Ultrasonic Transducer Drive Pulse Width Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ultrasonic transducers face measurement errors due to ringing and reflection issues, leading to decreased time resolution and precision in sound speed measurements in liquids, particularly when the acoustic characteristic impedance of the backing layer differs from that of the piezoelectric resonator, and the pulse width of the drive pulse is not optimally controlled.
Innovation Solution
A method of driving the ultrasonic transducer is developed, where the pulse width of the drive pulse is set between 2 and 6 times the propagation time of the ultrasonic wave in the piezoelectric body, and the thickness of the backing layer is adjusted to ensure the ultrasonic wave is separated from reflections, with the acoustic characteristic impedance of the backing layer matching the piezoelectric body, and the distance between transducers is optimized to minimize diffracted wave interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the acoustic characteristic impedance of the backing layer is made different from that of the piezoelectric resonator, then the ultrasonic wave can be absorbed and attenuated effectively, but sound wave reflection occurs at the boundary surface causing resonance and ringing
Solution Approach 1:
An impedance matching layer is introduced as an intermediary between the piezoelectric resonator and the backing layer. This matching layer has an acoustic characteristic impedance that is intermediate between the two, allowing gradual impedance transition that reduces reflection at the boundary while maintaining effective ultrasonic wave attenuation in the backing layer.
Solution Approach 2:
The acoustic characteristic impedance parameters of the backing layer and matching layer are specifically optimized and adjusted to achieve the desired balance between attenuation and reflection suppression. By changing the impedance parameters to specific values, the system achieves both effective energy absorption and minimal boundary reflection.
2Power
If the pulse width of the drive pulse is made wide, then the ultrasonic wave transmission is enhanced, but the peak and valley become separated in time reducing detection precision
Solution Approach 1:
The drive pulse is designed with specific periodic characteristics including controlled peak and valley timing. By using periodic pulse action with optimized duration and spacing, the system maintains sufficient transmission power while ensuring the peak and valley remain temporally correlated for accurate zero-cross point detection.
Solution Approach 2:
The pulse width parameter of the drive signal is optimized to a specific range that balances transmission power and detection precision. By adjusting this temporal parameter, the system achieves both adequate ultrasonic wave transmission and maintained correlation between peak and valley for accurate timing detection.
3Adaptability or versatility
If the distance between ultrasonic transducers is increased, then the measurement range is expanded, but the time required for transmission and receiving increases
Solution Approach 1:
The system uses periodic pulsed ultrasonic transmission with optimized pulse timing and duration. By controlling the pulse frequency and width, the system can accommodate various distances while maintaining efficient measurement cycles, reducing the impact of increased transmission time on overall measurement 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 enhances the detection precision of the zero-cross point, improves time resolution, and reduces measurement errors by ensuring the ultrasonic wave is efficiently transmitted and received, unaffected by reflections, thereby allowing for accurate sound speed measurements.
Implementation Method 1
an ultrasonic transducer has a piezoelectric resonator including a pair of electrodes which sandwich a piezoelectric body, and is provided with a backing layer on the back surface of one of the electrodes of this piezoelectric resonator... When a drive signal is applied across the pair of electrodes, the piezoelectric resonator is excited to transmit an ultrasonic wave
Implementation Method 2
when an ultrasonic wave is received, the piezoelectric resonator converts the vibration into an electrical signal, and outputs the electrical signal
Implementation Method 3
the backing layer is provided in order to absorb and attenuate an ultrasonic wave emitted from the piezoelectric resonator to the back surface at the time of excitation
Data Source
AI summary
An ultrasonic transducer includes a piezoelectric resonator including a pair of electrodes sandwiching a piezoelectric body and provided with the backing layer in contact with one of the electrodes of the piezoelectric resonator and having the same acoustic characteristic impedance as the piezoelectric body. A method includes the step of driving the ultrasonic transducer so as to satisfy a condition: 2Th≦Td≦6Th where Th is a propagation time of an ultrasonic wave in the piezoelectric body sandwiched by the pair of electrodes, and Td is a pulse width of a drive pulse driving the piezoelectric resonator.