sensor coil associated with the drive coils are scanned in defined intervals of the clocking signal to obtain the measuring signal (91, 92). The method and sensor device of the invention allow an increased sensitivity and/or a larger sensing distance while ensuring a compact design.