Inductive Proximity Sensing for Fast Ferromagnetic Target Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional proximity sensors in modern aircraft applications lack the necessary speed, reliability, and economic viability to meet the demands of advanced systems, particularly in terms of accurately sensing the position of ferromagnetic targets with improved precision and response time.
Innovation Solution
A proximity sensor method involving the transmission of a magnetic field signal, measurement of inductor impedance, and calculation of target position using a ratio of voltage changes across the inductor and reference resistor, allowing for near/far output status determination within 4 milliseconds, with trapezoidal current sent through the reference resistor to eliminate series resistance and enhance signal conditioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional proximity sensing methods are used, then the system is simple and economical, but the sensing speed and reliability are insufficient for modern aircraft applications
Solution Approach 1:
The patent replaces mechanical contact-based proximity sensing with an electromagnetic induction system. The controller generates an alternating current through the inductor, creating a magnetic field that induces current in the ferromagnetic target. This electromagnetic approach eliminates mechanical wear and contact issues, significantly improving reliability while maintaining reasonable system complexity through integrated circuitry.
Solution Approach 2:
The patent measures changes in inductance parameters caused by the proximity of ferromagnetic targets. By monitoring the alternating current flow through the inductor and detecting variations in magnetic field coupling, the system translates physical proximity into electrical parameter changes, enabling reliable non-contact sensing with fast response times suitable for modern aircraft applications.
2Speed
If conventional proximity sensors are used, then the system is compact, but the response speed is insufficient (above 4 milliseconds)
Solution Approach 1:
The patent employs periodic alternating current through the inductor at optimized frequencies, creating cyclic magnetic field variations that rapidly interact with ferromagnetic targets. This periodic electromagnetic excitation enables the system to detect target proximity changes within below 4 milliseconds, achieving the required sensing speed through resonant frequency selection and pulse-width modulation techniques.
3Measurement precision
If conventional proximity sensing methods are used, then the system is simple, but the measurement precision and accuracy are insufficient
Solution Approach 1:
The patent implements feedback through voltage measurement across a reference resistor, which monitors the alternating current flow through the inductor. By comparing voltage changes and calculating inductance variations, the system achieves precise target position measurement. The feedback mechanism compensates for environmental variations and maintains measurement accuracy through continuous monitoring and computational correction.
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 approach results in a more reliable, compact, and cost-effective proximity sensor system capable of accurately sensing target positions with increased speed and stability, reducing size, weight, and complexity.
Implementation Method 1
transmitting a magnetic field signal by a controller of a proximity sensor at a target
Implementation Method 2
measuring impedance of an inductor of a proximity sensor
Data Source
Figure 1
Figure 2
AI summary
A method of measuring target proximity comprising the steps of transmitting a magnetic field signal by a controller of a proximity sensor at a target, measuring impedance of an inductor of a proximity sensor, calculating a relative position of the target in relation to a sensor face, and providing a near/far output status of the target at a predetermined rate.