50results about How to "Achieving High-Precision Estimation" patented technology

The invention provides an MODIS satellite high-precision monitoring method for chlorophyll-a in a eutrophic lake water body. The method comprises the following steps: screening a chlorophyll-a evaluation index (BNDBI) which is sensitive to the concentration change of chlorophyll-a and not affected by highly suspended matters, thin cloud and solar flares; acquiring the quantitative relationship between BNDBI and the concentration of chlorophyll-a on the basis of biological optical model simulation; acquiring a chlorophyll-a inversion algorithm based on ground measured spectrum (Rrs) and BNDBI by referring to water body spectral information and corresponding water body chlorophyll-a concentration of 2013-2014 lake field monitoring; acquiring the quantitative relationship between the ground monitoring and remote sensing reflectance ratio (Rrs) and Rrc after simulated Rayleigh scattering correction by simulating different aerosol types and thicknesses and different solar elevation angles, satellite observation angles and azimuth angles; and extending the chlorophyll-a inversion algorithm based on ground measured spectrum data to satellite image data after Rayleigh scattering correction. Based on the method, inter-annual and inter-monthly change rules and spatial distribution of chlorophyll-a in a eutrophic lake can be acquired accurately.

The invention relates to a deep space detector astronomy/radio combination navigation method based on ephemeris correction. The method comprises the following steps: establishing a Mars detector state model and astronomy astronomy navigation and radio navigation subsystem measurement models, acquiring the measured values of astronomy and radio navigation subsystems, and carrying out filtering estimation to obtain the position of the detector in an inertia coordinate system treating a target heavenly body as a center and the speed of the detector; and establishing the ephemeris error state model and the measurement model of the target heavenly body based on the position and the speed, obtaining the ephemeris error measurement value of the target heavenly body according to the estimation states of the two astronomy and radio navigation subsystems, utilizing a Kalman filtering method estimate the ephemeris error of the target heavenly body, feeding back to a navigation system model, and carrying out information fusion. The deep space detector astronomy/radio combination navigation method belongs to the technical field of spaceflight and navigation, can realize the online estimation of the heavenly body ephemeris error and the correction of the navigation system model error, and is suitable for the capture segment of a detector.

The invention relates to a deep space explorer acquisition phase celestial navigation method based on target object ephemeris correction. According to the method, firstly, a Martian explorer state model, a startlight angle navigation sub system measuring model and an X-ray pulsar navigation sub system measuring model are built; then, the startlight angle and the X-ray pulsar quantity measurements are respectively obtained; filtering estimation is performed to obtain the position and the speed of a detector in a heliocentric inertia coordinate system and a target object center inertia coordinate system; on the basis, a state model and a measuring model of target object ephemeris error are built; the quantity measurement about the target object ephemeris error is obtained through estimation state vectors of the startlight angle navigation sub system and the X-ray pulsar navigation sub system; a Kalman filtering method is used for estimating the target object ephemeris error; the target object ephemeris error is fed back into a navigation system model; the position of a target object in the navigation model is corrected. The deep space explorer acquisition phase celestial navigation method belongs to the technical field of aerospace navigation, can be used for estimating the object ephemeris error and correcting the model error of the navigation system on line, and is applicable to the explorer acquisition phase.

The invention relates to a power battery multi-dimensional fusion SOC and SOH online joint estimation method. According to the invention, the method comprises the steps: selecting a dual extended Kalman filter (Dual-EKF) method and a multi-dimensional fusion estimation method to solve the problems of large workload, low estimation precision and the like of separately designing SOC and SOH estimation systems; obtaining related data through a mixed pulse power performance test, and establishing second-order RC equivalent circuit model identification model parameter values R1, R2, C1 and C2; performing online accurate estimation on three state parameters of SOC, internal resistance and rated capacity by using a Dual-EKF method so as to determine SOHRi and SOHQi; and finally, calculating health state weight coefficients alpha R and alpha Q of two dimensions by using a normalized least square method, and performing fusing to obtain a comprehensive health state value SOHTi; finally, accurately estimating the SOH value of the power battery, achieving the SOC and SOH combined online estimation, and improving the estimation precision of the SOC and SOH values. Therefore, the applicability of the method to an embedded power battery management system is high.

The invention discloses an ephemeris correction-based autonomous celestial navigation method for a deep space probe in a capturing stage. The method comprises the following steps: firstly, establishing an ephemeris error state model and an ephemeris error measurement model of a target celestial body, and measuring ephemeris error according to a position difference between a predicted celestial body image and an actual celestial body image; secondly, simultaneously taking the ephemeris error state model and an orbital dynamic model as a celestial navigation system state model, taking the ephemeris error measurement model and a starlight angular distance measurement model as measurement models of a celestial navigation system, estimating the position and speed of the probe and the ephemeris error of the target celestial body by a Unscented Kalman filtering method, feeding back the estimated ephemeris error to the state model, and correcting the ephemeris data of the target celestial body, thereby obtaining the position and speed of the probe, relative to the target celestial body and the heliocenter, after autonomously correcting the ephemeris error. The method provided by the invention belongs to the technical field of aerospace navigation, can perform on-line estimation on ephemeris error of celestial bodies and correct model error of the navigation system, and is suitable for the probe capturing stage.

A determining method for ultrahigh-accuracy attitude of a spacecraft multi-stage compound control system. The determining method comprises the following steps: (1) establishing an attitude constraintmodel between a star and a load as well as between the load and a fast reflective mirror of the spacecraft multi-stage compound control system; (2) establishing a relative attitude quaternion model between the star and the load as well as between the load and the fast reflective mirror; (3) judging whether a star guiding sensor has a measured value or not; (4) establishing a load attitude estimation error state equation if the star guiding sensor has no the measured value, estimating a load attitude by adopting a Kalman filtering method, and realizing determination on high accuracy of the loadattitude; (5) establishing a star attitude estimation error state equation, and realizing determination on high accuracy of a star attitude by adopting the Kalman filtering method; (6) estimating a load sight attitude by adopting a measured value qfm of the star guiding sensor if the star guiding sensor has the measured value; (7) establishing the load attitude estimation error state equation, estimating the load attitude by adopting the Kalman filtering method, and realizing the determination on high accuracy of the load attitude; (8) establishing the star attitude estimation error state equation.

The invention discloses a geosynchronous orbit determination and parameter determination method based on differential algebra. A kinetic model described based on geosynchronous satellite orbit elements is selected and used, use of a relatively greater integration step in a numerical integration process is avoided and appearance of singular points is avoided for the kinetic model, moreover, a perturbative force item is added in the kinetic model, polynomial form integration is executed, thus, obit statuses and spacecraft parameters are obtained, high-order prediction is executed for the obtained parameters, and meanwhile, high-order prediction of observed quantity is executed; by means of nonlinear information of the kinetic model and an observation model, estimation accuracy is improved; in combination with actual observed values of a spacecraft, high-order prediction values of the obit status and the spacecraft parameters are updated and high-order estimated values as initial values are obtained; and by repeating the implementation process above, geosynchronous orbit determination and parameter determination can be completed. The method provided by the invention not only can improve accuracy of obit estimation and realize high-precision estimation of the parameters, but also can greatly reduce calculation cost.

The present invention discloses an arrival angle estimation method based on the sparse Bayesian theory in existence of cross coupling. The method comprises the steps of: constructing a sparse signal model in the existence of antenna array cross coupling and arrival angle grid deviation; initializing unknown parameters in the sparse signal model; according to the current unknown parameter values, solving a joint probability distribution function based on the Bayesian theory, and estimating a receiving signal mean value and a covariance matrix; through adoption of the maximization likelihood function, estimating the variance of noise and variance of the receiving signals; calculating and obtaining a spatial spectrum of the receiving signals; through adoption of the maximization likelihood function, estimating the arrival angle grid deviation, and updating a dictionary matrix in the existence of the grid deviation; estimating the variance of the array antenna cross coupling vector and thecross coupling vector of the array antenna; and performing iteration calculation until reaching the set number of times of iteration, finishing the iteration, and outputting the spatial spectrum of the receiving signals and the solved receiving signal arrival angle. The arrival angle estimation method based on the sparse Bayesian theory in existence of cross coupling improves the arrival angle estimation performance and achieves the high-precision estimation of the signal arrival angle.

The invention discloses a method for estimating a pedestrian height position in a multi-story building based on an MEMS sensor. The method comprises the steps of: fixing an MEMS integrated sensing device on a pedestrian's lower limb; employing the MEMS integrated sensing device to collect acceleration data, angular velocity data and pedestrian height data in the process that the pedestrian walks astaircase; employing a multi-threshold detection method to determine an attitude phase and the swing phase of the pedestrian gait movement; performing correction of the accelerations of the attitudephase and the swing phase in the vertical direction, updating the speed of the attitude phase to be 0, and performing secondary integration for the corrected acceleration in the vertical direction toobtain the estimated heights of the attitude phase and the swing phase of the pedestrian; and determining whether there is deviation between the estimated height data obtained by the attitude phase and the target height data measured by a micro manometer or not, if yes, performing error linear compensation for the estimated height obtained by the swing phase and finally obtaining the updated pedestrian positioning data. The accurate estimation of the pedestrian height position is achieved based on one sensor node.

The invention relates to a dual parallel antenna array-based coherent distributed non-circular signal DOA estimation method, which belongs to the field of array signal processing. The two-dimensionalDOA estimation method for coherent distributed non-circular signals comprises steps: an array output matrix is calculated by using two parallel uniform linear arrays; by using the non-circular characteristics of a source, an extended output matrix is constructed; four selection matrices are set, and an extended steering vector array has rotational invariance; the covariance matrix of an extended array output matrix is calculated; the covariance matrix is subjected to eigenvalue decomposition to obtain signal subspace; an equivalent matrix is calculated, the equivalent matrix is subjected to eigenvalue decomposition respectively, eigenvalues are paired, and estimation on an azimuth angle and a pitch angle are realized. By using the non-circular characteristic of the signal, the number of array elements is extended virtually, and the estimation performance is improved.

The invention discloses an external radiation source radar same-frequency interference time delay and energy rapid estimation system and method. The method comprises the following steps that the reference antenna obtains reference signals directly reached by the same-frequency interference base stations through beam forming; the echo antenna receives echo signals containing same-frequency interference and target echoes; a pilot cross-correlation algorithm is usedto obtain coarse time delay parameters of reference signals and same-frequency interference signals, clustering matching processing is performed on the reference signals and the same-frequency interference of each base station, then a same-frequency interference signal matrix is constructed, and a subspace projection method is utilized to obtain two-dimensional accurate estimation of same-frequency interference time delay and energy. The method can achieve the precise estimation of the same-frequency interference time delay andenergy from different radiation sources under the condition of the same-frequency interference of a plurality of radiation sources of the mobile communication external radiation source radar, and further achieves effective inhibition. The invention also discloses an external radiation source radar same-frequency interference time delay and energy rapid estimation system. The system is low in costand convenient in networking.

The invention relates to an interleaved OFDMA uplink carrier frequency deviation CFO estimation method for iterative multi-user interference cancellation. The CFO of the OFDMA can damage the orthogonality between subcarriers, serious inter-carrier interference ICI is generated, and multiple access interference MAI can also be brought. In the scheme of the invention, the method comprises the following steps: the base station sorts the users according to the received signal intensities; the base station estimates from the user with the strongest receiving power to the user with the lowest power; feedback signals of the estimated users with the higher receiving power and feedback signals of the weak users estimated in the last iteration are all subtracted from the receiving signals, interference of frequency deviation of other users on pilot frequency point signals of the users is eliminated and then multiplied by a phase compensation factor, and the CFO of the current user is obtained by maximizing the power of the pilot frequency point. And the next iteration is entered until the CFO of the user with the weakest receiving power is estimated. The estimation method has the advantages that the estimation precision is high, the convergence speed is high, a small number of pilots are inserted into data sent by a user, and a large number of frequency bands do not need to be occupied.

The invention provides a circular target pose measurement method and device based on binocular inverse projection transformation. The method comprises the following steps: respectively carrying out elliptic contour feature detection on spatial circular target images shot by a left camera and a right camera to obtain corresponding elliptic contour pixel coordinates; inversely projecting the elliptic contour pixel coordinates corresponding to spatial circular target images shot by the left camera and the right camera into the space, and constructing a feature vector which starts from the optical center of the camera, passes through elliptic contour image plane coordinates and points to contour world coordinates of the spatial circular target ; according to the feature vectors, the initial pose information of the spatial circular target and the poses of the left camera and the right camera, acquiring world coordinates of the contour features of the reconstructed spatial circular target; constructing a residual function according to the difference between the radius of the reconstructed spatial circular target contour and the real radius of the circular target; and constructing an optimization model according to the residual function, and solving to obtain an optimal pose parameter of the space circular target, thereby realizing high-precision estimation of the pose of the long-distance small-size space circular target.

The invention discloses a Mars atmosphere entry section accompanying flight beacon auxiliary navigation method, relates to a beacon auxiliary navigation method, and belongs to the technical field of deep space exploration. According to the method, on the basis of the Mars atmosphere entry section inertial navigation, an accompanying flight beacon is introduced; by adding the radio distance measurement and speed measurement among a landing device, a rail device and the accompanying flight beacon as a measuring quantity, an initial state deviation is corrected; a geometrical configuration during the radio navigation of the landing device and the rail device is improved; the entry section navigation precision is further improved. The Mars atmosphere entry section accompanying flight beacon auxiliary navigation method disclosed by the invention can solve the problems of the inertial navigation that the initial state deviation cannot be corrected during inertial navigation, and the measurement errors are accumulated along with time. The geometrical configuration of the radio navigation can be improved; the high-precision estimation of a full state of the landing device is obtained; the entry section navigation precision is further improved.

The invention relates to a method for determining an error coefficient of an inertial device, in order to overcome the deficiency that the estimated value of the existing kalman filter is not unique by performing linear processing on a nonlinear state equation and a nonlinear observation equation and by calculating the error coefficient of the inertial device by using an extended recursive least square method. The method can adapt to the situation when the state equation and the observation equation are nonlinear functions, and can also meet the situation when the state equation and the observation equation are linear functions. The method can be used for realizing real-time calculation, is easy to implement and has a value of engineering practical application.

The invention relates to a four-wheel independent drive electric vehicle reference vehicle speed fault-tolerant adaptive estimation method. A robust adaptive Kalman filtering reference vehicle speed estimation module and a reference vehicle speed estimation module based on rule logic are selected for estimation, wherein the reference vehicle speed estimation module based on the rule logic is usedas a backup of the robust adaptive Kalman filtering reference vehicle speed estimation module, and when Kalman filtering diverges, Kalman filtering can be replaced by a method based on the rule logicto be output; the method is small in dependence on preset parameters, high in estimation precision, good in working condition adaptability and high in fault-tolerant capability, vehicle speed estimation under various complex working conditions such as wheel locking, slipping, ramp driving and steering driving can be achieved, the function safety requirement of automobile control system software design is met, and reliability is effectively guaranteed.

The invention provides a lithium battery nuclear temperature evaluation method and system based on transfer learning. The method comprises the following steps: acquiring target domain lithium battery parameter data; obtaining a lithium battery nuclear temperature evaluation result according to the obtained lithium battery parameter data and a target domain neural network model, wherein the target domain neural network is obtained by training according to historical data of a source domain lithium battery to obtain a source domain neural network model, and retraining a full connection layer of the source domain neural network model according to target domain data. According to the invention, transfer learning is adopted, and the established source domain model is transferred to the target domain lithium battery, and the nuclear temperature of other lithium batteries in the target domain can be accurately estimated with only a small amount of information of the target domain being used as training data, so that the model training progress is accelerated, and the training efficiency is improved.

The invention provides an FY-3D passive microwave data under-cloud surface temperature inversion and verification method, and the method comprises the steps: obtaining FY-3D passive microwave data, carrying out the data preprocessing, and extracting the dual-channel brightness temperature of 18.7 GHz and 23.8 GHz vertical polarization channels; eRA5 atmosphere profile data are obtained, and data processing is carried out to extract the content of atmosphere water vapor and liquid water; based on the dual-channel brightness temperature of the 18.7 GHz and 23.8 GHz vertical polarization channels, combining the corresponding atmospheric water vapor and liquid water content data, and adopting a dual-channel physical algorithm to estimate the surface temperature under the clouded condition; and verifying and correcting the estimated surface temperature by using the surface temperature data under the cloud measured by the site. According to the method, the influence of the atmospheric water vapor and the liquid water content in the cloud on passive microwave radiation is quantified, the estimation precision of the under-cloud surface temperature is improved, and the precision comparison verification of the under-cloud surface temperature of the ground point data and the FY-3D passive microwave data is realized.

The invention discloses a design method of a tiny fault estimation system used for a CRH2 high-speed railway inverter, and belongs to the field of fault diagnosis and fault estimation. The method specifically comprises the following steps of in a first stage, building an offline data model: 1) collecting steady state running data of a high-speed train and preprocessing offline data; 2) calculatinga score matrix of a rotation subspace where the preprocessed data is located; and 3) determining a nonlinear relationship between a fault estimation value and a fault magnitude, thereby performing online estimation; and in a second stage, performing online fault estimation: 4) processing online data; 5) calculating online score vectors; and 6) estimating the existent fault magnitude by utilizinga fault estimator. The invention designs a multivariate statistical analysis-based estimation method. The method combines Kullback Leibler divergence and a neural network approximation method, can realize relatively accurate fault estimation, and has a certain advantage in sensitivity to tiny fault estimation.

The invention relates to a distributed coherent radar angle measurement method. Aiming at the problem of angle measurement ambiguity caused by grating lobe influence of beams of a distributed array, high-precision measurement and ambiguity resolution are carried out on an angle by adopting a plurality of combined array methods. The method comprises the specific steps of (1) array element level beam forming, (2) sub-array level beam forming, (3) fuzzy angle estimation, (4) combined array DBF, (5) combined array angle estimation and (6) ambiguity resolution processing, and can carry out ambiguity resolution processing on a monopulse phase ratio measurement angle to obtain a high-precision ambiguity-free angle estimation value.