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180results about How to "Estimates are accurate" patented technology

Method for estimating lithium ion battery remaining available capacity

The invention discloses a method for estimating lithium ion battery remaining available capacity. The method comprises the steps of acquiring standard temperature, a standard discharging current and battery internal resistance from a battery instruction book, acquiring battery nominal capacity based on battery bench testing data, drawing a temperature-current-SOC three-dimensional surface, estimating the remaining available capacity of a battery under a battery future current according to the current battery temperature, the current battery SOC, the battery standard nominal capacity, the battery internal resistance, the battery future current and the temperature-current-SOC three-dimensional surface, and calculating the battery remaining battery capacity according to the remaining available capacity, a battery current end voltage, the battery internal resistance and the battery future current. According to the method for estimating the lithium ion battery remaining available capacity, influences on the lithium ion battery remaining available capacity by the battery discharging current, the battery temperature and the battery internal resistance are taken into solid consideration, an accurate estimation value of the lithium ion battery remaining available capacity can be offered, and the estimation value of the lithium ion battery remaining available capacity is further used for estimation of remaining mileage of an electric automobile and automobile overall energy management.
Owner:BEIJING KEY POWER TECH

Method and device for estimating power battery charge state on line

The invention discloses a method and device for estimating a power battery charge state on line. The method comprises the steps that a capacity correction factor of a power battery is calculated according to the accumulated released energy of the power battery, the internal resistance of the power battery is calculated, a state space model of the power battery is established, and the state space model of the power battery is substituted into an unscented Kalman filter to obtain the estimated value of the battery charge state. According to the method and device for estimating the power battery charge state on line, the capacity correction factor of the power battery is calculated according to the accumulated released energy of the power battery, the accumulated released energy of the power battery is the sum of energy consumed by load acting and energy consumed by the internal resistance from the first time up to now, the accumulated released energy of the power battery can reflect the using history of the battery like the cycle index and is more beneficial to accurate measuring in numerical value, and therefore the method of correcting the related parameters of the battery through the accumulated released energy of the power battery is better in operability and is more accurate in estimated value.
Owner:SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV +1

Self-adaption radio frequency interference offsetting device, method and receiver

The invention relates to the technical field of mobile communication and provides a self-adaption radio frequency interference offsetting device, method and receiver and a wireless full-duplex communication system. The device comprises an amplitude and phase adjusting module, a subtractor and a baseband extracting and filtering module. The amplitude and phase adjusting module is used for adjusting the amplitude and the phase of radio frequency reference signals and outputting radio frequency adjusting signals to enable the radio frequency adjusting signals to be collected in self-interference signals of radio frequency receiving signals. The subtractor is used for outputting radio frequency residue signals which are the difference value signals between the radio frequency receiving signals and the radio frequency reference signals. The baseband extracting and filtering module is used for receiving the radio frequency reference signals and radio frequency residue signals outputted from the subtractor and extracting the baseband signals. The baseband signals are processed in a minimum mean square self-adaption filtering mode to obtain amplitude phase control signals which are outputted to the amplitude and phase adjusting module. The self-adaption radio frequency interference offsetting device, method and receiver adopt an LMS self-adaption filtering algorithm, so that the convergence rate is higher and the estimation results are more accurate.
Owner:HUAWEI TECH CO LTD

Water loss and soil erosion remote-sensing dynamic monitoring method based on modified universal soil loss equation

InactiveCN102609615AReduce difficultyReflect long-term dynamic monitoringSpecial data processing applicationsVegetationTerrain
The invention discloses a water loss and soil erosion remote-sensing dynamic monitoring method based on a modified universal soil loss equation, which includes the implementation steps: 1) acquiring a rainfall erosivity factor, a soil erodibility factor and a terrain factor; 2) acquiring remote sensing images of a to-be-monitored area, performing land use/coverage category division according to the remote sensing images to obtain multiple land categories, and respectively estimating a vegetation coverage-management factor of each land category so as to obtain a comprehensive vegetation coverage-management factor; 3) extracting characteristic information affecting water and soil conservation from the remote sensing images, and estimating a water and soil conservation measure factor according to the characteristic information affecting water and soil conservation; and 4) calculating an average annual soil loss amount estimated value of the to-be-monitored area according to the modified universal soil loss equation, and outputting the value. The water loss and soil erosion remote-sensing dynamic monitoring method based on the modified universal soil loss equation has the advantages of reasonable estimated result, high universality, suitability for long-term dynamic monitoring of water loss and soil erosion in the area and wide application range.
Owner:ZHEJIANG UNIV

Attitude control method and system for quad-rotor aircraft based on auto-disturbance rejection control technology

The invention discloses an attitude control method and system for a quad-rotor aircraft based on an auto-disturbance rejection control technology, and can effectively improve the robustness of the attitude control of the quad-rotor aircraft. The method comprises the following steps of using auto-disturbance rejection control to implement angular velocity loop control in attitude control; in an auto-disturbance rejection controller, obtaining given angular velocity and angular acceleration after performing smooth noise reduction on a given angular velocity signal by a tracking differentiator; adopting a second-order extended state observer, and performing observation and estimation on the state of each order of the angular velocity control model, internal and external disturbances acting onthe model and the sum of system un-modeled dynamics by using the feedback angular velocity of the controlled object and the control quantity u(t-tau) added to the motor response delay; using the difference between the output quantity of the observer and the given quantity to obtain a preliminary control quantity through the calculation of a nonlinear control rate, using the disturbance estimationquantity obtained by the observer to perform compensation on the basis of the preliminary control quantity, and obtaining the final output control quantity u(t).
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Raininess estimation method based on dual polarization Doppler weather radar detection

The invention relates to a raininess estimation method based on dual polarization Doppler weather radar detection. The method comprises the steps that when echo intensity ZH of rainfall is small, the rainfall is estimated through the echo intensity ZH; when the echo intensity ZH of the rainfall is increased, if a value of ratio differential phase shift KDP and a value of a differential reflectivity factor ZDR are small, the rainfall is estimated through the echo intensity ZH and the differential reflectivity factor ZDR, if the value of the ratio differential phase shift KDP is small and the value of the differential reflectivity factor ZDR is large, the rainfall is estimated through the ratio differential phase shift KDP and the differential reflectivity factor ZDR, and if the value of the ratio differential phase shift KDP and the value of the differential reflectivity factor ZDR are large, the rainfall is estimated through the ratio differential phase shift KDP. According to the meteorology feature of precipitation particles, the raindrop spectrum feature of the precipitation particles of different sizes and the influence of rain belt attenuation are considered, a combined rainfall algorithm is adopted, the estimation result is accurate, precision is improved, and flash flood monitoring capacity is improved.
Owner:ANHUI SUN CREATE ELECTRONICS

Docking ring circle center extraction method based on close-range short-arc image

The invention relates to a docking ring circle center extraction method based on a close-range short-arc image. The docking ring circle center extraction method comprises the following steps: carrying out epipolar rectification on a binocular image containing a short-arc docking ring, dividing a threshold by using a standard deviation method, extracting a ring surface by means of regional attributes, and then extracting inner and outer edges; carrying out dense reconstruction on the extracted ring surface region by using a semi-global matching method to obtain three-dimensional point cloud in a camera coordinate system; calculating a ring surface normal vector of the point cloud, and projecting a coordinate in a plane vertical to the normal vector; distinguishing the inner and outer edges in a new plane, and respectively carrying out perfect circle fitting on the inner and outer edges; and finally, obtaining an accurate circle center coordinate of the docking ring by use of concentric ring constraint according to obtained centers and radiuses of the inner and outer edges. According to the docking ring circle center extraction method provided by the invention, from the characteristics of the docking ring, three-dimensional point cloud data are directly projected into a normal incidence spatial plan, ellipse fitting is simplified to circle fitting, and meanwhile, error points are eliminated by constraint conditions of inner and outer rings, and the docking ring circle center extraction method has the advantages of accurate result and small calculated amount.
Owner:BEIJING INST OF CONTROL ENG

Method and system for detecting and identifying rotating speed of wind power generation set

The invention discloses a method and a system for detecting and identifying the rotating speed of a wind power generation set. The method comprises the steps of measuring generator bearing pedestal vibration acceleration signals of the wind power generation set, firstly moving a trend item in the signals, and carrying out band-pass filtering, wherein upper and lower cutoff frequencies of the filter pass band respectively take the lowest and the highest rotating frequencies of a generator shaft of the double-fed wind power generation set; carrying out singular value noise reduction processing on filtered signals, and bringing forward a prominent rotating frequency component in the band-pass signals; and finally, carrying out discrete Fourier transform on the filter and denoised signals, and acquiring an estimated value of the rotor rotating frequency by using an interpolation Fourier transform method. According to the method disclosed by the invention, precise estimation for the generator rotor rotating frequency can be given, necessary rotating speed information is provided for fault feature extraction of different components, and rotor rotating speed signals are acquired without installing a rotating speed measurement system, thereby simplifying a vibration monitoring system, reducing the system cost, and being easy for engineering implementation.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING) +1

Time bias estimation device and method for orthogonal frequency division multiplexing system

The invention discloses a time bias estimation device and a time bias estimation method for an orthogonal frequency division multiplexing (OFDM) system. The time bias estimation method comprises the following steps of: acquiring a pilot-bit frequency domain channel estimation value of a target user according to a received frequency domain demodulation reference mark and a local frequency domain demodulation reference mark; transforming the acquired pilot-bit frequency domain channel estimation value to a time domain by using inverse Fourier transform; realizing pilot-bit channel estimation multiuser separation by computing the length of an effective channel shock response window of the target user, and performing time domain noise reduction treatment on each user on an antenna of the user; searching for a peak value of each user in the effective channel shock response window, and finding a main path position of a signal; and computing a time bias estimation value of the user accordingto the peak value corresponding to a main path and generating a time adjustment command word. The time bias estimation device and the time bias estimation method of the invention can effectively estimate the relative time bias between a base station and a terminal, simplify the computation method of the time bias, reduce device complexity and obtain an accurate estimation value even on a working site with a low signal-to-noise ratio.
Owner:ZTE CORP

Method for extracting fault feature of antifriction bearing based on sliding entropy-ICA algorithm

InactiveCN107024352AAddressing the Limitations of the Separation Assumption PremiseSolve the lack of false weightMachine bearings testingTime domainFeature set
A method for extracting the fault feature of an antifriction bearing based on a sliding entropy-ICA algorithm is provided. The method comprises main steps of: (1) subjecting a single-channel actually measured signal to EMD to obtain respective IMF components; (2) screening out effective IMF components by using a sliding entropy cross correlation coefficient to form a virtual channel signal; (3) integrating the single-channel actually measured signal with the effective IMF components to form a composite signal matrix, separating the composite signal matrix by using a FastICA algorithm to obtain respective source signal estimated values; (4) retaining a source signal containing a bearing fault feature, and extracting a plurality of time-domain feature parameters and frequency-domain feature parameters to form a feature parameter set; and (5) subjecting a high-dimensional feature set to data fusion by using an LLE algorithm to obtain an accurate low-dimensional feature parameter. The method uses the sliding entropy-ICA algorithm in combination with the LLE algorithm, is suitable for extracting the fault feature of rotating machines including the antifriction bearing, and can extract the source signal containing fault information just by using the single-channel signal. The low-dimensional feature parameter obtained by the method can describe bearing fault information.
Owner:HARBIN UNIV OF SCI & TECH

Method and system for calibrating interference of space-based interferometric imaging radar altimeter

The invention relates to a method and system for calibrating interference of a space-based interferometric imaging radar altimeter. The method comprises the following steps: determining the radar viewing angle of each pixel point of a reference target according to the altitude information of the reference target as well as rail and slant distance parameters acquired by the space-based interferometric imaging radar altimeter; performing polynomial fitting on the spatial variation relation between the unrapping phase and the radar viewing angle; determining the sensitivity of the unwrapping phase and the slant distance on the radar viewing angle separately; determining the length and the inclination angle of a base line; and determining interferometric phase offset. The system comprises a radar viewing angle calculation module, a fitting coefficient calculation module, a sensitivity calculation module, an interferometric base line determining module and an interferometric phase offset determining module. Estimation of the interferometric base line and the interferometric phase offset can be separated by fitting and estimating the sensitivity of the unwrapping phase on the radar viewing angle, so that the three parameters such as the length of the base line, the inclination angle of the base line and the interferometric phase offset, can be completely estimated.
Owner:TECH & ENG CENT FOR SPACE UTILIZATION CHINESE ACAD OF SCI

Preparation method of C/C composite tube of optical telescope

The invention discloses a preparation method of a C/C composite tube of an optical telescope. The method comprises the following steps: 1) carbon fiber fabrics and carbon fiber felts are spread layer by layer, needle-punching is performed on each layer to prepare a preformed reinforcement body, the density of the preformed reinforcement body is estimated before layer spreading and the radial density of the preformed reinforcement body is calculated according to the estimation result; 2) composite densifying is performed; 3) high temperature treatment is performed; and 4) the subsequent treatment is performed. The densifying process comprises the following steps: 201) performing gas-phase carbon-settling densifying treatment, namely using a gas-phase carbon-settling device to perform gas-phase carbon-settling treatment; and 202) performing resin impregnation, curing and carbonization treatment, namely performing further densifying treatment on the preformed reinforcement body after thegas-phase carbon-settling densifying treatment. The method has reasonable design, simple processing steps, low input cost, simpleness in operation and convenience in quality control; and the processed C/C composite tube has good performance, higher overall strength and stability and an ultralow thermal expansion coefficient.
Owner:XIAN AEROSPACE COMPOSITE MATERIALS INST

Method for estimating identification error intervals of flight vehicle pneumatic parameters

The invention discloses a method for estimating identification error intervals of flight vehicle pneumatic parameters, and is used for estimating the error intervals of the pneumatic parameters identified from flight test measuring data. On the basis of the common method for estimating a standard C-R (Cramer - Rao) bound of the parameter identification error intervals, aiming at solving the problem of too small estimating value of the error intervals when the standard C-R bound is applied to the flight test measuring data, a C-R bound correction method is derived by a principle, and the correction method can be used for accurately estimating the identification error intervals of the flight vehicle pneumatic parameters. The method for estimating the identification error intervals has the advantages that the convenience and the practicality are realized, and the error interval of each pneumatic parameter identification result is given by only needing the samples of the single flight test measuring data; and compared with the prior art, more accuracy and more reliability are realized, and a foundation is laid for applying the pneumatic parameters identified from the flight test measuring data into the design and improvement of the flight vehicle.
Owner:CHINA ACAD OF AEROSPACE AERODYNAMICS

Channel estimation method and device

The invention relates to a channel estimation method and device which are used to perform channel estimation according to the received frame signal, wherein the frame signal consists of known sequence and data sequence. The method of the invention comprises the following steps: predicting the channel estimation predicted value of the i-th frame according to the channel estimated values of frames before the i-th frame, then obtaining the estimation predicted values of the i-th frame and the (i-1)th frame according to the channel estimation predicted value of the i-th frame; obtaining the smearof the known sequence of the i-th frame in the data sequence of the i-th frame according to the estimation predicted value of the i-th frame and the channel estimation predicted value of the i-th frame; obtaining the smear of the data sequence of the (i-1)th frame in the known sequence of the i-th frame according to the estimation predicted value of the (i-1)th frame and the channel estimation predicted value of the i-th frame, and reconstructing the known sequence of the i-th frame in time domain to obtain the frequency-domain channel estimated value and time domain channel estimated value of the i-th frame. The channel estimation method and device of the invention simplify the complexity of channel estimation and can be used to track the rapidly changing dynamic channel.
Owner:ZHANGJIAGANG KANGDE XIN OPTRONICS MATERIAL

Permanent magnet synchronous motor sensorless control method based on high-frequency signal injection

The invention discloses a permanent magnet synchronous motor sensorless control method based on high-frequency signal injection. Due to the existence of the magnetic resistance torque of an interior permanent magnet synchronous motor, when a sensorless algorithm based on traditional high-frequency pulse vibration voltage signal injection is adopted, electromagnetic torque high-frequency pulsationis generated, especially in a control method when the non-id is equal to 0, the high-frequency pulsation of the electromagnetic torque is more obvious. When the injected d-axis and q-axis high-frequency voltage components are distributed, the minimum electromagnetic torque high-frequency pulsation is taken as the principle, the optimal high-frequency current angle and the optimal high-frequency voltage angle are obtained according to a torque formula, and the most appropriate high-frequency voltage injection direction is selected; when a rotor position estimation value is calculated, the responded high-frequency current component is controlled to be zero at the orthogonal position of the optimal high-frequency current angle, so that the error of the rotor position estimation value is zero,and an accurate rotor position estimation value is obtained. According to the method, the electromagnetic torque high-frequency pulsation caused by high-frequency signal injection can be effectivelyreduced, so that the performance of a sensorless control system is improved.
Owner:SOUTHEAST UNIV

Method and system for estimating carrier frequency deviation

The invention provides a system for estimating a carrier frequency deviation, comprising the following modules: a correlator module, a peak value search engine, an averaging device module, a phase angle difference calculator module and a carrier frequency deviation calculator module, wherein the correlator module is used for carrying out correlation calculation on a baseband signal and a locally-generated PN (Pseudo-Noise) sequence; the peak value search engine is used for carrying out peak value searching after receiving a parallel correlated value output by the correlator module, further determining a starting position of a PN section in the input baseband signal and feeding the position information back to the correlator module; the averaging device module is used for averaging results of the multiple times of correlated calculation of front and back sections, which are output by a correlator; the phase angle difference calculator module is used for calculating a phase angle difference of the correlated calculation and outputting the result; and the carrier frequency deviation calculator module is used for calculating an estimation value of the carrier frequency deviation and taking the estimation value of the carrier frequency deviation as an estimation value of PN rough estimation. The system has the beneficial effects that the problem that PN rough capturing is inaccurate when stronger multi-path interference exists can be effectively solved, and the robustness of the system under an actual wireless transmission channel can be improved.
Owner:SHANGHAI HIGH DEFINITION DIGITAL TECH IND

Moving target positioning method based on TDOA (Time Difference of Arrival) and FDOA (Frequency Difference of Arrival)

ActiveCN109581281AAvoid Converging to Local MinimaAvoid divergencePosition fixationComputation complexityFDOA
The invention discloses a moving target positioning method based on a TDOA (Time Difference of Arrival) and an FDOA (Frequency Difference of Arrival). The moving target positioning method comprises the steps of: setting that one moving target for transmitting a signal, one mobile sensor used for receiving the signal and used as a reference sensor and a plurality of mobile sensors only used for receiving the signal exist; then calculating a distance difference between a transmission distance from the moving target to each mobile sensor only used for receiving the signal and a transmission distance from the moving target to the reference sensor and a distance difference change rate; next, calculating initial values of a position and a speed of the moving target; then determining a positioning problem of the moving target so as to solve to obtain an accurate estimated value of the position of the moving target; and finally, optimizing an estimated value of the speed of the moving target by utilizing the accurate estimated value of the position so as to obtain an accurate estimated value of the speed. The moving target positioning method has the advantages that the position and the speed of the moving target can be accurately estimated; calculation complexity is low; and running time is short.
Owner:NINGBO UNIV

Non-local wavelet coefficient contraction-based image denoising method

The invention discloses a non-local wavelet coefficient contraction-based image denoising method, which mainly solves the problem that image details are lost when denoising is performed by adopting a traditional image denoising method. The non-local wavelet coefficient contraction-based image denoising method comprises the following implementation steps: (1) establishing noise image-contained similarity groups, performing two-dimension wavelet transformation on similarity blocks in the similarity groups, and calculating non-local means of wavelet coefficients of the similarity groups; (2) contracting the wavelet coefficients by using a double-L1 norm model, then, performing wavelet inverse transformation to obtain estimated values of the similarity blocks, and performing integration on the estimated values to obtain primary estimation images; (3) performing residual cover on the primary estimation image, and executing the step (1) and the step (2) to obtain base estimation images; (4) establishing similarity groups of the base estimation images, and further obtaining the noise image-contained similarity groups; (5) performing Wiener collaborative filtering on the noise image-contained similarity groups to obtain denoised images. According to the non-local wavelet coefficient contraction-based image denoising method disclosed by the invention, while noise is smoothened, edge textures of images can be kept better. The non-local wavelet coefficient contraction-based image denoising method can be used for denoising processing of natural images.
Owner:XIDIAN UNIV
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