25 results about "Distortion factor" patented technology

The invention relates to the technical field of connector detection, and discloses a reliability detection method based on a connector. The method comprises the following steps: acquiring real-time monitoring data of a multi-channel electrical sensor of a connector in a power-on state, wherein the real-time monitoring data covers a contact impedance fluctuation sequence, temperature rise gradient distribution and an electromagnetic leakage intensity spectrum; performing time-frequency domain fusion processing on the monitoring data, and extracting dynamic characteristic parameter sets such as impedance attenuation rate, heat conduction lag coefficient and field intensity distortion factor of each contact point; then, according to the parameter space distribution difference, a three-dimensional degradation model comprising a material performance attenuation layer, a contact surface deformation topology layer and an insulating medium loss layer is constructed; coupling mechanical stress and electric heating field intensity distribution based on the model, and generating life prediction indexes of each region; and finally, completing reliability grading according to the indexes, and outputting a detection report with key failure position marks. According to the method, comprehensive and accurate evaluation of the reliability of the connector is realized, and an effective technical path is provided for quality control of the connector.

The invention relates to the technical field of granulator anomaly detection, and discloses a granulator cutting precision anomaly detection method and system. According to the method, a vibration signal and a three-phase load current signal during operation of the granulator are collected in real time, an impact characteristic spectrum and a current distortion factor are extracted through time-frequency domain transformation and harmonic decomposition, a pre-trained deep learning model is input for time sequence characteristic fusion, and a cutting state vector is generated. And judging that the cutting precision is abnormal based on dynamic threshold comparison, triggering an alarm, and marking raw material batch information associated with an abnormal time period. According to the method, the accuracy and real-time performance of cutting precision anomaly detection are remarkably improved, the method adapts to dynamic factors such as raw material characteristic changes and tool abrasion, unqualified products are reduced, and the production cost and market risks are reduced.

A model library-based multi-domain evaluation and compensation method for space radio frequency signal quality belongs to the technical field of wireless communication. The method comprises the following steps: determining signal system parameters based on various CCSDS standards and space protocol systems, extracting relevant parameters of space standards in the time-frequency domain, generating standard time-frequency domain radio frequency signals, and converting them to related domains, modulation domains, energy domains and polarization domains to establish a sub-model library of space radio frequency signals in each domain; obtaining time-frequency domain measured signals through a receiver, comprehensively analyzing time domain information and frequency domain information, and constructing a time-frequency domain sub-evaluation model; constructing a multi-domain comprehensive evaluation model by using a parallel data transmission method and a weight data processing method; calculating the weight of each domain evaluation result by using an entropy weight method to obtain a comprehensive quality evaluation result of the spacecraft radio frequency signal; and based on distortion coefficients, using a robust signal equalization algorithm to process the signal, compensating for the influence of distortion effects on signal quality, and improving the robustness and anti-interference ability of signal transmission.

This invention discloses a method for amplitude and phase distortion correction in ISAR broadband direct sampling receivers. First, an amplitude and phase distortion echo signal model for the ISAR broadband direct sampling receiver is constructed. Matched filtering is applied to the amplitude and phase distortion echo signal at a single scattering point, and a fitness function is constructed based on the matched filtering results. Then, the PSO algorithm is used to iteratively optimize the amplitude and phase distortion coefficient vector of the echo signal at each scattering point, obtaining an estimated vector of amplitude and phase distortion coefficients, thus obtaining the amplitude and phase distortion estimates for the echo signal at each discrete point. Finally, an amplitude and phase compensation factor is calculated based on the estimated amplitude and phase distortion values ​​of the echo signal at the discrete points. This factor is used to correct the amplitude and phase distortion echo signal at each discrete point in real time, obtaining the corrected echo signal at each discrete point. The corrected echo signals at each discrete point are then superimposed to obtain the final corrected echo signal. This method solves the problems of insufficient targeting and easy getting trapped in local optima in high-dimensional solutions, thus improving ISAR imaging performance.

The present application relates to the technical field of roller shutter door assembly wear evaluation, and particularly relates to a silent roller shutter door assembly wear evaluation method based on vibration signal analysis, which comprises the following steps: collecting a roller shutter door vibration signal, performing wavelet packet decomposition, reconstructing a denoising signal according to energy entropy and kurtosis product, and generating a window adjustment coefficient; calculating a slope ratio to construct a double-threshold band scaled by the adjustment coefficient to determine candidate pulse points; dividing pulse clusters according to time interval mutations, extracting amplitude Gini coefficient, interval discrete entropy and center frequency offset to fuse into a distortion factor; constructing a wear characteristic vector from the distortion factor cumulative slope and peak interval ratio, determining a wear grade through Mahalanobis distance comparison; recursively updating a covariance matrix based on a forgetting factor, and performing a remaining service interval penalty compression measurement. The present application overcomes the strong noise masking problem and guarantees the reliability of the prediction result.

The invention belongs to the technical field of micro-ring modulator optimization, and particularly relates to a micro-ring modulator feedback control system for realizing optical modulation amplitude and linearity optimization. A low-speed PAM-4 test signal easy to process is generated through a test code generation module and is pre-distorted through a feedback control module to drive a micro-ring modulator, a signal acquisition module acquires a response signal of the modulator in real time, and an eye pattern calculation module extracts current light modulation amplitude and linearity of quantitative performance from the response signal and calculates the light modulation amplitude and linearity of the micro-ring modulator. And the feedback control module synchronously adjusts the working points of the micro-ring modulator based on the indexes to optimize the light modulation amplitude, and adjusts the pre-distortion coefficient to optimize the linearity, thereby solving the problems of performance compromise and power consumption increase caused by the separation of the light modulation amplitude and the linearity optimization in the prior art. Compared with the prior art, collaborative optimization is achieved, and energy efficiency is improved while performance compromise is avoided.

This invention discloses a dynamic frequency allocation method for wireless communication networks, belonging to the field of wireless communication processing technology. Through offline measurement and model identification, a quantitative relationship between the input signal of the preceding time slot and the nonlinear distortion at the current moment is established. Historical usage sequences of frequency bands and power are collected and stored in real time, providing the input signal characteristics of the preceding time slot for memory effect residual assessment. Combining the historical usage sequences with the memory effect model, the residual intensity of the memory effect in each frequency band is calculated in real time, providing a quantitative basis for frequency band scheduling. Protective time slots are set for high-residual frequency bands to avoid their use before the memory effect has completely disappeared. Low-residual frequency bands are preferentially allocated to high-power users through priority ranking. The memory effect residual of power amplifiers is compensated in real time by dynamically updating the predistortion coefficients. The predistortion coefficients are adjusted according to the preceding and current signal characteristics to ensure good predistortion performance in different operating scenarios.

The invention discloses a transformer winding deformation and turn-to-turn short circuit simulation fault feature diagnosis method, and relates to the technical field of power equipment winding fault detection. According to the transformer winding deformation and turn-to-turn short circuit simulation fault feature diagnosis method, high-fidelity simulation of winding deformation and turn-to-turn short circuit is realized through a mechanical structure, and oscillatory wave signals of a transformer winding under different fault conditions are obtained; according to different fault types, feature parameters of the fault types are extracted from five different dimensions, and fault type response weights and dynamic distortion factors are calculated; because the fault device contains many fault types, different fault types are simulated through the adjusting device, thereby influencing the change of the response weight of the fault types. And finally, obtaining a self-adaptive threshold comprehensive degradation degree. Accurate identification and degree evaluation of winding health state, turn-to-turn short circuit and deformation faults are realized.

The application discloses a digital pre-distortion compensation method based on a genetic algorithm, and comprises the following steps: acquiring a plurality of initial signal characteristics and initial pre-distortion coefficients; obtaining a first population and a second population according to the initial signal characteristics and the initial pre-distortion coefficients; processing the first population and the second population respectively by using a genetic algorithm to obtain a first lookup table and a second lookup table respectively; acquiring a corresponding first pre-distortion coefficient in the first lookup table according to a to-be-compensated baseband signal; when it is judged that the first pre-distortion coefficient meets a preset accuracy requirement, the first pre-distortion coefficient is used for compensation; or when it is judged that the first pre-distortion coefficient does not meet the preset accuracy requirement, a corresponding second pre-distortion coefficient is acquired in the second lookup table, and the second pre-distortion coefficient is used for compensation. By setting the first lookup table and the second lookup table, different rules are used for lookup table searching of signals with different requirements, and the pre-distortion compensation efficiency and accuracy can be further improved.

The invention discloses a distortion velocity field inversion method and system considering a distortion factor, and belongs to the technical field of non-contact flow field measurement. The inversion method comprises the following steps: determining a corresponding average speed according to the flying time and the path length of each sound wave path; defining the average speed meeting a preset condition as a standard speed; determining a distortion degree factor according to a deviation absolute value of the average speed and a standard speed; redividing a basic measurement area of the section of the air inlet channel based on the distortion degree factor; and solving the average speed of the re-divided region and reconstructing an air inlet speed field. According to the invention, the pertinence, accuracy and stability of air inlet channel measurement can be obviously improved.

A wireless communication device includes a pre-distortion circuit configured to generate a pre-distortion signal by pre-distorting an input signal based on a pre-distortion coefficient, a power amplifier configured to generate an output signal by amplifying the pre-distortion signal, a measurement circuit configured to measure a magnitude of a first frequency component of a first adjacent channel and a magnitude of a second frequency component of a second adjacent channel of the output signal, a filtering circuit, that includes an error filter, configured to generate a filtered error signal by filtering an error signal that is based on the input signal and the output signal, the error filter is configured based on the magnitude of the first frequency component and the magnitude of the second frequency component, and a pre-distortion coefficient update circuit configured to update the pre-distortion coefficient based on the error signal or the filtered error signal.

The invention provides a rapid detection device and method for evaluating the fatigue life of an aluminum alloy welding seam, and relates to the technical field of fatigue detection.The device comprises an ultrasonic excitation and acquisition module, a signal processing module and a signal processing module, the ultrasonic transducer is configured to inject a group of high-energy and continuous-frequency-sweeping ultrasonic excitation signals into a welding seam; the receiver and the high-frequency piezoelectric probe are integrated, and the receiver is used for synchronously collecting a first ultrasonic response signal modulated by micro damage in the welding seam; the feature extraction module is configured to demodulate a high-order harmonic component caused by material fatigue damage from the first ultrasonic response signal; the relative energy ratio of the high-order harmonic component to the fundamental component is calculated, and a nonlinear resonance spectrum distortion factor is generated; a first fatigue damage physical model is embedded in the service life evaluation module, and the service life evaluation module is configured to calculate and output the first residual fatigue service life of the to-be-detected aluminum alloy welding seam by taking the nonlinear resonance spectrum distortion factor as an input parameter.

The invention relates to the technical field of data calibration, and discloses an accurate calibration system and method for a steel bar detector, and the system comprises a detection unit, a calculation unit, an analysis unit, a balance unit and a calibration unit. The calculation unit firstly decomposes the signal mode to obtain a double-main-mode response vector and a secondary-mode cooperative value, and then calculates a double-frequency distortion factor in combination with parameters such as an interlayer variable amplitude value and a cooperative abnormal interlayer rate, so that the intensity of the electromagnetic lens effect can be quantized, and a mode adaptation critical value obtained by the analysis unit can provide a judgment basis for signal calibration, so that the accuracy of the signal calibration is improved. The signal equalization coefficient of the equalization unit can determine the direction of signal calibration, and finally the calibration unit carries out superposition calibration on the dual-frequency signal component based on the signal equalization coefficient in combination with parameters such as the dual-frequency layer domain superposition degree and the medium adaptation superposition adjustment amount, thereby effectively correcting signal distortion, and realizing accurate calibration of historic building wall steel bar detection.

This invention relates to the field of optical imaging testing, and more particularly to a camera field of view testing device and method. The method includes first acquiring a calibration image and a test image; calibrating the distortion parameters of the vehicle-mounted camera using the calibration image; and using these distortion parameters to correct the distortion of the subsequent test image used for field of view calculation, resulting in a distortion-free test image. On the distortion-free test image, the full field of view of the camera under test is calculated based on angle markings with known angle values. This invention innovatively employs a calibration-correction-calculation approach to test the camera's field of view, fundamentally eliminating the influence of distortion factors on the measurement results, achieving a breakthrough in technical principles, and thus improving the accuracy of field of view testing.

A control unit for a switching converter operating in continuous conduction and peak current control mode. The control unit has an inductor element coupled to an input and a switching element coupled to the inductor element, generates a command signal having a switching period to switch the switching element, and determines a first time period in which an inductor current flows in the inductor element for storing energy and a second time period in which energy is delivered to a load. The input current is distorted with respect to a sinusoidal curve by a distortion factor caused by a current ripple on the inductor current. A duration of the first time period is determined based on a comparison between a value of a peak of the inductor current and a current reference dependent on an output voltage of the voltage converter. A reference modification stage modifies the current reference to compensate for the distortion introduced to the input current by the distortion factor.

The invention discloses a signal correction method for a pulse type terahertz system, and relates to the technical field of terahertz waves. After frequency spectrum data of terahertz signals are obtained through a terahertz waveform standard device, a distortion coefficient is calculated, frequency domain data, obtained in a terahertz system, of the terahertz signals are corrected through the distortion coefficient, and then undistorted terahertz time domain waveforms are obtained through inverse Fourier transform. The problems that in a current pulse type terahertz system, the inherent influence elimination cost of the system is high, and signals are prone to distortion are solved.

The application provides a rapid detection device and method for evaluating aluminum alloy weld fatigue life, and relates to the technical field of fatigue detection. The device comprises: an ultrasonic excitation and collection module, which comprises a broadband power amplifier and a high-frequency piezoelectric probe, is used for contacting an aluminum alloy weld to be detected, and is configured to inject a group of high-energy and continuously swept-frequency ultrasonic excitation signals into the weld; a receiver, which is integrally integrated with the high-frequency piezoelectric probe, is used for synchronously collecting a first ultrasonic response signal modulated by internal micro-damage of the weld; a feature extraction module is configured to demodulate a high-order harmonic component caused by material fatigue damage from the first ultrasonic response signal; the relative energy ratio of the high-order harmonic component and a fundamental wave component is calculated, a nonlinear resonance spectrum distortion factor is generated; and a life evaluation module, which is embedded with a first fatigue damage physical model, is configured to take the nonlinear resonance spectrum distortion factor as an input parameter, calculate and output a first residual fatigue life of the aluminum alloy weld to be detected.

A digital pre-distortion achieving near ideal spectral regrowth suppression with a bandlimited loopback. To eliminate mismatch between the bandwidth of the pre-distortion model terms and the bandwidth of the signal used to determine the model a band limiting operation may be applied to both the loopback signal and the input to the power amplifier used for estimating the pre-distortion coefficients. In addition, oversampling may be performed in the digital domain to avoid aliasing in the nonlinear terms of the pre-distortion model.

A communications device and a method for compensating frequency response distortion of the communication device are provided. The communications device includes a transmitting path circuitry, a receiving path circuitry, a memory pre-distortion circuit, a pre-equalizer circuit and a pre-equalization calculation circuit. The transmitting path circuitry and the receiving path circuitry are configured to generate a feedback signal according to a pre-distortion test signal, where a set of pre-distortion coefficients of the memory pre-distortion circuit are calibrated according to the feedback signal. After calibration of the set of pre-distortion coefficients is finished, the pre-equalization calculating circuit performs calculation on the set of pre-distortion coefficients to generate a calculation result for calibrating the pre-equalizer circuit. After calibration of the pre-equalizer circuit is finished, a transmission signal is processed by the pre-equalizer circuit and the memory pre-distortion circuit first, and then output to outside of the communications device via the transmitting path circuitry.

Systems and methods are disclosed for utilizing frequency multiplier (FX) based transmitters to generate wideband, substantially distortion-free signals, when a transmitter operates under bandwidth constraints. A receiver is configured to acquire the feedback signal at the multiplier output. The systems and methods alleviate the bandwidth constraints of the receiver. Additionally, the invention includes a training methodology for estimating predistortion coefficients configured to operate under constrained transmitter and receiver bandwidth conditions.

The present application relates to the technical field of defect detection, in particular to a railway contact line surface defect detection method and system. The method comprises: acquiring a sequence image; calculating a space-time matching weight based on the tracking duration and normal distance of a feature point pair, obtaining a global homography matrix through a weighted random sample consensus algorithm for preliminary correction; calculating a local affine transformation matrix and a distortion factor for the segmented image, and generating a two-dimensional development map through splicing; projecting the candidate defect area segmented on the development map back to the original image, calculating the gradient direction entropy ratio, and determining the real defect based on the adaptive threshold determined by the distortion factor. That is, the scheme of the present application can compensate for the non-rigid deformation of the contact line, adaptively distinguish between geometric distortion and real defects, and improve detection accuracy.

The present application relates to the field of optical imaging test, especially to a camera field of view test device and its test method, including first collecting calibration image and test image, using the calibration image to calibrate the distortion parameters of the vehicle-mounted camera, and using the distortion parameters to correct the distortion of the test image used for field of view calculation, obtaining the non-distortion test image, on the non-distortion test image, according to the angle mark of the known angle value, calculating the full field of view of the camera to be tested. The present application innovatively adopts the mode of first calibration, then correction, and then calculation to realize the test of the camera field of view, fundamentally eliminates the influence of the distortion factor on the measurement result, realizes the breakthrough in the technical principle, and further improves the test precision of the field of view.

The invention belongs to the technical field of data processing of the computer information disciplinary, and relates to a broadband power amplifier linearization method and system based on predistortion, and the method comprises the steps: collecting and preprocessing a radio frequency input baseband signal, an actual output baseband signal and tube core heat flow data of a broadband power amplifier, and obtaining an initial data set; calculating a transient heat dissipation gradient at each sampling moment based on the signal energy difference and the tube core temperature change rate; in combination with broadband distribution characteristics of radio frequency input baseband signals, broadband thermal teratogenesis factors at all sampling moments are obtained; performing dynamic tracking compensation on a cross term coefficient of a generalized memory polynomial based on the distortion factor to obtain an update coefficient; and the pre-distortion signal is reconstructed by utilizing the updating coefficient, so that high-linearity output of the broadband power amplifier is realized. The dynamic response speed of coefficient updating can be improved, thermally induced nonlinear distortion of a power amplifier is effectively offset, and the linearity and stability of a high-power broadband radio frequency test are improved.

This invention belongs to the field of communication engineering technology and relates to a digital predistortion and dispersion compensation method for frequency hopping communication systems, comprising: generating S mixing signals x s (n), s∈(1,S), the signal x s (n) Input the signal x into the frequency hopping communication system respectively. s (n) The power amplifier forward signal z in a frequency hopping communication system s (n), power amplifier output signal μ s (n) System feedback signal v s (n); based on signal v s (n) and μ s (n) Calculate the group delay residual equalization signal r s (n); will the signal r s (n) and z s (n) Perform time alignment to obtain the time alignment signal r s '(n); based on signal x s (n) and r s (n) Estimate the predistortion coefficients and update them in the digital predistorter to obtain the updated frequency hopping communication system; input the mixing signal into the updated frequency hopping communication system to obtain the output signal with predistortion and dispersion compensation; This invention mathematically models the nonlinear behavior of the power amplifier under the excitation of a broadband signal for fast frequency hopping, and uses a combination of digital predistortion and dispersion compensation to accurately compensate for signal distortion caused by the nonlinearity of the power amplifier, thereby improving signal quality.