Piezoelectric Sensor Self-Calibration via Dual-Electrode Voltage Comparison
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Solution Overview
Problem
Existing sensor devices with piezoelectric elements face challenges in maintaining precise calibration due to temperature and aging effects, which affect the piezoelectric coefficient and lead to inaccurate measurements of structure-borne sound signals.
Innovation Solution
A method involving the application of an electrical excitation voltage to a calibration electrode of the piezoelectric element, allowing for the comparison of induced deformation voltage with a measurement electrode, and calculating an electrical field to determine a calibration factor that compensates for aging effects and ensures reliable measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a piezoelectric element is used for capturing structure-borne sound signals, then the sensor can detect vibrations and deformations, but the piezoelectric coefficient changes due to temperature and aging effects, leading to measurement inaccuracies
Solution Approach 1:
The piezoelectric element serves dual functions: it acts as both the sensing element for capturing structure-borne sound signals and as the actuating element for self-calibration. By applying a calibration voltage to the same piezoelectric element, the system enables self-testing and self-adjustment without requiring external calibration equipment, thereby maintaining measurement accuracy despite changes in piezoelectric coefficient due to temperature or aging
Solution Approach 2:
The system measures the voltage generated by the piezoelectric element during calibration and compares it with the applied calibration voltage. Based on this feedback, a calibration factor is calculated and applied to subsequent measurements, compensating for drift in the piezoelectric coefficient and maintaining long-term measurement reliability
2Reliability
If a calibration electrode is added to the piezoelectric element for applying excitation voltage, then calibration can be performed to compensate for aging effects, but the device complexity increases
Solution Approach 1:
The calibration electrode is designed to perform multiple functions: it applies excitation voltage for calibration, and can also serve as an additional sensing electrode for capturing structure-borne sound signals. This multi-functionality reduces the need for separate calibration equipment and minimizes the increase in device complexity
Solution Approach 2:
The calibration function is merged with the existing sensor structure by integrating the calibration electrode into the piezoelectric element assembly. The calibration process is combined with the measurement process, allowing both calibration and sensing to occur within the same device framework, thereby reducing overall system complexity
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 method enables precise calibration and reliable measurement of piezoelectric elements, even when aging affects their performance, by calculating a calibration factor that accounts for changes in the piezoelectric coefficient, thereby maintaining accurate data capture of structure-borne sound signals.
Implementation Method 1
The deformation of the piezoelectric element generates an electrical voltage, with is captured with the measurement electrode with reference to the counter electrode
Implementation Method 2
an electrical excitation voltage for creating a mechanical deformation of the piezoelectric element is applied to at least one further electrode of the piezoelectric element, embodied as a calibration electrode
Data Source
AI summary
In a method for calibrating at least one sensor, wherein the sensor includes at least one piezoelectric element with at least one electrode, and wherein at least one electrode is embodied as a measurement electrode, it is provided as essential to the invention that an electrical excitation voltage is applied to at least one further electrode of the piezoelectric element, embodied as a calibration electrode, to create a mechanical deformation of the piezoelectric element, that the voltage induced by the deformation of the piezoelectric element is captured with at least one measurement electrode, and that the applied excitation voltage and captured voltage are compared.