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95 results about "Time domain model" patented technology
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A method for hiding audio error based on sine model
InactiveCN101261833ALower latencyQuality improvementSpeech analysisCode conversionLoss rateError concealment
The invention provides a method for using a sine model to conceal an audio mistake, which belongs to the network and communication field. The operation procedures include: 1. the rebuilding of the whole system is classified into four parallel instances according to the mistakes of a previous frame and a current frame: A. the previous frame and the current frame are both correct and return after being correctly decoded; B. the previous frame is correct and the current frame is wrong, then a time domain model is analyzed and synthesized, and a rebuilding frame is made by overlapping the odd symmetrical section of a synthesized frame and the residual even symmetrical section; C. the previous frame is wrong and the current frame is correct, then a rebuilding frame is made by overlapping the even symmetrical section of the synthesized frame obtained from the model analysis and the residual odd symmetrical section; D. both the previous frame and the current frame are wrong, then the current frame is treated in a simple way; 2. output the obtained decoding result or the wrongly concealed time domain rebuilding. The method is suitable for treatment under various frame loss rates, and the continuous frame loss probability is relatively small for the medium or low frame loss rates, while the medium or high frame loss rates are treated by using a simple frame loss strategy, which can not cause greater audio distortion.
Owner:TSINGHUA UNIV
Intelligent variable time domain model prediction energy management method for hybrid power vehicle
PendingCN111267831AImprove robustnessGuaranteed powerHybrid vehiclesControl engineeringHybrid vehicle
The invention discloses an intelligent variable time domain model prediction energy management method for a hybrid power vehicle. The method belongs to the field of plug-in hybrid electric vehicle energy management, and mainly comprises: establishing a double-neural-network working condition prediction model, and further establishing an MPC parallel hybrid electric vehicle energy management systembased on double-neural-network working condition prediction; establishing a DDPG controller by using a depth deterministic strategy gradient (DDPG) algorithm; combining the built models, building anintelligent variable time domain model prediction energy management model of the hybrid power vehicle, and training the model; and when an automobile runs, obtaining the relevant state and traffic condition information of the automobile to act on the trained model, and achieving energy management of the intelligent variable time domain MPC of the parallel hybrid electric vehicle. By adopting the method, the problem that the MPC adopting a fixed prediction time domain is poor in working condition adaptability can be effectively solved, the control effect of an energy management strategy is effectively improved, and the fuel economy of the vehicle is further improved.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Reservoir thickness prediction method based on dipolar wavelet
InactiveCN101158724AHigh precisionGood effectSeismic signal processingGeomorphologyLongitudinal wave
The invention discloses a prediction method for reservoir thickness which is based on dipole wavelet. Steps are as follows, parameters are extracted, time difference of sound wave between a reservoir and a non-essential reservoir as well as the density are resolved; the time difference of sound wave and the density are converted into a time domain by time-depth conversion, the reflectances of the top and bottom of the reservoir are computed, and a time domain model at the well point is set up, the velocity of longitudinal wave, the density, the wave impedance, and the reflectances are involved in the time domain model; the seismic wavelet is extracted and optimized; a seismic responsing pattern store of reservoir is built by the following steps, the seismic wavelet is taken as a basic wavelet function, the reflectances of the top and bottom of the reservoir are respectively coefficients c and d of the dipole wavelet function to be inputs of the dipole wavelet function, and a reservoir seismic responsing pattern store with a given reservoir section of the work area is set up, spectrum of reservoir thickness is set up; the distribution of the reservoir in three dimensions is predicated quantitatively.
Owner:中国石油集团西北地质研究所有限公司
Three-dimensional pavement generating method applying to virtual prototype system
The invention discloses a 3D pavement generation method applicable to a virtual prototype system. The method comprises the following steps: the first step, establishing a 3D random pavement elevation model of a fast Fourier transform (FFT) algorithm based on a single-point FFT pavement roughness random excitation time domain model; the second step, programming a general program of the FFT 3D pavement model in MATLAB software, and selecting the pavement of a specific level to simulate the pavement roughness according to needs, thus obtaining coordinate data of the 3D pavement; the third step, establishing a generalized pavement file which is applicable to common multibody dynamics software: establishing a general model which generates the 3D pavement file and comprises the node generation and the unit generation algorithm, thus compiling the coordinate data of the 3D pavement obtained in the second step into a pavement file that can be identified by virtual prototype simulation software; and the fourth step, performing virtual prototype modeling simulation. The method has faster computation speed of the 3D FFT model, and is more suitable to the research requirements of multi-dimensional complicated systems, real-time systems and the like.
Owner:SOUTHEAST UNIV
Method and Receiver For Jointly Decoding Received Communication Signals Using Maximum Likelihood Detection
ActiveUS20120033683A1Balance performanceReduce complexityModulated-carrier systemsFrequency-division multiplexTelecommunicationsInverse discrete fourier transform
The present invention relates to a method in a receiver for decoding at least two received communication signals, wherein the communication signals are modulated, pre-coded by a discrete Fourier transform and transmitted by means of single-carrier frequency division multiple access scheme (SC-FDMA). The method comprises the steps of: performing an antenna combining and equalization on a signal observed at the receiver; performing inverse discrete Fourier transform on a model of the observed signal; whitening a time domain model of the observed signal; and jointly detecting the received at least two communication signals by performing soft value calculations based on maximum likelihood detection of a whitened time domain model using a whitened time domain channel estimate.
Owner:TELEFON AB LM ERICSSON (PUBL)
Method for eliminating underwater acoustic channel interference in underwater acoustic communication
ActiveCN108900443AEliminate distractionsImproved error propagation effectsTransmitter/receiver shaping networksInterference eliminationChannel impulse response
The invention discloses a method for eliminating an underwater acoustic channel interference in underwater acoustic communication. The method comprises: step one, establishing an impulse response timedomain model and an impulse response frequency domain model of an underwater acoustic channel; step two, carrying out training by using a training sequence according to the impulse response time domain model of the underwater acoustic channel to obtain a channel impulse response matrix; step three, eliminating a channel interference of an information sequence by the training sequence by using thechannel impulse response matrix, thereby obtaining an information sequence after the interface elimination; step four, carrying out balancing between channels on the information sequence after the interface elimination to obtain estimation of the information sequence after channel balancing; and step five, carrying out soft-decision decoding on the estimation of the information sequence to obtaina final hard decision bit. According to the method disclosed by the invention, an accurate feedback symbol can be obtained; the inter-symbol interference is eliminated well; and the error propagationeffect is improved.
Owner:浙江望海潮科技有限公司
Method and device for eliminating multi-symbol subcarrier jamming and performing channel estimation jointly
The invention discloses a method and a device for eliminating multi-symbol subcarrier jamming and performing channel estimation jointly. The method comprises the following steps of: obtaining a slope matrix of a multipath channel by utilizing two pilot frequency data successively received on a same subcarrier; obtaining a nodal increment matrix of the multipath channel by utilizing the pilot frequency subjected to slope matrix removal; and determining a time-domain model of the multipath channel for channel estimation by utilizing the slope matrix and the nodal increment matrix. According to the method, the time-domain model of the multipath channel is established, so that the frequency response of each subcarrier channel can be accurately obtained, and the subcarrier jamming can be effectively eliminated.
Owner:ZTE CORP
Time domain model identification pilot protection method suitable for wind power system
ActiveCN105356428ANot affected by impedance instabilityImprove reliabilityEmergency protective arrangements for automatic disconnectionCapacitanceDomain model
The invention discloses a time domain model identification pilot protection method suitable for a wind power system. The method comprises the following steps: collecting three-phase voltage and current at the protection installation place and forming differential voltage and differential current; judging whether to start time domain model identification pilot protection according to the differential current value; calculating each phase of differential current and correlation coefficient rho of a first-order derivative of the differential voltage obtained after zero sequence compensation; judging internal and external faults by comparing the value of each correlation coefficient rho with a set threshold value; if the correlation coefficient rho of any phase is smaller than the set threshold value, judging that the fault is the internal fault, and then, pilot protection at the two ends of a line is carried out to protect the device to act reliably; or otherwise, judging that the fault is the external fault so as protect the device not to act reliably. The time domain model identification pilot protection method is easy to realize, can carry out split-phase judgment, is fast in action speed, is not influenced by line distributed capacitive current and fault resistance, and can be widely applied to the wind power system.
Owner:STATE GRID CORP OF CHINA +2
Method and system for predicting nonlinear wind-induced response of suspension bridge, and storage medium
ActiveCN109359418AGeometric CADSustainable transportationPredictive methodsNonlinear finite element model
The invention provides a method and system for predicting the nonlinear wind-induced response of a suspension bridge, and a storage medium. Firstly, the aerodynamic time histories of the girder section under different wind speed and amplitude are numerically simulated by CFD, and then all aerodynamic parameters in the unified nonlinear and unsteady aerodynamic time domain model are identified by nonlinear least square fitting method, and the results are compared with the CFD results. Then the unified aerodynamic model is coupled with the three-dimensional nonlinear finite element model of thebridge to predict the nonlinear wind-induced response of the bridge in the process of the wind speed increasing from zero to the preset limit wind speed. The unified aerodynamic time domain model of the present invention includes static wind, The mathematical expressions of self-exciting force, buffeting force, vertical vortex force and torsional vortex force and their corresponding parameters canbe used to accurately predict the nonlinear wind-induced response of bridges in different wind speed ranges, which provides important reference for the evaluation of wind-resistant performance of suspension bridges during the passage of strong / typhoon.
Owner:SHENZHEN UNIV
Model-based diagnosis in frequency domain
ActiveUS20190383700A1Machine part testingTesting/monitoring control systemsPhysical systemModel parameters
One embodiment can provide a method and a system for diagnosing faults in a physical system. During operation, the system obtains a time-domain model of the physical system and converts the time-domain model to the frequency domain to obtain a frequency-domain model of the physical system. The time-domain model can include one or more model parameters having known values. The system also obtains time-domain input and output signals and converts the time-domain input and output signals to the frequency domain to obtain frequency-domain input and output signals. The system identifies at least one model parameter having an expected value that is different from a known value of the at least one model parameter based on the frequency-domain model and the frequency-domain input and output signals, and generates a diagnostic output indicating at least one component within the physical system being faulty based on the identified at least one model parameter.
Owner:XEROX CORP
Vibration suppression method and system for variable-load servo system based on notch filter
ActiveCN109474222AStrong real-timeGood filtering effectMotor control for motor oscillations dampingResidual vibrationAnalysis method
The invention provides a vibration suppression method and system for a variable-load servo system based on a notch filter. The method comprises the steps: starting from a time domain model of the servo system, directly analyzing the real-time position data transmitted from a position sensor, preferentially using the time difference between the two extreme points at the time when the residual vibration starts to analyze the vibration center frequency, configuring the notch filter, and then correcting the center frequency by the time difference of the adjacent maximum points after the vibration.The invention has the beneficial effects that the time domain analysis method adopted by the technical solution proposed by the invention can quickly detect the change of the center frequency, and the center frequency can be obtained in one cycle after the load changes to generate vibration; the real-time performance is strong, and according to the subsequent vibration condition, the real-time correction of the filter parameters and the center frequency is performed, an excellent filtering effect is obtained; in the case of the variable load, the method is a simple and highly real-time vibration suppression method.
Owner:CHINA UNIV OF GEOSCIENCES (WUHAN)
Nonlinear circuit time domain model reduction method and device
ActiveCN102467593AHigh precisionEasy to controlSpecial data processing applicationsTerm memoryLinear circuit
The invention belongs to the field of design of an integrated circuit and relates to a nonlinear circuit time domain model reduction method and a nonlinear circuit time domain model reduction device. The method comprises the following steps of: forming a track in a state space through a 'training signal', and selecting an expansion point on the track to approach a nonlinear circuit through a segmented linear method; and obtaining a final reduction model through a time domain model reduction method based on wavelet collocation. The device comprises an input unit, an output unit, a program storage unit, an external bus, a memory, a storage management unit, an input / output bridging unit, a system bus and a processor. A nonlinear system is directly subjected to model reduction in a time domain, the time domain reduction accuracy of the nonlinear system can be guaranteed, and a time domain error can be controlled; therefore, an accurate and compact reduction model can be acquired, and the simulation accuracy and efficiency are improved.
Owner:FUDAN UNIV
Multi-target fusion intersection dynamic vehicle networking speed guide control method
ActiveCN113299107AImprove operational efficiencyEnsure safetyRoad vehicles traffic controlIntelligent NetworkControl engineering
The invention discloses a multi-target fusion intersection dynamic vehicle networking speed guide control method, which comprises the following steps of: setting a reasonable initial vehicle prediction range according to vehicle and road information, and formulating a target function under multi-target fusion in a vehicle running process; adopting a rolling time domain model predictive control method, performing dynamic motorcade division on all automatic driving vehicles in an intelligent network connection environment, optimizing the operation efficiency of the motorcade, and guaranteeing the operation safety and stability of the motorcade ; and solving an optimization result of the control variable and the state variable of the vehicle after multi-target fusion by adopting a quadratic programming solving method, and providing a dynamic speed suggestion for the operation of the vehicle. According to the invention, the defects of the existing vehicle networking speed guide control method can be effectively made up.
Owner:SOUTHEAST UNIV
Interconnection line model reduction method based on time-domain trapezoidal method difference
ActiveCN102915385AGuaranteed passivityAvoid conversion errorsSpecial data processing applicationsHat matrixNumerical stability
The invention belongs to the field of integrated circuits, and relates to an interconnection line model reduction method based on time-domain trapezoidal method difference. The method comprises the steps as follows: reading performance data of an interconnection circuit, utilizing an improved node voltage method to build a corresponding time-domain equation; utilizing a trapezoidal method to discretize the time-domain equation of the interconnection circuit and obtain a nonhomogeneous recurrence relation; using a nonhomogeneous Arnoldi algorithm to construct a projection matrix, and then using the projection matrix to perform contragradient transformation on the time-domain equation of the interconnection circuit to obtain a reduction system; and finally, using the trapezoidal method to discretize the reduction system to obtain time-domain output. By virtue of the method, the matching of state variables between the reduction system after the time-domain trapezoidal method difference and the original system is ensured; the time-domain reduction precision is ensured; and the numerical stability during the reduction process and the passivity of the reduction system are ensured. Compared with the original time-domain model reduction method, the computing complexity is greatly reduced; and the method has higher precision in time-domain compared with a frequency-domain reduction method.
Owner:FUDAN UNIV
Device and method for measuring optical parameter field of dispersion medium based on time-frequency optical information fusion
ActiveCN109632718ATroubleshoot rebuild issuesHigh precisionScattering properties measurementsTransmissivity measurementsLight-field cameraFrequency modulation
Owner:HARBIN INST OF TECH
Frequency-domain-based method for lipid and water suppression treatment of magnetic resonance spectrum imaging data
The invention belonging to the field of medical imaging provides a frequency-domain-based method for lipid and water suppression treatment of magnetic resonance spectrum imaging data. The method comprises: one-dimensional Fourier transform is carried out on collected single voxel magnetic resonance spectrum time-domain data to obtain a frequency-domain FID signal; according to prior knowledge, four lipid peaks and one water signal frequency range are determined; a nonlinear parameter attenuation coefficient in a spectrum time-domain model by using a singular value decomposition method; on the basis of a spectrum peak frequency in the prior knowledge and the attenuation coefficient obtained by quantification, the amplitude and phase of a linear parameter are estimated by using an amplitude-phase adaptive FIR filtering method; the frequency range is changed and the previous two steps are executed circularly until quantification of the four group of lipid and water signal parameters is completed; the time-domain FID model and the lipid and water signal quantification parameters form lipid and water time-domain signals; and one-dimensional Fourier transform is carried out on the time-domain signals, difference processing is carried out on the frequency domain and an original spectral signal, thereby obtaining magnetic resonance spectrum imaging data after lipid and water suppression treatment.
Owner:杭州全景医学影像诊断有限公司
Two-dimensional DOA estimation method based on L-shaped array
ActiveCN111239678ASolve underdetermined problemsLarge apertureRadio wave direction/deviation determination systemsHigh level techniquesArray elementSpatial spectrum
The invention discloses a two-dimensional DOA estimation method based on an L-shaped array in the technical field of array signal angle estimation. The two-dimensional DOA estimation method comprisesthe following steps: 1, establishing a time domain model of array receiving; 2, decomposing an actual steering vector, and processing the decomposed vector by utilizing a Hadamard product; placing thelast Q elements of the vector processed by the Hadamard product at the tail of the actual steering vector to construct a virtual steering vector; 3, constructing estimation of a received signal autocorrelation matrix according to the virtual steering vector, and carrying out eigenvalue decomposition to obtain estimation of a noise subspace; and 4, constructing a spatial spectrum function, and estimating the DOA of the incident signal according to spectral peak search. The underdetermined problem that the number of signal sources to be estimated is greater than the number of physical array elements under the condition of limited array elements is effectively solved. The complexity and hardware cost of equipment in practical application are reduced, and the signal DOA estimation precision is effectively improved.
Owner:XIJING UNIV
Variable time domain model prediction energy management method for plug-in hybrid electric vehicle
The invention discloses a variable time domain model prediction energy management method for a plug-in hybrid electric vehicle, and belongs to the field of plug-in hybrid electric vehicle energy management. The method mainly comprises the following steps: defining variables in a fuzzy controller, carrying out fuzzy processing on model parameters, defining a fuzzy control rule, and completing the construction of the fuzzy controller; obtaining related input parameters of the fuzzy controller at the current moment, and outputting a predicted time domain increment delta Np through the fuzzy controller; and superposing an initial predicted time domain Np initial and the predicted time domain increment delta Np, updating the predicted time domain Np and acting on an MPC controller, thereby realizing prediction control energy management of the parallel hybrid power vehicle variable time domain model. The problem that the traditional MPC adopting a fixed predicted time domain is difficult toadapt to the working condition change can be effectively solved, the control effect of an energy management strategy is effectively improved, and the fuel economy of the vehicle is further improved.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Weak fault traveling wave signal denoising and precise recognition method based on Bayes filter
InactiveCN107103160AReliable identificationAccurate identificationSpecial data processing applicationsPattern recognitionElectric power system
The invention belongs to the field of electrical systems, and relates to a weak fault traveling wave signal denoising and precise recognition method based on a Bayes filter. From the respective of a time domain, a modern signal processing method and a Bayes filter technology are adopted for analyzing and modeling a weak fault traveling wave signal, when main features of an original signal are kept, various kinds of noise jamming in which changes of time domain features are taken as a principle thing are effectively filtered out, instantaneous amplitudes and modeling residual errors of the traveling wave signal are estimated in real time, therefore mutational sites of the travelling wave signal are accurately extracted, reliable and accurate recognition of the weak travelling wave signal is achieved, and thus the accuracy and reliability of travelling-wave based fault location are improved. According to the study, a time domain modeling analytic method of a disturbed traveling wave signal is put forward, various kinds of fault lightning current simulation models are compared and analyzed, and thus accurate recognition of singular points of the weak fault traveling wave signal under various kinds of noise jamming is achieved. The weak fault traveling wave signal denoising and precise recognition method based on the Bayes filter has important theoretical and practical significance in improving the precision of travelling-wave based fault location and pragmatizing travelling wave protection.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
A pre-bending and pre-twisting design method for a flexible blade of a wind turbine based on an aeroelastic model
ActiveCN109902384AGuaranteed accuracyGuaranteed to be fastMachines/enginesWind energy generationAeroelasticityTurbine blade
The invention discloses a pre-bending and pre-twisting design method for a flexible blade of a wind turbine based on an aeroelastic model. The method comprises the following steps: S1, giving a targetaerodynamic shape of the blade and basic parameters of the wind turbine; S2, establishing an aeroelasticity time domain model of the wind turbine blade; S3, calculating the aeroelastic deformation ofthe original blade; S4, estimating the pre-bending and pre-twisting shapes of the blade; And S5, calculating the aeroelastic deformation of the blade after pre-bending and pre-twisting, and judging whether to converge or not. An aeroelastic model aeroelastic model is established by adopting a nonlinear beam theory and a lifting surface method based on a potential flow theory; the accuracy and thespeed of model calculation in the iteration process are ensured; According to the method, the pre-bending and pre-twisting geometric shape of the blade can be efficiently obtained, and the deformation of the blade at all radius positions is taken into the convergence judgment standard, so that the target aerodynamic shape can be achieved within the whole blade extension range after the flexible blade generates aeroelastic deformation, and the flexible blade can work in the optimal state.
Owner:SHANGHAI JIAO TONG UNIV
Modeling method of binary airfoil nonlinear flutter time domain model
The invention discloses a modeling method of a two-dimensional airfoil nonlinear flutter time domain model, which comprises the following steps of: simplifying a system by taking the system that a rudder blade is connected with a torsion spring as an object, and deducing a bending-torsion coupling beam transfer matrix based on MSTMM; determining a transfer matrix of each element, assembling the transfer matrixes into a total transfer matrix, and establishing a system overall dynamic model; superposing a rigid center and a mass center in the transfer matrix, and solving the kinetic model to obtain key parameters of a binary flutter model, namely rudder blade pure bending and pure torsion frequencies; taking a cross section of a 3 / 4 blade extension part, and establishing a binary airfoil nonlinear flutter model; solving the two-dimensional airfoil nonlinear flutter model, and solving the time domain response of the two-dimensional airfoil nonlinear flutter model. According to the method,key kinetic parameters, namely pure bending and pure torsion frequencies of the rudder system, required by the binary flutter model are calculated by adopting the MSTMM, a modeling thought of the binary airfoil flutter model considering gap nonlinearity and geometric nonlinearity is provided, and an effective technical approach is provided for nonlinear hydroelasticity research of the rudder system.
Owner:YANGZHOU UNIV
Passive synthetic aperture-based multi-unmanned aerial vehicle cooperative direct positioning method
PendingCN114636970AHigh positioning accuracyImprove resolutionPosition fixationAlgorithmCarrier signal
The invention discloses a passive synthetic aperture-based multi-unmanned aerial vehicle cooperative direct positioning method. The method comprises the following steps of: establishing an array signal time domain model related to arrival signal complex envelope, carrier phase and Doppler frequency offset based on a plurality of unmanned aerial vehicle array receiving models; each unmanned aerial vehicle arranges array signal time domain data according to a time sequence to form an expanded array signal time domain model based on a passive synthetic aperture thought, and converts the expanded array signal time domain model into frequency domain data by using a radix-2-FFT algorithm; the central station forms frequency domain data into a multi-machine frequency domain observation vector, establishes a mathematical optimization model for joint estimation of a target position vector and a propagation coefficient according to a subspace orthogonal criterion, extracts an information matrix only containing a target position, and performs grid search of multiple regions by taking a minimum characteristic value of the minimum information matrix as a target; and accurate positioning of multiple targets is realized. According to the method, the multi-target positioning precision and the multi-target resolution capability can be remarkably improved, and the problem of data association in the multi-target positioning process can be avoided.
Owner:PLA STRATEGIC SUPPORT FORCE INFORMATION ENG UNIV PLA SSF IEU
Optical imaging device and method for mammary gland based on image segmentation and time-frequency information fusion
ActiveCN110151133AReduce in quantityImprove rebuild efficiencyImage enhancementDiagnostic signal processingImage segmentationMammary gland structure
The invention provides an optical imaging device and method for the mammary gland based on image segmentation and time-frequency information fusion and belongs to the technical field of near-infraredoptical chromatography imaging. The method comprises the steps that firstly, radiation intensity information in all directions of the boundary of the to-be-detected mammary gland tissue under the function of a frequency modulation laser and a pulse laser is acquired, and by simulating the infrared radiation transmission process in the to-be-detected mammary gland tissue under the function of the frequency modulation laser, a reconstructed image for optical parameter distribution under a frequency domain model is primarily obtained; then, a threshold value division method is used for dividing the reconstructed image, an optical parameter distribution initial value of a target area of a time-frequency model is obtained, and by simulating the infrared radiation transmission process under thefunction of the pulse laser, an internal structure of a target area of the mammary gland tissue is obtained. According to the optical imaging device and method, the problem is solved that in the priorart, in the reconstruction process for optical distribution of the mammary gland, a measurement signal of a single model is used for reconstruction, and the reconstruction precision or efficiency islow. The optical imaging device and method can be applied to reconstruction of a high-efficiency and high-precision mammary gland detection optical parameter field.
Owner:HARBIN INST OF TECH
Generalized state space average modeling method based on aircraft electric power system dynamic characteristics
InactiveCN104915470AHas time-invariant nonlinear dynamic characteristicsGood engineering precisionSpecial data processing applicationsTransient analysisDecomposition
The invention relates to a generalized state space average modeling method based on aircraft electric power system dynamic characteristics. The method includes the steps that time-variant nonlinear differential equations of all links of an aircraft electric power system are built according to an aircraft electric power system structure; state variables are determined according to the differential equations in the above step, Fourier decomposition is conducted on the state variables, and the state variables described by the Fourier coefficients are obtained; the obtained Fourier coefficient state variables are substituted into the differential equations, and a generalized state space average model of the aircraft electric power system is obtained; the dynamic characteristics of different time scales of the aircraft electric power system are analyzed according to different flying working conditions of an aircraft; the generalized state space average model of the aircraft electric power system is simplified according to the dynamic characteristics. The generalized state space average modeling method has the advantages that by means of the method, the operating working conditions and dynamic characteristics of the aircraft electric power system can be discriminated, a time domain model can be replaced in system analysis and design, the time domain model can be simplified into the state space average model in the steady state, good engineering accuracy is achieved, fast analysis ability is achieved as well, and the generalized state space average modeling method is suitable for the field of steady state and transient state analysis of different aircraft models.
Owner:CIVIL AVIATION UNIV OF CHINA
Method for predicting energy consumption of hybrid truck based on variable time domain model
ActiveCN112298155AHigh precisionEasy to manageHybrid vehiclesOther vehicle parametersDomain modelEngineering
The invention discloses a method for predicting the energy consumption of a hybrid truck based on a variable time domain model, and the method comprises the steps: repeatedly operating the hybrid truck in an urban working condition at a test stage, obtaining the original operation data of the truck, carrying out the preprocessing, carrying out the classification through a k-means clustering algorithm, and generating a plurality of state segments; establishing a Makarov working condition prediction model, and providing a plurality of prediction time domains for each state segment to obtain predicted vehicle speeds in the prediction time domains; calculating and recording the actual vehicle speed of the vehicle, and selecting the prediction time domain with high prediction precision as the parameter of the state segment; in the application stage, according to the characteristic parameters of normal running of the truck, the prediction time domain corresponding to the working condition with the high matching degree in the state fragments under the cyclic working condition is found to serve as the prediction time domain under the running working condition, and energy consumption is obtained according to the Makarov working condition prediction model. According to the prediction method, timely adjustment of the prediction time domain can be realized, and the calculation burden is not increased too much while the vehicle speed in the time domain is predicted more accurately.
Owner:江苏紫琅汽车集团股份有限公司
Variable time domain model prediction energy management method for plug-in hybrid electric vehicle
InactiveCN111731262AGuaranteed powerImprove robustnessHybrid vehiclesInternal combustion piston enginesBattery state of chargePower battery
The invention discloses a variable time domain model prediction energy management method for a plug-in hybrid electric vehicle, which belongs to the field of plug-in hybrid electric vehicle energy management. The method comprises the following steps of constructing a fuzzy logic controller, determining a track of a battery state of charge reference SOCr, solving a local optimal solution in the determined prediction time domain length Np by using a model prediction control method and taking fuel consumption as an optimization target, and updating a vehicle state, obtaining a predicted time domain increment deltaNp through a fuzzy logic controller according to the deviation deltaSOC between the actual power battery state of charge SOC and the battery state of charge reference SOCr and the model prediction control single-step calculation time Tc, superposing the predicted time domain increment deltaNp with the initial predicted time domain Npinitial, and updating the predicted time domainlength Np. By adopting the method, the problem that the traditional MPC adopting a fixed predicted time domain is difficult to adapt to the working condition change can be effectively solved, the control effect of an energy management strategy is effectively improved, and the fuel economy of the vehicle is further improved.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Method for protecting break variable distance based on time domain model
InactiveCN102361320ASolve the problem of easy overtaking movementLower reliability factorEmergency protective circuit arrangementsDomain modelLossless circuits
The invention discloses a method for protecting a break variable distance based on a time domain model. The method comprises the following steps of: (1) computing mode current and mode voltage: performing phase-mode transformation on protecting data to obtain current ix and voltage ux in a mode domain; (2) computing a compensating voltage mode component: establishing a line voltage mode component computing equation according to a uniform lossless circuit model and computing each voltage mode component at a setting point according to each mode current and mode voltage of the circuit obtained in the step (1); performing phase-mode reverse transformation: performing phase-mode reverse transformation on the compensating voltage mode component obtained by computing in the step (2) to obtain a phase component of compensating voltage; and (4) judging an action: comparing the break variable of each phase of compensating voltage computed in the step (3) with the action threshold of a break variable distance element to judge whether each loop break variable relay is required to act. According to the method, the influence of a non-periodic component on break variable distance protection can be avoided effectively, and sufficient sensitivity is achieved on the premise of ensuring the safety.
Owner:NANJING GUODIAN NANZI POWER GRID AUTOMATION CO LTD
Artificial swarm-based direct positioning method
ActiveCN109581291ANo estimation errorHigh positioning accuracyPosition fixationHigh level techniquesNeighborhood searchResource consumption
The invention provides an artificial swarm-based direct positioning method. According to the method, an array antenna to receive a signal time domain model; a frequency domain observation model of a received signal is obtained; a target function is established to determine a fitness function; control parameters are initialized, a fitness value of each initial solution is calculated, neighborhood search is carried out by honey gathering bees to generate new solutions, and fitness values corresponding to the new solutions are calculated to carry out greed selection; selection probabilities related to the solutions are calculated, neighborhood search is carried out again to generate new solutions, and fitness values corresponding to the new solutions are calculated to carry out greed selection; judgement is carried out to determine whether a to-be-abandoned solution exits or not, of the judging result is positive, a new solution is generated to replace the to-be-abandoned solution and thenew solution is recorded; and finally, judgement is carried out to determine whether a termination condition is satisfied or not, if the judging result is positive, an optimum result is output, and otherwise, new solutions are continuously and repeatedly generated to replace the old solutions and subsequent steps are carried out. According to the method, an artificial swarm algorithm is introduced to solve the solving of non-linear optimization problems in direct positioning process, so that the operation resource consumption is decreased and the positioning time consumption is shortened.
Owner:HARBIN ENG UNIV
Pilot-assisted CO-FBMC/OQAM system phase noise compensation method
ActiveCN113300779AReduce computational complexityHigh phase noiseBaseband system detailsMulti-frequency code systemsComputation complexityPhase noise
The invention discloses a pilot-assisted phase noise compensation method in a CO-FBMC / OQAM system, and the method comprises the steps: carrying out the compensation of CPE noise of data at a receiving end based on pilot data through employing an extended Kalman filter (EKF) algorithm, and carrying out the pre-judgment after the compensation; then selecting data within a proper range after CPE compensation, recording the position of the data, and taking the pre-judged data as a data estimation value symbol of a transmitting end for later use; and then, constructing a DCT primary function, carrying out approximate estimation on the phase noise, establishing a DCT time domain model of the phase noise, obtaining a DCT coefficient by using LS estimation, and carrying out more accurate compensation on the phase noise in a time domain. According to the invention, the system has higher tolerance to the phase noise generated by the laser, and the calculation complexity of the algorithm is low.
Owner:ZHEJIANG UNIV OF TECH
System and method of implementing finite difference time domain models with multiple accelerated processing components (APCs)
InactiveCN105531602ADesign optimisation/simulationSeismic signal processingFinite difference modelAlgorithm
Owner:CHEVROU USA INC
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