45results about "Acoustic wave reradiation" patented technology

An instrument is disclosed for measuring resistivity of Earth formations from within a conductive pipe inside a wellbore drilled through the formations. The instrument includes a plurality of housings connected end to end and adapted to traverse the wellbore. At least one electrode is disposed on each housing. Each electrode is adapted to be placed in electrical contact with the inside of the pipe. The instrument includes a source of electrical current, a digital voltage measuring circuit and a switch. The switch is arranged to connect the source of electrical current between one of the electrodes and a current return at a selectable one of the top of the pipe and a location near the Earth's surface at a selected distance from the top of the pipe, and to connect selected pairs of the electrodes to the digital voltage measuring circuit. The pairs are selected to make voltage measurements corresponding to selected axial distances and selected lateral depths in the Earth formations.

A towrope type ocean controllable source electromagnetism and earthquake data collection system is composed of electric field sensors (non-polarized electrodes) distributed in three or more towropes uniformly or not, three-component induction coil type or three-component fluxgate type magnetic field sensors and sonic sensors composed of hydrophones or accelerometers and is used for measuring ocean three-component magnetic-field components, electric field components EX distributed in the cable direction, electric field components EY distributed in the vertical cable direction and ocean earthquake data. The towrope type ocean controllable source electromagnetism and earthquake data collection system can collect ocean electromagnetism data and ocean earthquake data in the time domain and the frequency domain at the same time, increase the collection quantity of ocean geophysics data of advancing construction at a time in a multiplying mode, effectively improve the target detection precision and explore and evaluate ocean mineral products, oil and gas resources and methane hydrates through combination and comprehensive application of ocean controllable source time-frequency electromagnetism and the earthquake exploration technology.

The invention discloses an underwater three dimensional terrain reconstruction method based on multi-beam sonar data, comprising the following steps of: firstly, collecting echo wave strength data and also measuring sounding data; secondly, carrying out linear interpolation on the sounding data and obtaining the sounding data having the same space resolution with the echo wave strength data; thirdly, calculating an angle and a range between a beam of each sounding data point and a horizontal line; fourthly, calculating the beam incident angle of each sounding data point by a point-by-point way; fifthly, fitting model parameters of a reflection model based on the echo wave strength data and correcting the angle between the beam and the horizontal line; seventhly, setting an iteration number N and enabling an average relative error absolute valve of estimated echo wave strength data and the collected echo wave strength data to be minimum; and eighthly, calculating sounding data and reconstructing an underwater three dimensional terrain. The method can enhance the space resolution of the sounding data and has an important significance on the aspects of underwater substance exploration, three dimensional visualization, underwater target detection and the like. The reconstructed underwater three dimensional terrain is also nearer to the real terrain.

The invention provides an ultrasonograph having excellent operability and mobility that are achieved by allowing, during operation and movement of the device at a standing position of the user, an operation panel to be compactly placed on the upper surface of the casing and also allowing, during operation of the device in a sitting position of the user, the operation panel to be disposed forward. The ultrasonograph has a body casing (100) having movement wheels (101), an operation device (200) having an operation switch group (400), and a movable arm (300) for connecting the body casing (100) and the operation device (200). The body casing (100) has a tilt surface (103) tilted rearward from the front surface to the upper surface. The movable arm (300) movably supports the operation device (200) through a lifting function mechanism part (301). The lifting function mechanism part (301) moves the operation device (200) from a first attitude (Q1) up to a second attitude (Q2) through a movement path above the tilt surface (103) with the attitude of the operation device (200) maintained. In the first attitude (Q1), the operation device (200) is located above the tilt surface (103), within a projection area of the body casing (100). In the second attitude (Q2), the operation device (200) is located below the tilt surface (103), allowing at least a part of the operation device (200) to protrude from the body casing (100).

The invention provides a quick beamforming method capable of improving array resolution and gain, comprising the following steps: adopting the construction of a minimum redundant array to optimize an M-element uniform linear array into a P-element non-uniform linear array; carrying out FFT processing on primitive data of a P-element array; in a frequency domain, constructing a covariance matrix of data based on the uniform linear array in accordance with the array aperture extension characteristics of fourth-order cumulants; carrying out normalization processing on the beam space and carrying out estimation on a Bartlett spatial spectrum. By adopting the array aperture extension characteristics of the fourth-order cumulants, the invention realizes that the optimized element layout form is employed to obtain high resolution and overcomes the defects of high requirements of the original fourth-order cumulant-based methods on snapshots and great computational complexity to enable the computation process to be simple and easy to operate. When the signal to noise ratio is higher than the supercritical signal to noise ratio, the method of the invention has higher array gain than that of conventional beamforming. The normalization processing of the beam space realizes effective inhibition to background interference. The beamforming method of the invention is simple and easy to operate and is especially suitable for project application.

The present invention proposes a hardware and software architecture for dynamic modal structural monitoring that uses a robust modal filter to monitor a potentially very large-scale array of sensors in real time, and tolerant of asymmetric sensor noise and sensor failures, to achieve aircraft performance optimization such as minimizing aircraft flutter, drag and maximizing fuel efficiency.

An ultrasonic imaging method includes activating a transmit aperture within a multi-element transducer array, transmitting one or more ultrasonic beams along scan direction(s) that span the region of interest, for each transmit event, receiving ultrasound echoes from each element of a receive aperture, grouping the receive channel echo data into two or more sets corresponding to different receive sub-apertures, combining each sub-aperture data set to generate partially focused echo-location data for one or more reconstruction lines, and storing all the sub-aperture echo data sets during a storage period in a format that can be retrieved for later analysis. A method includes, during a post-storage period, retrieving stored sub-aperture data, combining the sub-aperture data to form one or more selected reconstruction lines, processing echo data to extract motion information from one or more sample positions along the selected reconstruction lines, and displaying an image representative of the processed motion information.

A multicomponent induction logging tool is used on a MWD bottomhole assembly. Multifrequency focusing that accounts for the finite, nonzero, conductivity of the mandrel is applied. Using separation of modes, the principal components and a direction of a conductivity tensor are determined. The results are used for reservoir navigation in earth formations. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b)

A sensor device, comprising two symmetrically disposed sonolucent wedges (5), and a connecting piece for fixedly connecting the two sonolucent wedges (5); the upper surfaces of the sonolucent wedges (5) are provided with inclined planes; installation holes are formed on the inclined planes; transducers (3) are installed in respective installation holes; one transducer (3) is used to generate ultrasonic waves, and the other transducer (3) is used to receive the ultrasonic waves generated by the previous transducer (3). The residual stress detection system comprises a sensor device, an ultrasonic transmission card, and a data acquisition card.

An improved axial gas bearing for a gas-driven NMR MAS sample rotor is disclosed that utilizes inward flow with a low rotational component over a rotor conical end. A conical flow region is formed between the rotor conical end and a conical stator bearing surface such that the included angle defining the stator surface is not less than the included angle defining the rotor conical end. Gas is injected radially inward with a significant axial rearward component from a number of small holes at high velocity from the periphery into the conical flow region. Compared to the radial velocity components, the tangential flow components of the injected gas are small and preferably opposed to the direction of the rotor rotation. The high and accelerating negative radial velocities may result in significant Bernoulli effect, such that the mean axial pressure over the conical rotor end may be less than atmospheric pressure for a given axial clearance, but as the clearance decreases, the hydrostatic effects exceed the Bernoulli effects and the mean axial pressure over the conical rotor end may then exceed atmospheric pressure by a substantial amount. Thus, a self-stabilizing axial bearing is formed with improved stability and stiffness for rotor surface speeds up to at least 80% of the speed of sound. Motive power required to spin the rotor may be provided by a radial-inflow microturbine at the opposite end of the rotor in a way that is readily compatible with automatic sample change.

Complex magnetic resonance (MR) image data, acquired from an examination subject that has at least two different spin species, are processed in a method and a device. At least one MR parameter that influences data acquired in an MR data acquisition is determined with spatial resolution. Complex image data are respectively acquired with each of multiple acquisition units in an MR data acquisition at multiple echo times, such that a phase difference between the first spin species and the second spin species is different at least two of the echo times. For multiple image points, a value of the at least one MR parameter is determined so that a function that depends on the at least one MR parameter and the corresponding image point in the complex image data satisfies an extreme condition.

The present invention relates to a single horizontal array passive speed measurement and distance measurement method based on sound field interference fringe, belonging to the field of underwater acoustic engineering and sonar signal processing. The method comprises a step of carrying out condition processing and collection on the signal received by each array element of a sonar, a step of carrying out beam formation on the collected signals and obtaining an azimuth time journey map after accumulation, a step of tracking an interested object, taking a tracking beam as object azimuth estimation, carrying out short-time Fourier transform spectrum analysis on the output of the tracking beam, obtaining the interference structural map of the interested object, selecting two equal time intervals of a single horizontal array in a motion process, forming interference structural maps, carrying out preprocessing and Radon transform on the two interference structural maps, and estimating an object heading angle with the combination of the waveguide invariant theory, and a step of realizing the estimation of the distance and speed of the interested object. According to the method, the physical nature of an underwater sound field is fully dug, the prior knowledge of a marine environment is not needed, the algorithm is simple and easy and is convenient and flexible to use, and the application prospect is wide.

A wireless sonar receiver is provided including a wireless receiver configured to receive sonar data from a wireless sonar transducer configured to receive sonar returns from an underwater environment as first sonar return data, convert the first sonar return data into sonar image data, and transmit the sonar image data wirelessly to the wireless sonar receiver. The wireless sonar receiver also includes a receiver processor and a receiver memory including computer program code configured to, with the receiver processor, cause the wireless sonar receiver to convert the sonar image data to second sonar return data corresponding to the sonar returns received by the wireless sonar transducer. The wireless sonar transducer also includes an output port configured to transmit the second sonar return data to a marine electronic device for processing of the second sonar return data to generate at least one sonar image for display on a user interface.

A sensing and data acquisition system may provide a sensing assembly including a signal conditioner to receive an electrical signal from a sensor affixed onto an asset and supply an encoded digital representation of a sensed parameter. An acoustic modem may be connected to the signal conditioner to receive the encoded digital representation of the sensed parameter and transmit an acoustic signal based on the encoded digital representation of the sensed parameter. A data acquisition line may be proximate to the asset and may be non-contactively coupled to the sensing assembly. The data acquisition line may include an optical fiber acoustically coupled to the acoustic modem and responsive to the encoded digital representation of the sensed parameter transmitted by the modem to effect an optical change in an acoustically-responsive portion of the fiber. The optical change may be measurable to detect the encoded digital representation of the sensed asset parameter.

The invention discloses a resistive type space debris detection device. The resistive type space debris detection device comprises a detection casing, a first film group, a second film group and a piezoelectric effect detection layer, wherein the first film group and the second film group are identical in structure and are respectively composed of two layers of polymer films, parallel metal conductive wires at equal intervals are plated on each polymer film layer, the metal conductive wires between the adjacent film layers are perpendicular to each other, and the square grid closely-packed structure is formed. The invention further discloses a method utilizing the detection device to carry out space debris detection. The device is advantaged in that the structure is simple, control is convenient, and detection on the size, the speed, the direction and the mass of the space debris can be realized.

A magnetic field generator includes a power source and a segmented or un-segmented coil connected to the power source to generate a time-varying magnetic field. Energy is applied to the coil so that the coil generates a time-varying magnetic field gradient with a magnitude of at least 1 milliTesla per meter and a rise-time of less than 10 microseconds. The coil may be comprised of overlapping, non-overlapping or partially overlapping coil segments that may individually energized to further improve the operating characteristics of the coil to further decrease bio-effects in magnetic resonance imaging through the use of reduced pulse lengths and multi-phasic magnetic gradient pulses.

Provided are a method and device for ultrasonic imaging by synthetic focusing. The method comprises: exciting a plurality of matrix elements of an ultrasonic probe to transmit plane waves many times, wherein transmitting apodizations at the time of every transmission of the plane waves by the plurality of matrix elements correspond to the respective lines in a measurement matrix in which elements are randomly distributed; after every transmission of the plane waves, exciting all the matrix elements of the ultrasonic probe to receive echo signals, in order to obtain channel data; recovering a synthetic focusing channel data set by use of a compressed sensing reconstruction algorithm according to a channel data set and the measurement matrix; and subjecting the synthetic focusing channel data set to beamforming so as to generate an ultrasonic image.

The invention discloses a sonar detection device for a three-dimensional space of a mine gob. The sonar detection device comprises a control case and a stepping motor, wherein an output shaft end of the stepping motor is connected with a sonar sensor through an angular sensor, the control case is respectively connected with the stepping motor, the angular sensor and the sonar sensor through cables. The sonar sensor emits and receives a sound signal, a true signal can be obtained by filtering the sound signals, and is processed by ranging control software, and finally a three-dimensional simulation image under the underwater environment can be displayed on a screen. The sonar detection device is low in cost, good in effect, and convenient and fast, the underwater environment information can be conveniently detected, and the sonar detection device is especially applicable to detection of the information on the three-dimensional space of the mine gob.

The invention relates to a rotary sonar fish finder. The rotary sonar fish finder comprises a base in the shape of a rotating body, and a sonar sensor is fixed to the bottom of the base. A water suction pump which is used for pumping water from bottom to top is further fixed to the bottom of the base. A centrifugal drainage plate which is coaxial with the base is connected to the upper portion of the base in a rotating mode. The centrifugal drainage plate comprises an axial water inlet, an internal water cavity and horizontal drainage channels from bottom to top, wherein the horizontal drainage channels are circumferentially and evenly distributed and are symmetrical in a rotating mode. The included angles formed between the drainage directions of outer ports of the drainage channels and the radius directions of the outer ports range from 45 degrees to 80 degrees. The rotary sonar fish finder enables sundries and duckweeds around the rotary sonar fish finder to be removed; meanwhile, the situation that the fish finder is wound by the duckweeds and algae can be effectively prevented.

A wireless magnetic resonance imaging scanner has one or more local coils, a microwave antenna array, and a local oscillator, and an upconverter. The local oscillator signal from the local oscillator is transmitted from the microwave antenna array to illuminate the local coils. The local coils generate magnetic resonance signals at a first frequency and the magnetic resonance signals at the first frequency are upconverted in the upconverter to microwave frequencies. The local oscillator operates at a frequency within an unlicensed band, chosen such that desired sidebands for reception of the upconverted local coil magnetic resonance signals fall outside the unlicensed band.

An ultrasound breast imaging assembly includes first and second compression plates angled with respect to one another, a breast compression area defined between the first and second compression plates, at least one pivot assembly, and an ultrasound probe. The pivot assembly allows relative motion between the first and second compression plates. The ultrasound probe, which is configured to translate over one of the first and second compression plates, includes an active matrix array (AMA) positioned on one of the first and second compression plates.

A RF coil according to the invention is made up of an 8-shaped coil having a crossed conductive path, and an impedance adjustment coil that performs connection between crossing points of the conductive path. The crossing points of the conductive path are connected in parallel by the impedance adjustment coil and a floating capacitance between the crossing points of the conductive path. An impedance between the crossing points of the conductive path is increased, and a current that flows between the crossing points of the conductive path reduces in a Larmor frequency that is in proportion to the intensity of the magnetostatic field of an MRI apparatus. The RF coil according to the invention is made up of an 8-shaped coil having a crossed conductive path, an impedance adjustment coil that performs connection between the crossing points of the conductive path in parallel, and an impedance adjustment coil.

Methods and apparatuses for 3D tomographic imaging of objects such as soft-tissues in humans are disclosed. They are similar to the Magnetic Resonance Imaging (MRI) methods and apparatuses but they are based on the new Field Paradigm founded on the principle that the field intensity distribution in a 3D volume space uniquely determines the 3D density distribution of the field emission source and vice versa. The object to be imaged is first magnetized by a polarizing magnetic field pulse. The magnetization of the object is specified by a 3D spatial Magnetic Density Image (MDI) that needs to be determined. The magnetic field due to the magnetized object is measured in a 3D volume space that extends in all directions and in particular substantially along the radial direction from the center of the object being imaged. Further, magnetic field intensity may be measured along multiple directions at each point. This measured data captures all the available information and facilitates fast and accurate 3D image reconstruction. This is unlike prior art where measurements are made only on a surface at a nearly constant radial distance from the center of the target object. Therefore useful and available data is ignored and not measured in prior art. Consequently, prior art does not provide a fast and accurate solution to 3D imaging. The methods and apparatuses of the present invention are combined with frequency and phase encoding techniques of MRI in prior art to achieve different trade-offs.

The invention relates to a robot capable of automatically overturning and walking. The robot capable of automatically overturning and walking comprises a robot body, four legs which are of the same structure and are uniformly distributed on the outside of the robot body, an undersurface ultrasonic distance measuring system and a front ultrasonic distance measuring system, wherein each leg has three joint freedom degrees, and each joint is controlled by a steering engine; the robot body is internally provided with an stc12c5a60s2 single-chip microcomputer and a steering engine controller which is in output connection with the robot body, the steering engine controller controls all paths of steering engines which are connected to the four legs respectively, the undersurface ultrasonic distance measuring system is arranged at a bottom panel or a top panel of the robot body, and the front ultrasonic distance measuring system is arranged at the side part of the robot body in the heading direction of the robot. The provided robot capable of automatically overturning and walking can not only walk on a flat ground, but can also crawl on a rough ground, and when running into a special circumstance, the robot can overturn by itself and afterwards continue moving on, and thus the robot capable of automatically overturning and walking has a wide range of application.

The invention belongs to the ultrasonic wave field, particularly relates to an ultrasonic ranging system based on a single-chip microcomputer and aims to realize properties of strong directivity and small-amount energy consumption. The ultrasonic ranging system comprises a pulse generator and a driver. The ultrasonic ranging system is characterized in that the pulse generator and the driver are respectively connected with the single-chip microcomputer, the single-chip microcomputer is further connected with a display and an automatic gain module, the single-chip microcomputer is connected with a callback discriminator through a shaping circuit, and the single-chip microcomputer is further connected with a conversion module.

The invention discloses a microwave sensor. The microwave sensor is characterized by comprising a power supply circuit, an oscillating circuit, an amplifying circuit, an output circuit and an indicating circuit, wherein the power supply circuit is used for supplying power for the oscillating circuit and the amplifying circuit; the oscillating circuit is connected with the power supply circuit; the amplifying circuit is connected with the oscillating circuit and the output circuit; the output circuit is connected with the amplifying circuit; and the indicating circuit is connected with the output circuit and comprises a light-emitting diode (LED) lamp. When the sensor is touched, the LED lamp is lighted. The oscillating circuit of the microwave sensor is adopted to generate microwaves and receive reflection waves without additionally arranging a microwave emission probe and a microwave receiving probe, so compared with other microwave sensors, the microwave sensor provided by the invention saves cost and eliminates the trouble of installing the microwave probes. The microwaves serve as detection means, so the microwave sensor is high in sensitivity and is not affected by the interference of sound waves; and the microwaves have strong penetrability, so the microwave sensor is easy to mount reconditely, is not easy to damage and is safer in use.