88 results about "Linear methods" patented technology

The invention provides a calibration method for a binocular stereo measurement system, and belongs to the technical field of measurement and test. The invention adopts a plane calibrating board having a characteristic dot array with an accurate given distance between the centers of two characteristic dots; the calibrating board is shot from more than three angles; initial values of the intrinsic and extrinsic parameters of two cameras are solved by using the linear method under a pinhole model; the distortion effect is considered; the intrinsic and extrinsic parameters of the two cameras are taken as optimization variables for a first optimization; the space coordinates of the centers of the characteristic dots on the calibrating board are taken as optimization variables for a second optimization; the translation vector between the cameras is scaled to the ratio of the calculated distance to the given accurate distance, thus getting a calibration result of the parameters; the result of the second optimization is got by using the intrinsic parameters and the relative attitude parameters of the two cameras. Considering the influence of the geometrical errors of the calibrating board, the method reduces the manufacturing, measurement and calibration requirement of the calibrating board and gets calibration result of high precision.

The invention discloses an image sequence category labeling method based on a mixed graph model. The method comprises a step of performing superpixel segmentation of an image sequence and characteristic description of superpixels; a step of performing nearest neighbor matching of inter-frame superpixels of a two-continuous-frame image; a step of using the mixed graph model to carry out global optimization modeling of the image sequence category labeling based on the spatial domain adjacency relation among superpixels of a single frame image and the time domain matching relation among superpiexels of a multi-frame image; and a step of using a linear method to solve a global optimization problem to obtain category labels of superpixles of a continuous multi-frame image. Compared with previous graph models, the mixed graph model created by the invention can describe the first-order and symmetric relation among superpixels in a single frame image and also the high-order and non-symmetric relation among superpixels in a two-continuous-frame image; the linear method is used for solution; and a category label which is better in consistency of time domain and higher in accuracy is effectively provided for each superpixel of an image sequence.

The invention provides a multi-AUV formation optimization control method under an obstacle environment, and belongs to the technical field of ship control. A path tracking error model is established based on a sight distance navigation method, a path tracking controller is designed by adopting a feedback linear method, a multi-AUV communication topological relation and a coordination error model are established by utilizing a graph theory, and a speed coordination controller is designed, so that the formation control is achieved, and a formation optimization obstacle avoidance strategy considering the environment constraints is designed according to the obstacle environment, the optimal formation topological structure is obtained through solving the environment fitness function, so that the formation can pass through the region in the obstacle environment in an optimal formation mode.

The invention discloses a robot calibration method based on exponent product model, comprising the following steps: providing an industrial robot, a measuring instrument independent of the robot, an end three-dimensional imaging device and a three-dimensional calibration block; building a robot kinematics model according to the mode of combination of spinor theory and exponent product; giving closed-form solution of all joint parameters; directly solving the joint spinor parameters by utilizing a linear method; compensating the nominal value of joint angle of the robot, thus avoiding the conversion of a coordinate system and a measuring coordinate system of the robot. In addition, the calibration process is simple, and calibration can be realized through the method that all joints rotate once and the coordinate values of n numbered mark points (n is more than or equal to 3) are measured simultaneously. The robot calibration method in the invention is realized simply, has good stability, and low introduced external error.

The invention discloses a higher-order non-singularity Terminal sliding-mode control method of a high supersonic speed aircraft. A nonlinear model of the high supersonic speed aircraft is processed ina feedback linear method, and modeling errors and outside disturbance of a system are compensated via an RBF neural network control strategy. On the basis of the linearized vertical model, a novel neural network sliding-mode controller is in a nominal cruse flight condition based on a sliding mode surface of a regression structure, and an instruction signal and elevator deflection signal set by an engine throttle valve of the high supersonic speed aircraft are controlled to control the speed and height of the aircraft. The controller is highly robust for uncertainty of aerodynamic nonlinearity, pneumatic interference and system parameters. According to a simulation result, the instruction signal can be tracked effectively, and the response speed is higher.

The invention provides a curvature fairing method for a high-speed numerical control processing track. The curvature fairing method comprises the steps of: inputting tool location points of an initial processing track; interpolating the initial tool location points by utilizing B-spline curve repeatedly to obtain a tool processing track line, and representing the tool processing track line by using the B-spline curve; calculating a stiffness matrix of a track curve according to node vectors of the B-spline curve; calculating a closest point from each initial tool location point to the B-spline curve and curve parameters corresponding to the closet points, and calculating a first-order derivative of a distance (from the initial tool location points to the closest points of the B-spline curve) to control points of the B-spline curve; solving a tool processing track curvature derivative fairing model by adopting a sequence linear method to obtain a processing track after fairing optimization; and outputting tool locating points of the tool processing track after fairing optimization. The curvature fairing method solves the problem of generating the high-speed numerical control processing tool track with fair curvature, and is suitable for generating a 2.5-axis cavity high-speed processing track.

The invention discloses a linear optimal power flow (LOPF) model containing a unified power flow controller (UPFC). DC optimal power flow (DCOPF) is the most popular OPF linear method so far, and is fast in solution speed but relatively low in calculation accuracy, and two electrical quantities of a node voltage amplitude value and a circuit reactive power cannot be solved; the UPFC can be used for improving the power supply capability of a regional power grid, the UPFC is introduced into a DCOPF model, thus, the problem complexity is improved, and the linear DCOPF is also converted to a non-linear model; on the basis, the invention proposes a novel LOPF model which is higher in accuracy and is more perfect; by the model, the voltage and the reactive power can be solved, a current source type steady-state model of the UPFC is processed and is equivalently embedded into a circuit, and thus, the novel LOPF model is applicable to the LOPF model proposed by the invention; and an example simulation result shows that the high efficiency of the linear model is maintained, the calculation result has relatively high accuracy, and moreover, power flow information which is more perfect than the DCOPF model can be figured out.

The invention discloses a method and system for identifying an oil spilling target of a ship. The method comprises the following steps of: establishing a conventional oil type actual measurement spectrum database of the ship by use of actual measurement spectrum data of a conventional oil type through an ASD (Analytical Spectral Device) ground spectrometer; synchronously acquiring actual measurement spectrum data and imaging spectrum image data of different oil types by utilizing the ASD ground spectrometer and a vehicle-mounted high-spectrum sensor, acquiring rebuilt spectrum data by utilizing an experimental linear method, and carrying out precision evaluation on the rebuilt spectrum data by utilizing a similar coefficient method and optimizing a rebuilt scheme; and optimizing spectrum characteristics of an oil film according the actual measurement spectrum data and the rebuilt spectrum data, and selecting a spectrum section to carry out spectrum angle map identification. According to the invention, a problem that continuous spectrum data on the same ground can not match because absorption characteristics of multi-waveband images and satellite-mounted high-spectrum images are attenuated due to space scale change is solved, the oil spilling identification precision is improved to more than 85%, and fast identification of the oil spilling target based on a high-spectrum image is realized.

The invention belongs to the technical field of numerical control machining, and particularly relates to a spline curve compensation method for measuring profile deviation based on a path unit. The method comprises the following steps: selecting profile measurement points, measuring the profile measurement points one by one, and calculating the deviations between the measurement data of the measurement points and the standard profile data; mapping the calculated deviation data of the measurement points to a coordinate system, and connecting the deviation data points together with a spline curve; acquiring the deviation value of each of machining points from the spline curve; and compensating the deviation values to corresponding path points. According to the invention, the path unit is used as the object and the mode of spline error compensation is used to effectively avoid unsmooth inflection points of the path caused by a linear method, so that a compensation path can be more smooth, the high-precision and high-speed machining requirements can be met, a better surface effect can be acquired, and the path compensation can be carried out on a work piece with relatively large deformation; and the method is simple and easy to use, the programming efficiency is high, and the production cost can be effectively lowered.

The invention relates to a method for modifying the contour after changing the contour interpolation point in the contour picture, by obtaining the coordinates of n points in the plane point in the contour picture, and treating the interpolation point p(x, y) Perform hyperboloid interpolation. The method of the invention can effectively improve the interpolation error caused by the obvious trend of the data and the inconsistency of the spatial distribution of the data because the weight is quoted in the polynomial interpolation algorithm. The invention also relates to the establishment of a non-degenerate straight line method, and on this basis, a new algorithm for the relationship between points and polygons (points within polygons) is developed, and the algorithm is used in isoline boundary clipping to reduce computing time.

The invention relates to a three-dimensional reestablishing method for intelligent video monitoring, which comprises the following steps: calibrating a camera and calibrating the camera deeply by adopting a direct linear method to obtain a transformation matrix M; calculating the position coordinates of a shooting point according to the perspective matrix M; and generating a three-dimensional outline altitude chart according to an isometric triangle theory in solid geometry and constructing a three-dimensional point set in a world coordinate system. According to the three-dimensional reestablishing method for intelligent video monitoring, the performance of an intelligent monitoring system is enhanced, and three-dimensional altitude information in a monitoring range can be accurately obtained; and moreover, the calculating speed is high.

The invention discloses device and method for sampling frequency offset estimation and compensation, particularly device and method for executing the calculation of phase difference by mathematical linear method to reduce the application of the multiplier and the storage circuit thereof in the sampling frequency offset estimation and compensation. In a preferable embodiment, the method comprises the following steps: receiving signals by employing a sampling frequency offset estimation circuit, then calculating the phase value of each signal, capturing pilots in the signals, calculating the phase difference by subtracting the received singles from the pilots after several symbol delays, further storing the phase difference by employing a phase difference storing circuit, calculating the phase difference between two neighbor symbols by employing the accumulation and the least error sum of squares circuit, calculating the estimated value of sampling frequency offset of the communication system according to the phase difference, and applying the estimated value to compensate the sampling frequency offset.

The invention discloses a multi-mode depth network embedding method for fusing structure and attribute information, and relates to the technical field of complex network analysis. The method comprisesthe steps of establishing a network adjacency matrix and an attribute matrix, performing preprocessing, serially inputting structural features and attribute features into an encoder and a decoder, outputting a reconstructed adjacency matrix and an attribute matrix, updating a parameter iterative calculation and the like, and finally taking the output of the encoder as a final node representation.Based on the depth learning method, the invention can overcome the shortcoming that the existing shallow linear method is difficult to depict the highly nonlinear structure of the network, can map nodes in the network to a low-dimensional embedded space, and effectively maintains the structural characteristics and attribute characteristics of the nodes.

The invention discloses a real-time individual working dust concentration exposure space rule monitoring and early warning system and method. The system comprises a dust concentration sensor network, a cloud server and protective clothing positioning wearable equipment. The method comprises the steps of: a dust concentration sensor at each position is calibrated by adopting a multivariate linear method; then the cloud server combines dust concentration values detected by the dust concentration sensors with respective position information, obtains a dust concentration spatial distribution rule of a workplace after comprehensive analysis, and delimits an area exceeding the threshold value in the space of the workplace as an overrun area according to a set dust concentration threshold value; and finally, the protective clothing positioning wearable equipment sends a position of a worker in the place to the cloud server in real time, the cloud server compares each piece of real-time position information with the real-time over-limit area, and if the worker is in the real-time over-limit area, the cloud server sends an alarm signal to the protective clothing positioning wearable equipment, so that an audible and visual alarm gives an alarm to remind the worker that the dust concentration exceeds the limit.

The invention discloses a loop-analysis method based linear method for calculating a three-phase power distribution network tide. The loop-analysis method based linear method comprises the following steps: obtaining the relation function of node voltages and node injection currents of a power distribution network according to a loop-analysis method; for a single-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load, a constant power load and a mixed mode respectively, and introducing in the relation function for calculation to obtain node voltage values; and for a three-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load and a constant power load, and introducing in the relation function for calculation to obtain node voltage values, wherein the three-phase system comprises a star connection load and a delta connection load. The method disclosed by the invention is high in calculation efficiency, few in occupied resources and high in calculation accuracy.

The invention relates to a DNS agent cache optimization method and system based on multi-dimension aggregation. The method comprise following steps of 1), filtering requests for illegal domain names; 2), directly responding user requests if the domain names are legal and the domain names are hit in a DNS agent cache; finishing domain name inquiry behaviors; otherwise, going to a step 3); 3), forwarding the domain name requests to a cache domain name server by the DNS agent cache; receiving and storing response results of the cache domain name server; 4), successively interposing the legal domain names in a multi-layer hash table; updating the inquiry frequency and inquiry time for each cache item; carrying out aggregation storage to multi-response IPs of the final stage domain names according to a format of { network segment names: host number lists }; 5), processing a conflict by using a linear method if there is a hash conflict; 6), calculating a replacement probability for each table item if the hash table is full; and replacing the table items according to the minimum replacement probability.

The invention discloses a shadow area phase noise correction method based on an improved monotonic method, and belongs to the technical field of machine vision. The standard four-step phase shift andmulti-frequency heterodyne are used to solve the absolute phase information of the workpiece surface to ensure that the phase value is unique in the entire measurement space. By using monotonic non-decreasing phase noise correction, the phase frequency matrix is used to calculate the frequency of non-zero phase occurrence in the fixed length interval to the discrete phase noise correction, and twoconsecutive phase noise determination criteria are defined. By comparing the actual and predicted phases between adjacent discontinuity points for correction, the shadow area phase noise can be effectively corrected. By calculating the slope between the discontinuous points and the fitting slope of the non-zero phases on both sides and determining whether the interpolation condition is satisfied,and using the linear method to fill in the partial phase that is zero due to random noise, the integrity of the workpiece information is ensured, and the reconstruction precision is improved. The method can improve the reconstruction precision while ensuring the three-dimensional contour point cloud data of the workpiece at the same time.

The invention belongs to the field of design of an integrated circuit and relates to a nonlinear circuit time domain model reduction method and a nonlinear circuit time domain model reduction device. The method comprises the following steps of: forming a track in a state space through a 'training signal', and selecting an expansion point on the track to approach a nonlinear circuit through a segmented linear method; and obtaining a final reduction model through a time domain model reduction method based on wavelet collocation. The device comprises an input unit, an output unit, a program storage unit, an external bus, a memory, a storage management unit, an input/output bridging unit, a system bus and a processor. A nonlinear system is directly subjected to model reduction in a time domain, the time domain reduction accuracy of the nonlinear system can be guaranteed, and a time domain error can be controlled; therefore, an accurate and compact reduction model can be acquired, and the simulation accuracy and efficiency are improved.

The invention discloses a seafloor seismograph position and orientation inversion method based on water wave first arrival polarization orientation. A nonlinear inversion method is adopted. For a submarine seismograph to be corrected, the difference of the water wave first arrival polarization azimuth residuals is constructed. The position of the seismograph which minimizes an objective function is acquired. After the exact position of the seismograph is acquired, the actual orientation of the seismograph is acquired by using the difference between the shot point orientation and the polarization orientation. In particular, the sum of the squares of the difference of pairs of water wave first arrival polarization azimuth residuals is taken as the objective function. A DE optimization methodis used to acquire the position of the seismometer which minimizes the objective function. The influence of the seismograph orientation is eliminated in the objective function. The method has the advantages of faster convergence speed and better stability, and has better accuracy than a linear method.

The invention discloses a hydropower station plant inside economic scheduling method considering an anomaly restriction operation zone, comprising steps of scattering the water head variable zone in the scheduling period into a plurality of continuous subintervals, introducing water head subinterval indication variables for replacement to realize the water head dynamic changing, on the basis of that, determining a representative water head in each water head subinterval to determine the characteristic of machine set dynamics, and realizing the fact that the dynamic characteristics of the machine set are changed along with the water head, for each water head subinterval, performing pre-processing on a machine set limitation operation zone, generating a rectangle machine set operation zone, introducing an indication variable of the operation zone for identification, and realizing the fact that the machine set limitation operation zone changes along the dynamic of the water head. A segmentation linear method is adopted to describe the water level-reservoir capacity relation and the tail water level-discharge non-linear relation. The invention utilizes the whole plant optimum dynamic characteristics and adopts the principle of determining water by electricity to perform initial estimation on the power generation water head dynamic characteristics of the dynamic machine set and the limitation operation zone, and solves the problem through a branch and bound algorithm.

Systems and devices for processing image or other data using non-linear methods to compensate for localized slopes are described. In one implementation, the slope of the sample values in an image or other dataset is estimated in one or more directions using a non-linear filter, such as a median filter. The values of at least some of the samples of interest are compensated using the estimated slope values to remove the effects of the slope. The compensated values may then be processed to determine if the target is present in the samples of interest, or for any other purpose.