26 results about "Amplitude reduction" patented technology

The invention relates to an optical time domain reflectometer and a control method of the optical time domain reflectometer, and relates to the technical field of photoelectricity. The optical time domain reflectometer OTDR comprises a single photon detector, and the OTDR is used for being connected with an optical fiber to be measured; the OTDR is further used for sending a plurality of detection signals to the optical fiber to be detected in sequence and receiving a plurality of detection echo signals from the optical fiber to be detected in sequence, and the detection echo signals are used for indicating the transmission state of the same section of transmission area in the optical fiber to be detected; performing amplitude reduction processing on each detection echo signal at a certain time interval to obtain a processed detection echo signal; the positions, corresponding to the same section of transmission area, of the signal sections subjected to amplitude reduction processing in the different processed detection echo signals are not completely the same; each processed detection echo signal is subjected to photoelectric conversion based on the single-photon detector to obtain a first electric signal, a first OTDR oscillogram is output based on the multiple first electric signals, and the first OTDR oscillogram is used for indicating the transmission state of the same section of transmission area. Therefore, the problem of OTDR curve distortion can be solved.

The invention discloses a cable-beam combined structure 1 / 2 subharmonic resonance vibration reduction method. The method comprises the following steps that S1, the optimal damping force needed by a cable in the current motion state is obtained according to a time-lag vibration reduction rule; s2, calculating a target current required by the MR damper according to the obtained optimal damping force; s3, mapping the target current to a current interval which can be actually applied by the MR damper by using a mapping algorithm to obtain a mapping current; s4, adjusting individual overlarge mapping current to obtain applied current; and S5, current is applied to the MR damper so as to control the cable-beam combined structure. According to the method, the optimal damping force and the target current are accurately calculated, and the time-delay selection rule is combined, so that 1 / 2 subharmonic resonance can be accurately inhibited, the vibration amplitude of the cable-beam composite structure under the specific frequency is effectively reduced, the fatigue damage risk of the structure is reduced, and the service life of the bridge is prolonged.

The invention relates to the technical field of temperature rise adjustment, and particularly discloses a temperature rise adjustment method of a dv / dt amplitude reduction filter, which comprises the following steps: S1, setting a voltage range of the filter, and setting an environment temperature range; obtaining the temperature rise of the filter under the same environment temperature and different voltages, and obtaining a curve that the temperature rise of the filter changes along with the voltage and the environment temperature through nonlinear regression analysis; s2, when the temperature rise of the filter is greater than or equal to a preset value, setting an ideal temperature rise value of the filter, obtaining a real-time environment temperature, and substituting the real-time environment temperature into a curve that the temperature rise of the filter changes along with the voltage and the environment temperature to obtain a target voltage; and S3, when the Upeak value of the filter is greater than or equal to a preset value, adjusting the load at a preset fixed load interval until the Upeak value is less than the preset value, and reducing the temperature rise of the filter and the Upeak value. According to the invention, the relationship between the temperature rise of the filter and the Upeak value can be balanced, the service life of equipment is prolonged, and the system performance and reliability are improved.

The invention provides a discontinuous pulse signal frequency acquisition system and method, and the system comprises an attenuation unit, a filtering unit, an impedance matching unit, a first comparator, a second comparator and a main control unit, and the attenuation unit is used for reducing the amplitude value of an input pulse signal; the filtering unit is used for filtering the signal after the amplitude value is reduced; the main control unit is connected with the first comparator and the second comparator. According to the invention, the discontinuous pulse signal is attenuated and subjected to filtering impedance matching and then is input into the first comparator and the second comparator at the same time, the main control module triggers the first comparator to count when detecting the rising edge output by the second comparator, and the first comparator calculates the period of two continuous square waves, so that the frequency of the discontinuous pulse signal is obtained; effective and rapid acquisition of discontinuous pulse signal frequency is realized.

The invention relates to the technical field of pulse width modulation, and discloses a frequency conversion critical triangular wave pulse width modulation method and device, and the method comprises the steps: obtaining the overlapping conduction time of two lower tubes of a secondary side of a dual-active bridge converter, and enabling the overlapping conduction time to be obtained through current closed-loop control; judging whether the switching period exceeds a preset time threshold value or not according to the overlapped conduction time and the inductor follow current time; and if the switching period exceeds the preset time threshold value, converting the preset time threshold value and the overlapping conduction time into a duty ratio and a frequency, and then carrying out frequency conversion critical triangular wave pulse width modulation on the dual-active bridge converter. According to the technical scheme, the frequency variable can be introduced, so that the inductive current triangular wave stably works in a critical continuous state all the time. The power is improved through the synergistic effect of frequency conversion and peak current increase, and meanwhile, the increment influence of the stage that the inductive current is reduced to 0 on the peak current is counteracted through frequency compensation, so that the turn-off loss at the inductive peak current is greatly reduced, and the heating problem of a system switch tube is effectively relieved.

The invention provides a multi-energy system cluster fault intelligent diagnosis and analysis method, which comprises the steps of collecting original vibration signal data corresponding to a bearing wear signal from a multi-energy system cluster equipment node, extracting specific frequency vibration and amplitude reduction process characteristics, and performing material type identification; according to the material type identification result, the propagation process of the bearing wear signal from the source device to the adjacent device is analyzed, and propagation path analysis data is obtained; according to the propagation path analysis data, identifying the signal contribution degree of each equipment node corresponding to the fault feature difference, and judging the origin point of the potential fault feature; obtaining a vibration frequency subset corresponding to the origin point of the fault feature, and extracting the fault feature after feature correction; and determining the position of fault source equipment in the multi-energy system cluster according to the extracted fault features.

This invention provides a method for noise reduction using reflected waves in a motorcycle muffler. A reflective noise reduction device is installed inside the muffler's cylinder, dividing the internal portion of the muffler into a first noise reduction cavity and a second noise reduction cavity. The first noise reduction cavity is connected to the second noise reduction cavity via the reflective noise reduction device. The method involves the following steps: after a sound wave enters the first noise reduction cavity, part of the sound wave is silenced by passing through the first noise reduction cavity and the reflective noise reduction device; another part of the sound wave, as an incident sound wave, enters the reflective noise reduction device and is reflected by the smooth, flat walls of the device. The reflected sound wave and the incident sound wave undergo destructive interference, resulting in amplitude reduction or cancellation. The remaining sound wave enters the second noise reduction cavity for further silencing, and finally, the remaining sound wave is discharged. This invention achieves noise reduction through active control of the reflected wave, significantly improving noise reduction performance within the limited space of a motorcycle muffler.

The utility model discloses a flexible gyrocompass north seeker which comprises a mounting seat, a case is mounted at the top of the mounting seat, a flexible gyrocompass assembly is mounted at the bottom of the inner wall of the case, a vibration reduction connecting assembly is arranged below the mounting seat, and the vibration reduction connecting assembly is connected with the mounting seat through a limiting and fixing assembly. According to the utility model, the double vibration damping design is realized through the vibration damper and the buffer spring, the mechanical lag error of the flexible gyroscope assembly is reduced through the composite vibration damping structure, the static north-seeking precision is less than or equal to 0.1 degree and the dynamic north-seeking error is less than or equal to 0.3 degree by matching with the real-time inclination angle compensation of the biaxial accelerometer, and the noise amplitude of vibration transmitted to the signal conditioning circuit is reduced. The accuracy of resolving the north angle by the STM32H7 processing chip is ensured, the limiting and fixing assembly and the vibration reduction connecting assembly can be detached from the mounting seat, so that the mounting seat can be recycled, and the flexibility in use is improved.

The invention discloses an output circuit. The output circuit comprises an amplifying circuit; and the buffer circuit is electrically connected with the amplifying circuit. According to the output circuit and the amplification circuit, a single-ended input signal and an output feedback signal are subjected to primary differential amplification and are output to the buffer circuit, and the output impedance of the circuit can be greatly reduced by using the source follower, so that the gain of the circuit is improved; meanwhile, the output circuit gain is converted from being in direct proportion to the input impedance ZL of the next-stage circuit to being in direct proportion to the trans-impedance ro, the circuit gain is greatly improved, the output impedance Rout of the circuit is reduced from 1 / 2or to be in direct proportion, reduction of the resistor output impedance and use of the differential amplifier are achieved, the circuit can be used in cooperation with a source follower, a negative feedback circuit is constructed, and the output impedance Rout of the circuit is reduced to be in direct proportion to the trans-impedance ro. The output impedance of the circuit is further reduced, and the gain of the circuit is further improved.

The invention provides a PCB differential line equal-length wiring method based on AD software. The method comprises the following steps of S1, AD item configuration and multi-dimensional parameter presetting, S2, AD script development and differential pair intelligent identification grouping, S3, AD priority dynamic wiring and line length real-time feedback, and S4, line length optimization and verification of AD simulation driving. Through linkage of script development and simulation functions of AD software, the method has the following beneficial effects: the differential line identification and grouping time is shortened from 4 hours to 8 minutes, and the wiring efficiency is improved by 96.7%; the wire length error is controlled within 3 mil, and the precision is improved by 66.7% compared with manual wire checking; the AD priority wiring rule avoids signal channel preemption, the clock signal crosstalk amplitude is reduced by 55%, and the 10Gbps signal transmission error rate is reduced to below 10; the DRC verification passing rate is improved to 100% from 75% of a traditional method, and the later plate changing cost is reduced by 80%.

The invention discloses a zero-frequency signal amplitude reduction method and system based on a multi-cut full-parallel FIR filter, and belongs to the technical field of chip digital design, and the method comprises the steps: executing the CSD multiplication of a filter coefficient and input data, and obtaining a plurality of partial products; carrying out cutting processing on the plurality of partial products respectively; calculating a compensation value of a truncation error based on the symbol attributes of the plurality of partial products and the state of the least significant bit after truncation; and accumulating the plurality of partial products after cutting processing and the compensation value to obtain filtering output. The invention solves the problems that the zero-frequency signal amplitude of the filter is obviously increased and the resource efficiency and the signal precision are difficult to consider at the same time due to the fact that the truncation digits are increased for reducing hardware resources in the prior art.

The invention discloses a transmitting device for optical communication transmission, and the device comprises a modulator which generates four-level amplitude modulation PAM4 signals in X and Y polarization states; the marker tone provider is used for respectively embedding low-frequency marker tone signals with preset frequencies into the four-level amplitude modulation PAM4 signals in the X and Y polarization states; and the beam combiner is used for carrying out beam combination on the four-level amplitude modulation PAM4 signals in the X polarization state and the Y polarization state which are respectively embedded into the low-frequency marking sound signals, and introducing a path of synthesized DP-PAM4 signals into a transmission optical fiber. According to the invention, the PAM4 signal is subjected to polarization multiplexing without depending on a phase recovery technology, and the requirement on a receiving side of optical communication transmission is greatly reduced through an IM-DD intensity modulation mode and polarization multiplexing transmission. Polarization state self-identification is achieved by combining low-frequency marks, polarization state identification and separation are achieved by monitoring mark signal differences, a complex polarization tracking algorithm is replaced, and a high-cost modulator and a local oscillator needed by high-order coherent modulation are avoided.

The present invention belongs to the field of medical device technology, and in particular relates to a short-range open ultrasonic scalpel center rod. The present invention comprises a scalpel body, on which a first center rod segment, a second center rod segment, a third center rod segment, a fourth center rod segment, a fifth center rod segment, and a sixth center rod segment are provided. The sixth center rod segment is connected to the scalpel body, the first center rod segment is provided with a primary amplitude amplification structure, the second center rod segment is provided with an amplitude reduction control structure, the third center rod segment is provided with a slowdown transition structure, and the fourth center rod segment is provided with an amplitude expansion structure. The present invention is applied to open abdominal surgery, using a short-range center rod. By providing a primary amplitude amplification structure, an amplitude reduction control structure, a slowdown transition structure, an amplitude expansion structure, a conduction structure, and a high-amplitude output structure, the center rod emission response is reduced by 8 to 12 dB, thereby significantly reducing the center static impedance and achieving instantaneous tissue dehydration and coagulation.

The application discloses a kind of OTFS modulation methods of Doppler axis zero insertion extension.There is the pretreatment of Doppler axis zero insertion extension to transmitting end signal, and the signal in delay-Doppler domain after extension is obtained, the inverse symplectic Fourier transform is carried out to the signal in delay-Doppler domain after extension, and the time-frequency domain signal is obtained, the amplitude reduction is carried out to the time-frequency domain signal, and the restored signal is obtained, the Heisenberg transformation is carried out to the restored signal, and the time-domain signal after extension is obtained, the time-domain output signal after extension is obtained after the time-domain signal after extension passes through delay-Doppler channel, sampling and Wigner transformation are carried out to the time-domain output signal after extension, and the time-frequency domain output signal after extension is obtained, the symplectic Fourier transform is carried out to the time-frequency domain output signal after extension, and the output signal after extension in delay-Doppler domain is obtained, and this method effectively solves fractional Doppler problem.

The invention relates to the field of blade monitoring, and discloses a passive eddy current sensing system and a passive eddy current sensing method for monitoring the blade state of a rotating machine. A plurality of passive eddy current sensors are arranged on a shroud ring of a moving blade, and multi-dimensional feature processing of amplitude modulation, phase deviation detection and harmonic component analysis is combined; and the comprehensive perception of the blade operation state is realized. The system can simultaneously capture amplitude reduction caused by cracks, phase deviation caused by material performance change and subharmonic characteristics appearing under a resonance condition, so that multi-dimensional health characteristic information of the blade is obtained, fusion processing is carried out through the data analysis module, and finally accurate blade state data is formed.

The application discloses a DAC gain modulation circuit, which can realize flexible adjustment of the output gain of a multi-channel DAC, each channel can be adjusted by using an independent resistor or a single resistor. Compared with a conventional DAC circuit using a single resistor, the circuit can independently adjust the output amplitude of the multi-channel DAC, reduces the need of a user for an additional external channel gain adjustment device, and facilitates switching use in various application modes such as interleaving, independence and modulation. Meanwhile, by adjusting the internal resistance ratio, the output current ratio of each channel can be flexibly adjusted, and the circuit has the characteristics of simple structure, low channel error and flexible modulation, and can be applied to the design of high-precision multi-channel current type DACs, DDSs and the like.

The invention belongs to the technical field of electric power engineering. The multi-nonlinear broadband-domain semi-active seismic isolation device suitable for the converter valve equipment is provided, the rigidity of an air spring and damping of magnetorheological fluid are regulated and controlled in real time based on monitoring data of vibration of a structure in all directions by an acceleration sensor, then the overall dynamic characteristics of the device are changed to adapt to the dynamic working condition, and the purpose of broadband intelligent seismic isolation is achieved; the apparent mass of the system in the earthquake process is amplified in combination with the inerter concept, energy is further dissipated through inertia force while the weight of the device is not increased, and the seismic isolation effect of the device is improved; the air spring, the shape memory alloy spring and the negative Poisson's ratio structure form a multiple non-linear vibration absorption system, the vibration isolation amplitude reduction performance of the device is enhanced, the device automatically restores to the original position after working is completed, the mass is light, release of seismic kinetic energy and limitation of displacement of a converter valve tower are both considered by adopting semi-rigid connection, insulator stress is not increased, and the service life of the device is prolonged. And the ground space is not occupied.

A computer-implemented method may include receiving a first signal corresponding to a first acoustic energy flow; applying a transform to the received first signal using a first amplitude-independent window size at at least a first frequency and a second amplitude-independent window size at a second frequency, the second amplitude-independent window size improving a time response at the second frequency, wherein the second frequency experiences amplitude reduction due to a resonance phenomenon associated with the first frequency; and storing a first encoded signal based on applying the transform to the received first signal.

The present invention relates to the technical field of analysis of the coupling effect of mechanical vibration and fluid excitation, and in particular to a method for measuring the pressure pulsation amplitude of a crown modification on a runner. The pressure gradient distribution and cavitation phase change characteristic parameters on the flow channel surface are extracted through fluid dynamics simulation, and the targeted arrangement of the high-frequency pressure sensor array in the vortex core area, the critical position of boundary layer separation, and the mutation area of ​​the modification structure is guided. The ring encryption and axial equal spacing arrangement strategies are adopted to improve the signal acquisition accuracy. A dynamic error feedback mechanism for actual measurement and simulation is established. The proportion of abnormal frequency bands is verified by frequency domain kurtosis and envelope spectrum harmonic analysis, and a modification parameter combination with a pressure pulsation amplitude reduction that meets the standard and a stable frequency band distribution is screened. The present invention solves the measurement error problem caused by the frequency domain aliasing of multi-source high-frequency noise and effective signals, provides a high-precision quantitative basis for the optimization of runner modification, and is suitable for the field of dynamic characteristic testing of mechanical systems.

The present invention relates to the technical field of laser frequency drift testing, and more particularly to a single-frequency laser frequency drift testing device and method based on a temperature-controlled wavelocker. The testing device includes single-wavelocker and dual-wavelocker structures. The present invention utilizes temperature-controlled wavelockers to address issues such as ambient temperature fluctuations and the poor stability of optical devices such as external FP cavities, ensuring the stability of frequency drift measurements while significantly reducing equipment costs. The use of two phase-matched temperature-controlled wavelockers addresses the problem of a single wavelocker or FP cavity being unable to determine the direction of frequency drift when measuring frequency drift, thereby limiting the measurement range.

The invention discloses an identification method of a piezoelectric ceramic deformed mirror surface shape response nonlinear model, and belongs to the technical field of adaptive optics. The method comprises the following steps: firstly, transmitting calibration light to a Shack-Hartmann wavefront sensor through a piezoelectric ceramic deformable mirror and a relay optical system; then grouping the piezoelectric ceramic drivers, sequentially applying continuous step, variable period square wave and reduced amplitude triangular wave voltage signals, and synchronously collecting slope data output by a wavefront sensor; extracting the slope of the nearest sub-aperture surrounding area of the driver, calculating the slope in the x / y direction, and synthesizing the slope into a total slope; and finally, the creep characteristic of the surface shape response is fitted through the transfer function model, the resonance characteristic of the surface shape response is fitted through the multi-order resonance model, and the hysteresis characteristic of the surface shape response is fitted through the KP hysteresis model, so that nonlinear characteristic high-precision identification is realized. According to the invention, the open-loop control precision and stability of the piezoelectric ceramic deformable mirror can be improved, and the method can be used for open-loop control of a multi-target adaptive optical deformable mirror.

The invention relates to the field of converter control, in particular to a current reference current limiting method, system and device with equivalent reactance characteristics and a storage medium. Obtaining the original current reference and the maximum allowable output current amplitude of the grid-forming type GFM converter; calculating an original phase angle and an original amplitude based on the original current reference; calculating an amplitude reduction proportion according to the original amplitude and the maximum allowable output current amplitude; calculating a current reference rotation angle based on the amplitude reduction proportion; calculating a current reference phase angle after amplitude limiting based on the original phase angle and the current reference rotation angle; calculating the amplitude of the current reference after amplitude limiting based on the original amplitude and the amplitude reduction proportion; generating a current reference after amplitude limiting according to the phase angle and the amplitude of the current reference after amplitude limiting; according to the current reference current limiting method, the defect that the equivalent output impedance cannot be a reactance characteristic after the network construction type GFM converter enters current limiting in the existing current reference current limiting method is overcome, and the transient stability margin of the system is remarkably improved.

The invention provides a self-adaptive ringing system based on an SLIC and a telephone system. Expected ringing amplitude and frequency parameters are configured for a client, and whether self-adaptive ringing is enabled or not is selected through a self-adaptive ringing enabling signal; if self-adaptive ringing is enabled, configuring delay time after oscillation starting, step length of self-adaptive amplitude reduction and error tolerance of peak detection; and if the self-adaptive ringing is not enabled, the SLIC chip generates sine waves according to the configured ringing amplitude and frequency after receiving the oscillation starting command. And after the start oscillation exceeds the delay time, when the ringing phase is 90 degrees and 270 degrees, detecting whether the error between the peak value of the ringing current signal and the expected peak value exceeds the error tolerance or not. And if yes, reducing the ringing amplitude by the step length of self-adaptive amplitude reduction at 180-degree and 360-degree phases, and recalculating the expected peak value after the amplitude reduction until the detected ringing signal peak value and the expected peak value are within the error range.

This invention discloses a radar timing processing method based on wide-speed coverage, belonging to the field of radar signal processing technology. It aims to solve the problems of poor clutter suppression, limited velocity measurement range, and severe range-folded clutter interference in complex clutter environments by traditional moving target indication (MTI) filters. This method achieves wide-speed coverage at three times the speed of sound and effectively suppresses range-folded clutter through a timing design that alternates between positive and negative frequency modulation slopes and uses carrier frequency agility, combined with a genetic algorithm-optimized staggered pulse repetition period (PRT) and MTI filter weight coefficients. Experimental results show that this method can reduce the average amplitude of folded clutter by approximately 45 dB, successfully separate target signals obscured by clutter, and significantly improve the radar's target detection performance in complex environments.

The invention relates to an ultrasonic water-agnostic touch detection sensor. An ultrasonic touch sensing system for touch and water detection using both compression waves and shear waves is disclosed. When no touch or water is present, less shear wave energy and compression wave energy are absorbed, so both shear wave reflection and compression wave reflection do not have a significant amplitude reduction. When a finger is in contact with the sensing plate, both shear wave energy and compression wave energy are absorbed, so both shear wave reflection and compression wave reflection have a significant reduction in amplitude. When water is in contact with the sensing plate, compressive energy is absorbed and little or no shear wave energy is absorbed, so that the shear wave reflection does not have a significant amplitude reduction although the compressive wave reflection has a significant amplitude reduction. From the amplitudes, it may be determined whether there is no touch on the sensing plate, whether there is a touch on the sensing plate, or whether there is water on the sensing plate.

The application discloses a Ku frequency band double-antenna interference cancellation module and relates to the field of measurement and control communication.The application comprises a Ku wave band amplitude and phase control module, a Ku wave band coupling module, a Ku wave band detection module and a control module;an omnidirectional antenna is configured to actively collect interference signals;the interference signals are processed in amplitude and phase;and the processed interference signals are added in equal amplitude and opposite phase with interference signals received by a low-sidelobe directional antenna to realize interference cancellation.The interference cancellation module has small insertion loss, high sampling, control and coupling precision, thereby realizing high-precision control of amplitude and phase, making the interference cancellation capability of the whole module extremely high and greatly reducing the adverse effects of interference signals on data link reception signals.