29 results about "Higher order harmonics" patented technology

The invention relates to the technical field of composite material detection, in particular to a fiber-reinforced thermosetting thermoplastic composite structure interface quality detection method and system.The method comprises the steps that vibration excitation is applied to a target area of the surface of a to-be-detected sample, and the amplitude of the excitation is lower than the damage critical value of a weak bonding interface; a dynamic response signal perpendicular to the interface is collected in a vibration field non-diffusion area of the excitation point of the target area; performing frequency domain transformation on the dynamic response signal, and separating a fundamental frequency component and at least one high-order harmonic frequency component; according to the nonlinear enhancement effect of the high-order harmonic frequency component relative to the fundamental wave frequency component, whether the weak bonding defect exists in the target area or not is judged. According to the method, the technical bottleneck that the dynamic evolution process of the weak bonding defect of the composite material interface is difficult to capture in real time is effectively solved, sensitive response to the microdefect is realized through a nonlinear harmonic characteristic enhancement effect, and the recognition precision of traditional ultrasonic detection is improved.

The invention discloses a rotating machine fault diagnosis method based on an expansion residual network, and relates to the technical field of mechanical faults, and the method comprises the steps: collecting a continuous time sequence vibration signal of a rotating machine through an acceleration sensor, obtaining a high-order harmonic energy sequence set after fast Fourier transform, and determining an abnormal trend segment; then, obtaining and updating a structural anomaly candidate set based on the anomaly trend segment and the operating environment state of the rotating machine, generating a first drift vector set according to the updated structural anomaly candidate set, and identifying a structural offset section according to the first drift vector set and historical operating data; and backtracking the structural offset section to an original time domain signal to establish a second drift vector set, and finally, inputting the first drift vector set and the second drift vector set into the expansion residual network to analyze whether the rotating machinery is evolved into a fault state.

The invention provides an in-vehicle acoustic enhancement method and device fusing determinacy-randomness hybrid modeling, and the method comprises the steps: collecting a fitted vehicle acceleration sound sample, extracting audio data, carrying out the analysis, constructing a determinacy component synthesis algorithm, and associating with a vehicle working condition; the method comprises the following steps: constructing a multi-physics-field coupled random noise generation module, wherein the multi-physics-field coupled random noise generation module comprises an aerodynamic noise module for simulating air inlet turbulence, a low-frequency pulse module for representing mechanical shock, a detonation module for simulating combustion uncertainty and a nonlinear distortion module for enhancing exhaust roughness and generating high-order harmonics; each random noise generation module is matched with the deterministic component, and mixing of the deterministic component and the random component is realized through weight adjustment; details are enhanced through dynamic compression, and target sound waves are generated; through collaborative optimization of determinacy-randomness components, the naturalness and brand identification degree of synthetic sound waves are improved, the vehicle working condition and driving information can be converted into perceptible sound effect characteristics, and the problem of information perception simplification in the electric vehicle driving process is solved.

The invention discloses a permanent magnet synchronous motor current harmonic suppression method based on model prediction control, and the method comprises the following steps: S1, building a mathematical model of a permanent magnet synchronous motor in a rotating coordinate system, and carrying out the discretization through an Euler discretization method, and obtaining a prediction model for predicting the state of the permanent magnet synchronous motor at a future moment; s2, designing and constructing a cost function including a fundamental current tracking item and a high-order current harmonic suppression item in the prediction model; calculating a current harmonic term factor; s3, traversing voltage vectors corresponding to all switching states of the inverter, calculating predicted current and a cost function under the action of the voltage vectors, selecting an optimal voltage vector enabling the cost function to be minimum, and generating a switching signal to drive the permanent magnet synchronous motor to operate; according to the method, the prediction model containing fundamental wave tracking and high-order harmonic suppression is constructed, and the harmonic suppression factor is optimized in real time by using the Lagrange multiplier method, so that current harmonic suppression and system loss reduction are realized.

The invention relates to the technical field of motor control in the intelligent power grid industry, and discloses a space vector control method for a twelve-phase permanent magnet synchronous motor flywheel energy storage system, a control circuit of the flywheel energy storage system relates to power electronic components such as various semiconductor field-effect tubes, and the space vector control method is used for high-precision control of a motor. Comprising the steps of S1, twelve-phase space vector decoupling fault-tolerant control, S2, high-order harmonic energy recovery closed loop, S3, quantum annealing parameter optimization layer, S4, flux linkage adaptive observer network construction and S5, 18-dimensional switching vector table construction. According to the scheme, through multi-reference coordinate system transformation and a redundant phase reconstruction algorithm, rapid fault-tolerant response of the twelve-phase motor during a single-phase or two-phase fault is realized, a current path is dynamically recombined during the fault, a negative-sequence current compensation ring is combined, torque ripple is effectively suppressed, and the reliability of the motor is improved under a high-speed charging and discharging working condition. The harmonic distortion rate is detected in real time through the sliding window FFT, the bandwidth of the controller is adjusted, and the problem that the dynamic response of a traditional fault-tolerant strategy is insufficient is solved.

This invention relates to the field of general control or adjustment system technology, and discloses an adaptive adjustment system for the machining process of a laser cutting rotary table. The system includes: an adjuster that synchronously acquires C-axis angle and displacement data before machining and performs harmonic analysis to identify the harmonic parameters of the workpiece; the adjuster performs quality control decisions based on higher-order harmonics and generates a feedforward compensation model using first- and second-order harmonic parameters; during machining, the model is queried, and Z-axis focus compensation signals and C-axis angular velocity compensation signals are output in real time. This invention enables the control system to actively identify the true geometric model of the workpiece before machining. Its feedforward compensation based on the true model avoids the lag of traditional feedback control and ensures the stability of the machining process.

The application discloses a high-order overtone DOR measurement method, system, device and medium, relates to the technical field of information acquisition and processing, and comprises the following steps: performing local correlation processing on a carrier channel signal acquired through a satellite antenna to obtain interference phases in multiple first integral periods, and determining a first phase polynomial of a carrier model based on all the interference phases; determining a high-order overtone model based on the phase polynomial of the carrier model; correcting multiple high-order overtone signals acquired through the satellite antenna based on the high-order overtone model; determining a residual phase corresponding to each high-order overtone signal through the multiple corrected high-order overtone signals; and determining a DOR time delay observation corresponding to each high-order overtone signal through a multi-side tone DOR time delay calculation method based on the residual phase corresponding to each high-order overtone signal. The application can realize acquisition of a DOR measurement time delay observation, and has a wide application prospect in the field of deep space interferometric measurement.

The invention provides an encodable information system and method based on a high-order harmonic soliton attraction state. The system is composed of a pulse signal generating device, a pulse signal receiving and storing system and a pulse signal processing system. The pulse signal generating device is used for generating a high-order harmonic mode-locked pulse signal; the pulse signal receiving and storing system realizes photoelectric conversion, electric signal acquisition and numerical storage of pulse signals; and the signal processing system is responsible for analyzing and processing the obtained pulse signal, realizing binary coding according to the number of harmonic soliton pulses and the frequency characteristics of the harmonic soliton pulses, and mapping the obtained coding sequence into corresponding text information according to a preset coding rule. The system provided by the invention adopts an all-fiber structure, avoids dependence on external modulation signals, and has the advantages of low cost, high signal stability, simplified operation process, convenience in practical application and the like in implementation.

The invention discloses a motor rotor which comprises a plurality of stacked rotor punching sheets, each rotor punching sheet is provided with a plurality of symmetrical magnet grooves, and magnetic isolation bridges are formed between the magnet grooves and the outer edges of the rotor punching sheets; the outer edge of each rotor punching sheet is symmetrically provided with a wave absorbing groove corresponding to each magnet groove, the included angle between the connecting line of the two ends of each wave absorbing groove and the circle center of the rotor punching sheet and the horizontal direction is sigma 1 and sigma 2, and sigma 1 and sigma 2 meet the formula: # imgabs 0 # imgabs 1 #, P is the number of magnetic pole pairs of the motor, and S is the number of magnetic pole pairs of the motor. Theta mu is the mu1th harmonic initial phase after Fourier decomposition of mu * P-order no-load air gap harmonic generated by rotation of the motor, mu1 is a positive odd number greater than or equal to 3, and K is greater than or equal to 0 and less than 2P and is a positive integer. According to the motor rotor, the permanent magnet motor comprising the motor rotor and the compressor comprising the motor rotor, the peak point of the high-order harmonic flux density on the outer diameter of the rotor is found through formula calculation, the high-order harmonic flux density generated in the rotation of the motor is effectively reduced by forming the wave absorbing grooves, the harmonic amplitude is attenuated and distorted, and therefore the radial electromagnetic force density of the motor during operation is reduced.

The application discloses a magnetic resonance near-field super-resolution sensing unit with high-order harmonic suppression, comprising a first layer metal patch, a first dielectric substrate arranged in close connection with the first layer metal patch, a second layer metal ground arranged in close connection with the first dielectric substrate, a second dielectric substrate arranged in close connection with the second layer metal ground, and a third layer metal patch arranged in close connection with the second dielectric substrate; the first layer metal patch comprises a first sensing horizontal arm and a second sensing horizontal arm, wherein the first sensing horizontal arm and the second sensing horizontal arm are arranged in parallel and spaced apart, and a subwavelength slit is formed between the first sensing horizontal arm and the second sensing horizontal arm; the third layer metal patch comprises a microstrip feed line and a resonance structure, and the third layer metal patch is a symmetrical structure. According to the application, a good dynamic range and low loss are achieved, and the symmetrical structure can effectively suppress the influence of high-order harmonics and realize wide-spectrum operation.

The utility model provides a slotted rotor iron core and a scroll compressor, the slotted rotor iron core comprises an iron core body, the iron core body is provided with a slot part, and the slot part comprises a plurality of mounting slot groups and a plurality of magnet slots; on a horizontal projection, the plurality of magnet grooves are sequentially arranged at the edge of the iron core body at intervals along the circumferential direction of the iron core body, the plurality of mounting groove groups are arranged in one-to-one correspondence with the plurality of magnet grooves, and the mounting groove groups are arranged on the outer sides of the magnet grooves in the radial direction of the iron core body. The slotted rotor iron core can effectively reduce high-order radial force, and can reduce the density of high-order harmonic waves and optimize the harmonic waves of electromagnetic force through the mutual cooperation of the plurality of mounting groove groups and the plurality of magnet grooves; the installation groove group can reduce the cogging torque of the motor and enable the waveform of the motor to be close to a sine type in a wireless mode, the front cogging torque is improved, and vibration generated by the motor and high-order electromagnetic noise can be effectively reduced.

The present invention belongs to the field of micro-shell vibrating gyroscope resonant structure processing, and specifically relates to a micro-shell vibrating gyroscope resonant structure processing method, comprising the following steps: S1, placing a substrate on a molding cavity, and matching n matching holes arranged in a circular array on the substrate with n positioning pins arranged in an annular array on the molding cavity one by one, wherein n is equal to a multiple of 8; S2, heating the substrate for a set time, and simultaneously evacuating the molding cavity; S3, taking out the incompletely molded substrate, rotating the substrate 360 ​​degrees / n, and placing the substrate on the molding cavity again, and matching n matching holes with n positioning pins one by one; S4, repeating S2 and S3 for a total of n times to obtain a micro-shell curved surface structure. The micro-shell curved surface structure obtained by the method provided by the present invention is blown in steps to achieve frequency doubling conversion of low-order harmonic errors, and can convert the fourth harmonic error into a higher-order harmonic component with a smaller amplitude, thereby effectively reducing the frequency cracking of the gyroscope.

A capacitive gyroscope includes a vibrating structure, a primary drive transducer configured to oscillate the structure in a primary mode of motion, a primary pick off transducer to detect oscillation of the structure in the primary mode of motion. The gyroscope may also include a secondary pick off transducer configured to detect oscillation of the structure in a secondary mode of motion, a secondary drive transducer configured to null oscillation of the structure in the secondary mode of motion, a divider configured to determine an angular rate of rotation of the capacitive gyroscope based on an output from the primary pick off transducer and an output indicative of a secondary drive signal for the secondary drive transducer. The gyroscope may also include a linearizer linearize the output from the primary pick off transducer based on at least one higher order harmonic of the output from the primary pick off transducer.

A method for switching interval modulation includes modulating an RF input data signal while generating and inserting additional pulses in transitions of the data signal. The additional pulses are structured to shift transition noise into higher order harmonics. Higher order harmonics are easily filtered. The generating is conducted in the digital domain. The additional pulses can be used to simplify the transmit chain through optical modulators and improve the signal integrity over long distances, can be applied at the output of a transmitter to filter power amplifier distortion, and can be applied to non-linear RF over fiber for a distributed MIMO system.

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 embodiment of the present disclosure provides a millimeter wave frequency doubling circuit with reconfigurable harmonic suppression function, comprising: a frequency doubling unit adopting a Push-Push structure, a reconfigurable LC trap unit, and an output matching network; wherein the input end of the reconfigurable LC trap unit and the input end of the output matching network are sequentially connected with the output end of the frequency doubling unit; the frequency doubling unit is used for receiving a differential signal and processing the differential signal to output a frequency doubled signal; the reconfigurable LC trap unit is used for suppressing specific high-order harmonics of the frequency doubled signal; and the output matching network is used for impedance matching and outputting the frequency doubled signal after harmonic suppression. In this way, through the collaborative design of the frequency doubling unit adopting the Push-Push structure, the reconfigurable LC trap unit and the output matching network, a millimeter wave frequency doubling circuit with miniaturization, high efficiency, high harmonic suppression precision and frequency reconfigurability is realized.

The application discloses a kind of ultra-wideband step frequency radio frequency front ends with high-order harmonic suppression, comprising: transmitter and receiver, high-frequency local oscillator passes through driver amplifier and band-pass filter, into power divider, one-way output signal as the intermediate frequency signal of down-conversion mixer, with step frequency signal is mixed, through low-pass filter to take lower sideband signal, then through power amplifier to transmitting antenna;In receiver, the signal of receiving antenna sequentially passes through low-noise amplifier and band-pass filter, into mixer, with coupled step frequency signal is mixed, take the upper sideband signal in output signal, after driver amplifier and band-pass filter, with the other way signal of power divider output IQ mixing is carried out, and AD sampling is carried out to I channel and Q channel respectively.According to the application, without switch filter group, the effective suppression of the high-order harmonic of transmitting signal can be realized, while reducing the complexity of system, the cost is effectively reduced.

The invention relates to the technical field of general control or regulation systems, and discloses a self-adaptive regulation system for the machining process of a laser cutting rotary worktable, which comprises a regulator for synchronously acquiring C-axis angle and displacement data before machining, executing harmonic analysis to identify harmonic parameters of a workpiece, executing a quality control decision based on high-order harmonics, and adjusting the quality of the workpiece according to the quality control decision; generating a feed-forward compensation model by using the first-order and second-order harmonic parameters; according to the method, the control system obtains the capability of actively identifying the real geometric model of the workpiece before machining, the hysteresis of traditional feedback control is avoided based on feed-forward compensation of the real model, and the stability of the machining process is ensured.

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.

The application discloses a SAR noise FM saturation interference suppression method based on time-frequency characteristics and belongs to the technical field of radar signal processing. The method comprises the following steps: a SAR echo model under NFM saturation interference is established, short-time Fourier transform is performed on the disturbed SAR echo, fundamental wave and high-order harmonic detection is performed, notch filtering is performed in each STFT window, the echo time domain is transformed back, and finally, SAR echo data after interference suppression is obtained. The application can effectively suppress NFM saturation interference, the effectiveness of the method is verified through semi-actual measurement data of Radarsat-1, and compared with a time domain cancellation method, the method has better saturation interference suppression capability.

The invention relates to the technical field of chemical production, in particular to a construction method and device of a viscoelastic material model, electronic equipment and a storage medium. The construction method comprises the steps that through dynamic mechanical testing of a linear viscoelastic area, the change relation of the energy storage modulus and the loss modulus along with the angular frequency is obtained; determining the shear viscosity and the characteristic relaxation time of the material; acquiring a stress response signal under a large-amplitude oscillation shear condition, extracting a high-order harmonic coefficient representing a nonlinear behavior through harmonic analysis, preliminarily determining a nonlinear parameter of the constitutive model according to the high-order harmonic coefficient, and calculating a theoretical stress response; and finally, by taking the nonlinear parameter, the shear viscosity and the relaxation time as initial values and minimizing the deviation between a theory and actually measured stress response, iterative optimization is carried out until convergence, so that the viscoelastic material model is obtained. According to the method, the non-linear parameter identification precision and the calculation efficiency can be remarkably improved, and the constructed model has excellent prediction capability and reliability in a wide frequency and wide strain range.

The application relates to the field of motor control technology in the smart grid industry, and a control circuit of a flywheel energy storage system involves various power electronic components such as semiconductor field effect tubes, and serves high-precision control of a motor; the application discloses a space vector control method for a twelve-phase permanent magnet synchronous motor flywheel energy storage system, which comprises the following steps: S1, twelve-phase space vector decoupling fault-tolerant control, S2, high-order harmonic energy recovery closed loop, S3, quantum annealing parameter optimization layer, S4, flux linkage self-adaptive observer network, and S5, 18-dimensional switching vector table construction. Through multi-reference coordinate system transformation and redundant phase reconstruction algorithm, the scheme realizes quick fault-tolerant response of the twelve-phase motor under single-phase or two-phase fault, dynamically recombines a current path under fault, combines a negative sequence current compensation loop, effectively suppresses torque pulsation, and through sliding window FFT real-time detection of a harmonic distortion rate and adjustment of a controller bandwidth under high-speed charging and discharging conditions, the problem of insufficient dynamic response of a traditional fault-tolerant strategy is solved.

The invention relates to a predictive spare part method based on the abrasion degree of a numerical control machine tool, and belongs to the technical field of predictive spare parts. The method comprises the steps that the meshing frequency and the corresponding frequency characteristic value of the numerical control machine tool during normal work are determined; acquiring a time domain vibration signal of the ith day, and performing fast Fourier transform processing on the signal to obtain a frequency domain signal; determining a center coefficient score, and determining a center frequency index score; determining a central frequency criterion index score, and determining a central frequency serial number score; determining a center frequency score; respectively determining a fundamental frequency wear score, a low-order harmonic wear score and a high-order harmonic wear score; determining the wear degree score of the ith day, and determining the wear degree score of each machine tool to form wear degree time sequence data of the machine tool; and determining a residual life score according to the wear degree time sequence data of the machine tool, and predicting a spare part purchase plan according to the residual life score. The spare part purchase plan is guided by predicting the remaining life of the spare part.

The present invention discloses a scooter strength testing system and a folding scooter based on a mechanical sensor, relating to the technical field of scooter strength testing. The system records a reference signal through a vibration loading module; a frequency marking module gradually adjusts the loading frequency and marks the resonance interval, and simultaneously collects aligned loading signals and response signals; a phase difference analysis module calculates phase difference fluctuations using fast Fourier transform; a nonlinear harmonic component analysis module further decomposes the resonance signal and quantifies the nonlinear proportion of the fundamental frequency and high-order harmonics; a comprehensive analysis module predicts test accuracy through a comprehensive evaluation of phase difference and nonlinear anomalies; a measurement result classification module performs hierarchical processing on the signal, and optimizes the loading conditions in combination with a prediction and adjustment module to ensure the reliability and consistency of the test signal, thereby significantly improving the accuracy and stability of the scooter structural mechanical test and providing a scientific basis for optimizing scooter design and manufacturing.

The present invention discloses a method for estimating the rotor position of a switched reluctance motor based on linear Hall, comprising: detecting the marginal magnetic flux generated by the armature magnetomotive force in the stator slot by three linear Hall elements installed at the stator slot; converting the output voltage signals of the three linear Hall elements into digital signals by using a digital signal processor and preprocessing them into an orthogonal signal containing a pair of orthogonal components and a DC component through linear combination; extracting the positive sequence component of a fundamental frequency signal containing only a very small amount of high-order harmonics from the orthogonal signal by using a multi-repetition coefficient filter with harmonic selection capability; and extracting the motor rotor position contained in the positive sequence component of the fundamental frequency signal by using a synchronous reference frame phase-locked loop. The present invention realizes low-cost, high-compactness, and high-precision estimation of the rotor position of the switched reluctance motor.

The invention discloses an LED self-feedback photoelectric encoder chip system based on harmonic analysis and suppression. The system comprises an LED light source module (1), a photoelectric detection array module (2), a signal conditioning and analog-to-digital conversion module (3), an FFT harmonic analysis unit (4), a harmonic compensation control unit (5) and an LED driving current control module (6). The system performs fast Fourier transform analysis on sine and cosine signals output by the photoelectric detection array, extracts and identifies high-order harmonic components, generates compensation signals according to harmonic amplitude and phase, adjusts LED driving current in real time, and realizes stable light source output and signal harmonic suppression. Chip-level harmonic detection and dynamic compensation of the signal quality of the photoelectric encoder are realized, the linearity and the signal-to-noise ratio of incremental signals can be remarkably improved, the anti-interference performance and the resolution stability of a system are improved, and the method is suitable for the field of design and manufacturing of high-precision photoelectric encoder chips.

The application discloses a radio frequency front-end module, a power amplifier and electronic equipment. The radio frequency front-end module comprises a substrate provided with a first connecting node and a second connecting node, a power amplification chip, a first connecting piece, a second connecting piece and a matching module. The power amplification chip is provided with a first output port and a second output port. The first connecting piece is connected between the first output port and the first connecting node. The second connecting piece is connected between the second output port and the second connecting node. The matching module comprises a balun provided with a first input end and a second input end, a first wire and a second wire. The first wire is connected between the first connecting node and the first input end. The second wire is connected between the second connecting node and the second input end. By arranging the first wire and the second wire, the application can suppress high-order harmonics in a pair of radio frequency differential signals output by the power amplification chip, thereby improving the signal quality of radio frequency signals output by the subsequent balun.

The application discloses a rotating machinery fault diagnosis method based on an expanded residual network, relates to the technical field of mechanical faults, and comprises the following steps: firstly, collecting continuous time sequence vibration signals of rotating machinery by using an acceleration sensor; obtaining a high-order harmonic energy sequence set and determining an abnormal trend segment after fast Fourier transform; obtaining and updating a structural abnormal candidate set based on the abnormal trend segment and the running environment state of the rotating machinery; generating a first drift vector set according to the updated structural abnormal candidate set; identifying a structural deviation section according to the first drift vector set and historical running data; tracing the structural deviation section back to an original time domain signal to establish a second drift vector set; and finally, inputting the first drift vector set and the second drift vector set into an expanded residual network to analyze whether the rotating machinery is evolving into a fault state.