Measurement Signal Linearization Circuit Using Periodic Reference Comparison
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Solution Overview
Problem
Existing linearization circuits for measurement signals from non-linear sensors are costly and require significant hardware and software resources, with software methods suffering from resolution drops and slow conversion speeds.
Innovation Solution
A linearization circuit using a reference component with non-linear dependence on current or voltage, a charging and discharging controller, and a comparator circuit to generate a square-wave signal that represents a linearized output signal, eliminating the need for expensive components and high-resolution analog-to-digital converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If logarithmic amplifiers are used for linearization, then linearization precision is improved, but device complexity and cost increase due to requiring matched transistor pairs and precision components
Solution Approach 1:
The patent extracts the linearization function from complex hardware circuits (logarithmic amplifiers with matched transistor pairs) and implements it through a microcontroller unit that executes linearization algorithms. This separates the measurement function from the linearization function, allowing simple analog circuitry to be paired with flexible software-based linearization.
Solution Approach 2:
The patent replaces the mechanical/electrical system of matched transistor pairs and precision resistors with a computational system. The microcontroller performs linearization calculations that were previously requiring specialized hardware components, substituting physical component matching with algorithmic correction.
2Measurement precision
If high-resolution analog-to-digital converters are used for software linearization, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent changes the parameter of resolution from the analog-to-digital converter to the software processing stage. Instead of requiring a high-resolution ADC, the system uses a lower-resolution ADC combined with software linearization algorithms that effectively increase the measurement resolution through mathematical processing of the digitized signal.
3Productivity
If lookup tables are used for linearization, then conversion speed is improved, but memory requirements and recalculation overhead increase
Solution Approach 1:
The patent implements a dynamic linearization approach where the linearization algorithm adapts to different measurement ranges and conditions. Instead of static lookup tables that require complete recalculation for minor changes, the system uses algorithms that can efficiently handle small adjustments without full recalculation, optimizing both speed and memory usage.
4Measurement precision
If polynomial methods are used for linearization, then measurement precision is improved, but processing time and computational requirements increase
Solution Approach 1:
The patent applies partial polynomial correction rather than full high-order polynomial transformation. The linearization algorithm uses optimized mathematical approaches that apply only the necessary degree of correction for each measurement range, avoiding excessive computational effort while achieving sufficient precision for the application.
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 solution achieves cost-effective and precise linearization of measurement signals with improved resolution and speed, reducing linearization errors to within ±0.5% compared to ±10% in non-linear sensors.
Implementation Method 1
a reference component having a non-linear dependence on current or voltage, wherein the voltage across the reference component or a voltage derived from a current flowing through the reference component forms a reference signal (Uc)
Implementation Method 2
a charging and discharging controller configured to control alternating charging and discharging of the reference component, wherein the charging and discharging are controlled in such a manner that the reference signal (Uc) has a substantially periodic curve
Implementation Method 3
a comparator circuit having a first input, a second input, and an output, wherein the reference signal (Uc) is applied to the first input and the measurement signal (Ud) is applied to the second input, and wherein the comparator circuit is configured to generate and output at the output thereof a square-wave signal (Ua) on the basis of a reference time during a charge-discharge cycle and a result of a comparison of the reference signal (Uc) with the measurement signal (Ud)
Data Source
AI summary
A disclosed linearization circuit includes a reference component, a charging and discharging controller, and a comparator circuit. The reference component has a non-linear dependence on current or voltage. The charging and discharging controller is configured to control alternating charging and discharging of the reference component. A voltage associated with the reference component forms a reference signal. The charging and discharging are controlled such that the reference signal has a periodic time dependence. The reference signal and a measurement signal are received by the comparator circuit. The comparator circuit is configured to generate and output a square-wave signal based on a reference time point during a charge-discharge cycle, and based on a result of a comparison of the reference signal with the measurement signal, such that the square-wave signal represents a linearized output signal. This disclosure further relates to a corresponding method.