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34 results about "Differential transformation" patented technology
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The differential transformation technique can be used to obtain both numerical and analytical solutions of both linear and non-linear differential equations. The differential transformation technique uses the polynomials as the approximation to the exact solution. The high-order Taylor series method can also be applied to differential equations.
Low-complexity differential spatial modulation detection algorithm
ActiveCN105245477ASolve the problem that cannot be reversedIncrease the number of information bitsSpatial transmit diversityError preventionRound complexityMaximum likelihood detection
The invention provides an LC-DSM algorithm (low-complexity differential detection algorithm). Firstly, a symbolic matrix is constructed at the transmitting end of a differential spatial modulation system by applying a bit filling scheme and a transmission bit calculation formula, and a receiving signal is obtained at the receiving end through differential transformation and transmitting. Then a search mode of detection by column is adopted on a receiving matrix based on the equation structure of a differential maximum likelihood detection algorithm to perform signal decision column by column so that a transmitting symbol and the sequence number of a transmitting antenna are obtained. Finally information bits are obtained through inverse mapping according to the corresponding relation of the bit and the transmitting symbol and the bit and the sequence number of the transmitting antenna. The method is obtained by combination of the low-complexity detection algorithm under spatial modulation and the equation structure formed by the maximum likelihood detection algorithm under the differential spatial modulation system. The research indicates that complexity is greatly reduced relative to the differential maximum likelihood detection algorithm by using the LC-DSM algorithm under the premise of guaranteeing no loss of algorithm performance.
Owner:CHINA JILIANG UNIV
Magnetic vortex array imaging detection method and detection device for detecting defect of steel plate
ActiveCN107255671AEasy to achieve high-precision detectionLow cleanliness requirementsMaterial magnetic variablesMagnetic vortexDifferential signaling
The invention discloses a magnetic vortex array imaging detection method and a magnetic vortex array imaging detection device for detecting the defect of a steel plate, wherein the method comprises the following steps: acquiring a characteristic parameter and determining an optimal excitation frequency; exciting a sinusoidal alternating current magnetic field and inducing an alternating vortex current; acquiring an induction alternating magnetic signal near a detected area of the detected steel plate; processing the induction alternating magnetic signal and conducting the first differential transformation operation to obtain a transformed differential signal; judging whether the differential signal is less than the preset threshold, if so, judging that no defect exists, otherwise, judging that the defect exists, and extracting an area signal; inputting the area signal into a constructed neural network model to implement defect reverse inversion to obtain a defect profile parameter; and drawing a defect profile according to the defect profile parameter to realize imaging. The method uses a concentric ring type magnetic vortex array detection array to detect the defect, so that the defect of the steel plate is detected at the high accuracy, the detection accuracy is improved, and the defect imaging effect is improved.
Owner:TSINGHUA UNIV
Constant speed servo unit for controlling angle signals and control method thereof
InactiveCN102849201AImprove anti-interference abilityStrong error correction abilitySteering initiationsProgrammable logic controllerReducer
The invention relates to a constant speed servo unit for controlling angle signals and a control method thereof. A steering vertical column is supported to a flange in a rotation manner, a lower gearbox is fixed to the lower portion of the steering vertical column, a large swiveling gear is mounted on the upper portion of the steering vertical column, a hydraulic steering motor is fixed onto the flange, an output shaft of the hydraulic steering motor is connected with an input shaft of a planetary reducer, a drive pinion is mounted on an output shaft of the planetary reducer, the drive pinion is meshed with the large swiveling gear, the large swiveling gear is further meshed with a reduction gear which is provided with a rotary encoder, the rotary encoder is in communication connection with a rubber angle display and a PLC (programmable logic controller) control unit respectively, the PLC control unit is in control connection with a potentiometer on an operation handle and a proportional valve respectively, and the proportional valve is located in an oil circuit of the hydraulic steering motor. Margin calculation is performed to a rubber angle instruction and rubber angle feedback, a rubber angle feedback signal is subjected to differential transformation of time to calculate steering speed, and the proportional valve is regulated according to difference between a steering speed instruction and actual steering speed.
Owner:SMMC MARINE DRIVE SYST SUZHOU
Semi-bridge type PFC bus voltage eqaulation control method and device
InactiveCN1409471ASmall distortionDoes not affect gainEfficient power electronics conversionEnergy industryBridge typeDistortion
This invention discloses a control method for PFC bus bar voltage-sharing of half-bridge type and its device, in which the positive and negative bus bar differential voltage is underground a proportion-integral-differential transformation, then the signal is directly superinposed on the duty ratio signal not to be front end of current loop. Even if the current loop exists, its variation would notinfluence the gain of equalizer ring, since the adjuster parameters of the internal current loop are adjusted independently and the parameters of the equalizer ring need to be adjusted once, and the equalizer ring would not influence current loop to generate little distortion to current order and THD of the current would not become large because of the qualizer ring.
Owner:LIANYUNGANG RES INST NANJING UNIV OF SCI & TECH
Driving compensation method for rope-driving continuum robot
ActiveCN110193827AImprove Motion Control AccuracyHigh control precisionProgramme-controlled manipulatorSimulationVirtual work
The invention discloses a driving compensation method for a rope-driving continuum robot. The method specifically comprises the following steps of establishing a kinematic model of the continuum robot by combining a segmented constant curvature arc hypothesis and a geometric analysis method; solving Jacobian matrix of the robot based on differential transformation principle; establishing a statics model of the robot based on virtual work principle; building a force transmission model of a rope-wheel drive system based on Coulomb friction; solving the elongation of a robot driving rope based on Hooke's law; and feeding back the driving rope length compensation amount to a control unit to realize error compensation of the transmission system of the continuum robot and improve the motion control precision of the robot. The method of has the characteristics of simplicity, high efficiency, low cost, good universality and the like, avoids using expensive measuring sensors, and realizes thepurpose of improving the motion control precision of the robot by establishing a driving error compensation model of the continuum robot system.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Sequence overlapping differential direction protection method for power transmission line with static synchronous series compensator
ActiveCN103762563ACriterion is reliable and validUnaffected trendEmergency protective circuit arrangementsTransient stateElectric power system
The invention relates to a sequence overlapping differential direction protection method for a power transmission line with a static synchronous series compensator, and belongs to the technical field of relay protection of power systems. The method includes the steps that when a failure occurs in the power transmission line with the static synchronous series compensator, line mode voltage transient quantity ul and line mode current transient quantity il with fault phases are collected and calculated through a direction relay R1 at the measurement end M, four-order sequence overlapping differential transformation is conducted on ul and il, and then a voltage differential sequence Sul and a current differential sequence Sil are acquired; the power differential sequence SPl is acquired by multiplying the voltage differential sequence by the current differential sequence, and the direction of the failure is judged according to whether the polarity of a first nonzero mutation in the SPl is positive or negative; if the polarity is negative, the failure is judged as the forward failure, or else the failure is judged as the reverse failure. According to the method, the power differential sequence acquired by multiplying the voltage differential sequence by the current differential sequence, the direction of the failure is polarized, and judgment is reliable and effective.
Owner:KUNMING UNIV OF SCI & TECH
Method for calculating inherent frequency of Euler-Bernoulli beam through improved differential transformation method
InactiveCN103902504ASolve problems such as computational complexityThe calculation process is fast and accurateComplex mathematical operationsDifferential transform methodAlgebraic equation
The invention relates to a method for calculating the inherent frequency of a Euler-Bernoulli beam through an improved differential transformation method. The method comprises the steps that the improved differential transformation method is deduced on the basis of a differential transformation method; a corresponding oscillatory differential equation is built, the improved differential transformation method is used for solving the free vibration problem of the homogeneous Euler-Bernoulli beam with two freely-supported ends, a control differential equation is converted into an algebraic equation, and boundary conditions are changed to an algebraic frequency equation convenient to calculate; corresponding algebraic operation is carried out to obtain the inherent frequency and the modal shape of any order of the differential equation. According to the method for calculating the inherent frequency of the Euler-Bernoulli beam through the improved differential transformation method, the improved differential transformation method is used for solving the free vibration problem of the homogeneous Euler-Bernoulli beam, an approximate solution of a nonlinear problem is obtained in the mode that iteration is carried out to converge the series, closed-form solutions such as the four-order inherent frequency and the modal shape are obtained, the solution of a Taylor expansion power series can be converged at a larger time interval, and the calculation process is rapider and more accurate.
Owner:BEIJING UNIV OF TECH
Comparison type directional protection method for travelling wave polarity by utilizing crossing sequence differential transformation
The invention provides a comparison type directional protection method for travelling wave polarity by utilizing crossing sequence differential transformation, and belongs to the field of power system relay protection. The directional protection method comprises the following steps: when a power transmission line breaks down, extracting signals of a failure voltage and a failure current by a protecting and measuring device; performing the crossing sequence differential transformation on the extracted travelling wave signals so as to obtain a transformation quantity of the crossing sequence differential transformation of the failure voltage and the failure current; distinguishing a positive direction failure and an opposite direction failure by utilizing a discriminant of the comparison type directional protection method for the travelling wave polarity. According to the invention, a faulted travelling wave is detected by utilizing an algorithm of the crossing sequence differential transformation, so that although an interference signal is amplified, the interference information is restrained to a certain extent as compared with the amplification effect of failure information.
Owner:KUNMING UNIV OF SCI & TECH
Cloud computing load prediction method based on deep belief network
ActiveCN104954185AReduce forecast errorSuitable for long-term forecastingData switching networksAnalysis dataRestrict boltzmann machine
The invention provides a cloud computing load prediction method based on a deep belief network. The cloud computing load prediction method comprises the following steps of (1) extracting and aggregating load observed values from a cloud group; (2) performing differential transformation on the observed values of the step (1), so as to reduce the linearity of data, normalizing the data, and analyzing autocorrelation and autoregression characteristics in the data; (3) training RBM (Restricted Boltzmann Machines) layer by layer from bottom to top, and optimizing a whole network structure through a BP (Back Propagation) algorithm; (4) performing short-term and long-term prediction on cloud attributes by using the network trained in the previous step; (5) performing inverse transformation opposite to the step (2) on prediction results in the step (4), so as to obtain predicted values of raw data. The cloud computing load prediction method has the advantages of small prediction error, being suitable for long-term prediction and the like, a reliable basis can be provided for resource scheduling of a cloud platform, and the effects of efficient scheduling and use of cloud resources are achieved.
Owner:青岛邃智信息科技有限公司
Outpatient number prediction method and system based on automatic deep belief network
ActiveCN106407690AEasy to useEasy to trainData processing applicationsHealthcare resources and facilitiesDeep belief networkCluster algorithm
The invention discloses an outpatient number prediction method and system based on an automatic deep belief network. The everyday outpatient number is collected from a hospital registration system to obtain historical outpatient number data, differential transformation pretreatment is carried out on the historical outpatient number data to obtain differential data, a deep belief network structure is automatically constructed in dependence on the differential data, groups are automatically created by means of a clustering algorithm to obtain grouped data in different time series, then the deep belief network is trained in dependence on the grouped data to obtain an outpatient number prediction model, finally the outpatient number prediction model is called to predict the outpatient number in a designated time series to obtain a prediction result, and inverse transformation of the pretreatment is carried out on the prediction result to obtain the predicted outpatient number. The deep belief network is advantaged by being convenient to use and simple to train, and can provide a reliable basis for the prediction of the hospital outpatient number, and is small in prediction error, and is especially suitable for long-term prediction.
Owner:XIAMEN UNIV OF TECH
Intelligent terminal for achieving multi-channel electrocardiogram QRS automatic planning
InactiveCN105943030AAvoid the problem of wrong R peak detectionPrevent false detectionDiagnostic recording/measuringSensorsEcg signalSignal wave
The invention discloses an intelligent terminal for achieving multi-channel electrocardiogram QRS automatic planning. The intelligent terminal comprises a processor and a Bluetooth communication module connected with the processor. The processor comprises a signal receiving module, a wavelet transformation module, a differential transformation module, a kurtosis and weight calculation module, a signal superposition and filter module and an R peak detection module. The intelligent terminal solves the problem of R peak detection errors caused by desynchronization of certain channel signal planning through multi-channel electrocardiosignal fitting; meanwhile, the kurtosis value of signals is taken as reference in the signal fitting process, and the problem that the quality of an integral comprehensive energy curve is decreased due to the fact that the quality of signal waves of a certain channel is too poor is solved. Thus, the electrocardio R peak detected by the intelligent terminal is stable and accurate in effect, and especially the position of the R peak can be accurately detected even when the quality of the signals of part of channels in the electrocardio signals does not meet the standard.
Owner:ZHEJIANG MEDZONE BIOMEDICINE VENTURE INVESTMENT
Fast and real-time video coding and decoding compression algorithm
ActiveCN106101711ASolve real-timeSolve storage problemsDigital video signal modificationMegabyteDifferential transformation
The invention discloses a fast and real-time video coding and decoding compression algorithm. The coding algorithm comprises the following steps of S01, inputting a bitmap image sequence, and performing the brightness color difference signal transformation on the bitmap image sequence; S02, performing the differential transformation on the bitmap image sequence after the brightness color difference signal transformation process; S03, performing the fast frequency domain transformation on the bitmap image sequence after the differential transformation process; S04, performing the rapid quantization on the bitmap image sequence after the fast frequency domain transformation process; S05, conducting the entropy compression on the fast quantized bitmap image sequence, and outputting the coded data of a compressed video. In addition, the invention discloses the specific steps of the decoding algorithm. According to the invention, the information of a high-definition image can be compressed at about 8-16 megabytes per second based on software. In this way, the transmission and storage problem during the video real-time coding and decoding process of a video processing host and partly embedded equipment without special hardware processing in the prior art is solved. The method can be widely applied to the fields of remote control, remote monitoring and the like for computer equipment.
Owner:成都杰华科技有限公司
A power distribution network disaster prevention backbone network frame planning method based on a Steiner tree model
ActiveCN109558990AEnhance disaster recoveryImprove disaster resilienceForecastingResourcesPower gridTower
The invention relates to a power distribution network disaster prevention backbone network frame planning method based on a Steiner tree model. The method comprises the following steps: firstly, on the basis of meeting the power supply of important users of a power distribution network under typical disaster conditions, establishing a Steiner tree model of a disaster prevention backbone network frame of the power distribution network based on network connectivity constraint and power flow constraint by taking the minimum construction cost and disaster risk of a line and a tower as an optimization target; and solving the optimization model by using a binary particle swarm algorithm to obtain an optimal backbone network frame scheme, and realizing power supply of the power grid to importantusers in disasters. According to the method, the comprehensive cost of carrying out differential transformation on the backbone network frame is considered, power supply of the power grid to importantloads during disasters is guaranteed, and the power supply self-guarantee capability of the power grid under the disasters is improved.
Owner:STATE GRID FUJIAN ELECTRIC POWER CO LTD +1
A Low Complexity Differential Spatial Modulation Detection Algorithm
ActiveCN105245477BSolve the problem that cannot be reversedIncrease the number of information bitsError preventionRadio transmissionRound complexityMaximum likelihood detection
The invention provides an LC-DSM algorithm (low-complexity differential detection algorithm). Firstly, a symbolic matrix is constructed at the transmitting end of a differential spatial modulation system by applying a bit filling scheme and a transmission bit calculation formula, and a receiving signal is obtained at the receiving end through differential transformation and transmitting. Then a search mode of detection by column is adopted on a receiving matrix based on the equation structure of a differential maximum likelihood detection algorithm to perform signal decision column by column so that a transmitting symbol and the sequence number of a transmitting antenna are obtained. Finally information bits are obtained through inverse mapping according to the corresponding relation of the bit and the transmitting symbol and the bit and the sequence number of the transmitting antenna. The method is obtained by combination of the low-complexity detection algorithm under spatial modulation and the equation structure formed by the maximum likelihood detection algorithm under the differential spatial modulation system. The research indicates that complexity is greatly reduced relative to the differential maximum likelihood detection algorithm by using the LC-DSM algorithm under the premise of guaranteeing no loss of algorithm performance.
Owner:浙江知多多网络科技有限公司
Automatic battery parameter identification method
ActiveCN112433161AReasonable eliminationReduce fluctuations and even discreteElectrical testingTime domainHemt circuits
The invention relates to an automatic battery parameter identification method, which comprises the following steps of: establishing a second-order RC equivalent circuit model, and carrying out discrete and differential transformation to obtain an electrical expression of the circuit model; carrying out Laplace transformation on the electrical expression of the circuit model, converting the electrical expression into a z transformation form, carrying out linear transformation, and converting the electrical expression into a time domain discrete equation; converting the time domain discrete equation into a vector form based on a time domain discrete equation; establishing a recursive least square method with a forgetting factor lambda, and performing recursive iteration based on the recursive least square method to calculate a to-be-identified vector; after the recursion frequency d is set to reach the recursion frequency d, obtaining a set of model parameters through a recursion least square method, calculating the SOC of the battery through the model parameters in combination with extended Kalman filtering, and because of a certain linear relation between the SOC and the open-circuit voltage OCV, obtaining the open-circuit voltage OCV through the calculated SOC; and calculating an absolute value of a difference value (delta OVC) between the open-circuit voltage OCV and the open-circuit voltage, and if the absolute value of the difference value (delta OVC) exceeds a set range, performing parameter suppression.
Owner:GREE ELECTRIC APPLIANCES INC
Household load prediction method and system based on load characteristics and power consumption behavior mode
PendingCN112418485AHigh precisionRealize data dimensionality reductionForecastingCharacter and pattern recognitionAlgorithmOriginal data
The invention discloses a household load prediction method and system based on load characteristics and a power consumption behavior mode. The method comprises the steps: firstly collecting a household original power consumption load time sequence to obtain an original data set, and carrying out the preprocessing of the original data set to obtain a complete original data set; then collecting power utilization data characteristics from the complete original data set by adopting a PCA algorithm based on load characteristics and a power utilization behavior mode, completing characteristic extraction based on an SVD decomposition covariance matrix, realizing data dimension reduction, obtaining a stable sequence through differential transformation and Exponential motion averge processing, capturing a more complex nonlinear relationship of the sequence by utilizing a combined model, and obtaining a power utilization characteristic matrix. A data input structure is optimized, so that the model is combined with a historical state during prediction, the fitting precision is improved through a multivariable model, and the precision of an existing power load prediction method is improved.
Owner:XI AN JIAOTONG UNIV +1
A Sequence Overlap Differential Directional Protection Method for Transmission Lines with Static Synchronous Series Compensators
ActiveCN103762563BCriterion is reliable and validUnaffected trendEmergency protective circuit arrangementsTransient stateElectric power system
The invention relates to a sequence overlapping differential direction protection method for a power transmission line with a static synchronous series compensator, and belongs to the technical field of relay protection of power systems. The method includes the steps that when a failure occurs in the power transmission line with the static synchronous series compensator, line mode voltage transient quantity ul and line mode current transient quantity il with fault phases are collected and calculated through a direction relay R1 at the measurement end M, four-order sequence overlapping differential transformation is conducted on ul and il, and then a voltage differential sequence Sul and a current differential sequence Sil are acquired; the power differential sequence SPl is acquired by multiplying the voltage differential sequence by the current differential sequence, and the direction of the failure is judged according to whether the polarity of a first nonzero mutation in the SPl is positive or negative; if the polarity is negative, the failure is judged as the forward failure, or else the failure is judged as the reverse failure. According to the method, the power differential sequence acquired by multiplying the voltage differential sequence by the current differential sequence, the direction of the failure is polarized, and judgment is reliable and effective.
Owner:KUNMING UNIV OF SCI & TECH
Magnetic spin array imaging detection method and detection device for steel plate defects
ActiveCN107255671BEasy to achieve high-precision detectionLow cleanliness requirementsMaterial magnetic variablesMagnetic vortexDifferential signaling
The invention discloses a magnetic vortex array imaging detection method and a magnetic vortex array imaging detection device for detecting the defect of a steel plate, wherein the method comprises the following steps: acquiring a characteristic parameter and determining an optimal excitation frequency; exciting a sinusoidal alternating current magnetic field and inducing an alternating vortex current; acquiring an induction alternating magnetic signal near a detected area of the detected steel plate; processing the induction alternating magnetic signal and conducting the first differential transformation operation to obtain a transformed differential signal; judging whether the differential signal is less than the preset threshold, if so, judging that no defect exists, otherwise, judging that the defect exists, and extracting an area signal; inputting the area signal into a constructed neural network model to implement defect reverse inversion to obtain a defect profile parameter; and drawing a defect profile according to the defect profile parameter to realize imaging. The method uses a concentric ring type magnetic vortex array detection array to detect the defect, so that the defect of the steel plate is detected at the high accuracy, the detection accuracy is improved, and the defect imaging effect is improved.
Owner:TSINGHUA UNIV
Use method for driving transmission device
The invention discloses a use method for a driving transmission device. In the method, a driving transmission device is used. The driving transmission device comprises a device body and a first cavityarranged in the device body; a second cavity located at the lower end of the first cavity is arranged in the device body; a power input cavity located at the right end of the second cavity is arranged in the device body; a climbing cavity located at the right end of the first cavity is arranged in the device body; the inner wall of the bottom end of the first cavity is connected in a running fitmanner with a first transmission shaft which is located at the upper end of the second cavity and extends vertically; a first belt pulley is arranged at the tail end of the upper end of the first transmission shaft; a first bevel gear located in the second cavity is arranged at the tail end of the lower end of the first transmission shaft; and the interior of the first cavity is connected in a running fit manner with a second transmission shaft which is located at the right end of the first transmission shaft and extends vertically in a running fit manner. The use method disclosed by the invention has a high linkage property; the differential transformation is accomplished by the interaction of magnetic mechanisms to achieve a small-range turning; and the forward travelling and climbing are completed synchronously through a planetary gear set.
Owner:叶机林
Semi-bridge type PFC bus voltage equalization control method and device
InactiveCN1228907CSmall distortionDoes not affect gainEfficient power electronics conversionEnergy industryBridge typeEngineering
Owner:LIANYUNGANG RES INST NANJING UNIV OF SCI & TECH
Transient-state quantity polarity comparison type bus protection method on basis of sequence overlapping and differential transformation
ActiveCN106353629AGood effectImprove reliabilityElectrical testingTransient stateElectric power system
The invention relates to a transient-state quantity polarity comparison type bus protection method on the basis of sequence overlapping and differential transformation, and belongs to the field of relay protection technologies for electric power systems. The transient-state quantity polarity comparison type bus protection method includes extracting voltage and current signals of various lines connected with bus when faults of the lines or the bus occur and computing line-mode voltages and line-mode currents by the aid of three-phase voltages and currents; carrying out sequence overlapping and differential transformation on the line-mode voltages and the line-mode currents of the various lines, solving differential transformation voltages and differential transformation currents, carrying out sign function transformation on product results of the differential transformation voltages and the differential transformation currents to obtain sgn(SP<k>), adding the sgn(SP<k>) of all the lines connected with the bus, acquiring absolute values to obtain values and determining that the faults of the lines occur if the values are smaller than the quantities of current transformers; determining that the faults of the bus occur if the values are equal to the quantities of the current transformers. The line-mode voltages and the line-mode currents comprise fault phases.
Owner:KUNMING UNIV OF SCI & TECH
A Fast Real-Time Video Codec Compression Algorithm
ActiveCN106101711BSolve real-timeSolve storage problemsDigital video signal modificationMegabyteDifferential transformation
Owner:成都杰华科技有限公司
Heat supply pipeline dynamic simulation method based on differential transformation
PendingCN114218728AReduce dissipationReduce mistakesGeometric CADComplex mathematical operationsBoundary valuesPartial differential equation
The invention relates to the field of comprehensive energy system calculation and analysis, in particular to a heat supply pipeline dynamic simulation method based on differential transformation, which comprises the following steps of: S1, differentiating a pipeline partial differential equation by using a semi-discrete difference scheme with a total variation non-increasing property so as to convert the pipeline partial differential equation into an ordinary differential equation set; s2, converting an ordinary differential equation set into a linear recursion relational expression by using differential transformation; and S3, recursively solving a differential transformation coefficient of the state quantity of the ordinary differential equation set according to an initial value condition and a boundary value condition of the equation, obtaining an approximate analytical expression of each state quantity, and further obtaining a change track of each state quantity along with time. By means of the method, dispersion and dissipation errors in the heat supply pipeline simulation process can be effectively eliminated, meanwhile, due to the linear recursion characteristic of differential transformation, a solution with high time precision can be easily obtained, and therefore the accuracy and reliability of pipeline dynamic simulation are guaranteed.
Owner:SOUTHEAST UNIV +1
Contemplation wave communication device
Provision of a new communication device that uses pneumatronic waves as transmission medium, taking advantage of the characteristics of responsive materials such as ceramics. The space communication device contains a transmission means that generates pneumatronic waves vibration-modulated by letting electromagnetic waves carrying information signals act on wave-transferred inorganic materials, a receiving means that detects as information signals electromagnetic waves generated by the coming pneumatronic waves, which act on the said wave-transferred inorganic materials to vibration-demodulate such materials, and a differential transformation means that prevents the said electromagnetic waves from impeding receiving action.
Owner:MIDDLE WAY GSH
A method and system for calibrating the pose error of a mechanical arm
ActiveCN107639635BHigh precision and reliabilityProgramme-controlled manipulatorIndependent motionClassical mechanics
The invention provides a method and system for calibrating the pose error of a mechanical arm. The method includes: performing equivalent differential transformation on the pose error of the tail endof the mechanical arm to obtain an equivalent differential motion vector, decomposing the equivalent differential motion vector into the equivalent differential motion vector of each joint shaft, during independent motion, of the mechanical arm, and performing calibration and decoupling transformation on the pose error of each joint shaft, during independent rotation sampling, of the mechanical arm to calibrate the pose error of the tail end of the mechanical arm. The method and system has the advantages that equivalent different transformation description is performed on the pose error at thetail end of the mechanical arm to obtain the equivalent differential motion vector, the equivalent differential motion vector is decomposed into the equivalent differential motion vector of each connecting rod coordinate system, and decoupling calculation and transformation are performed on the connecting rod coordinate systems and joint motion coupling relations to achieve high-precision and high-reliability synchronous calibration of the absolute pose error of the mechanical arm in a full working space range.
Owner:杨聚庆
Dynamic energy flow calculation method for electric heating comprehensive energy system based on differential transformation
PendingCN114219296AGuaranteed numerical stabilityImprove computing efficiencyResourcesComplex mathematical operationsIntegrated energy systemAlgebraic equation
The invention relates to the field of comprehensive energy system calculation and analysis, in particular to an electric heating comprehensive energy system dynamic energy flow calculation method based on differential transformation, which comprises the following steps: S1, defining differential transformation under a per unit value system; s2, applying the defined differential transformation to a nonlinear-partial differential-algebraic equation model of the dynamic energy flow of the electric heating integrated energy system, and converting the nonlinear-partial differential-algebraic equation model into a group of explicit linear recursive relational expressions; s3, by solving the relational expression, obtaining an expression of each state quantity about time, and further obtaining a change track of each variable of the model along with time; and S4, an adaptive time window strategy based on local truncation error estimation is used to accelerate the energy flow calculation process, the convergence of the calculation is ensured, and the efficiency and robustness of the energy flow calculation are improved. According to the method, efficient and robust calculation of the dynamic energy flow can be realized.
Owner:SOUTHEAST UNIV +1
Metal plate strain measurement method and system based on Fourier differential transformation
ActiveCN112730051AGood precisionMaterial strength using tensile/compressive forcesUsing optical meansEngineeringDiscrete Fourier transform
The invention discloses a metal plate strain measurement method based on Fourier differential transformation. The method comprises the steps of smearing a measured metal plate with uniform speckles, taking the speckles as mark points during signal collection, carrying out a tensile experiment on the measured metal plate, and collecting the image signals of the mark points during the stretching of the metal plate; converting the image signal of the mark point into a displacement signal, and simultaneously performing spline interpolation for three times along the x and y directions to obtain an interpolation signal; extending the interpolation signal along the x and y directions at the same time to obtain an extended signal of the mark point; carrying out discrete Fourier transformation on the continuation signal in the x direction and the y direction to obtain a displacement signal in a wave number domain; respectively carrying out differential transformation on the displacement signals in the wave number domain to obtain a dependent variable of the continuation signal in the wave number domain; and carrying out inverse Fourier transform on the dependent variable of the continuation signal in the wave number domain to obtain real strain values of the metal plate in the x and y directions.
Owner:XI AN JIAOTONG UNIV
A single-phase grounding protection method for distribution network based on zero-sequence current multi-order differential transformation direction
ActiveCN103474981BAvoid compensatory effectsImprove reliabilityEmergency protective arrangements for limiting excess voltage/currentElectric power systemEngineering
The invention relates to a distribution network single-phase ground protection method based on zero-sequence current sequential overlapping derivative transformation direction, belonging to the technical field of power system relay protection. For a resonant earthed system, when single-phase earth fault occurs on one feed line, firstly, a bus zero-sequence voltage in a short time window and zero-sequence currents of feed lines after the fault are intercepted and subjected to sequential overlapping derivative transformation respectively; then, a bus zero-sequence voltage sequential overlapping derivative transformation result is multiplied by zero-sequence current sequential overlapping derivative transformation results respectively to obtain a series of wave fronts on a time axis; finally, the amplitude of the first wave front in the series of wave fronts is used as a basis for protective start; when the amplitude of the first wave front is less than zero to determine positive-direction fault occurs on the feed line, a protective element acts; when the amplitude of the first wave front is larger than zero to determine reverse-direction fault occurs on the feed line, and the protective element does not act. The distribution network single-phase ground protection method is low in using difficulty and high in protection reliability.
Owner:KUNMING UNIV OF SCI & TECH
A Construction Method of Spatial Jacobian Matrix for Robot Parameter Identification
ActiveCN110722562BFast constructionRealize parameter identificationProgramme-controlled manipulatorVirtual coordinate systemsAlgorithm
The invention discloses a space Jacobian matrix construction method for robot parameter identification, including S100: constructing a robot kinematics model; S200: analyzing the differential motion characteristics of robot joints based on the robot kinematics model, and establishing a coordinate system in the case of differential motion The homogeneous transformation matrix between them; S300: Assuming that a joint coordinate system undergoes differential motion, on this basis, establish a virtual coordinate system corresponding to the joint, and construct a transformation matrix between the two, and then calculate the robot end relative to the base The actual pose of the coordinate system is compared with the original theoretical pose to obtain the pose error of the robot end relative to the base coordinate system caused by the motion error of the joint coordinate system, and construct the space Jacobian matrix of the robot. The method of the present invention is a robot space Jacobian matrix construction method based on the differential transformation principle and the virtual coordinate system method, has lower time consumption, and can quickly construct the robot space Jacobian matrix.
Owner:HUAZHONG UNIV OF SCI & TECH
Direct-current fan failure alarm circuit
The invention discloses a direct-current fan failure alarm circuit. The direct-current fan failure alarm circuit comprises a power supply, a direct-current fan, a sample resistor, a differential transformation circuit, an integral transformation circuit, a driving circuit and a dry contact alarm output circuit. The power supply is connected with the direct-current fan and the sample resistor in series, the signal receiving end of the differential transformation circuit is connected between the direct-current fan and the sampling resistor, the differential transformation circuit filters direct-current components after receiving pulse voltage signals output by the sampling resistor to obtain periodic alternating signals which are the same as rotating speed of the direct-current fan, and transmits the periodic alternating signals to the integral transformation circuit, after the integral transformation circuit conducts integral processing on the received periodic alternating signals, the periodic alternating signals are transmitted to the driving circuit to be amplified and then output to the dry contact alarm output circuit, and alarm output is controlled through control of switching-on and switching-off of an electromagnetic relay coil in the dry contact alarm output circuit.
Owner:CHANGZHOU INST OF TECH
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