Inductive Sensor Assembly Using LC Resonance for Position Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing actuation systems face challenges in reliably detecting changes in the position of metallic actuating elements while maintaining economic efficiency.
Innovation Solution
An actuating arrangement incorporating an inductive sensor system with an LC resonant circuit, excitation supply, decoupling element, and evaluation arrangement, utilizing a rectifier circuit and ADC for robust position detection by measuring rectified voltage signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional sensing system is used for detecting position changes, then the system structure is simple, but the measurement precision and reliability are insufficient
Solution Approach 1:
The patent employs an LC resonant circuit that operates at a specific resonant frequency to detect position changes. By exciting the circuit at its resonant frequency and measuring changes in resonance characteristics (frequency, amplitude, or quality factor) caused by the metallic actuating element's movement, the system achieves high measurement precision. The resonant circuit's natural oscillation provides a sensitive detection mechanism that amplifies small position changes into measurable electrical signal variations.
Solution Approach 2:
The invention detects position changes by monitoring parameter changes in the LC resonant circuit, specifically changes in resonant frequency, amplitude, or quality factor that occur when the metallic actuating element moves within the electromagnetic field. These parameter changes are directly related to the position of the actuating element and provide a reliable basis for precise measurement while maintaining a relatively simple circuit structure.
2Reliability
If timing-based detection methods are used, then the device complexity is reduced, but the reliability of detection is compromised due to timing accuracy dependencies
Solution Approach 1:
The patent replaces timing-based detection methods with a resonant circuit-based detection system that measures electrical parameters (frequency, amplitude, quality factor) instead of time intervals. This substitution eliminates the system's dependence on precise timing accuracy while providing more reliable detection results. The resonant circuit's inherent oscillatory behavior provides a stable reference that is less susceptible to measurement errors compared to time-based methods.
Solution Approach 2:
The LC resonant circuit acts as an intermediary between the metallic actuating element and the detection system. Instead of directly measuring position or time, the system measures the resonant characteristics of the circuit that are influenced by the actuating element's position. This intermediary approach transforms mechanical position changes into electrical parameter changes that are more reliable and easier to measure accurately.
3Measurement precision
If high-precision detection components are used, then measurement precision improves, but manufacturing cost increases
Solution Approach 1:
The LC resonant circuit is designed to utilize the metallic actuating element itself as part of the sensing mechanism. The actuating element's interaction with the electromagnetic field naturally modifies the circuit's resonant characteristics, eliminating the need for separate, expensive sensing components. The system essentially uses the object being detected (the metallic element) to provide the sensing function, thereby reducing component costs while maintaining high measurement precision.
Solution Approach 2:
The LC resonant circuit serves multiple functions: it generates the electromagnetic field, detects position changes, and provides the measurement signal all in a single integrated structure. This multi-functionality reduces the need for multiple separate components, simplifying the overall system and reducing manufacturing costs while maintaining precise detection capabilities.
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 system provides reliable and cost-effective detection of position changes in metallic actuating elements, reducing dependence on timing accuracy and enhancing measurement sensitivity.
Implementation Method 1
The operating principle of inductive sensor systems is based on the detection of a change in an electromagnetic field when a metallic or ferromagnetic actuating element moves within that field. The underlying physical effect is the change in inductance and/or the quality factor of the inductance due to a change in the position of the conductive and/or ferromagnetic element relative to the component generating the inductance.
Implementation Method 2
an LC resonant circuit with an inductive element (L), preferably a coil or a combination of several coils, and with a capacitive element (C), for example a capacitor or several capacitors
Data Source
Figure 1a~2
AI summary
The invention relates to an inductive sensor assembly for detecting a change in position of an actuating element, wherein the sensor assembly comprises: - an LC resonant circuit having an inductive element (L) and a capacitive element (C); - an excitation supply which is coupled to the LC resonant circuit in order to excite the LC resonant circuit with an excitation voltage (U); - a decoupling element arranged between the excitation supply and the LC resonant circuit; - an evaluation arrangement for evaluating the signal decreasing across the resonant circuit. The invention also relates to an actuating assembly.