This paper demonstrated the feasibility of utilizing miniaturized piezoelectric micromachined ultrasonic transducer(PMUT)to form a symmetric V-shaped acoustic beam pattern,which enables the ability to synchronously tr...This paper demonstrated the feasibility of utilizing miniaturized piezoelectric micromachined ultrasonic transducer(PMUT)to form a symmetric V-shaped acoustic beam pattern,which enables the ability to synchronously transmit bidirectional ultrasonic signals,and offers a promising technology to address the frame rate limitations in traditional ultrasonic flowmeters based on time-of-flight(ToF).In contrast to the previous two-step flow rate monitoring scheme,where paired ultrasonic transducers are used as transmitter and receiver alternately to obtain the upstream and downstream ultrasound propagation time sequentially,we proposed one-step mid-air flow rate measurement with a remarkable frame rate through the V-shaped bidirectional beam generated by a 3.6mm×3.6mm 5-channel~250 kHz PZT PMUT phased array.By utilizing the grating lobe produced through optimized array pitch design and sequential control,this 5-channel PMUT array breaks the conventional design limitations typically associated with grating lobes,and generates the V-shaped beam with dual main lobes measured at 27°and 153°,enabling 1000 times of upstream and downstream ToF measurements in 1 s.Furthermore,installation geometry optimization was proposed to enhance the ToF resolution and adaptation to various pipe circumstances,where flow rate measurements in conventional straight pipe and optimized zigzag-shaped pipe with 150mm sufficient ultrasound propagation length were investigated.The experiment results demonstrated the superior flow rate monitoring performance of our device and system,where large-range(0.5-35 L·min^(-1)or 0.045-3.177 m·s^(-1),airflow)and high-resolution(185 ns/(L·min^(-1))or 2032 ns/(m·s^(-1)))flow metering with significant linearity(0.997)was successfully obtained,revealing great potential in advanced flow monitoring application scenarios.展开更多
基金supported by the National Key R&D Program 2023YFB3211200,and the National Natural Science Foundation of China 62471008.
文摘This paper demonstrated the feasibility of utilizing miniaturized piezoelectric micromachined ultrasonic transducer(PMUT)to form a symmetric V-shaped acoustic beam pattern,which enables the ability to synchronously transmit bidirectional ultrasonic signals,and offers a promising technology to address the frame rate limitations in traditional ultrasonic flowmeters based on time-of-flight(ToF).In contrast to the previous two-step flow rate monitoring scheme,where paired ultrasonic transducers are used as transmitter and receiver alternately to obtain the upstream and downstream ultrasound propagation time sequentially,we proposed one-step mid-air flow rate measurement with a remarkable frame rate through the V-shaped bidirectional beam generated by a 3.6mm×3.6mm 5-channel~250 kHz PZT PMUT phased array.By utilizing the grating lobe produced through optimized array pitch design and sequential control,this 5-channel PMUT array breaks the conventional design limitations typically associated with grating lobes,and generates the V-shaped beam with dual main lobes measured at 27°and 153°,enabling 1000 times of upstream and downstream ToF measurements in 1 s.Furthermore,installation geometry optimization was proposed to enhance the ToF resolution and adaptation to various pipe circumstances,where flow rate measurements in conventional straight pipe and optimized zigzag-shaped pipe with 150mm sufficient ultrasound propagation length were investigated.The experiment results demonstrated the superior flow rate monitoring performance of our device and system,where large-range(0.5-35 L·min^(-1)or 0.045-3.177 m·s^(-1),airflow)and high-resolution(185 ns/(L·min^(-1))or 2032 ns/(m·s^(-1)))flow metering with significant linearity(0.997)was successfully obtained,revealing great potential in advanced flow monitoring application scenarios.
