100 results about "Parametric array" patented technology

A parametric sound system for creating an acoustical column along an axis of propagation having a quiet zone an audible zone is disclosed. The system comprises a parametric electro-acoustic emitter configured for emitting a plurality of focalized parametric ultrasonic waves. A plurality of decoupled acoustic waves are maximized at a focalizing area within the audible zone. The system also includes a signal source for applying a parametric ultrasonic signal to the parametric electroacoustic emitter. The signal includes an ultrasonic carrier signal and one or more sideband signals corresponding to an audio input signal. The system further comprises a signal processor for controlling phases of the parametric ultrasonic signal so that the plurality of focalized parametric ultrasonic waves emitted by the parametric electro-acoustic emitter will create a quiet zone along the same direction of propagation as the audible zone. The plurality of decoupled audio waves are substantially in phase within the audible zone while the plurality of decoupled audio waves are largely out-of-phase within the quiet zone.

An ultrasonic ranging method for measuring a distance to an object in an air includes the steps of generating a first and a second primary ultrasonic waves having a frequency f₁ and f₂, respectively, transmitting the first and the second primary ultrasonic waves in a same direction, wherein a secondary ultrasonic wave having a frequency corresponding to the difference of two frequencies f_d=f₁−f₂ is created by a nonlinear property of the air and radiated to the object, detecting an echo pulse of the secondary ultrasonic wave reflected from the object, and measuring the distance to the object based on a propagation time of the secondary wave.

The invention relates to a method for preparing a periodic aluminum alloy lattice structure by utilizing 3D printing. According to the method, a periodic aluminum alloy structure is composed of a plurality of basic units with different hollowed-out shapes, and a lightweight structure which has a high-strength relative density ratio and is obtained through 3D printing by utilizing modeling softwarefor parametric array modeling serves as the periodic aluminum alloy lattice structure. The method provided by the invention has the beneficial effects that 3D software is utilized for modeling and design; a laser selective melting technology is adopted for 3D printing; the simulation of the powder spreading process during the workpiece printing operation of a 3D printer as well as the abrasion process of a powder spreading device and a deformed workpiece by utilizing finite element software is focused on; the process is optimized by selecting a scraper with an appropriate shape and corresponding powder spreading parameters; based on the optimized process, printing process parameters which conform to the optimum workpiece forming characteristics are acquired through experimental verification; and finally, the uniform formed periodic lattice structure is obtained.

The invention provides a sound oriented transmission method of a mobile terminal and the mobile terminal. The method comprises the steps of: storing auricle images of a user into the internal storage of the mobile terminal in advance; when the mobile terminal plays sound, starting an image obtaining device to obtain the front image of the mobile terminal; recognizing that whether auricle characteristics are included in the front image; if the auricle characteristics are recognized, matching the auricle characteristics in the auricle images stored in the mobile terminal with the auricle characteristics in the front image; if the matching is successful, obtaining relative three-dimensional space coordinates of the ears of the user relative to a parametric array loudspeaker in the mobile terminal, starting the parametric array loudspeaker, and transmitting sound signals towards the directions of the ears according to the obtained relative three-dimensional space coordinates. According to the sound oriented transmission method of the mobile terminal and the mobile terminal, after being recognized, the ears of the user are positioned, sound is transmitted in an oriented manner by the parametric array loudspeaker, and thereby sound diffusion is reduced, and interference of the sound on people nearby is avoided.

An ultrasonic transducer having a reduced cost of manufacture. The ultrasonic transducer includes a first insulative retaining layer, a second insulative retaining layer, and a vibrator film layer sandwiched between the first and second retaining layers. The first retaining layer includes a first plurality of apertures formed therethrough, and the second retaining layer includes a second plurality of apertures formed therethrough, in which the second apertures are substantially in registration with the first apertures. The ultrasonic transducer further includes a first cover portion having a plurality of spring/backplate assemblies connected thereto, and a second cover portion. The combination of the first retaining layer, the vibrator film layer, and the second retaining layer is sandwiched between the first and second cover portions of the ultrasonic transducer. The laminated construction of the ultrasonic transducer allows the formation of an array of ultrasonic film transducers using a single piece of ultrasonic vibrator film.

The invention provides an audio parametric array speaker system and a modulation method thereof. A pulse density modulation module is added in the system, and a signal having a follow-up processing function can be obtained. The method comprises the following steps of: performing carrier wave modulation, pulse density modulation, demultiplexing, direction adjustment and multi-direction signal superposition on digital audio signals, and transmitting ultrasound through an energy amplification and ultrasonic transduction array. Therefore, an outputted audio signal has functions of timely adjusting a direction and simultaneously playing sound in a plurality of strong directional directions. In addition, a digital signal system has the advantages of anti-interference, high integration and chip design.

A sound frequency special effect editor based on acoustic parametric array acoustic beam reflection is composed of a sound source, an acoustic parametric array speaker array, an acoustic beam reflection body, an acoustic beam reflection body moving component and an acoustic beam reflection body motion control component. According to the sound frequency special effect editor based on the acoustic parametric array acoustic beam reflection, local transmission and reflection characteristics of high directivity acoustic beams generated by an acoustic parametric array are utilized, three dimensional multibeam dynamic mixed audio effects are achieved, and completely novel sound frequency special effect experience can be brought for the audience.

The invention discloses a directional sound wave detector for underwater buried object detection and belongs to the technical field of underwater sonar of detection equipment. The detector comprises a control main machine, a display, a category-D power amplifier, a signal processing main machine and a transducer array. A controller coordinates various parts to operate synchronously, controls the pulse width and the frequency of the generated acoustic signals and outputs control instructions to the signal processing main machine. The signal processing main machine generates signals to the category-D power amplifier according to the control instructions. The category-D power amplifier is connected with a wide-band transducer which provides enough electric power drive. The wide-band transducer transforms the electric power provided by the category-D power amplifier to acoustical power and sends the acoustical power. Echo reflected by the detected objects is received by the transducer and echo signals are sent to the signal processing main machine which classifies and identifies the echo signals and sends detection results to the control main machine for display.

The invention provides a control system design method. According to the method, distortion of a sound parametric array system signal is improved through neural network opposite identification and control, and a self-adaptive piping and instrument diagram (PID) controller. The method mainly comprises the steps of obtaining a neural network model of an existing sound parametric array system in a training mode through a great number of data obtained through tests for the existing sound parametric array system, obtaining an opposite model of the existing sound parametric array system in a reverse training mode, enabling the identified opposite model to be in series connection with the front portion of the sound parametric array system, achieving a false linear system, and achieving pretreatment for system signal distortion through addition of the auxiliary self-adaptive PID. Compared with the prior system, the control system design method can reduce the sound distortion of the system to a large degree, and has the advantages that due to the fact that training is conducted through random signals, extensive performance is provided, system properties are enabled to be better through the self-adaptive PID controller, a system hardware circuit is simple, an operating process is reliable, a processing result is ideal, and achievement cost is low.

A sound generator includes a transducer converting electric energy to mechanical energy, a mechanical amplifier mechanically amplifying a vibration generated in a piezoelectric component of the transducer, and a radiation plate radiating a sound wave from a signal amplified by the mechanical amplifier, wherein the radiation plate includes a first step having a height for compensating for a first resonance frequency and a second step having a height for compensating for a second resonance frequency.

The invention relates to the field of underwater acoustic communication, in particular to a differential Pattern time delay shift coding underwater acoustic communication method for based on a parametric array. The method comprises the following steps of generating preformed Pattern code signals and a preformed synchronizing signal by adopting parametric pre-modulation, wherein one group of the preformed Pattern code signals are produced for modulation and call of a differential time delay difference; carrying out channel coding on information source information, quantizing and mapping the coding information to a time delay value, modulating the time delay value on the time delay difference between the preformed Pattern code signals, when the length of a communication signal reaches one frame, packaging the frame of signal and adding the preformed synchronizing signal; and emitting the signal through the parametric array after power amplification. Through the narrow directional property of difference frequency sound wave generated by parametric emission, the frequency for reflecting the sound wave in an interface can be reduced, and the inter-symbol interference caused by multi-path extension is inhibited. Through the narrow directional property of difference frequency wave of the parametric matrix, the risk of exposure of an emission node is reduced, and concealment and confidentiality of communication are improved.

The invention provides a parametric array audio play system which is used for playing preset audible tones composed of a plurality of frequencies. The parametric array audio play system comprises a receiver, a high frequency pulse signal generator, a multiway digital power amplifier and an ultrasonic transducer array, wherein the receiver is used for receiving the control signal of the amplitude of each frequency in the frequency combination; the high frequency pulse signal generator is used for generating a high frequency pulse signal at carrier frequency and a modulated high frequency pulse signal of the amplitude corresponding to each frequency in the frequency combination; the multiway digital power amplifier is used for independently amplifying high frequency pulse signals at different frequencies, which are generated by the high frequency pulse signal generator, and outputting the corresponding ultrasonic signals; and the ultrasonic transducer array is used for receiving the ultrasonic signals and generating audible tones at the frequency combination. The parametric array audio play system has the advantages of simple structure, low performance requirements for ultrasonic transducer, and the like.

The invention relates to a multi-beam seafloor sub-bottom profile detection device. The multi-beam seafloor sub-bottom profile detection device comprises a dry end and a wet end. The dry end is composed of a transmitting module and a signal processing and display module, and the wet end is composed of a parametric array and a vector hydrophone. According to the multi-beam seafloor sub-bottom profile detection device, LFM detection signals with frequency bands overlapped are designed on the basis of an FrFT technology, the parametric array with a small aperture serves as a phased transmitting transducer, the vector hydrophone serves as a receiving transducer, and the aperture of the array is reduced while the system bandwidth utilization rate is increased. Because multi-component signals with frequency bands overlapped can be transmitted, the number of transmitted beams is increased, the system bandwidth utilization rate is greatly increased, the detection efficiency is greatly improved, and the multi-beam seafloor sub-bottom profile detection device is more suitable for large-area sea sweeping detection. Because the aperture of the array is reduced, the device is more convenient to carry and has higher application and popularization value.

The invention pertains to the field of underwater acoustic measurement, and specifically relates to a method for measuring the phase difference between a parametric array difference-frequency wave and a same-frequency small-amplitude wave signal. The method of the invention comprises the following steps: a parametric array sound source, a small-amplitude wave sound source, a first hydrophone and a second hydrophone are hung in the water, and two trigger signal are generated by a trigger signal generator; signals are transmitted by the parametric array sound source and the small-amplitude wave sound source separately after a time interval of delta t, and signals received by the first hydrophone and the second hydrophone are acquired and stored by an acquiring device; correlated processes are performed to find out the correlation peak in the processing result; and the phase difference between the parametric array difference-frequency wave and the same-frequency small-amplitude wave signal is obtained. According to the invention, the measured data processing method is simple, and no complex signal processing algorithm is needed.

The invention relates to a real-time control device of a flight simulator sound parametric array. A command editing module edits a sound playing control command in advance and stores the same, allowing a sound playing unit to be called at any time; an interface unit receives a control command from a flight simulator and transmits the control command to a sound control unit in a program execution cycle according to a time sequence; the sound control unit determines generation conditions and a change range of a sound signal through systematic need analysis, establishes a mathematical model meeting a real aircraft sound environment and resolves the mathematical model, and transmits resolution results to the sound playing unit; the sound playing unit can select and call a sound source according to the control command, changes the frequency and amplitude of sound, volume and cycle state and constantly keeps the sound to be consistent to the control command of the flight simulator. The real-time control device is simple in structure and convenient to use, allows editing of sound signals, allows multi-path control and output and is highly consistent to the flight simulator sound environment.

The invention belongs to the parametric array sound field, and particularly relates to a parametric array sound field space distribution obtaining method based on a conservation upwind scheme. The parametric array sound field space distribution obtaining method based on the conservation upwind scheme includes: reading a geometry scale, axial symmetry information and elementary wave frequency of a parametric array sound source and sound speed, density and a nonlinear coefficient of a communication media, obtaining a sound field calculation area in a shape which can be matched with the shape of a parametric array element according to basic data, and performing discrete gridding; reading initial conditions of a parametric array transmitting system: obtaining a source point frequency domain signal of each node in the first axial layer of grid elements; converting the source point frequency domain signals of all the nodes in the first axial layer of the grid elements into source point time domain signals through Fourier inversion; using a non-viscous Burgers equation which describes parametric array nonlinear effects, and obtaining a source point frequency domain signal of each node in the second axial layer of grid elements through the conservation upwind scheme; obtaining parametric array sound field space distribution. The parametric array sound field space distribution obtaining method based on the conservation upwind scheme uses the conservation upwind scheme to improve calculation efficiency, and can regularly and simply partition the grid elements in the calculation area.

A parametric-array remote fish finding system comprises a parametric acoustic array subsystem, a receiver transducer, a control/display module and a power supply. High-point low-frequency acoustic beams are generated by the aid of the parametric acoustic array subsystem, reflection echoes are received, the positions, distribution forms and scales and fish species of fish school are judged according to features of the reflection echoes and acoustic waves sent out by the fish school, and fish school signals are dynamically displayed in an image and character mode. The parametric-array remote fish finding system has the advantages that the shortcoming that the detection range of a traditional ultrasonic detection system is close is overcome, problems that a low-frequency acoustic fish finding system is easily influenced by reverberation and poor in shallow-water detection effect is solved, the fish finding system is distant in the detection range, high in detection precision and good in judgment capability of the positions, the distribution shapes and scales and the species of the fish school.

A system configured to dynamically adjust the ultrasonic carrier level in a parametric array system in response to changing source signal input levels, and which employs a look-ahead delay strategy to enable optimal modulation of the carrier wave to eliminate constant ultrasonic carrier emission and reduce the ultrasonic carrier emission to what is actually needed to accommodate the db range of the source material, and at the same time, to also minimize noticeable distortion and sound artifacts of a high-power ultrasonic carrier, and/or distortion/artifacts arising from modulation of an ultrasonic carrier to reduce average power output; and thus it realizes advantages of carrier modulation based on source-signal level, while minimizing inherent drawbacks of carrier modulation.

The invention discloses a frequency-division ultrasonic parametric array-based mobile phone under-screen receiver realization method and device. According to the basic principle of the invention, callcommunication audio signals and ultrasonic carrier signals are modulated; based on a characteristic that sound signals generate a nonlinear effect when being propagated in the air, and the audio signals can be demodulated again from the ultrasound carrier waves; since the ultrasonic waves have good directivity and penetrability, when an ultrasonic wave sensor is tightly coupled with screen glass,the ultrasonic waves can be transmitted through a screen module; and therefore, with the method and device of the present invention adopted, holes are not required to be formed in the screen glass, and thus, the display area of the screen of a mobile phone is not required to be occupied, and good sound directivity, high call communication quality and privacy can be ensured; the method and deviceof the present invention are based on a frequency division technique, a parametric array loudspeaker is combined with ultrasonic detection, so that the method and device provided by the technical schemes of the invention can integrate functions such as ultrasonic-based distance measurement, human ear positioning, and even facial recognition.

The invention belongs to parametric array project application and particularly relates to a sound field acquisition method with multi-column arithmetic frequency elementary waves interacting to form parametric arrays. The method includes: reading sound waveforms combined by multi-column high-frequency elementary waves; radiating specific sound wave signal waveforms by a broadband high-frequency transducer, and finally generating series difference frequency wave beams with low frequency and high directivity through the nonlinear demodulation effect of transmission media; setting the calculating area of a parametric array sound field, and performing gridding dispersing; using a finite difference method to obtain the parametric array sound field under the interaction of multi-column sound waves. By the method, calculation precision is increased, the sound field distribution characteristics of a parametric array radiation system are calculated accurately, parametric array sound field distribution is displayed visually, and sound field performance is reflected accurately and comprehensively.