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387 results about "Principle of orthogonal design" patented technology

The principle of orthogonal design (abbreviated POOD) was developed by database researchers David McGoveran and Christopher J. Date in the early 1990s, and first published "A New Database Design Principle" in the July 1994 issue of Database Programming and Design and reprinted several times. It is the second of the two principles of database design, which seek to prevent databases from being too complicated or redundant, the first principle being the principle of full normalization (POFN).

Obstacle identification method for smart vehicles

InactiveCN104931977AImprove processing efficiencyAvoid under-segmentation problemsElectromagnetic wave reradiationPoint cloudRadar
The invention relates to an obstacle identification method for smart vehicles. The obstacle identification method includes the following steps that: 1) data points of original scanning point cloud three-dimensional laser radar of surrounding environment of the vehicles under a spherical coordinate system are obtained, and obstacle points are screened out from all the data points; 2) the obstacle points are grouped according to the horizontal azimuth angles of the obstacle points and the radial distances of the obstacle points relative to a three-dimensional laser radar sensor; and 3) each group of obstacle points correspond to one obstacle, and the categories of the obstacles can be obtained according to the relative position relationships of the obstacle points in each group. Compared with the prior art, and according to the obstacle identification method for the smart vehicles of the invention, the intrinsic unity of the measurement principles of the a three-dimensional laser radar and a point cloud data spherical coordinate representation method is utilized; it is point cloud data that are analyzed based on spherical coordinates, and the Cartesian coordinates of the point cloud data are not analyzed, and therefore, high efficiency can be realized; and at the same time, the original data of point cloud are directly analyzed, and grid division is not needed to perform on the point cloud, and therefore, processing efficiency can be improved.
Owner:TONGJI UNIV

Pre-stack inversion thin layer oil/gas-bearing possibility identifying method

The invention provides a pre-stack inversion thin layer oil / gas-bearing possibility identifying method. The pre-stack inversion thin layer oil / gas-bearing possibility identifying method comprises the following steps of: (1) constructing interpreting data and logging data by utilizing earthquake, and establishing an initial elastic parameter model based on a deposition mode; (2) obtaining an initial model and a model restrain range of random inversion through determination inversion based on a Baysian principle; (3) carrying out random sampling on three-parameter-related Monte Carlo simulationestablished by utilizing rock physical diagnosis and regression analysis so as to obtain a logging scale model; (4) calculating to obtain an elastic parameter model under an earthquake scale by utilizing a Hash in-Shtrikman boundary average method; (5) simulating forwards an angular domain pre-stack earthquake record and a actual earthquake record to calculate a cost function and calculate acceptance probability of the elastic parameter model, and determining a new logging scale elastic parameter model according to the acceptance probability; (6) iterating repeatedly the steps of (3), (4) and(5) and determining an optimal logging scale elastic parameter mode as a final result of earthquake three-parameter pre-stack inversion; and (7) carrying out thin layer oil / gas-bearing possibility identification of an oil reservoir by utilizing a three-parameter three-dimensional space intersection method.
Owner:CHINA UNIV OF PETROLEUM (BEIJING)

Three-dimensional detection system for surface of large thin-shell object and detection method thereof

The invention is applied to the technical field of three-dimensional sensing, and provides a three-dimensional detection system for the surface of a large thin-shell object and a detection method thereof. The detection method comprises that: three groups of sensors project fringes to the surface of an object to be detected in the upper, middle and lower directions of the object to be detected, acquire a deformation fringe graph, acquires phase distribution information, and acquires three-dimensional depth data of each viewing field by combining phase and depth mapping principle; multi-sensor calibration information is matched with the depth data acquired by the three sensors, and multi-angle data is matched to the same coordinate system; and dimensions are acquired and models are compared, namely the measured three-dimensional data is matched with a computer-aided design (CAD) model, distances from all measuring point to the CAD model are calculated, error distribution pseudo-color pictures of the inner side face, outer side face, inner bottom surface and outer bottom surface of the object, and the related dimension of the object, such as the length, width, height, wall thickness and the like are calculated by methods such as ray tracing and the like.
Owner:SHENZHEN ESUN DISPLAY

Four-rotor aircraft control method based on PID neural network (PIDNN) control

The invention discloses a four-rotor aircraft control method based on PID neural network (PIDNN) control. First, dynamic equations of a four-rotor aircraft are established based on the Newton-Euler equations, and then, a nested controller is proposed. An inner loop decentralized controller is designed based on a PIDNN method to realize attitude control, and the outer loop adopts a classical PID control method. Next, online learning of a PIDNN controller is realized by an error back propagation method, the connection initial weight of PIDNN is determined based on the principle of PID control, and an appropriate learning step is selected according to the discrete Lyapunov theory to guarantee the convergence of the controller. Thus, the control problem of a four-rotor aircraft caused by high degree of nonlinearity, strong coupling and under-actuating capability, disturbance from the external environment in the process of flight and other factors can be effectively solved.
Owner:BEIHANG UNIV

Heart rate measuring method based on low-end imaging device

The invention discloses a heart rate measuring method based on a low-end imaging device. The method is mainly applied to measuring a non-contact heart rate under daily ambient light illumination conditions. The method comprises the following steps that the video including the human face area is read according to RGB channels, the grey average of the human face area in each frame is calculated, and three curves are drawn with the number of frames as variables. A threshold value is set based on the information entropy principle, and the cross-color situation of the imaging device is judged according to the entropy of the three curves. When the cross-color situation is serious, the waveform of a representative pulse wave is extracted by utilizing the independent component analysis method. When the cross-color situation is not serious, a simple division algorithm is carried out on a red channel curve and a green channel curve, the waveform of the representative pulse is obtained, the Fourier transform is carried out on the waveform, and the heart rate is obtained by extracting the frequency corresponding to the maximum frequency value within the range between 0.5Hz and 3Hz.
Owner:中国人民解放军第一五二中心医院 +1

Fusing method of 3D laser point cloud and 2D image

The invention relates to the technical field of 3D point cloud data processing and 3D scene reconstruction. A fusing method of a 3D laser point cloud and a 2D image comprises the following steps: (1) making a black-and-white grid vertical hole calibration board; (2) collecting 3D laser point cloud and 2D images; (3) calculating the space coordinates of the centers of the vertical holes; (4) calculating the pixel coordinates of the centers of the vertical holes; and (5) calculating a mapping matrix to complete data fusion. The method has the advantages as follows: firstly, linear point cloud data of a laser scanner and image data shot by a camera are used, and the amount of data sampled is small; secondly, for solving of the mapping relation between 3D laser point cloud and 2D images, the amount of calculation is small, the calculation process is simple, and the calculation efficiency is high; thirdly, real-time 3D laser point cloud and 2D image fusion can be realized; fourthly, the space coordinates of the centers of the vertical holes are calculated using an interval matrix, there are multiple constraints, and calculation is more accurate; and fifthly, the homographic relation between the laser scanning plane and the camera imaging plane is directly constructed based on the imaging principle of the camera to solve the mapping matrix, and the calculation method is simple and reliable.
Owner:DALIAN UNIV OF TECH

A detection method for identifying static mechanical performance parameters of materials in different regions of welds

InactiveCN102288499AOvercome technical bottlenecks such as difficulty in accurately obtaining performance parameters of millimeter-level characterization dimensions such as weld areasTrue reflection of material propertiesInvestigating material hardnessTarget ResponseElement model
The invention relates to a detection method for identifying static mechanical performance parameters of materials in different regions of a weld joint, which comprises the following steps of: (1) preparing a test piece of a weld joint indentation test; (2) selecting a plurality of points to carry out hardness test in the whole weld joint region of the test piece in the vertical weld joint direction and carrying out reasonable partitioning according to an obtained hardness value; (3) obtaining load-depth curves of different regions; (4) establishing an indentation test finite element model andcarrying out verification on the accuracy of the finite element model; (5) forming a target response function mathematical optimization model in different regions of the weld joint according to an analog result of the indentation test finite element model and a corresponding experimental result; and (6) combining an optimization genetic algorithm and carrying out iteration according to selected target response functions to obtain optimal solutions so as to obtain the static mechanical performance parameters in different regions of the weld joint. The detection method has simple principle and is convenient to operate. The local mechanical performance parameters of the materials in the range of millimeter even micrometer can be measured. The application range of the indentation test is expanded.
Owner:HUNAN UNIV

Three-dimensional display device based on random constructive interference principle

The invention discloses a three-dimensional display device based on a random constructive interference principle, which adopts an amplitude and phase regulator array to regulate the amplitude and phase of incident laser and the converging function of a reflective or transmissive holographic optical element or binary optical element or tilted microlens to generate a coherent sub light source array of which the position is random, so that coherent sub light sources generate constructive interference to form a three-dimensional image. The device adopts a gray scale liquid crystal panel as well as the partitioned lighting by red, green and blue lasers to realize real-time color three-dimensional display, can be widely used in fields of three-dimensional display in computers and televisions, three-dimensional man-machine exchange, robot vision and the like.
Owner:李志扬

Complex index refraction tomography with sub lambda/6-resolution

The present invention discloses a method to improve the image resolution of a microscope. This improvement is based on the mathematical processing of the complex field computed from the measurements with a microscope of the wave emitted or scattered by the specimen. This wave is, in a preferred embodiment, electromagnetic or optical for an optical microscope, but can be also of different kind like acoustical or matter waves. The disclosed invention makes use of the quantitative phase microscopy techniques known in the sate of the art or to be invented. In a preferred embodiment, the complex field provided by Digital Holographic Microscopy (DHM), but any kind of microscopy derived from quantitative phase microscopy: modified DIC, Shack-Hartmann wavefront analyzer or any analyzer derived from a similar principle, such as multi-level lateral shearing interferometers or common-path interferometers, or devices that convert stacks of intensity images (transport if intensity techniques: TIT) into quantitative phase image can be used, provided that they deliver a comprehensive measure of the complex scattered wavefield. The hereby-disclosed method delivers superresolution microscopic images of the specimen, i.e. images with a resolution beyond the Rayleigh limit of the microscope. It is shown that the limit of resolution with coherent illumination can be improved by a factor of 6 at least. It is taught that the gain in resolution arises from the mathematical digital processing of the phase as well as of the amplitude of the complex field scattered by the observed specimen. In a first embodiment, the invention teaches how the experimental observation of systematically occurring phase singularities in phase imaging of sub-Rayleigh distanced objects can be exploited to relate the locus of the phase singularities to the sub-Rayleigh distance of point sources, not resolved in usual diffraction limited microscopy. In a second, preferred embodiment, the disclosed method teaches how the image resolution is improved by complex deconvolution. Accessing the object's scattered complex field—containing the information coded in the phase—and deconvolving it with the reconstructed complex transfer function (CTF) is at the basis of the disclosed method. In a third, preferred embodiment, it is taught how the concept of “Synthetic Coherent Transfer Function” (SCTF), based on Debye scalar or Vector model includes experimental parameters of MO and how the experimental Amplitude Point Spread Functions (APSF) are used for the SCTF determination. It is also taught how to derive APSF from the measurement of the complex field scattered by a nanohole in a metallic film. In a fourth embodiment, the invention teaches how the limit of resolution can be extended to a limit of λ / 6 or smaller based angular scanning. In a fifth embodiment, the invention teaches how the presented method can generalized to a tomographic approach that ultimately results in super-resolved 3D refractive index reconstruction.
Owner:ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)

A lane departure warning method

The invention discloses a lane departure warning method, comprising the following steps: (1) information perception: providing the state information and the environment information of the current vehicle motion by a vehicular sensor; (2) track prediction: according to a driving behavior model of a human driver, predicting the possible traveling track range of a vehicle within a certain period of time in the future by combining with vehicle kinematics and a kinetic model; (3) lane departure warning decision: according to the possible traveling track of the vehicle and a left and right road boundary point range detected on a front road marker line, analyzing the vehicle motion safety by taking the relative relationship between calculation time from the possible traveling track of the vehicle to the detection point range on the lane marker line and a preset threshold time Tthre as an index of lane departure warning; and (4) man-machine interface: if the system judges that the vehicle is in the danger of departing from a lane, reminding the driver in sound or in other manners of taking proper actions. The lane departure warning method has the advantages of simple principle, high detection precision, simple integral structure after implementation, low cost, and the like, is simple to operate and can work stably and reliably.
Owner:NAT UNIV OF DEFENSE TECH

Non-contact sight tracking method based on corneal reflex

The invention provides a non-contact sight tracking method based on corneal reflex. The method comprises steps as follows: step one, positioning of human eyes; steps two, calculation of light spot coordinates; step three, accurate positioning of pupils; and step four, space mapping: mapping of space coordinates is performed according to the calculated coordinates of four light spots on a screen, the coordinates of the pupil centers and the invariant principle of a cross ratio in the projective geometry. According to the provided technical scheme, a user doesn't need to wear other devices, so that limitation to the user is reduced greatly; a new pupil edge fitting scheme is proposed and used for circularly fitting and rejecting ideal points, so that the accurate pupil center is obtained, and the mapping accuracy is improved; and compared with the conventional correlational research, the accuracy is improved greatly.
Owner:HARBIN INST OF TECH SHENZHEN GRADUATE SCHOOL

Three-dimensional hot spot localization

A non-destructive approach for the 3D localization of buried hot spots in electronic device architectures by use of Lock-in Thermography (LIT). The 3D analysis is based on the principles of thermal wave propagation through different material layers and the resulting phase shift / thermal time delay. With more complex multi level stacked die architectures it is necessary to acquire multiple LIT results at different excitation frequencies for precise hot spot depth localization. Additionally, the use of multiple time-resolved thermal waveforms, measured in a minimized field of view on top of the hot spot location, can be used to speed up the data acquisition. The shape of the resulting waveforms can be analyzed to further increase the detection accuracy and confidence level.
Owner:DCG SYST +1

Space-based phased-array radar space multi-target orbit determination method

The invention discloses a space-based phased-array radar space multi-target orbit determination method, which mainly solves the problems that the space weak target cannot be evaluated effectively and the target orbit determination precision is low in the prior art. The method comprises the following steps of: processing target echo data by a zero-setting conformal algorithm, acquiring distance prior information by utilizing a distance pulse compression principle, and segmentally processing echo signals according to the distance prior information; segmenting the echo signals according to the number of the targets, wherein each segment of data is a target signal and an adjacent unit signal; performing multi-target two-dimensional angle evaluation on each segment of data by utilizing a sum-difference multi-beam angle-measuring principle; performing coordinate conversion based on a space target tracking result and detection satellite orbit information; and performing orbit determination on different space targets by a Laplace type iterative algorithm, and improving the orbit determination precision by a least square algorithm. According to the method, the influence of strong signals on weak targets can be reduced and the parameters of the weak targets can be evaluated accurately. The method can be applied in the actual application fields of space situation awareness, orbit resource management and the like.
Owner:XIDIAN UNIV

Blind source separation-based gear box compound fault diagnosis method

The invention discloses a blind source separation-based gear box compound fault diagnosis method and belongs to the gear box fault diagnosis method technical field. According to the method, a single acceleration sensor is adopted collect the vibration signals of a gear box. The method includes the following steps that: SVD noise reduction processing is performed on acquired signals; EEMD signal decomposition is performed on the signals which have been subjected to the noise reduction processing, so that the signals can be decomposed into a plurality of paths of IMF components and residual components; signals are reconstructed, source number estimation is performed, the number of source signals is estimated; according to the result of the source number estimation, a plurality of paths of IMF components of which the variance is large are extracted on the basis of variance, and signals are reconstructed; a JAD blind source separation method is adopted to solve the extracted IMF components, and the source signals are estimated; spectrum analysis is performed, so that the characteristic frequency of the signals is extracted, and therefore, the compound fault diagnosis of the gear box is completed. The method of the invention is simple in principle; the algorithm of the method is easy to implement; and the physical meaning of the signals is clear; and the blind source separation-based gear box compound fault diagnosis method is an effective gearbox compound fault diagnosis method.
Owner:SHIJIAZHUANG TIEDAO UNIV +1

Triangular matrix multiplication vectorization method of vector processor

The invention discloses a triangular matrix multiplication vectorization method of a vector processor. The triangular matrix multiplication vectorization method of the vector processor comprises the steps that (1) triangular matrix elements in a multiplicand triangular matrix T are stored continuously by row; (2) a multiplier matrix B is divided into a plurality of sub-matrixes Bi by row according to the number of vector processing units of the vector processor and the number of MAC parts of the vector processing units; (3) the sub-matrixes Bi are multiplied by the multiplicand triangular matrix T in sequence and then the results are stored on storage positions of the original sub-matrixes Bi; (4) the sub-matrixes Bi of the multiplier matrix are traversed and then the fact that whether sub-matrixes Bi which are not multiplied by the multiplicand triangular matrix exist is judged, the I is updated according to the formula i=i+1 and the steps are repeated from the step (3) if sub-matrixes Bi which are not multiplied by the multiplicand triangular matrix exist, and step (5) is executed if sub-matrixes Bi which are not multiplied by the multiplicand triangular matrix do not exist; (5) triangular matrix multiplication is accomplished. The triangular matrix multiplication vectorization method of the vector processor has the advantages that the principle is simple, operation is easy and convenient, and the calculation efficiency of the vector processor can be fully performed.
Owner:NAT UNIV OF DEFENSE TECH

Flexible, micro-array and three-portion precision t pulse testing system

The invention belongs to the field of biomedical testing instruments, and mainly relates to a precision pulse testing system which comprises a forearm positioning device, three channels of signal acquiring devices, a power supplying module, a pressure monitoring and controlling module, a signal acquiring and converting module, a signal processing and displaying module and the like. The precision pulse testing system has the advantages that three-portion and nine-pulse taking procedures carried out by traditional Chinese physicians can be precisely simulated by the aid of a manipulator on the basis of a bionic principle; sensors are graphene capacitive micro-array flexible thin-film sensors, are effectively adaptive to individual tissue structure difference and accordingly can be effectively in contact with tissues of the skins of the wrist of a patient, 400 channels micro-array signals can be acquired by each sensor in real time, and transversal and longitudinal spatial resolution (of 0.4 millimeter) of the signals can be greatly improved; postures of the forearm elbow, the wrist and the palm of the patient can be adjusted and keep in optimal acquisition states by the aid of the precision pulse testing system, pulses can be simultaneously acquired from the forearm elbow, the wrist and the palm of the patient, and the forearm elbow, the wrist and the palm of the patient can be repeatedly and precisely positioned; by the aid of the precision pulse testing system, 28 pulses of the patient can be precisely judged and taken, a microscopic pulse condition of the patient can be analyzed, and four-dimensional image maps of pulse waves of the patient, time-domain pseudo-color topographical maps and the like can be outputted.
Owner:郭福生

Image registration method based on synthetic aperture radar (SAR) image and digital elevation model (DEM) data

The invention discloses an image registration method based on a synthetic aperture radar (SAR) image and digital elevation model (DEM) data, wherein the problems that the positioning precision to ground target points in SAR image is not high and positioning is difficult to realize in actual projects in the prior art are mainly solved. The method comprises the following steps of: solving a longitude L, a latitude B and an elevation value h' of a ground target point in a spherical coordinate system by using a steepest descent method according to the Range-Doppler (RD) principle and the earth model equation, and transforming the values into a geodetic coordinate system; looking up the elevation value h' corresponding to B and L in a DEM database, and comparing the absolute value of h'- h' with a set threshold value epsilon, if the absolute value of h'- h' is greater than epsilon, enabling h to be equal to h' and returning to resolve the equation system again, and if the absolute value ofh'- h' is identical to or less than epsilon, stopping iteration, and taking h' as the elevation value of the ground target point, and the corresponding latitude B and longitude L as the latitude and longitude of the ground target point; linearly correcting the longitude and latitude to eliminate system errors, so that a final ground target point positioning result is obtained. The image registration method disclosed by the invention has the advantages of small operand and high positioning precision, and can be used for positioning ground target points in SAR images in actual projects.
Owner:XIDIAN UNIV

Device and method for detecting high sound pressure-phase shifting characteristic of microphone

ActiveCN102655628ASolving the Calibration Problem of Sensitivity Nonlinear Phase ShiftImplement Feedback ControlElectrical apparatusSound sourcesPhase difference
The invention provides a device and a method for detecting a high sound pressure-phase shifting characteristic of a microphone. A variable-section closed space is formed by an equal-phase coupling cavity, a variable-section reflection end cover, a standing wave tube and a bottom reflection end cover; a loudspeaker in the standing wave tube is connected with a power amplifier; the power amplifier is connected with a signal source; the signal source is connected with a computer; a reference microphone and a calibrated microphone are respectively arranged on the side wall of the equal-phase coupling cavity and are connected with a signal amplifier; and the signal amplifier is connected with the computer. The method comprises the following steps of: controlling the signal source by the computer, and driving the loudspeaker in the standing wave tube to send a sound wave signal by the power amplifier; and performing cross-spectrum analysis on a signal which is acquired by the reference microphone and the calibrated microphone, so as to obtain a phase difference of the calibrated microphone relative to the reference sensor under a certain condition. A sound source has high sound pressure of 94 to 160 decibels according to a standing wave sound field theory, and the distortion degree is less than 1 percent; and therefore, the phase shifting characteristic of the phase sensitivity of the microphone is calibrated under a high sound pressure environment.
Owner:BEIJING AEROSPACE INST FOR METROLOGY & MEASUREMENT TECH +1

Active pen for touch module, touch input system and driving method of active pen

The invention discloses an active pen for a touch module, a touch input system and a driving method of the active pen. The active pen comprises a gravity induction part, an amplifying circuit connected with an output end of the gravity induction part and a signal emission part arranged at a nib of the active pen and connected with an output end of the amplifying circuit, wherein the gravity induction part is used for outputting a corresponding gravity induction output signal according to an included angle between the active pen and the horizontal plane; the amplifying circuit is used for amplifying the gravity induction output signal at corresponding multiple; and the signal emission part is used for sending the amplified signal to the touch module. According to the invention, based on the principle of gravity induction, the change of signal output can be realized through changing the included angle between the active pen and the horizontal plane, namely, the output signal is changed along with the change of the tilt angle of the active pen, so as to provide handwritings at different degrees of thickness and realize difference of line width; in addition, the nib of the active pen can be made of materials without any requirement, thereby lowering the cost.
Owner:BOE TECH GRP CO LTD +1

FPGA (Field Programmable Gate Array)-based lane line detection method

The invention discloses an FPGA (Field Programmable Gate Array)-based lane line detection method which comprises the steps of: 1, setting initial parameters; 2, acquiring an original image Ii of a road condition in front of a vehicle in a vehicle running process; 3, carrying out image preprocessing on the original image Ii to obtain an edge image Iiedge; 4, carrying out coodinaet translation on the edge image Iiedge, wherein a coordinate system PX2Y2 with an end point position (xi-1, yi-1) of the former frame of image as a coordinate original point is used for replacing a coordinate system PX1Y1 with a top left corner of the image as an original point so that coordinate translation is realized; 5, carrying out parallel Hough commutative operation in the PX2Y2, for the ith frame of image, obtaining rho through a formula rho=(x-xi-1)*cos(theta)+(y-yi-1)*sin(theta), when the rho meets the condition that the absolute value of rho is less than P, storing parameters (theta, rho), or otherwise, discarding; 6, finding out a position of a maximum value in a parameter space to obtain a corresponding straight line, i.e., a lane line to be detected, updating the end point (xi, yi) of the current frame; and 7, turning to the step 2. The invention has the advantages of simple principle, high efficiency, capability of reducing the demands on the storage space, reduction of hardware cost, andthe like.
Owner:NAT UNIV OF DEFENSE TECH

Three-dimensional scanning method containing multiple lasers with different wavelengths and scanner

The invention relates to a three-dimensional scanning method containing multiple lasers with different wavelengths. A scanner for implementing the three-dimensional scanning method comprises a camera and at least two laser projectors with the position being fixed, wherein the at least two laser projectors correspond to at least two different wavelengths, and positional relations between spatial positions of light curtains projected by the laser projectors and the camera are calibrated to be known. The three dimensional scanning method comprises the steps of recognizing and acquiring a highlight center two-dimensional line according to a 2D pattern, which is shot by the camera, of a laser contour line projected to the surface of a scanned object, and then calculating according to a triangle method principle to acquire spatial three-dimensional point cloud data. The invention provides a scanner for implementing the three-dimensional scanning method containing multiple lasers with different wavelengths. The three-dimensional scanning method containing multiple lasers with different wavelengths and the scanner have multiple different wavelengths, are good in applicability, increase the reusability of the single scanner, and improve the cost performance ratio.
Owner:SCANTECH (HANGZHOU) CO LTD

Axis-invariant-based multi-axis robot inverse kinematics modeling and solving method

The invention provides an axis-invariant-based multi-axis robot inverse kinematics modeling and solving method. The method is implemented based on the fixed axis invariant D-H system and D-H parameterdetermination principle, the Ju-Gibbs quaternion and quasi direction cosine matrix principle, the axis invariant general 6R mechanical arm inverse solution principle and the axis invariant general 7Rmechanical arm inverse solution principle. The principles have the characteristics of being general, convenient and accurate and can be set into circuits and codes and be executed directly or indirectly and partially or totally in a multi-axis robot system. Besides, an analysis and verification system established based on the principles is also included and used for designing and verifying the multi-axis robot system.
Owner:居鹤华

LiDar point cloud data morphological filtering method based on area prediction

InactiveCN103745436APreserve terrain featuresHigh speedImage enhancementTerrainPoint cloud
The invention relates to a LiDAR point cloud data morphological filtering method based on area prediction. The method includes the following steps: step one, building a filtering initial surface model; step two, removing gross error points of the initial surface model, and obtaining a filtering surface model; step three, performing partitioning on the filtering surface model; and step four, performing filtering processing. The method in the invention overcomes the defect in the prior art that morphological filtering cannot well realize filtering of complex scenes, and the problem that self-adaption is not strong which is caused by filtering processing using constant terrain parameters set manually, the partitioning principle and the advantage that using predicted terrain parameters of partitioned areas can adjust an altitude difference threshold value according to the up-and-down conditions of terrains are utilized, so that filtering on point cloud data can be performed in a self-adaption manner, and a relatively good filtering result can be obtained at last.
Owner:XIDIAN UNIV

Subcutaneous vein three-dimensional reconstruction method based on hybrid matching strategy

The invention discloses a subcutaneous vein three-dimensional reconstruction method based on a hybrid matching strategy and aims to obtain the three-dimensional information of veins. The method includes the steps of firstly, using IUWT and Hessian matrix analysis to respectively obtain the blood vessel segmentation result and the related blood vessel feature image in each view; secondly, extracting and dividing blood vessel central lines through morphology and a blood vessel tracking algorithm to obtain the radius and blood vessel direction of each central line branch; thirdly, using epipolar constraint to calculate the candidate point set, of points in the central line branch of single view, in another view; respectively extracting SURF in the blood vessel similarity image of each view, completing SURF feature point matching, and using a Ransac method to calculate the homograph matrix among views; fifthly, using the layered matching strategy from part to whole to realize point-point matching between the blood vessel central lines of the views of two eyes according to the homograph matrix and the candidate matching point set, and completing the optimization of the homograph matrix during matching; sixthly, completing the three-dimensional reconstruction of the matching central line points according to the principle of triangular measuring, and recovering a three-dimensional blood vessel surface according to two-dimensional blood vessel diameter information.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Instrument recognizing method for passive optical operation navigation

The present invention provides an appliance identification method used in passive optical operation navigation, pertaining to the application field of the information technology in clinic. Firstly, the sign points of appliances to be identified are distributed as follows: the shape of the fixed sign point on each appliance is totally the same but the distance among the sign points on the same operational appliance is different and the distance among the sign points on different appliances is obviously different. In detection, the binocular vision principle is firstly utilized to detect the sign points in the three-dimensional space; then a match detection is carried out according to the geometric relationship among the sing points according to the known sign points on the appliances; if such combination can be found, the match is completed and the appliance is thought to be constituted by the selected sign points. The advantages of the present invention include making the passive tacking and positioning of various operational appliances only by using one kind of sign points with same specifications, increasing the interchangeability of damageable sign points and reducing the cost for replacing sign points.
Owner:TSINGHUA UNIV +1

Human eye test model for evaluating three-dimensional imaging performance of OCT equipment of ophthalmology department and use method thereof

The invention belongs to the field of medical apparatuses and instruments and particularly discloses a human eye test model for evaluating the three-dimensional imaging performance of OCT equipment of the ophthalmology department and a use method of the human eye test model. A simulated human eye is provided with key parts of imaging of the ophthalmology department, wherein the key parts include the cornea (2), the atria (3), the crystalline lens (5), the vitreous body (7) and the retina (8). An OCT resolution test pattern (9) and a view marking ring (10) are designed and distributed on the surface of the retina. The OCT resolution test pattern (9) includes two parts. One part of patterns are used for evaluating the OCT transverse resolution, all sets of patterns are the same in height, each set of pattern is composed of three short lines in the horizontal direction and three short lines in the vertical direction on the two-dimensional plane, and the lengths of the short lines gradually decrease; the other part of patterns are used for evaluating the OCT axial resolution, each set of pattern is a square on the two-dimensional plane, the length and the width of each square are the same, but the heights of the squares gradually decrease. The human eye test model is designed and manufactured according to the imaging principle of the OCT equipment, and the three-dimensional resolution performance of the OCT equipment can be evaluated by carrying out measurement and imaging on the simulated human eye.
Owner:NAT INST OF METROLOGY CHINA

Ultra-thin, planar, plasmonic metadevices

An ultra-thin planar device is used for arbitrary waveform formation on a micrometer scale, regardless of the incident light's polarization. Patterned perforations are made in a 30 nm-thick metal film, creating discrete phase shifts and forming a desired wavefront of cross-polarized, scattered light. The signal-to-noise ratio of these devices is at least one order of magnitude higher than current metallic nano-antenna designs. The focal length of a lens built on such principle can also be adjusted by changing the wavelength of the incident light. All proposed embodiments can be embedded, for example, on a chip or at the end of an optical fiber.
Owner:PURDUE RES FOUND INC
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