Inductive Wheel Sensor Coil Orientation for Lateral Run-off Detection
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Solution Overview
Problem
Inductively acting wheel sensor arrangements struggle to reliably detect wheels with larger lateral run-off without reducing interference immunity to interference voltages at the working frequency, which can be caused by rail currents.
Innovation Solution
The wheel sensor arrangement features a transmitting and receiving resonant circuit with defined spatial arrangements, where the axis of the transmitting coil is in the transverse direction of the rail and the axis of the receiving coil is perpendicular to the longitudinal direction at an acute angle, ensuring the induced voltage increases with wheel presence and decreases without reaching zero, enhancing lateral run-off detection while maintaining interference immunity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the trigger threshold is reduced to detect wheels with greater lateral run-off, then the detection range for lateral run-off is improved, but the immunity to inductively coupled interference voltages at the operating frequency deteriorates
Solution Approach 1:
The patent introduces a new dimension of analysis by separating the detection of lateral run-off (transverse direction) from the detection of wheel presence (longitudinal direction). The receiving coil is oriented perpendicular to the rail longitudinal direction, creating a spatial dimension where lateral wheel movement produces detectable signal changes while longitudinal positioning maintains stable coupling. This dimensional separation allows the system to detect lateral run-off without lowering the trigger threshold, thereby preserving immunity to interference voltages.
Solution Approach 2:
The patent applies local quality by creating different functional zones within the sensor system. The transmitting coil generates a magnetic field with specific spatial characteristics, while the receiving coil is positioned and oriented to detect changes in coupling intensity locally. The system creates a localized detection zone where lateral wheel movement produces detectable signal variations, allowing the trigger threshold to remain high while still detecting lateral run-off within the specific spatial region defined by the coil arrangement.
2Measurement precision
If the coupling intensity change is amplified to improve signal detection, then the measurement precision is improved, but the susceptibility to interference voltages at the operating frequency increases
Solution Approach 1:
The patent uses the magnetic field coupling between the transmitting and receiving coils as an intermediary mechanism. Instead of directly detecting wheel position, the system detects changes in magnetic coupling intensity caused by lateral wheel movement. This intermediary magnetic field approach allows for amplified signal detection while the spatial arrangement of the coils provides inherent filtering of interference voltages, as the interference does not produce the same coupling intensity changes as lateral wheel movement.
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 allows for reliable detection of wheels with increased lateral run-off without compromising interference immunity, and improves interference immunity to rail current-induced interference signals.
Implementation Method 1
The transmitting resonant circuit acts on the receiving resonant circuit through its stray field and induces a voltage in its resonant circuit coil
Implementation Method 2
The mode of operation of the wheel sensor arrangement is based on a change in a coupling intensity, in which a transmitting part with a transmitting resonant circuit, which has a transmitting coil, and a receiving part assigned to the transmitting part, with a receiving resonant circuit, which has a receiving coil
Data Source
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AI summary
The invention relates to an inductively acting wheel sensor arrangement (DEK), the operation of which is based on a change in a coupling intensity (ΦK'), in which a transmitter part (SE1) with a transmitting resonant circuit (110), which has a transmitting coil (111), and a receiver part (SE2) associated with the transmitter part (SE1) with a receiving resonant circuit (120), which has a receiving coil (121), are separated from each other by the rail (S) in a state mounted on a rail (S) of a railway track system, wherein the transmitting resonant circuit (110) acts on the receiving resonant circuit (120) by its stray field (SF') and induces a voltage (u121) in its transmitting coil (121), and in which the transmitting coil (111) and the receiving coil (121) have a defined spatial arrangement relative to each other, such thatthat the voltage (u121) induced in the receiving coil (121) increases when a wheel (R) moving on the rail (S) enters the stray field (SF') of the transmitting resonant circuit (110) due to increasing coupling intensity (ΦK') between the two coils (111, 121) and decreases when the wheel (R) leaves the stray field due to decreasing coupling intensity (ΦK') between the two coils (111, 211), without ever reaching zero. In order to reliably detect wheels with greater lateral runout, it is provided that, in the state of the wheel sensor arrangement (DEK) mounted on the rail (S), the axis (112) of the transmitting coil (111) lies in the transverse direction (y) of the rail (α112=0°) and the axis (122) of the receiving coil (121) is perpendicular to the longitudinal direction (x) of the rail and thus in an acute angle (α122), in particular at an angle (α122) between 5° and 15°, to the transverse direction of the rail (y).