On the basis of analysis by analytic theory and finite element method, the manufacturing and test are both done about the plane and spherical surface transducer. We can find, on the same radiation diameter, the later can be applied more electric power and have wider radiation range, more beautiful shape than the former. The washing machine using the spherical radiation transducer has the advantages of bigger power, more efficiency, better effect etc. By cooperating with third -party authority, the abilities of sterilization and pesticide residue removal are both tested by using the washing machine based on the spherical radiation transducer. The laws have been grasped about the effects of sterilization and pesticide residue removal changing with temperature, power, the volume of the container. The best working points have been obtained about the sterilization and pesticide residue removal on the specified conditions. We can conclude that the washing machine based on the spherical radiation transducer does not only have the good washing ability, but also have good effect of sterilization and pesticide residue removal.

随着人们生活水平的不断提高,除菌消毒、去除农药残留的需求日益受到关注.为此,文章研制了一种用于清洗机的椭球型便携式超声换能器,可施加最大电功率450 W,稳定功率200 W,声场辐射均匀且范围广.采用此型换能器的清洗机已批量生产,具有清洗效果好、速度快、低噪音、声辐射范围广、便携等优点.

高精度流量计需要使用高发送电压响应的超声波探头,为此,文章设计了一种流量计用超声波探头.通过理论计算、建模仿真和封装测试,数据结果表明,该探头一致性好、灵敏度高、声源级高、水密可靠性好、计量准确.

Aiming at advantages of T type hydrophone,such as high sensitivity,low-frequency and strong anti-interference ability,an underwater acoustic ranging system controlled by MCU is designed and developed.Propagation velocity of sound in water is used as determined conditions,sound wave is sent by transducer and received by hydrophone.AT89S52 is used to control time of sending and receiving,distance between obstacles and hydrophone is calculated.Test results show that this system can receive the reflected sound wave signal stability,and achieve short-distance measurement and the measuring error is less than 1 %.

Processing the matrix signals of vector hydrophone was critical to the research on engineering application of vector matrix. However, such processing required massive computation. Accordingly, a vector matrix based modification of MUSIC algorithm was introduced to solve such issue. The said modification lowered computation amount by applying the Wiener Filter in MUSIC algorithm to skip decomposition of eigenvalues. The method of vector hydrophone Uniform Linear Array (ULA) was adopted to test the performance of the modified algorithm. The computer simulated outcome has verified the effectiveness of such modified MUSIC algorithm, showing that the modified MUSIC algorithm can clearly distinguish the coherent signals, and is superior to the original music algorithm.

In this paper, we analysis the working principle of a cilium-type MEMS vector hydrophone, by analyzing we obtained the errors of the vector micro-sensor are deviations from column cilium. Since the structure is mainly picking up sound vibrations by the cilium, the piezoresistor which on the beams connected by Wheatstone bridge circuit will output the signals, so the deviation of cilium cylinder have greater impact the sensitivity in both directions of vector hydrophone. Through theoretical calculation and finite element simulation of the sensitive structure of the error analysis. By the structure of the hydrophone error test ,we obtained the sensitivity of X direction is 0.755mv / g, the sensitivity of Y direction is 0.683mv / g, The relative sensitivity error of two directions is 9.5% which is close to the simulation results. Finally, this paper give a solution to the error. (Abstract)

A silicon machined double-cilia micro-hydrophone is developed for underwater acoustic measurement.These hydrophones have the advantages of miniaturization and directional compared to the conventional piezoelectric acoustic hydrophones.The package of hydrophone imitates the lateral line cell of fish to improve the reliability of the hydrophone,using polyurethane as the cupula for packaging cap and silicone oil as the mucus and the beam as the cilium.The packaged hydrophone is tested by sensor auto calibration vibration system and vector hydrophone calibration system.The sensitivity is measured to be-180 dB and the corresponding resonant frequencies are 2.03 kHz,the hydrophone has a cosine eight directivity patterns.

Processing the matrix signals of vector sensor is critical to the research on engineering application of vector matrix.However,such processing amount requires massive computation.Aiming at this problem,a new modified MUSIC algorithm(MMUSIC) based on vector matrix is introduced to solve such issue.The method reduces computation amount by applying the Wiener Filter in MUSIC algorithm to skip decomposition of eigenvalues.The method of vector sensor uniform linear array(ULA) is adopted to study the performance of the modified algorithm.The simulation and experiment verify the effectiveness of such new MMUSIC algorithm,showing that the new MMUSIC algorithm can clearly distinguish the coherent signals,and is superior to the original MMUSIC algorithm.

A novel encapsulation structure was proposed to package the sensitive unit,which imitated the fish lateral line cells.That was,polyurethane the same material as sound-transparent cap,instead of castor oil,was selected to encapsulate.And only half of the hair was submerged.It is desirable that the novel encapsulation can effectively improve vector hydrophone ' s sensitivity.By means of analysis vector hydrophone ' s theoretical model,the acoustical transmission coefficient was obtained.This paper simulated the encapsulation model by ANSYS and it could be concluded that the sensitivity was 0.259 mV/Pa,resonance frequency was 150 Hz.Finally,the prototype of the vector hydrophone was fabricated and tested.Results show that the free-field voltage sensitivity is-188.9 dB,which is 8.8dB higher than that of castor oil encapsulation.The hydrophone possesses satisfactory directional pattern and frequency response ranges from 50 Hz to 2 kHz.

A novel damping spring structure is designed based on the existing structure of MEMS vector hydrophone. It is desirable that this novel structure can improve the antinoise ability of hydrophone. According to finite element simulation by Ansys, the geometry, stiffness and location of the spring are determined. Two pairs of spring are adopted and placed inside and outside vertically. Simulation results show that the reducing flow noise ability of this damping structure can be increased by 3 times, as well as it does not affect the sensitivity of hydrophone. The advantages of this chip-level spring damping structure are one integrated, good consistency and engineering applications.