Electronic Control Unit for Inductive Sensor Resonance
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Solution Overview
Problem
Existing inductive sensors face limitations in measuring variables due to frequency dependencies and cross-sensitivities, requiring multiple oscillators and significant effort for ratiometric or differential measurements, and often struggle with optimal design for a specific frequency range, leading to compromised measurement accuracy and resolution.
Innovation Solution
An electronic control unit connected directly to a parallel resonant circuit, using an excitation frequency derived from a clock to oscillate the circuit and measure the measurand, allowing for self-sustaining oscillations and reduced energy consumption, while avoiding external amplifiers and optimizing signal strength and electromagnetic compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a resonant system is used for inductive sensing, then measurement sensitivity is improved due to high amplitude at natural frequency, but the system can only operate at a single frequency and requires multiple oscillators for multiple measurements
Solution Approach 1:
The electronic control unit integrates multiple measurement functions (self-inductance, mutual inductance, loss resistance) into a single device that can perform all measurements using one oscillator circuit. The unit selectively connects different inductive components to the oscillator through switching elements, allowing one oscillator to serve multiple measurement purposes rather than requiring separate oscillators for each function.
Solution Approach 2:
The system dynamically reconfigures the oscillator circuit by switching between different inductive components (first inductive component for self-inductance, second inductive component for mutual inductance, third inductive component for loss resistance) during operation. This dynamic switching allows a single oscillator to adaptively serve different measurement functions without requiring multiple fixed-frequency oscillators.
2Adaptability or versatility
If the oscillation frequency is changed to expand measurement range, then adaptability is improved, but frequency dependencies cause cross-sensitivities that distort measurement results
Solution Approach 1:
The system uses periodic switching between different inductive components at defined time intervals. Each inductive component is measured in sequence during specific time periods, allowing the oscillator to maintain a fixed frequency for each measurement while still providing comprehensive measurement coverage across different sensor configurations. This periodic measurement approach eliminates frequency-dependent cross-sensitivities.
Solution Approach 2:
The measurement process is segmented into distinct time periods for different measurements: first time period for self-inductance, second time period for mutual inductance, third time period for loss resistance. This temporal segmentation allows each measurement to be performed independently at the optimal fixed frequency without interference from frequency-dependent cross-sensitivities that would occur in continuous frequency-sweeping methods.
3Measurement precision
If multiple independent oscillators are used for multiple measurements, then measurement completeness is improved, but device complexity and cost increase significantly
Solution Approach 1:
A single electronic control unit is designed to perform all three measurements (self-inductance, mutual inductance, loss resistance) using one oscillator circuit. The unit incorporates switching elements that selectively connect different inductive components to the oscillator, making the oscillator universal for all measurement functions rather than requiring dedicated oscillators for each measurement type.
Solution Approach 2:
The patent merges the functions of multiple independent oscillators into a single integrated oscillator circuit within the electronic control unit. By combining the oscillation generation, switching control, and measurement functions into one unified device, the system achieves complete measurement capability without the complexity and cost of multiple separate oscillator circuits.
4Stability of the object's composition
If a lock-in amplifier is used for forced oscillations at constant frequency, then frequency stability is improved, but resonance advantages like high amplitude and low power requirement cannot be utilized
Solution Approach 1:
The inductive sensor system is configured to self-oscillate at its natural resonant frequency without requiring external forced oscillations. The oscillator circuit within the electronic control unit provides the excitation signal that allows the resonant circuit to sustain its own oscillations naturally. This self-service approach eliminates the need for external lock-in amplifiers while maintaining both frequency stability and the power efficiency advantages of resonance.
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
Enables efficient measurement of inductance with a single electronic control unit, reducing costs and complexity, while providing a stronger signal and improved electromagnetic compatibility, allowing for precise measurement without the limitations of traditional resonant systems.
Implementation Method 1
The electronic control unit is configured to excite the parallel resonant circuit to oscillate at an excitation frequency derived from a clock signal of the electronic control unit
Implementation Method 2
at least one measuring inductor, which is designed to sense the measured quantity
Data Source
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AI summary
The invention relates to an electronic control unit (ASIC) for a device for measuring a measurement variable, wherein a first inductance is supplemented by a capacitance to form a parallel resonant circuit and is excited by a micro-controller (MK). A measuring inductance coupled to the first inductance is measured by the electronic control unit. Therefore, a measured variable can be deduced and only very few components are required in addition to the electronic control unit.