25 results about "Linear least squares method" patented technology

Optical transmission property estimation device comprising:a transmission waveform restoration unit configured to restore a transmission signal from a reception signal obtained by receiving an optical signal by a coherent detection system; andan estimation unit configured to estimate an optical power distribution in a transmission line by estimating a nonlinear coefficient in a propagation equation of a light wave by a linear least square method based on the restored transmission signal and the reception signal.

The invention discloses a 4D radar point cloud segmentation method based on RRI embedded features and related equipment, and particularly relates to the field of 4D radars, and the method comprises the steps: firstly obtaining a plurality of frames of point clouds, carrying out the linear least square solution through a dynamic radial speed and a unit sight line vector, so as to estimate the speed of a vehicle, and compensating the dynamic radial speed; and unifying multiple frames of point clouds to the same coordinate system in combination with the inter-frame pose relationship. Adopting farthest point sampling, and obtaining a candidate point set based on four-dimensional distance measurement of coordinates and compensated radial components; constructing strict rotation invariant (RRI) feature embedding on the K-NN graph, and abstractly extracting layered local features through a layered set; and inputting the RRI feature into a three-level vector attention encoder, fusing the layered local feature and the layered global context of the encoder, obtaining a segmentation feature through self-attention aggregation, and finally outputting a point-level semantic tag by a segmentation network. The method has higher robustness and efficiency under attitude change and vehicle speed change.

This invention discloses a binocular vision hand-eye calibration method based on two-layer nonlinear optimization. The method first establishes the hand-eye matrix equation and solves for the initial values ​​of the hand-eye matrix using the linear least squares method. Secondly, it addresses the rotation component R in the hand-eye matrix. h2e Euler angle transformation is performed to ensure the orthogonality of the rotation matrix R. Then, an optimized model H1 of the hand-eye matrix is ​​constructed, and the initial values ​​of the hand-eye matrix are optimized for the first time using the traditional LM nonlinear optimization method to obtain the hand-eye matrix after the first optimization. Finally, the optimized model H1 of the hand-eye matrix is ​​corrected to obtain the second optimized model H2. Then, the LM nonlinear optimization method with sample selection is added to optimize the hand-eye matrix after the first optimization for the second optimization to obtain the second optimized hand-eye matrix. In view of the problem of insufficient accuracy of traditional hand-eye calibration methods, this method can reduce the influence of random errors in robot monocular vision systems and improve the calibration accuracy of robot hand-eye matrix.

The method comprises the following steps of: decomposing a measurement matrix of each strapdown triaxial magnetometer into a unit orthogonal matrix and a symmetric positive definite matrix by utilizing the characteristic that a magnetic field modulus is independent of the unit orthogonal matrix and adopting a polar decomposition technology, and obtaining an equivalent zero offset and the symmetric positive definite matrix of each strapdown triaxial magnetometer by adopting ellipsoid equation iteration linear least square fitting; a virtual coordinate system is introduced, a vector modulus value correction value of measurement data of each strapdown triaxial magnetometer is calculated, a correction value of a magnetic field horizontal modulus gradient is further obtained, and calibration of the strapdown triaxial cross magnetic array is completed. According to the method, the ellipsoid equation is solved with high precision by adopting the iterative linear least square method, the strapdown three-axis cross magnetic array does not need to be accurately rotated, high-precision calibration can be carried out under the condition of providing the geomagnetic field modulus, and the operation is simple and convenient; the iterative linear least square algorithm is simple, the calculation amount is small, and engineering implementation is easy.

A method for calibrating relative poses of heterogeneous sensors comprises the following steps: uniformly distributing a plurality of target points, and acquiring coordinates of the target points in a world coordinate system; establishing a camera coordinate system, and counting the coordinates of the target point in the camera coordinate system; shooting a target image containing all target points, identifying image coordinates of each target point, and reading two azimuth angles of the target points; establishing a microwave distance measurement coordinate system, and reading distance measurement information of each target point; calculating the coordinate of each target point in the microwave ranging coordinate system; establishing a microwave camera extrinsic parameter conversion relational expression and a camera world extrinsic parameter conversion relational expression; based on the microwave camera external parameter conversion relational expression and the camera world external parameter conversion relational expression, constructing an error equation, and solving an optimal solution by using a linear least square method; and completing the relative pose calibration of the two sensors by using the solved optimal solution.

The invention relates to the technical field of load measurement of engineering mechanical equipment, and discloses an excavator weighing method based on system identification, and the method comprises the steps: firstly setting working condition limitation: only a movable arm is lifted and a platform rotates, the action is stable, and the inclination of a vehicle body is less than or equal to 15 degrees; the mass and the mass center of accessories such as a hydraulic cylinder are superposed to a movable arm, a bucket rod and a bucket to obtain equivalent parameters, and a moment balance equation is established; the method comprises the following steps: collecting far-farther-middle-closer-near multi-attitude data, determining the upper and lower limits according to the physical meaning of parameters, solving by using a bounded constraint linear least square method, and substituting into a formula to calculate the mass of the material. The method is less in time consumption, and effectively improves the weighing precision and efficiency.

The invention relates to the technical field of pumped storage, in particular to a wear model correction method and system based on a high-speed rotating disc test. The method comprises the steps of obtaining multi-working-condition abrasion data through a high-speed rotating disc test, building an initial correction prediction model based on international standards, determining a correction flow coefficient and a correction speed index suitable for the disc test through global fitting of a nonlinear least square method, obtaining a correction material factor through material fitting of the linear least square method, and obtaining the multi-working-condition abrasion data of the disc test. And establishing a disc wear prediction model. And applying the disc wear prediction model to the pump turbine real machine working condition, respectively determining a first real machine flow coefficient suitable for the pump working condition and a second real machine flow coefficient suitable for the turbine working condition through inversion calculation, and finally forming a wear prediction correction model. According to the method, prediction formulas under different materials and working conditions are unified, and a reliable theoretical basis is provided for sediment wear evaluation of the pump turbine.

The application relates to a coal quality point cloud boundary point data processing method for a coal preparation plant and related components, and applies to the technical field of data processing of the coal preparation plant. The method comprises the following steps: obtaining an original point set; calculating the normal direction of each original point in the original point set; determining a first boundary point and a second boundary point based on the normal direction, the distance between each original point and a preset point spacing; fitting the xy plane coordinates of the first boundary point by using a linear least square method and a standard equation of a circle, and calculating the center coordinates of the circle; scaling the first boundary point based on the center coordinates of the circle to determine a projection point; determining an interpolation point based on the projection point, the first boundary point and the preset point spacing; correcting the z value of the projection point and the interpolation point based on the first boundary point and the second boundary point; and determining a target point set based on the original point set, the corrected projection point and the corrected interpolation point. The application has the effect of improving the comprehensiveness and accuracy of coal quality point cloud data.

The application relates to a positioning method for an ocean sensor network with uncertain parameters, and the method comprises the following steps: S1, constructing a ranging model based on received signal strength according to signal propagation loss; S2, selecting a reference node, performing a difference operation on the ranging model of the reference node, introducing a natural constant, constructing a differential ranging model, and solving an initial position of a target by using a linear unbiased estimation method; S3, establishing a target optimization function with a path loss factor as a variable to be solved based on the initial position of the target, constructing a constraint, and solving an optimal path loss factor by using an improved whale optimization algorithm; and S4, reconstructing the differential ranging model based on the optimal path loss factor, solving the reconstructed differential ranging model by using a linear least square method, and obtaining an optimized target position. Compared with the prior art, the application has the advantages of high positioning accuracy.

The application discloses a patch feeding device control method and system based on automatic material replacement, relates to the technical field of feeding device control, and comprises the following steps: acquiring feeding real-time operation parameters and material roll residual state parameters, and acquiring corresponding real-time operation parameter sets and material roll residual state data sets according to the feeding real-time operation parameters and the material roll residual state parameters. Through the feeding real-time operation parameters and the material roll residual state parameters, the application realizes integrated integration of feeding end and production line end data, fits a material roll outer diameter consumption model through a linear least square method and deduces a material roll residual feeding model, realizes accurate timing prediction of the material roll residual feeding times, analyzes replacement basic time consumption data, combines historical replacement data to calculate replacement deviation coefficients and early warning coefficients, realizes dynamic calculation of a replacement early warning threshold, makes the early warning standard fit actual replacement time consumption and feeding demand of the production line, and effectively improves the production line productivity and production efficiency.

The invention discloses a multi-base-station AOA cooperative positioning method based on dynamic PDOP weighting, belongs to the technical field of indoor positioning, and aims to solve the problems of positioning error amplification and trajectory hopping caused by poor geometric distribution of base stations. According to the method, AOA angle information of a plurality of base stations is obtained, and a linear least square method is used for resolving label rough coordinates; calculating the PDOP contribution degree of each base station to the current position based on the coordinates, and constructing a dynamic weighting matrix according to the PDOP contribution degree so as to reduce the weight of the base station with poor geometric configuration; and finally, carrying out iterative solution by utilizing a weighted nonlinear least square method based on the weighted matrix until convergence, and outputting a high-precision positioning coordinate. According to the method, the geometric error amplification effect can be effectively inhibited, and the robustness and precision of AOA positioning in a complex environment are remarkably improved.

The application belongs to the technical field of electronic compass calibration, and discloses a simple and independent calibration method and system for an electronic compass, which comprises the following steps: loading factory modification parameters, and solving the spatial posture of the device in real time; guiding the user to place the device horizontally, and completing a complete circular motion around the Z axis and the X axis or the Y axis respectively, and synchronously collecting six-axis sensor data; extracting and compensating the offset vector by using an extreme value estimation algorithm, and solving the parameters of each axis based on a linear least square method; and calculating the calibration quality score and storing the optimized parameter matrix. The application realizes the independent and rapid calibration of the electronic compass by means of two-axis spatial motion guidance and real-time state feedback without the need of external special calibration equipment, solves the problems of the existing method, such as the dependence on special equipment, the complexity of operation, and the difficulty in adapting to dynamic interference, and significantly reduces the dependence on the calibration environment, and improves the availability and operation efficiency of the on-site calibration.

The application discloses an aviation part round hole and end face cooperative detection method, device, equipment and medium, and relates to the aviation part detection field.The method comprises the following steps: performing outlier elimination on the surface three-dimensional point cloud data of the target aviation part by using the 3σ criterion, and obtaining a round hole effective point set and an end face effective point set; based on a double-thread parallel computing architecture, a first thread is used to perform iterative optimization on the round hole effective point set based on the linear least square method and the 3σ criterion, a round hole fitting result is obtained, a second thread is used to extract an end face plane normal vector based on the end face effective point set and the minimum eigenvalue method of the covariance matrix, and an end face fitting result is obtained; based on the fitting result, a normal error component in a three-dimensional round center vector is eliminated by using a vector projection method, so that the projection round center distance and the eccentricity of the nested round hole in the end face plane are calculated, and the concentricity of the nested round hole is evaluated.The application can realize the aviation part round hole and end face cooperative detection in a non-damage, accurate and efficient manner.

The embodiment of the invention provides a binocular microscope high-precision calibration method and system for an orthogonal projection model, and belongs to the technical field of medical image processing, and the method comprises the steps: collecting different inclination angle images of a calibration plate, estimating a radial distortion coefficient and a tangential distortion coefficient through a Zhang calibration method, and correcting the images; fitting the high-precision checkerboard characteristic points through a linear least square method based on the corrected image to obtain a monocular internal reference; solving binocular external parameters by combining constraints such as an optical axis included angle of 60 degrees and a baseline along an X axis, jointly optimizing internal and external parameters by using an L-M algorithm, finally verifying by using a step ruler, and if an error is greater than or equal to 1 [mu] m, performing iterative adjustment until an error lt; 1 [mu] m. According to the invention, the imaging model is simplified, sub-pixel-level calibration is realized, and the three-dimensional positioning precision of the binocular microscope in scenes such as precision positioning is improved.

The invention discloses a surface crack deformation quantitative identification method based on strain tensor inversion. The method comprises the following specific steps: arranging a plurality of triangular observation units in a crack influence area and arranging observation equipment; constructing a strain observation model based on side length change and a shear strain observation model based on included angle change; periodically collecting the lengths of the three sides of each triangular observation unit and the included angles of the three interior angles of each triangular observation unit; obtaining a strain tensor component according to the collected data in combination with the constructed model; obtaining a final strain tensor component from the strain tensor component through a linear least square method; calculating a surface swelling amount, a maximum shear strain value, a first main strain, a second main strain and a strain main direction according to the final strain tensor component; and dividing risk levels. The method is high in mining area earth surface crack deformation recognition capability.

The application discloses a controllable phase shifter optimization control method and system based on sensitivity factors, and belongs to the technical field of power grid operation optimization. The method comprises the following steps: firstly, based on a direct current power flow algorithm of a power grid, sensitivity factors of controllable phase shifters on the influence of transmission power of key lines are derived; secondly, based on the sensitivity factors of the controllable phase shifters, a controllable phase shifter control optimization model with the balanced key line load rate as the target is constructed, and a linear least square method is adopted to calculate, so that a final controllable phase shifter control scheme is obtained. Compared with a traditional method, the method has lower calculation complexity under the condition of ensuring the control effect, and is helpful to realize power grid operation optimization based on the controllable phase shifter.

According to the method, a polar decomposition technology is adopted, a measurement matrix of each strapdown triaxial magnetometer is decomposed into a unit orthogonal matrix and a symmetric positive definite matrix, and an ellipsoid equation is adopted for iterative linear least square fitting to obtain equivalent zero offset and the symmetric positive definite matrix of each strapdown triaxial magnetometer; and introducing a virtual coordinate system, calculating a measured data correction value of each strapdown three-axis magnetometer by using orthogonal Prusk decomposition, and further calculating a correction value of a magnetic gradient tensor measured by the strapdown three-axis cross-shaped magnetic array, thereby completing calibration of the strapdown three-axis cross-shaped magnetic array. According to the method, the iterative linear least squares method is adopted, the ellipsoid equation can be solved with high precision, the calibration precision is remarkably improved, the direction of the rotating shaft does not need to be kept stable in the rotating process, and the iterative linear least squares algorithm and the orthogonal Prushing analysis algorithm are small in calculated amount and easy to achieve in engineering. Under the condition that the geomagnetic field model and the magnetic array attitude are provided, calibration can be completed quickly, simply and conveniently, and the method is suitable for practical engineering application.

The application discloses a shield screw machine blade state detection method, device and system. The application relates to the technical field of shield screw machine blade state detection and aims to solve the problem that the existing shield screw machine blade state detection scheme is difficult to realize high-precision and non-stop real-time monitoring in an engineering site due to harsh sensor installation conditions. Two eddy current sensors are asymmetrically installed on a cylinder body to collect dynamic distance signals of blade rotation; signals at each time point are subjected to Gaussian fitting denoising; a linear equation with a blade wear amount and a central shaft offset amount as unknown quantities is constructed; an over-determined equation group is established based on equation groups at multiple sampling moments; the equation group is solved by using a linear least square method to obtain the wear amount and the offset amount. The application only needs two asymmetrically installed eddy current sensors, reduces installation difficulty and opening risk, realizes non-stop real-time and non-contact detection, and the system has data redundancy and strong robustness.

The invention discloses a large-bearing automatic aligning and leveling device and method for large disc parts of large rotary equipment, and belongs to the technical field of aero-engines. The method comprises the following steps: firstly, acquiring an initial value of an inclination angle of a guide rail by utilizing ellipsoid fitting, a linear least square method and Cholesky decomposition; and the inclination angle between the guide rails, the installation error angle of the sensor and the position of the rotation axis are accurately estimated through joint nonlinear optimization, effective compensation of the measurement error is finally achieved, and then calibration of the aero-engine blade measuring instrument is achieved. According to the'ball-to-three-parameter constraint model 'constructed by the invention, triple geometric constraints are constructed by utilizing the radiuses of the two balls and the distance between the centers of the balls, so that the combined calibration of the attitude parameters of the system is realized, and the measurement precision of the measurement system is effectively improved.

An undercarriage oil gas buffer device vertical force calculation and constant coefficient identification method adopts a method of introducing an acceleration term and a fractional power term of acceleration, combines a pseudo-linear least square method to carry out parameter estimation, and utilizes two-parameter selection and coefficient fitting to identify the vertical force of an undercarriage oil gas buffer device through an arranged buffer displacement sensor. All physical quantity calculation models and expressions are established, and the model fitting precision is remarkably improved through optimization of a multivariate nonlinear mathematical model structure of the undercarriage buffer.

The invention relates to the technical field of pumped storage, in particular to a sediment wear depth estimation method and system for a pump turbine. The method comprises the steps of obtaining multi-working-condition abrasion data through a high-speed rotating disc test, building an initial correction prediction model based on international standards, determining a correction flow coefficient and a correction speed index suitable for the disc test through global fitting of a nonlinear least square method, obtaining a correction material factor through material fitting of the linear least square method, and obtaining the multi-working-condition abrasion data of the disc test. And establishing a disc wear prediction model. And applying the disc wear prediction model to the pump turbine real machine working condition, respectively determining a first real machine flow coefficient suitable for the pump working condition and a second real machine flow coefficient suitable for the turbine working condition through inversion calculation, and finally forming a wear prediction correction model. According to the method, prediction formulas under different materials and working conditions are unified, and a reliable theoretical basis is provided for sediment wear evaluation of the pump turbine.

A method and an apparatus (15) for computer-implemented determination of physical properties of a porous layer (1) present on a surface of a substrate. The physical properties include at least a layer thickness (d) of the layer, a porosity (p) of the layer and a roughness (r) of the layer at an interface (9) with the substrate supporting the layer. The method includes recording a reflectance curve (39) concerning light (25) irradiated onto the porous layer within a wavelength range in which the porous layer is largely transparent, setting a predetermined roughness start value, setting a porosity start value based on knowledge concerning a manufacturing process for forming the porous layer, setting a layer thickness start value based on an evaluation of periodic fluctuations of reflectance intensities within the recorded reflectance curve, and determining the physical properties of the porous layer by computer-implemented fitting of the recorded reflectance curve using a non-linear least squares method.

The present invention provides a method for correcting an X-band tropospheric scatter prediction model based on measured data. The method comprises: obtaining measured tropospheric scatter path loss data and dividing it into a training set and a test set; calculating the median loss using the model to be corrected; constructing a characteristic matrix of a weighted linear regression model based on the number of communication links and the median radio wave propagation loss; constructing a target variable vector based on the training set; constructing a weight matrix; establishing a weighted linear least squares model; calculating regression parameters; and correcting the model to be corrected based on the regression parameters. This embodiment applies the weighted linear least squares method and fully incorporates a large amount of measured path loss data at different over-the-horizon communication distances at sea in the X-band to further correct the tropospheric scatter empirical model to be corrected. The corrected tropospheric scatter radio wave propagation prediction model can more accurately predict tropospheric scatter radio wave propagation path loss.

The application discloses a multi-line laser radar SLAM point cloud densification method based on indoor environment characteristics, and the method comprises the following steps: using first frame of rectified point cloud data as a reference point cloud to construct an initialization map; performing feature extraction, data matching and feature fusion on each frame of rectified point cloud data, and then constructing a residual equation; according to the residual equation, the non-linear least square method is used to iteratively optimize the residual of lines and planes, and finally the optimized pose is output; according to the optimized pose, the point cloud data of each frame on the current each scanning line is classified into plane points and corner points, the relationship between the plane points of the current frame and the surrounding neighborhood points is obtained, the straight line fitting of the plane points on the current frame is judged, and the point cloud densification processing is performed; the above method solves the problem that the multi-line laser radar data rapidly decreases in density far away from the radar, and through the intelligent densification algorithm, the uniform distribution of the point cloud at different depths is ensured, so that the quality of the entire indoor environment model is improved.

The invention discloses a shield screw conveyor blade state detection method, device and system. The invention relates to the technical field of shield screw conveyor blade state detection, and aims to solve the problem that the existing shield screw conveyor blade state detection scheme is difficult to realize high-precision and non-stop real-time monitoring on an engineering site due to harsh sensor mounting conditions. According to the invention, two eddy current sensors are asymmetrically installed on a cylinder body, and dynamic distance signals of blade rotation are collected; gaussian fitting denoising is carried out on the signal at each time point; a linear equation with the blade abrasion loss and the center shaft offset as unknown quantities is constructed; building an overdetermined equation set based on the equations at the plurality of sampling moments; and solving the equation set by adopting a linear least square method to obtain the abrasion loss and the offset. According to the invention, only two asymmetrically installed eddy current sensors are needed, the installation difficulty and the trepanning risk are reduced, non-stop real-time non-contact detection is realized, and the system has data redundancy and strong robustness.