227results about How to "Large dynamic range" patented technology

High dynamic range brightness information is acquired by inputting detection current to a high (adjustable) gain resettable integrator whose output V(t) is compared to a Vth threshold by a comparator whose output is counted by a reset counter as V(t).gtoreq.Vth. When a desired count is attained, data acquisition ends, the counter is read, and the entire circuit is reset. A TOF data acquisition circuit includes first and second sequences of series-coupled delay units, and a like number of latch units coupled between respective delay units. A phase discriminator compares output from each chain and feedback a signal to one of the chains and to a comparator and can equalize delay through each chain. A control voltage is coupled to the remaining chain to affect through-propagation delay time. The latch units can capture the precise time when V(t).gtoreq.Vth. Successive measurement approximation can enhance TOF resolution.

The invention relates to a wireless-receiving system for detecting microelectronic mechanical microwave frequency and a preparation method thereof. The wireless-receiving system for detecting the microelectronic mechanical microwave frequency has quite simple structure, large measurement magnitude range, no direct-current power consumption and easy integration. In the system for detecting the microelectronic mechanical microwave frequency, gallium arsenide is used as a substrate, wherein a microwave antenna (A), a one-three power splitter (B), a coplanar waveguide transmission line (C), a two-in-one power combiner (D), an MEMS cantilever capacitive microwave power sensor (E) and an MEMS thermoelectric microwave power sensor (F) are designed on the substrate; and then a phase difference between a signal 3 and a signal 2 after the signal 3 passes through the coplanar waveguide transmission line with the length of lambda/2 can be determined according to a law of cosines. Because the phase difference corresponds to the frequency of the signal, the frequency of the signal can be measured.

The invention discloses a narrow gap welding monitoring and welding line deviation detecting method based on infrared vision sensing and belongs to the technical field of welding. An infrared vision sensing system comprises an infrared complementary metal oxide semiconductor (CMOS) camera, a filtering system, an image collecting card, a computer, a display and the like. Narrow gap welding arc light and molten pool radiation light are used as a light source, an infrared narrow belt filtering system is used for filtering interference signals and adjusting light intensity, and the computer collects and displays a welding image obtained through the infrared CMOS camera. An image capturing window is used for capturing an image away from an arc side, the image is processed, welding line deviation information is obtained by extracting a groove single-side edge, and a real-time property of welding line deviation detecting is improved while arc noise is effectively avoided. The system is simple in formation, clear in monitored image, high in welding line deviation detecting precision, strong in anti-interference capacity and good in engineering practicality and can achieve the purposes of real-time monitoring of narrow gap welding and synchronous detecting of welding line deviation.

An autocorrelator apparatus and method for economically measuring physical properties of an object where the measurement path is at least semi-translucent to light, such as thicknesses in multilayered optical structures, group index of refraction, and distance to a surface. The apparatus includes a non-coherent light fiber interferometer and an optional coherent light fiber interferometer in association so as to share PZT fiber modulators. Thickness and boundary extent measurements can be made, for example, of solids, liquids, liquids moving along a horizontal plane, or liquids flowing down a plane.

The present invention is a hybrid RF-digital signal processor-based filter for multiband radio architectures systems capable of spectrum re-farming and software defined radios. It performs low-loss frequency agile multiple notch filtering at RF where a large dynamic range exists at a filter input between signals in a stopband and passband. It is a frequency dependent signal attenuation apparatus having two paths connected together by directional couplers. The first path comprising a component such as a delay component or duplexer. The second path comprising a bandstop filter connected to a down converter, a digital filter, and an up converter. At the output of a power amplifier, the invention can be used to attenuate spurs, or noise within bands with strict emission constraints. At the input of a low noise amplifier, the invention can be used to attenuate blockers and transmitter noise outside of the receiver passband.

The invention relates to an imaging spectral system based on compressed sensing and Hadamard transformation. The imaging spectral system comprises a telescope unit, an imaging lens, a first expanded beam collimating lens, a first digital micro-reflector, a camera, a concave surface collimation reflector, a light splitting optical grating, a first convergent lens, a second digital micro-reflector, a second convergent lens, a light combining optical grating, a third convergent lens, a point detector, a Hadamard inverse transformation module and a compression calculation association module.

The invention discloses a vehicle ranging and collision early warning method based on monocular vision. Firstly, a target dynamic video is collected through a monocular camera, each frame of the collected video is subjected to image preprocessing, then, the characteristics of an image is compared with positive sample characteristics obtained by training to detect a target, and the target is marked by a rectangular frame. The midpoint coordinate of the bottom edge of the rectangular frame is obtained, and a practical distance between two vehicles can be obtained according to pinhole imaging and the geometric proportion relationship of similar triangles; and according to the distance change of two vehicles within a given time, the relative speed is calculated, the collision time is calculated by combining with the distance, and a voice alarm is given when the time is smaller than the collision safety time so as to prompt a drive to adopt a corresponding measure. The vehicle ranging and collision early warning method only adopts one camera to collect videos, so that equipment is simple, an adopted target detection method has the advantages of being high in accuracy and instantaneity, a ranging method is simple and effective, timely early warning is realized, and traffic accidents are effectively avoided.

Provided is a method capable of automatically adjusting a rotation radius and measuring an inner diameter and an outer diameter of a pipe end of a steel pipe. The method is a measuring method which aims at a measuring device for the inner diameter and the outer diameter of the pipe end, wherein laser ranging probes rotate around the pipe end. According to the measuring method, by using the mode that the rotation radius is automatically adjusted during the rotation measuring process, the defect that a laser triangulation method ranging probe is limited in the measuring range is compensated, the requirement for the aligning precision between a rotating central axis and a steel pipe central axis of a rotating platform is greatly lowered, a dynamic range capable of measuring changes on a pipe diameter is enlarged, the equipment cost of an auxiliary machine is lowered, and the stability and the practicality of equipment are improved. Meanwhile, during the operation, aiming at steel pipes with different sizes, the positions of probe fixed arms do not need to be adjusted in advance, the operation procedure is reduced, and the maintenance cost is lowered.

The invention discloses a long-distance distributed optical fiber vibration sensing system and a method thereof. The system comprises an induction system for inducting outside vibration events and a detecting and controlling system for detecting and controlling vibration signals; the induction system is connected with the detecting and controlling system. The induction system comprises a light source, a pulse modulator, an optical fiber circulator, a first optical fiber amplifier, and a light switch of a first optical fiber filter. The detecting and controlling system comprises a plurality of optical-electrical converters and a system control unit; the system control unit collects output light of the converters, analyzing the collected signals and judges whether the alarm is needed according to the analysis result. The invention adopts the optical switch technology to adopt time-division processing on backward Rayleigh scattering light which is reflected back, the dynamic range of the system is large, and the sensible distance can be tens of kilometers as high as possible, even hundreds of kilometers; and the invention adopts phase detecting technology and optical time domain reflection technology and can greatly improve detecting sensibility of the system and positioning precision.

The invention provides an energy dispersion device, spectrograph and method that can be used to evaluate the composition of matter on site without the need for specialized training or expensive equipment. The energy dispersion device or spectrograph can be used with a digital camera or cell phone. A device of the invention includes a stack of single- or double-dispersion diffraction gratings that are rotated about their normal giving rise to a multiplicity of diffraction orders from which meaningful measurements and determinations can be made with respect to the qualitative or quantitative characteristics of matter.

A system and method for processing a wireless burst transmission. A sensor measures the energy of the wireless burst transmission. A first amplifier is in electrical communication with the sensor. A second amplifier is in electronic communication with the sensor. The first amplifier and the second amplifier are initially enabled and are selectively disabled based on an energy measurement from the sensor.

The invention discloses an optical voltage transformer which is composed of a light source, a coupler, a polarizer, a phase modulator, a polarization delay optical cable, a collimating lens, a faraday rotary mirror, an electro-optical sensing unit, a photoelectric detector and a signal processing module, wherein the electro-optical sensing unit is composed of a bismuth germinate and an A and a B electrodes which are respectively installed on an upper and a lower panels of the bismuth germinate. The invention adopts the technical proposal that an electric field leads to the change of the refractive index of the sensing bismuth germinate in the electro-optical sensing unit, the phase difference of two cross-line polarized lights passing through the bismuth germinate is changed due to the Pockels effect, and the magnitude of the electric field can be indirectly measured by measuring two coherent lights.

This invention discloses a self-correcting type time digital converter. The converter comprises a coarse measurement part, a fine measurement part and a correction part, wherein a counter is adopted to obtain a coarse time measurement result, a delay chain, a D trigger array and a search table unit are utilized to obtain a fine time measurement result, an offset correction unit is utilized to obtain a time measurement result, the time measurement result is the sum of the coarse time measurement result and the fine time measurement result, and then the time measurement result is corrected in combination with the temperature of current working environment which is measured by a temperature sensor. According to the scheme, the self-correcting type time digital converter can correct the measured time measurement result, and the environment adaptability of the time digital converter is improved.

The invention discloses a large dynamic optical fiber vibration sensor comprising a light source, a first optical fiber coupler, a high-sensitivity interferometer, a low-sensitivity interferometer and two optical detectors. The two arms of the high-sensitivity interferometer have same length and are wound on elastic cylinders at two ends of a mass block respectively, so that a symmetric push-pullstructure is formed and used for detecting a small signal; one arm of the low-sensitivity interferometer is wound on the two elastic cylinders after passing through the mass block; the lengths of theoptical fibers wound on the two elastic cylinders are different; and the other arm of the low-sensitivity interferometer is vacant and used for detecting a large signal. According to the large dynamic optical fiber vibration sensor disclosed by the invention, the dynamic range of an interference-type optical fiber vibration sensor is enlarged, simultaneous and large dynamic detection of a common point of the optical fiber vibration sensor is realized, and the vibration sensor is easy to miniaturize.

The invention belongs to the technical field of detection of performance of electric transmission line insulators, and discloses a method for automatically identifying hydrophobic grades of composite insulators. The method includes the steps of image enhancement, image filtering, image segmentation, image feature quantity extraction, neural network identification model establishment and the like. By analyzing hydrophobic images of the composite insulators, automatic identification of the hydrophobic grades of the composite insulators is achieved. Human factor influences are eliminated, the method is high in accuracy of the judgment result, easy to operate and capable of automatically identifying the hydrophobic grades of the insulators different in voltage grade, type, manufacturer, foul degree grade, operation age limit and the like.

The invention relates to a low-contrast image enhancement method based on YCrCb. The low-contrast image enhancement method comprises the following steps: (1) performing image de-noising on an obtainedoriginal image by utilizing a trapezoidal low-pass filter; (2) performing conversion between a RGB color space and a YCrCb color space on the de-noised image to obtain an image brightness component;(3) performing piecewise linear transformation on a brightness component image by adopting a traditional spatial domain linear transformation method; (4) performing Gamma correction on the transformedimage; (5) performing Gaussian filtering on the corrected image by utilizing a single-scale Retinex algorithm and estimating illumination component and reflection component images; (6) performing image sharpening by utilizing a Gaussian sharpening algorithm aiming at the reflection component image; and (7) performing conversion between the YCrCb color space and the RGB color space on the sharpened image.

The invention provides a tomographic method and a system for coherent optics in complex spectrum frequency domain, comprising a broadband light source, a light source coupling mechanism, a combined interferometer, a fiber-optics imaging probe, a spectrograph, a temperature controller and a computer; the method comprises the following steps of: firstly, measuring three groups of interference spectrum in state of three different phases of reference light; secondly, calculating two groups of differential interference spectrums; thirdly, taking the sum and the remainder of the two groups of differential interference spectrums as a real part and an imaginary part for a complex amplitude so as to reconstruct the interference spectrum of the complex amplitude in a wave number space; finally, making an inverse Fourier transform for the interference spectrum of the complex amplitude and obtaining depth-scanning information of a measured sample along an optical axis, that is chromatogram. Under the condition that a regulating device for the phase of the reference light is not used, the tomographic method and the system eliminate the effect for chromatogram quality caused by a parasitic image and a hetero conjugation image, and can realize the tomography which reflects the real structure of the measured sample with the advantages of simple system structure, wide dynamic scope and deep measurement in full scale.

When updating a data record identified by a version number, the problem exists that a simple not equal to comparison or greater than comparison is often insufficient for ascertaining the up-to-date nature of the newly received data record, particularly if the data record is transmitted to a receiving station via an unsecured data link and the version number originates from a limited range which is repeatedly run through periodically. The invention solves the problem by virtue of the fact that it divides the range of values of the version number into the ranges “old” and “new”, on the basis of the current value of a version number. The periodicity with which the range of values is run through is taken into account in this case, however. That is to say that the range “old” or the range “new” may perfectly well include the jump from the highest value in the range of values to the lowest value in the range of values. If the version number of the newly received data record lies in the range “new”, the new data record is accepted as a current data record, and if not it is correspondingly rejected.

The invention relates to the integrated circuit design filed and the digital image processing field of microelectronics. A CMOS asynchronous time domain image sensor capable of achieving real-time time stamp aims to solve the event-time mismatching problem caused by an AER asynchronous output mode, achieve accurate stamp output of image time among rows, and improve the accuracy of obtained images in a time domain. In order to achieve the purposes, according to the technical scheme, the CMOS asynchronous time domain image sensor capable of achieving the real-time time stamp comprises a light intensity change detector circuit CD and a double-sampling pulse width modulation circuit PWM and further comprises a row/column reset control circuit, a row arbiter circuit, a row level time stamp circuit and a row/column address coding circuit, wherein the column address coding circuit receives row selected signals transmitted by a row weighted arbiter structure and outputs a selected row address, and the row address coding circuit is triggered by the output signals of the CD circuit outputting pixels. The CMOS asynchronous time domain image sensor capable of achieving the real-time time stamp is mainly applied to the design and the manufacturing of image sensors.

The invention relates to a CMOS image sensor reading circuit, which comprises an analog-to-digital converter, and also comprises a variable gain amplifier, a comparator and a gain adjusting device, wherein the variable gain amplifier is suitable for receiving and adjusting pixel exposing voltage of the image sensor, and outputting the voltage to the analog-to-digital converter; the comparator is suitable for judging the pixel exposing voltage; and the gain adjusting device is suitable for receiving a judgment result output by the comparator, and adjusting an amplification factor of the variable gain amplifier according to an exposing voltage section where the exposing voltage is positioned. The invention also relates to a method for reading digital signals from pixels by the CMOS image sensor, which comprises the following steps: adjusting the pixel exposing voltage by the variable gain amplifier; converting analog voltage signals output by the variable gain amplifier into digital signals for output; judging the pixel exposing voltage; and adjusting the amplification factor of the variable gain amplifier according to the exposing voltage section where the exposing voltage is positioned. Under the conditions of different light intensities, both the reading circuit and the method can obtain clear images to meet the requirement of human eye on image quality.

The present invention discloses methane detecting fiber interference process and equipment. Two couplers are connected to form one interferometer, which has one detecting arm possessing metal casing coated with platinum film as catalyst and one reference arm. The platinum film catalyzes the oxidation reaction between methane and oxygen to release heat causing the detecting arm to become longer. The light beams the two arms output generate interference effect, and the relation between spectral line shift of the interferometer and the methane concentration is established. The interferometer is connected with a wideband light source and other demodulation equipment to constitute the methane detecting equipment with high sensitivity, high response speed and remote measurement.

A signal processing system is disclosed. The signal processing system comprises an AGC and pre-echo cancellation system for receiving an analog signal, boosting it up (over all frequencies) to a pre-determined range by AGC, and removing the immediate transmit pulse from this received signal by pre-echo canceller to provide a second analog signal. The signal processing system further comprises a summer for receiving the analog signal; a feed forward equalization (FFE) unit for receiving a signal from the summer; and a slicer for receiving a signal from the FFE unit and providing an output signal. The signal processing system also comprises an Echo and NEXT cancellation system for receiving the output signal and for providing a signal to the summer for canceling the echo and crosstalk in the signal processing system. Accordingly, in a system and method in accordance with the present invention the Echo and crosstalk components associated with a signal processing system can be subtracted prior to the FFE. This allows for a practical analog implementation which has a good dynamic range of the signal through the FFE and subsequent analog elements. This system can be utilized to great advantage in low power CMOS designs where supply voltages are limited.

The invention discloses a double-closed loop locking technology-based resonant optical gyro. The double-closed loop locking technology-based resonant optical gyro comprises an optical system composed of a tunable laser, an optical shunt, two frequency shifters of a first frequency shifter and a second frequency shifter, two modulators, an optical resonant cavity and a photoelectric conversion module, and a processing circuit composed of a modulation-demodulation module and three feedback locking modules. Main components of the optical system comprise the tunable laser as a double-closed loop feedback terminal and the two frequency shifters. A first signal extracted by the modulation-demodulation module can respectively change frequency shift amounts of the tunable laser and the first frequency shifter through two of the threes feedback locking modules. A second signal extracted by the modulation-demodulation module can change a frequency shift amount of the second frequency shifter through another feedback locking module. A rotation signal is obtained according to the difference between frequency shift amounts of the first frequency shifter and the second frequency shifter. The double-closed loop locking technology-based resonant optical gyro has a completely reciprocal resonant optical gyro structure, and is beneficial for elimination of reciprocal noise of a system, improvement of system linearity, broadening of a system dynamic scope, and reduction of optical Kerr noise.

The invention relates to the technical field of optical tests, in particular to an external field type infrared radiometer. According to the infrared radiometer, a main convergence mirror is connected with a wave chopper; the wave chopper is connected with a standard reference black body source and light filters; the light filters are connected with neutral attenuation pieces; the neutral attenuation pieces are connected with optical spectrum correcting pieces; the optical spectrum correcting pieces are connected with an infrared detector; a signal acquisition part is connected with the infrared detector and the wave chopper respectively. Through the embodiment, a corresponding optical spectrum curve of a whole system in a measurement waveband can be enabled to be a flat curve through the optical spectrum correcting piece, the linearity and the measurement accuracy of the whole system are improved, and the influence of a radiation spectrum of a tested object on a measurement structure is avoided; the neutral light filters with different attenuation ratios are adopted and the dynamic range of equipment is expanded. Therefore, the equipment has a plurality of ranges and strong and weak radiation targets can be measured.

This invention belongs to a compound particle inorganic hollow micro particle process technique field. This invention uses the method of two iron salt liquid control hydrolyze to process the hole magnetic ferric oxide to cover on the organic ball of polystyrene to get the nucleus or shell structure magnetic ferric oxide compound ball. It uses slow heating method and non-oxygen conditions to sinter the compound particles and the organic material in the particles to get the whole hole magnetic ferric oxygen hollow micro ball particles.

The invention discloses a servo circuit of quartz accelerometer, comprising an integrated part and a divided part wherein the integrated part comprises a triangle generator, a differential capacitance detector, an integrating amplifier and a transconductance amplifier; and the divided part comprises a negative feedback circuit, an outer timing capacitor, an outer timing resistance and outer offset resistance. The triangle generator outputs the triangular wave to the differential capacitance detector by an emitter follower. The differential capacitance detector charges and discharges the differential capacitor of the swinging subassembly of the accelerometer the detected differential capacitance signal is converted into the corresponding error current signal and the error current signal is output to the integrating amplifier. After the slowly varying pressure signal is obtained after integrate demodulation by the integrating amplifier, the transconductance amplifier is pushed. The slowly varying pressure signal is added on the electromagnetic torquer of the quartz accelerometer through the transconductance output terminal to form the restoring torque, so as to recover the swing slice at the balance position. The negative feedback circuit is mounted between the inverted input terminal of the integrating amplifier and the output feedback terminal of the transconductance amplifier to form a complete closed loop test system with deep negative feedback.

The invention discloses an interferometry-based optical fiber Verdet constant measuring system. The system comprises an ASE (amplified spontaneous emission) light source, a single-mode optical fiber coupler, a Y-waveguide integrated optical modulator, 1/4 wave plates, Faraday rotator mirrors, a solenoid, a sine alternating-current driving circuit, matching fluid, a probe, an information processing module, a computer and measured optical fibers. The ASE light source, the single-mode optical fiber coupler, the Y-waveguide integrated optical modulator, the measured optical fibers and the Faraday rotator mirrors are connected through optical fibers in sequence. Each 1/4 wave plate is arranged between the Y-waveguide integrated optical modulator and the corresponding measured optical fiber. A signal processing portion comprises a feedback servo circuit, an FPGA (field programmable gate array) module and a phase modulation driving circuit. The system is of an all-optical-fiber structure and simple and convenient to set up; by the aid of the Faraday rotator mirrors, influences of linear birefringence of the optical fibers on measurement can be eliminated, and measurement accuracy is improved; and Verdet constants of various optical fibers can be measured by the system.

The present invention provides an ultrasound probe and an ultrasound diagnostic apparatus. The present embodiment relates to the ultrasound probe having a first ultrasound vibrator group and a second ultrasound vibrator group, comprising a plurality of matrix switches and an adder. The ultrasound probe has a mode to send ultrasound to a predetermined observation point within a subject by the first ultrasound vibrator group, and to receive ultrasound echoes reflected within the subject by the second ultrasound vibrator group. The plurality of matrix switches extract, based on the distance between the second ultrasound vibrator group and the observation point, a plurality of ultrasound echoes having substantially the same phase from a plurality of ultrasound echoes output by the second ultrasound vibrator group. The adder adds the plurality of ultrasound echoes extracted by the plurality of matrix switches for each of the matrix switches and outputs them.

The invention discloses a distributed optical fiber sound sensing device and method based on dual-polarization double-sideband modulation. The distributed optical fiber sound sensing device comprisesa narrow linewidth laser source (1), a polarization-maintaining optical fiber isolator (2), a dual-polarization four-parallel Mach-zehnder electro-optic modulator (3), an arbitrary waveform generator(4) for drive in an X polarization direction, an arbitrary waveform generator (5) for drive in a Y polarization direction, an electro-optic modulator bias control panel (6), a 1*2 polarization-maintaining optical fiber coupler (7), an optical fiber polarization beam splitter (8), a first erbium-doped optical fiber amplifier (9), a first optical fiber (10), an optical fiber circulator (11), a second erbium-doped optical fiber amplifier (13), a second optical fiber (14), a four-way output-type 90-degree light mixer (15), a balance photoelectric detector (16), a data acquisition card (17) and a processing unit (18). The distributed optical fiber sound sensing device integrates the advantages of time-domain reflection and frequency-domain reflection, is free from electromagnetic interference,is electrically passive and can achieve distributed sound sensing with a large dynamic range and high spatial resolution.

The invention discloses an automatic LTE terminal receiver gain control achieving method. According to the method, an FPGA controls an analog attenuator and a digital attenuator to adjust the input signal power to be within the target range, and a CPU configures and adjusts the stepping value and all power gates; the AGC function is enabled, the FPGA conducts statistics on the baseband data power of one frame and sends the power to an AGC control module, and the AGC control module judges the segment of the power range according to the current statistics power value, so that operation of the analog attenuator or operation of the digital attenuator is conducted at the beginning of one frame, one stepping value is adjusted at a time, and the final target power is reached through multiple adjustment.