Resonant Inductive Measurement Circuit With ADC Dithering
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Solution Overview
Problem
Existing devices for measuring variables, such as position sensors, face challenges in scaling to multiple inputs and achieving high accuracy due to limitations in bit width of analog-to-digital converters, which increases production costs and complexity.
Innovation Solution
A device with a parallel resonant circuit and multiple measuring inductances, coupled with a capacitance, using an electronic control unit to generate an excitation frequency and a distortion signal for improved resolution through dithering without active components, allowing for efficient and cost-effective measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dithering technique is applied to improve measurement accuracy beyond ADC bit width, then measurement precision is improved, but device complexity increases significantly
Solution Approach 1:
The patent combines the distortion signal generator and ADC into a single integrated circuit module, merging previously separate components to reduce overall device complexity while maintaining the dithering functionality for improved measurement accuracy
Solution Approach 2:
The electronic control unit is designed to perform multiple functions: generating the distortion signal, performing analog-to-digital conversion, and processing measurement signals, thereby reducing the need for separate dedicated components and lowering device complexity
2Adaptability or versatility
If multiple measuring inductors are used to scale to multiple inputs, then adaptability is improved, but device complexity increases
Solution Approach 1:
The electronic control unit is designed as a universal interface that can handle multiple measuring inductors through a single standardized connection protocol, allowing the system to scale to multiple inputs without requiring separate processing circuits for each sensor
Solution Approach 2:
The patent introduces a common reference voltage node that serves as an intermediary connection point for multiple measuring inductors, simplifying the interface between multiple sensors and the control unit by providing a shared reference level
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 and cost-effective measurement with improved resolution beyond the limitations of bit width, suitable for high-frequency applications, and minimizes circuit complexity.
Implementation Method 1
a capacitor which is connected to the first inductor to form a parallel resonant circuit. Furthermore, the device includes an electronic control unit. The electronic control unit is directly connected to the parallel resonant circuit and configured to excite the parallel resonant circuit to oscillate at an excitation frequency
Implementation Method 2
at least one measuring inductor, which is configured for sensing the measurand
Data Source
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AI summary
The invention relates to a device for measuring a measurement variable, comprising an electronic control unit (MK) which is directly connected to a parallel resonant circuit (P; LP, CP) and which is configured to excite the circuit so as to oscillate at an excitation frequency. At least one measuring inductor (LS1. LS2, LS3) is designed to sense the measurement variable and is coupled to the inductor (LP) of the parallel resonant circuit (P). The electronic control unit (MK) has an analog-to-digital converter with a signal input (P4, P5, P6), which is directly connected to the at least one measuring inductor (LS1, LS2, LS3) in order to receive a signal, and a distortion signal generator with an output (P3, D), which is designed to deliver a distortion signal at a reference point (VRP) solely via passive components. The electronic control unit (MK) is configured to receive a respective number of measurement values from the signal of the at least one measuring inductor (LS1, LS2, LS3) in intervals, to analyze the frequency of the measurement values of each interval, and to determine at least one signal characteristic value which indicates the measurement variable at an analysis frequency. The distortion signal is used to increase the precision.