100 results about "Total least squares" patented technology

The invention discloses a method for estimating the direction of arrival of a radar low-elevation target, which mainly solves the problem of large calculation of the estimation of the direction of arrival of the low-elevation target in the prior art. The method comprises the following steps of: 1, transmitting a group of narrowband phase reference pulse signals with bandwidth of not exceeding 1 percent of carrier frequency; 2, receiving radar echo data by using a uniform line array; 3, carrying out beam forming on the radar echo data, wherein the beam points 0 degree; 4, measuring a distance sampling unit and a Doppler channel in which a target is disposed; 5, re-accumulating the received radar echo data according to the obtained distance sampling unit and the Doppler channel; 6, constructing a matrix beam by using the re-accumulated data; and 7, solving the direction of arrival of the target for the constructed matrix beam by adopting a total least square method of generalized eigenvalue decomposition.

The invention discloses a two-step positioning method of a wireless sensor network based on total least squares, and belongs to the technical field of signal processing. According to the method, a fitting model parameter obtaining module, a distance estimation module and a position positioning module are adopted, the fitting model parameter obtaining module serves the distance estimation module and the position positioning module, the relative distance between a reference node in a practical environment and the terminal and the corresponding RSS (received signal strength) value are collected in advance in real time, and the relative distance and the RSS value are subjected to relationship curve model fitting training to obtain model parameters; the distance estimation module utilizes the real-time collected RSS value for carrying out distance estimation according to the parameters obtained through fitting model training, and different model parameters are selected for estimation according to the RSS value; and the distance obtained by the distance estimation module and the reference node coordinate are used as the input of the position positioning module, and the output of the position positioning module is the estimation value of unknown node coordinates.

The invention discloses a combined DOA and TOA single-station passive positioning method based on error correction. According to measurement information obtained by a receiving station of an externalradiation source radar system, by introducing an auxiliary variable, a nonlinear equation is converted into a pseudo-linear equation, a pseudo-linear model between the state of a target position and the state of an observation station position is established, an iterative least square method is adopted for estimation, a constrained total least square estimation model is constructed, a constrainedoptimization problem is converted into an unconstrained optimization problem, a Newton iteration method is used for optimization and solution, and the correlation between the auxiliary variable and the target position is used for constructing a correlation least square estimation model, so that the target positioning performance is further improved. The target positioning accuracy is improved through combined estimation of the target position and system errors. Convenience is provided for improving the target positioning performance, the complexity of error registration under the premise of ensuring the estimation performance is reduced, and good positioning performance in the case of large measurement noise is achieved.

The invention discloses a non-parallel track compensation method of a distributed satellite SAR (Synthetic Aperture Radar) system, mainly solving the problems on non-parallel track compensation and along-track base line calculation of the distributed satellite SAR system. The implementation process of the non-parallel track compensation method of the distributed satellite SAR system comprises the following steps of: fitting the measurement data of an ephemeris position by adopting total least squares, to obtain a time parameter equation of a satellite track within an imaging time slot; resampling a track position to obtain a track position coordinate of the impulse transmission time of each direction; structuring a time parameter equation of a new concomitant satellite track parallel to a primary satellite track; compensating concomitant satellite echo data to obtain echoes equivalent to the echoes received along the new concomitant satellite track parallel to the primary satellite track; and calculating the length of the along-track base line. By means of the non-parallel track compensation method provided by the invention, the influence of measurement errors of a GPS (Global Position System) with short-range dependence can be overcome by fitting the measurement data of the ephemeris position, an image pair with higher dependence can be provided for GMTI (Ground Moving Target Indication) clutter suppression and the accurate along-track base line can be provided for the velocity measurement and the positioning of a moving target.

The invention discloses a high-voltage direct-current power transmission multi-channel supplementary damping control method based on a variable structure. The high-voltage direct-current power transmission multi-channel supplementary damping control method has the characteristics that sub-synchronous and low frequency oscillation frequencies and damps, and a system reduced-order model are identified by a TLS-ESPRIT (Total Least Squares-Estimation of Signal Parameters via Rotational Invariance Techniques) algorithm with high operation efficiency and anti-interference capability; a variable structure control principle is combined and an attached controller containing a virtual state variable is designed; finally, a state observer is led in to eliminate the virtual state variable so as to realize an HVDC (High Voltage Direct Current) variable structure controller with an output feedback form; then a variable structure control theory is used for designing a multi-channel direct-current attached damping controller so as to reduce the mutual influences between oscillation modes; the sub-synchronous and low frequency oscillation can be inhibited synchronously. The method is efficient and feasible; the variable structure control theory has strong disturbance rejection on complicated changeable working conditions of an actual power grid; meanwhile, a multi-channel structure is utilized by using the controller to solve a coordinated control problem among the plurality of controllers; the invention provides a controller design method of an actual large power grid with very strong operability.

The invention provides a panorama generation method based on character matching and a system. The method comprises the following steps: characteristic points of an image A and an image B which are adjacent are extracted, vector parameters of the characteristic points are established, and coordinates of the characteristic points are determined; the characteristic points of the image A are used as a sample, the characteristic points of the characteristic points are classified, and the characteristic points which are the best matching with the sample in the image A are selected out from each classification of the image B; a relational expression for the image A to be converted to be under the coordinate system of the image B is calculated by utilizing the matching relations of the characteristic points, and the image A is converted to be under the coordinate system of the image B according to the relational expression; and the image A and the image B are spliced to form an image A1. The panorama generation method and the system use a nearest neighbor method training classifier to match the characteristic points, and obtain a conversion relational-expression with high accuracy through a total least square method, thereby generating a panorama rapidly and accurately.

The invention discloses a method for directly correcting and compensating a course angle of a navigation system and belongs to the technical field of location of navigation systems. The method for directly correcting and compensating the course angle of the navigation system comprises the following steps: firstly expanding an error model of a magnetometer according to the basic principle of circulating the course angle by virtue of the magnetometer; secondarily obtaining a parameter estimation model according to distribution characteristics of an earth magnetic field; finally estimating parameters of the expanded error model of the magnetometer by using a two-step total least square method so as to directly correct the course angle of the navigation system at a system level. The method can be used for correcting and compensating the error of a course angle of an inertial integrated navigation and location system which comprises an inertia measurement unit (IMU) and the magnetometer (or an electronic compass). The method is capable of directly correcting the course angle of the navigation system, strong in robustness, strong in reliability, low in cost, high in accuracy, simple in calculation process, and capable of achieving high-accuracy location and navigation and achieving good effects.

The invention discloses a multi-harmonic-source harmonic contribution quantitative analysis method based on a total-least square method. The multi-harmonic-source harmonic contribution quantitative analysis method includes: selecting harmonic voltage as the index for evaluating harmonic contribution, and determining the joint action of the harmonic source of each node; sectioning measured data according to time, and calculating the harmonic contribution in each time section according to the projection of the harmonic voltage of one harmonic source at one node on the total harmonic voltage at the node; using the total-least square method to solve harmonic impedance and the harmonic voltage, namely background harmonic voltage, of other harmonic sources at the node, and using a singular value decomposition method to obtain the solution of the total-least square method to obtain the quantitative data of each harmonic source at each node at each harmonic time. The multi-harmonic-source harmonic contribution quantitative analysis method has the advantages that the total-least square method is applied to the harmonic quantitative analysis field, the defect that a traditional method only considers variable harmonic voltage measuring errors and does not consider the independent variable harmonic current measuring errors is overcome, and obtained results are accurate.

The invention discloses a low frequency oscillation online identification method based on a cross-correlation function denoising algorithm. The low frequency oscillation online identification method based on the cross-correlation function denoising algorithm is characterized in that cross-correlation functions are used for replacing actual measured signals to restrain color noise, and modal identification of low frequency oscillation is carried out by combining a total least square-rotation invariant technology parameter estimation (TLS-ESPRIT) algorithm. The algorithm can identify the modality of the low frequency oscillation of a power system under a color noise environment quickly and accurately, and an effective basis is provided for security and stability analysis and restraining measures of a system.

The invention discloses a monitoring recognizing method for determining the influence of a speed regulating system of a prime motor on low-frequency oscillation, and aims at recognizing whether a positive damping or a negative damping is provided by the speed regulating system of the prime motor for oscillating during the oscillating process in order to provide a certain reference value for the stable operation of a power system. The method comprises the following steps: recognizing the oscillation damping by the TLS-ESPRIT (total least squares-estimation of signal parameters via rotational invariance techniques) method; determining a first included angle of the left and right variables of a motor rotor equation based on the damping ratio; measuring the local electromagnetic power and the rotating speed of a generator to obtain a second included angle between the rotating speed deviation and the active power deviation; comparing the two included angles to determine whether the positive damping or the negative damping is provided by the mechanical power deviation to the oscillation. The determining method is simple and efficient and assists an operator improving the stabilizing level of the power system.

The invention discloses a remote-sensing image relative correction method and system integrating geometry and radiation. The method includes the steps of generating a control point on an image by means of combination of automatic matching and gross error detection, calculating an initial value of a geometry correction coefficient, detecting radiation invariant of the image to be corrected, calculating the initial value of a radiation correction coefficient, putting a geometric correction model into a linear radiation correction equation, building an error equation integrating geometry and radiation coefficients, calculating a correction coefficient by means of a weighing total least square method, solving the error equation to obtain a correction coefficient modification value and iterating and optimizing the correction coefficient modification value. According to the method, the geometry coefficient and the radiation coefficient in image correction can be calculated simultaneously, and the method lives up to the objective law, is scientific and can further improve correction precision.

The invention discloses a fast registration method of 3D point cloud data with color information. The method comprises a step of counting color values in a target point set and a registration point set and the quantity distribution of points with a same color and filtering the color of RGB point cloud, a step of screening points with a same RGB value in two point sets and then setting a certain color tolerance for the registration point set, a step of extracting four initial points from one point selected in the target point set in each time, constructing a candidate point set similar to the characteristics of the four initial points in the registration point set, and judging whether the candidate point set is same name points of the four initial points, a step of allowing the four initial points and the corresponding four same name points to form four point pairs, using a total least square algorithm to calculate a rigid transform matrix, and completing the global registration of the registration point set, and a step of using a neighboring point iteration method to complete a final local registration finally. According to the method of the invention, the efficiency of point cloud registration can be greatly improved under the premise of maintaining high precision, and the registration time is shortened.

The invention discloses a bumpy platform SAR three-dimensional motion error estimation method. A radar platform in the invention is a bumpy platform. For an imaging defocusing problem caused by a three-dimensional motion error of the bumpy platform, a plurality of strong scattering areas are screened according to an image contrast ratio in an original image without motion error compensation, a local phase error of each strong scattering area is estimated, and then, a total least square method is used to roughly estimate the three-dimensional motion error, and finally, the accurate three-dimensional motion error is obtained through Gaussian Newton iteration. In bumpy platform SAR imaging, by using the method of the invention, space variation compensation of the error can be realized, and then bumpy platform SAR imaging quality can be improved.

The invention relates to a passive radar target positioning method and device. The method comprises steps of linearizing an observation equation of angle and time difference to obtain a set of linearequations, obtaining rough estimation of a target position by using least squares, considering the observation error and the position error of the external radiation source in the linear equations toobtain a constrained total least squares model, taking a least squares solution obtained as an initial solution, and using the Newton iteration to obtain the accurate estimation of the target position. The invention considers the angle observation error, the time difference observation error and the position error of the external radiation source, the positioning result is the optimal estimation result when the external radiation source has an error, and the nonlinear angle and time difference observation equation is linearized to obtain the least squares algebraic solution as the initial solution of the Newton iteration to ensure the convergence of the algorithm.

The invention discloses a method for frequency estimation of a non-equilibrium three-phase power system. The method comprises the steps that the frequency of the non-equilibrium three-phase power system is estimated mainly on the basis of a widely-linear total least square self-adaption algorithm model, wherein the widely-linear model sufficiently utilizes three-phase voltage complete two-order information, and the frequency estimation robustness is enhanced. Compared with traditional linear self-adaptation estimation, the method is more applicable to the non-equilibrium system, and unbiased frequency estimation is given. Meanwhile, the model is not sensitive to changes of the three-phase voltage amplitude along with time passage and higher harmonic. The method is more stable and low in computation complexity, and the convergence performance, robust anti-noise performance and stable convergence precision are obviously improved.

The invention belongs to the technical field of satellite precise navigation and positioning, and particularly relates to an integrity monitoring based baseline deformation detection method capable of improving the monitoring reliability of satellite navigation and positioning for baseline deformation. The integrity monitoring based baseline deformation detection method comprises the steps of 1, detecting baseline deformation according to integrity monitoring, analyzing multiple types of errors, and acquiring an optimal estimated value of a baseline solution by combining multi-reference consistency detection and a total least square theory through introducing a multi-reference receiver; 2, introducing an adaptive attenuation factor into a positioning domain according to the characteristic that reference receiver faults and baseline deformation are major integrity risk sources, and designing a Kalman filtering based multi-reference consistency detection algorithm and the like. According to the detection for baseline deformation according to integrity monitoring, the multi-reference receiver is introduced, the optimal estimated value of the baseline solution is acquired through combining integrity monitoring for the deformation with the multi-reference consistency detection and the total least square theory, and integrity monitoring based baseline deformation detection is realized.

The invention discloses a point cloud registration method from a point to an optimal plane in data acquisition of a ground laser scanner, which comprises the following steps: how to search the optimalplane corresponding to each point and establish a pair of points to the optimal plane; the constrained weighted total least square method is used to calculate the plane parameters; the constrained weighted total least square method is used to calculate the transformation parameters. The invention has better registration accuracy.

The invention provides a vehicle positioning parameter estimation method based on DOA/TOA joint estimation in a multipath environment. Positioning parameters are extracted via the communication between a vehicle and roadside facilities, the wireless communication between a target vehicle and an RSU follows the IEEE802.11p protocol, and an orthogonal frequency division multiplexing signal is transmitted in a wireless channel thereof; the joint parameter estimation of DOA and TOA is achieved via the analysis of the multipath channel frequency response of the signal, and the channel noise interference is reduced by using the unscented Kalman filtering to improve the overall performance of the method; and the high-speed moving vehicle and a roadside unit RSU establish communication using the OFDM signal and use the total least squares algorithm TLS-ESPRIT based on the rotation invariant technique to calculate the vehicle positioning parameters, and the position information of the target vehicle can be obtained based on the estimated DOA and TOA.

The invention discloses an inversion method based on a polarization interference synthetic aperture radar. The inversion method includes the steps of step 1, obtaining one set of image data of the polarization interference synthetic aperture radar (PoLInSAR) of a target to be tested, carrying out straight line fitting on correlation coefficient estimated values obtained from the PoLInSAR image data by utilizing total least squares, and determining the earth surface phase estimated value of the target to be tested, step 2, obtaining a volume scattering decorrelation coefficient through a correlated area bound obtained from the PoLInSAR image data and the fitted straight line, step 3, carrying out inversion on the target to be tested through establishing a lookup table, obtaining inversion parameters of the target to be tested and regarding the inversion parameters as the parameter estimates of the target to be tested. The invention further discloses an inversion device based on the polarization interference synthetic aperture radar. According to the technical scheme, inversion accuracy can be improved, and the technical scheme is especially suitable for being used in inversion of forest parameters.

The invention discloses a multichannel robustness damping control method based on a static state H-infinite loop shaping method; the multichannel robustness damping control method comprises the following steps: adding a robustness damping controller to simultaneously control subsynchronous oscillations and low frequency oscillations; using a solve linearity matrix inequality to directly solve the controller; using the total least square rotation constant technology to identify a system oscillation modal and a reduced-order model; using a Butterworth band pass filter to decompose different oscillation modals into a plurality of channels; using the static state H-infinite loop shaping method to design different robustness damping controllers for different channels, thus reducing mutual influences between the controllers. Compared with a conventional proportion-integration-differential (PID) controller, the multichannel robustness damping control method has better control effect, can simultaneously control the subsynchronous oscillation and low frequency oscillation, and has better robustness; in addition, the controller is low in order, and output feedback is employed, so engineering practice is easy; the multichannel robustness damping control method is small in computational complexity and low in algorithm complexity.

In the method positioning is carried on by applying prebalance to error matrix and combining with at least square method according to feature of balanced error matrix covariance matrix being approximately to unit array in order to raise accuracy of positioning; the processed error model includes both of array element position error and estimation error of distance difference which is not the same to each other so it is more is accordance with actual situation comparing to existed positioning method.

The invention provides a DMWC spectrum sensing phase difference calibration method based on DOA estimation, aiming at the problem that the recovery rate is low due to the fact that each sensing node of the DMWC spectrum sensing system randomly generates phase difference due to spatial distribution. The DMWC spectrum sensing phase difference calibration method comprises the following steps: (1) acquiring a sampling signal from a DMWC spectrum sensing system structure in which single nodes are arranged into a uniform linear array; (2) obtaining the direction of arrival of the signals through DOA estimation, finding the azimuth parameter with the maximum correlation coefficient as the direction of arrival by applying an array signal processing TLS-ESPRIT algorithm combined with a total least square method, and further obtaining the phase difference of the signals received by the nodes; and (3) calibrating the measurement matrix by using the direction of arrival and the phase difference. Through the DMWC spectrum sensing phase difference calibration method, the influence of the phase difference between the nodes on the signal recovery rate in the DMWC spectrum sensing system is solved, and the noise resistance and the stability of the DMWC spectrum sensing system are greatly improved.

The invention relates to a near-infrared brain function signal processing method, in particular to a near-infrared brain function signal processing method based on differential pathlength factor estimation. The invention is intended to solve the problem of the prior art that since a big difference exists between a differential pathlength factor reference value used in modified Lambert-Beer's law and a real differential pathlength factor of an actual measurement object and measurement error disturbances also occur in time series signals of light intensity variation acquired by a light source detector, measurement and extraction of continuous wave near-infrared brain functional activity response signals are low in precision. The method of the invention includes: acquiring a time signal of light intensity variation under the fact that near-infrared rays of different wavelengths have an equal distance away from the detector; using modified Lambert-Beer's law to construct equations for thesignal; modifying the equations in matrix form; subjecting an augmented matrix to singular value decomposition so as to obtain a total least squares solution to concentration variation time signals ofoxyhemoglobin and reduced hemoglobin at the detector. The method of the invention is applicable to the field of brain function signals.