Transducer Calibration via Spatial Frequency Domain Smoothing
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Solution Overview
Problem
Current transfer impedance calibration methods for transducers are hindered by the difficulty in achieving ideal free field conditions, especially due to reflection issues in anechoic pools, and existing signal processing techniques like Prony spectrum analysis and multi-path modeling are sensitive to noise and complex, leading to inefficiencies and errors in low signal-to-noise conditions.
Innovation Solution
A transfer impedance calibration device utilizing spatial frequency domain smoothing technology, which processes transmitted and received signals by combining sound field spatial information to design a spatial domain smoothing filter, reducing reflection wave influence and expanding low-frequency measurement limits, featuring a simple algorithm and reduced calculation burden.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an anechoic pool is used for calibration, then the calibration environment is improved, but the noise attenuation effect is poor in the low frequency band and reflection influence remains
Solution Approach 1:
The patent extracts and removes the harmful reflection components from the measured signal by comparing signals measured at different positions. Through signal processing, the direct sound field component is separated from the reflected sound field component, effectively eliminating the influence of pool walls and interfaces on the calibration results.
Solution Approach 2:
The patent uses feedback by measuring the same transducer response at multiple positions and using these measurements to calculate and remove reflection effects. The system continuously refines the calibration by comparing measurements and adjusting for environmental influences.
2Measurement precision
If Prony spectrum analysis or multi-path modeling is used, then frequency resolution is improved, but the algorithms are very sensitive to noise and have large calculation amounts
Solution Approach 1:
The patent segments the measurement process into multiple position measurements, where each measurement provides partial information. By combining these segmented measurements through signal processing, the system achieves high frequency resolution without requiring complex single-measurement algorithms.
Solution Approach 2:
The patent uses simple, computationally inexpensive signal processing operations that can be applied rapidly to multiple measurements. Rather than using complex algorithms on single measurements, the system applies simpler operations to multiple data sets, achieving the same or better results with less computational burden.
3Ease of operation
If acoustic pulse transient suppression technology is used, then transient suppression is improved, but the method requires at least 2-3 steady-state waves in free field conditions
Solution Approach 1:
The patent adds the spatial dimension to the measurement process by taking measurements at multiple positions. This dimensional change allows the system to obtain sufficient information for accurate calibration without requiring multiple steady-state waves at each position, thereby improving test efficiency.
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 approach effectively suppresses reflection wave interference, enhances test efficiency, and is suitable for broadband signals, improving the accuracy and efficiency of transducer calibration by processing signals in the spatial frequency domain.
Implementation Method 1
the hydrophone is configured for converting the acoustic signal into an electrical signal E1
Data Source
AI summary
A transfer impedance calibration device for transducers based on spatial frequency domain smoothing technology is provided. The calibration device comprises a signal transmitter, a power amplifier, a transducer pair, a measurement amplifier, a signal collector, a measurement processor and a current sampler. The device extracts acoustic channel information through the sound filed spatial information or measurement method to design a spatial domain smoothing filter, and then comprehensively processes the transmitted current signal and the received signal through the spatial frequency domain smoothing technology to obtain the transfer impedance of the transducer pair.