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53 results about "Rotational transformation" patented technology

3D printing path planning method based on electric arc additive anisotropy and stress field

The invention discloses a 3D printing path planning method based on electric arc additive anisotropy and a stress field, and the method comprises the steps: constructing a CAD three-dimensional model of a part, and obtaining the stress field of the part through finite element simulation; determining a slice plane; mapping the stress field to a slice plane to form a force flow line; according to the obtained force flow line, rotation transformation regeneration is carried out according to the anisotropy of the used electric arc additive, and a reference trajectory considering the anisotropy of the material is obtained; under the principle of alternate arc starting and extinguishing, the corresponding printing sequence in the layers and between the layers is further planned, and the reference trajectory lines are connected end to end to be planned into a continuous path; and generating a code file, and printing according to the printing sequence. The comprehensive mechanical property of a printed piece is improved.
Owner:SOUTHEAST UNIV

Robot action redirection method, storage medium, electronic equipment and product

The invention provides a robot action redirection method, a storage medium, electronic equipment and a product, and relates to the field of robot control. The method comprises the steps that motion data of a to-be-simulated object and pre-configured joint offset parameters are obtained, wherein the joint offset parameters are used for describing rotation transformation data from a joint coordinate system of the to-be-simulated object to a joint coordinate system of a robot; based on the joint offset parameters, joint offset mapping from the to-be-simulated object to the robot is established; and based on the joint offset mapping, converting the motion data of the to-be-simulated object into motion data of the robot so as to drive the robot to execute corresponding actions. According to the method, the difference between the to-be-simulated object and the robot in joint coordinate system rotation transformation can be effectively eliminated, the physical feasibility and motion naturalness of robot actions are ensured, and the interaction requirements in a complex interaction scene are met.
Owner:AGIBOT INNOVATION (SHANGHAI) TECHNOLOGY CO LTD

Graphics processing with barycentric rotations

A graphics processing system that provides a micromap defining property values for sub-regions of a primitive of a scene to be rendered; and generates a first tree representation of the micromap; and applies a first barycentric rotational transform to the micromap and for the first barycentric rotational transform generates a second tree representation of the micromap; and selects one of the first or second tree representations for processing as the selected tree representation. The selected tree representation of a micromap is used when it is desired to determine whether and / or how a ray interacts with a sub-region of a primitive, the tree representation of the micromap is traversed to determine a property value for the sub-region of the primitive.
Owner:ARM LTD

Extreme horizontal wind shear identification and load reduction control method and system for wind turbines

The present invention discloses a method and system for identifying and controlling extreme horizontal wind shear for a wind turbine, including: obtaining blade root bending moments in two directions of the blade root, namely, the blade root flapping bending moment and the blade root shimmy bending moment; obtaining the blade root out-of-plane bending moment through rotational transformation based on the current measured pitch angle; obtaining the current blade azimuth angle, performing coordinate transformation on the blade root out-of-plane bending moment, and calculating the rotor shimmy bending moment; calculating the horizontal wind shear coefficient based on the rotor shimmy bending moment and the current average wind speed; identifying the current wind condition as extreme horizontal wind shear when the horizontal wind shear coefficient exceeds a preset threshold; and when the current wind condition is identified as extreme horizontal wind shear, calculating and outputting an additional independent pitch control command, which is superimposed on the pitch control command output by the pitch controller, so that the additional bending moment generated on the rotor counteracts the rotor shimmy bending moment. The present invention identifies whether the current condition is extreme horizontal wind shear based on the measured blade root load and reduces the load by providing the additional independent pitch control command.
Owner:GUANGDONG MINGYANG WIND POWER IND GRP CO LTD

A torque ripple compensation control method for permanent magnet synchronous motor

The present application belongs to the field of permanent magnet synchronous motor control technology, and relates to a kind of permanent magnet synchronous motor torque ripple compensation control method, comprising: acquisition stator phase current and cross axis given current, generate cross axis and straight shaft feedback current by coordinate rotation transformation;Extract cross axis and straight shaft harmonic current;According to the period difference of cross axis current feedback residual error, calculate cross axis time delay distortion coefficient;The coefficient is in situ input coordinate rotation transformation correction rotor electric angle, and combine electric angle change rate to calculate phase angle advance compensation angle;Using the angle to calibrate harmonic current space phase to synthesize offset current instruction and superimposed output, the present application eliminates control loop timing response lag, makes compensation current maintain spatial orthogonal state with rotor harmonic magnetic field under variable speed condition, avoid positive feedback excitation, guarantee the steady convergence and stability of closed loop.
Owner:AOYINSHEN INTELLIGENT EQUIP (SUZHOU) CO LTD

Vibration reduction periodic structure for guiding directional transmission of vibration energy and design method

The invention discloses a vibration reduction periodic structure for guiding directional transmission of vibration energy and a design method, and the vibration reduction periodic structure is formed by combining two basic unit cells with symmetrical structures to form the vibration reduction periodic structure in array arrangement; two basic unit cells are arranged on the two sides of a transmission path used for guiding directional transmission of vibration energy in the vibration reduction periodic structure respectively. Each basic unit cell is formed by original unit cells through rotation transformation; the original unit cell is of a hollow hexagonal embedded fan blade structure and comprises a hollow regular hexagonal frame and a plurality of fan blades evenly distributed on the inner side of the hollow regular hexagonal frame. The two basic unit cells in the vibration reduction periodic structure are obtained by rotating the fan blades in the original unit cells by the same angle in the forward direction and the reverse direction respectively. The problems that the implementation difficulty is increased and the vibration reduction effect is not ideal under the trend that a vibration structure system develops towards the direction of complexity, large scale and function diversification in an existing mode for reducing or avoiding harmful vibration are solved.
Owner:AVIC XIAN AIRCRAFT IND GRP CO LTD

IPMSM position estimation method and system based on rotating high-frequency injection

This invention discloses an IPMSM position estimation method and system based on rotating high-frequency injection, comprising: (1) injecting a high-frequency voltage signal into the stationary α-β coordinate axis of the motor; (2) sampling the three-phase current and obtaining the two-phase stationary coordinate system through Clark transformation; (3) obtaining the fundamental current through a notch filter; (4) obtaining the high-frequency response current of the stationary α-β coordinate axis; (5) rotating the transformation and obtaining the high-frequency response negative sequence current through low-pass filtering; (6) designing and modulating the compensation phase; (7) cross-multiplying the compensation phase vector with the modulated compensation phase vector to obtain the estimated angular velocity and rotor position of the motor. This invention uses a notch filter to process the signal, eliminating the band-stop filter in the d-axis and q-axis current feedback loop in the control loop, thus simplifying the system complexity; by compensating for the rotor position lag angle, it increases the system stability and improves the rotor position identification accuracy.
Owner:NANJING LINGOU CHUANGXIN ELECTRONICS CO LTD

An aviation swage positioning control method, system, device and medium

This application discloses a positioning control method, system, equipment, and medium for aerospace forgings, relating to the field of intelligent manufacturing technology for aerospace forgings. The method includes the following steps: acquiring a theoretical digital model of the target forging and a three-dimensional digital model of the target mold to obtain the theoretical placement pose of the target forging; acquiring a three-dimensional scanning digital model of the target forging after the manipulator grips it to obtain a rotation matrix R and a translation vector T; wherein the rotation matrix R represents the rotational transformation from the actual pose of the target forging to the theoretical placement pose, and the translation vector T represents the spatial offset of the target forging; and inputting the rotation matrix R and translation vector T into a preset trajectory planning model to generate the optimal motion trajectory for the manipulator to transport the target forging to the target mold. This application has the advantages of improving the placement positioning accuracy and efficiency, and improving the performance of the final product.
Owner:CHINA NAT ERZHONG GRP DEYANG WANHANG DIE FORGING CO LTD +1

Method for predicting concentricity of first fulcrum and second fulcrum of aero-engine fan casing

The invention relates to a method for predicting concentricity of first and second fulcrums of an aero-engine fan casing. Comprising the following steps: measuring mounting side column jump and end jump data of each stage of receiver and a first and second fulcrum bearing seat; defining a global coordinate system of the assembly body, and determining a machining error matrix and a high-low point position matrix according to end jump and column jump measurement data of the mounting side of each stage of rotor; determining an installation phase matrix of each stage of cartridge receiver; determining a positioning error matrix caused by coordinate translation transformation and a directional error matrix caused by coordinate rotation transformation after all the fan casings and the first and second fulcrum bearing seats are assembled; then determining a mounting seam allowance matching error matrix caused by deformation of the mounting edge; secondly, determining global positioning and orientation matrixes of the casings and the bearing seats at all levels after translation, rotation and high-low point corresponding deformation transformation; and finally, determining the global positioning and orientation matrix of the assembly, and determining the concentricity of the first and second fulcrums of the fan casing. According to the method, the false assembly workload is reduced, and the assembly efficiency of the fan unit body is improved.
Owner:STATE-OWNED SICHUAN WEST MASCH FACTORY

Seamless keystone correction method, projection equipment and storage medium

This invention provides a seamless trapezoidal correction method, a projection device, and a storage medium. The method includes the following steps: obtaining the attitude angle of the projection device; obtaining a first rectangular reference area based on a preset rotation transformation relationship, the attitude angle, and the original rectangular projection area; mapping the first rectangular reference area to a first plane based on the projection transformation relationship to obtain a second trapezoidal reference area; obtaining a second rectangular reference area with a preset aspect ratio within the second trapezoidal reference area; mapping the second rectangular reference area to the first rectangular reference area according to the inverse transformation relationship of the projection transformation relationship to obtain a third trapezoidal reference area; obtaining a fourth trapezoidal reference area according to the inverse transformation relationship of the rotation transformation relationship; and adjusting the projection area based on the fourth trapezoidal reference area. Using this method and the projection device and storage medium carrying this method, seamless correction is achieved, improving the user experience.
Owner:深圳市当智科技有限公司

A point cloud 3D object detection method not affected by rotation transformation

The application discloses a point cloud 3D object detection method not influenced by rotation transformation, comprising the following steps: (1) regarding the network weight of the first layer of the neural network as a vector set distributed in a feature space with the same dimension as the point cloud feature; (2) performing seed point sampling and neighborhood aggregation on the input point cloud data to obtain the local point cloud around each seed point; (3) performing principal component analysis on the network weight and the local point cloud; (4) aligning the weights of the network weight and the local point cloud to obtain a feature with rotation invariance; (5) inputting the local point cloud feature of step (4) into the neural network for feedforward transmission, detecting the prediction of the head output 3D object frame of the network; (6) training the neural network through gradient back propagation; and (7) after the training is completed, performing a 3D object detection task on the point cloud. According to the application, the classification accuracy of the point cloud under arbitrary rotation transformation can be greatly improved, and thus the accuracy of the 3D object detection task can be improved.
Owner:ZHEJIANG UNIV

Unified transformation method for image mirroring and rotation based on polar coordinate decoupling

The application discloses a polar coordinate decoupling-based image mirroring and rotating unified transformation method, which comprises the following steps: S10, inputting parameters: an original image, a transformation center point coordinate, a mirroring direction parameter and a rotating angle; S20, traversing each pixel position of an output image; S30, unified mirroring and rotating transformation mapping; S40, interpolation sampling; S50, assigning to the output image; S60, traversing all pixels until completion; and S70, outputting the image. The application abandons the traditional linear algebra idea of firstly constructing a mirroring matrix and then multiplying the mirroring matrix with a rotating matrix, and instead reconsiders the combined operation of mirroring and rotating from the perspective of polar coordinate transformation. In a local polar coordinate system around an arbitrary specified center point, the mirroring operation can be regarded as a sign operation or a shift operation on a polar angle, and the rotating is an addition operation on the polar angle. The two can be combined into a simple expression in the polar angle domain.
Owner:HANGZHOU HUICUI INTELLIGENT TECH CO LTD

Rotor position detection method, detection circuit and driving module for three-phase permanent magnet motor

The embodiment of the application discloses a rotor position detection method and detection circuit of a three-phase permanent magnet motor, acquires two-phase back electromotive force; performs coordinate transformation on the two-phase back electromotive force to obtain a rotating transformation component, and adjusts an estimated angular velocity according to a real-time value of the rotating transformation component, so that the real-time position of the motor rotor can be obtained, and the accuracy of the position of the motor rotor is ensured.
Owner:SILERGY SEMICON TECH (HANGZHOU) CO LTD

Method for determining deformation characteristics and related system

In one example, a method includes determining a feature displacement gradient (DG) tensor characterizing a deformation feature. The method includes, in an iterative routine, calculating an objective function value associated with a trial DG tensor, the calculating based at least in part on pixel values within an automatically determined ZOC, where the ZOC is based at least in part on the trial DG tensor. In another example, a method includes determining one or more rotational transformation components corresponding to a test image, and determining a feature DG tensor based at least in part on the rotational transformation components. In another example, a system includes an electro-optical assembly, a detector assembly, and a controller programmed to determine a feature DG tensor. In another example, a non-transitory computer-readable medium stores instructions that, when executed by a computer, cause the computer to perform a method of determining a deformation characteristic.
Owner:FEI CO

Chiral metasurface construction method based on rotation transformation

The invention discloses a chiral metasurface construction method based on rotation transformation, a metasurface device comprises a substrate and a chiral metasurface located on the substrate, and the chiral metasurface is a rectangular nanorod array arranged periodically. The metasurface unit is composed of rotating rectangular silicon nanorods, and selective regulation and control of spin angular momentum of incident light are achieved by introducing in-plane mirror symmetry of a geometric rotation destroying structure. Simulation results show that the metasurface shows remarkable circular dichroism at the resonant wavelength of 633 nm, the transmissivity of the metasurface to left-hand circularly polarized light reaches up to 73%, and meanwhile the transmissivity of right-hand circularly polarized light is restrained to 2%. The device has the advantages of compact structure, easiness in integration and the like, and is expected to provide an effective solution for chiral biosensing application.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Methods of determining a deformation characteristic and associated systems

In an example, a method includes determining a characteristic displacement gradient (DG) tensor that characterizes a deformation characteristic. The method includes, in an iterative routine, calculating an objective function value associated with a trial DG tensor based, at least in part, on pixel values within a zone of consideration (ZOC) that is determined automatically based at least in part on the trial DG tensor. In another example, a method includes determining one or more rotational transformation components corresponding to a test image and determining a characteristic DG tensor based at least in part on the rotational transformation component(s). In another example, a system includes an electron optics assembly, a detector assembly, and a controller programmed to determine a characteristic DG tensor. In another example, a non-transitory computer readable medium stores instructions which, when executed by a computer, cause the computer to perform a method of determining a deformation characteristic.
Owner:FEI CO

Inclination angle compensation method, system and equipment for vibration test of crystallizer and storage medium

The invention relates to an inclination angle compensation method, system and device for a crystallizer vibration test and a storage medium. The method comprises the steps that initial acceleration data, collected by a three-axis accelerometer of a crystallizer in a static state, of a machine body coordinate system are acquired; based on the initial acceleration data of the airframe coordinate system, constructing a rotation conversion relation from the airframe coordinate system to a natural coordinate system; in the vibration testing process, real-time acceleration data, collected by the three-axis accelerometer, of a machine body coordinate system are obtained in real time; and converting the real-time acceleration data into compensation vibration data under a natural coordinate system based on the rotation conversion relation. Through data processing such as inclination angle calculation and coordinate conversion, the inclination angle is directly compensated without manually leveling the vibration tester, so that the vibration data of the crystallizer can be obtained.
Owner:HENGYANG RAMON SCI & TECH CO LTD

Method for quickly reconstructing three-dimensional model of steel ingot in cogging process

The invention particularly discloses a rapid reconstruction method for a three-dimensional model of a steel ingot in the cogging process, and relates to the technical field of metal forging intellectualization. The method comprises the following steps: inputting an initial three-dimensional model of a steel ingot, detecting the size, uniformly slicing along the length direction, and independently numbering; shooting a front image of the steel ingot in real time through a black-and-white industrial camera, and extracting a current contour boundary; then the extracted contour is compared with the previous iteration contour of the corresponding slice, whether the slice is a deformed slice is judged, and the pressing position and displacement of the pressing head are obtained; the pressing condition of the pressing head is monitored in real time, the deformed slices are updated, and non-deformed slice data are reserved; for a rotating steel ingot, analyzing a pose signal of an operation machine to generate a rotating transformation matrix, and performing angle compensation on an affected slice to update a spatial orientation; and finally, a cyclic detection mechanism is adopted until forming is finished. According to the method, rapid reconstruction and real-time updating of the steel ingot three-dimensional model are achieved, the measurement precision and efficiency are improved, and support is provided for intelligent control of the cogging process.
Owner:LANZHOU UNIVERSITY OF TECHNOLOGY

Tail clamp locking fixer

The invention discloses a tail clamp locking and fixing device. The tail clamp locking and fixing device comprises a locking and fixing frame. A rotating mechanism used for rotating and adjusting is arranged at the bottom of the locking and fixing frame. Through the arrangement of the rotating mechanism, the supporting mechanism and the angle locking mechanism, the connector has the advantages of being simple in structure, light, reasonable, convenient to use, high in applicability, capable of being suitable for most connectors with positioning point openings meeting the requirements, capable of conducting adjustment operation according to the actual use requirement, convenient to use and high in practicability. Free rotation transformation among the rotating mechanisms can be guaranteed through the arrangement of the rotating mechanisms, the positions of the embedded supporting legs are controlled, the three supporting mechanisms can not only support the rotating mechanism on the top, but also control the opening angle of the needed support according to needs, and the supporting efficiency is improved. And the extension length of the support is freely adjusted according to the extendable effect, the angle locking mechanism is mainly used for locking the opening and closing angles of the three sets of support mechanisms, it is guaranteed that fixing and locking are carried out after opening and closing, and free change is avoided.
Owner:BEIJING INST OF SPECIALIZED MACHINERY

Method, apparatus, equipment and storage medium for smoothing feed surface based on curve fitting

This invention relates to the field of automotive mold design technology, and discloses a method, apparatus, equipment, and storage medium for smoothing the filler surface based on curve fitting. The method involves obtaining a set of height points from all height points of a cross-sectional line, calculating the rotation angle, and establishing a rotation transformation matrix based on the rotation angle for directional rotation processing. The height point set obtained after rotation is used as the fitting curve point set, and the fitting curve point set is processed for curve fitting. Data fusion is then performed to obtain XYZ discrete data points. An inverse rotation transformation is performed on the XYZ discrete data points, and a NURBS spline is created based on the transformed discrete data points as the optimization curve for the filler surface. New geometric parameters of the cross-sectional line are solved based on the target height point, and the optimized cross-sectional line is used to construct the filler surface, resulting in a smooth filler surface with height variations. This invention effectively solves the wavy surface defect of the filler surface, eliminates the need for manual adjustment of the cross-sectional line, and balances design speed and accuracy.
Owner:JIHUA LAB

Robot FKM kinematics modeling method

The invention provides a robot FKM kinematics modeling method, and aims to solve the problems of rotation and translation coupling, non-intuitive parameter significance, complex modeling and the like in the existing robot kinematics modeling process. The method comprises the following steps: establishing a joint coordinate system of the robot, and determining a transformation parameter of each joint and a homogeneous transformation matrix of an adjacent coordinate system; wherein the expression of the homogeneous transformation matrix has two forms according to different joint types, and the expression of a rotating joint is as shown in the specification, and the expression of a moving joint is as shown in the specification. A translation transformation matrix of the coordinate system relative to the coordinate system is in the formula; the rotation transformation matrix is a rotation transformation matrix rotating around the translated X axis; the forward kinematics model of the robot can be obtained by sequentially multiplying the homogeneous transformation matrixes of all the joints for the rotating joints as a rotation transformation matrix rotating around the rotated Z axis and for the moving joints as a translation matrix moving along the rotated Z axis. According to the method, basic transformation and joint variables of the coordinate system are decoupled, so that the modeling process is more visual, the parameter significance is clearer, and the method can be widely applied to the field of kinematics modeling and control of industrial robots and service robots.
Owner:CHANGSHA LINGDOU ROBOT TECHNOLOGY CO LTD

Rotational phase multi-cycle absolute solution method and device

ActiveCN120372128BComplex mathematical operationsAlgorithmComplex representation
The present invention provides a method and device for multi-cycle absolute phase calculation. The method collects first and second phase signals with different periods and processes them into non-orthogonal oblique trajectories. These trajectories are converted into complex form and then rotated and aligned by a set rotation angle. The rotated complex trajectories are then processed into discrete segments and interpolated to obtain the absolute phase. This method utilizes multi-cycle modulo phase signals to form non-orthogonal oblique trajectories, which are aligned with the rotation angle using complex representations. This achieves structural normalization, eliminates table lookup and inverse solution modules, and enables real-time angle recovery. The method is applicable to any period combination (including both coprime and non-coprime cases), offers high computational efficiency and accuracy, and can be directly deployed in an MCU / FPGA for real-time absolute phase calculation.
Owner:SHANGHAI INDASENS SEMICONDUCTOR TECHNOLOGY CO LTD

A method for precise feeding of a mechanical arm based on coordinate transformation

The application provides a kind of based on coordinate transformation realizes accurate feeding method of mechanical arm, this method is first assembled calibration needle and completes system self-checking, three-point method is used to establish user coordinate system of material taking area and feeding area respectively;Visual planning feeding and unloading point, generate no compensation initial coordinates;Through single feeding fine adjustment, collect compensation value, and in 0°, clockwise 90°, counterclockwise 90° three attitudes, batch collection multiple samples;Subsequently, the compensation data is substituted into the coordinate transformation algorithm, and the basic error of the origin offset and axial deflection of the two area coordinate systems is solved;Finally, combined with the actual rotation angle of the workpiece and the rotation transformation formula, the dynamic compensation parameters are calculated in real time and superimposed to the initial coordinates, and the mechanical arm is driven to complete the no demonstration accurate feeding.The application does not need artificial demonstration and three-dimensional model, and the calibration cost is low, the adaptability is strong, the full attitude adaptive compensation can be realized, the positioning accuracy and operation efficiency of mechanical arm feeding and unloading are effectively improved, and it is suitable for precision automatic production line.
Owner:NANJING LANHAO INTELLIGENT TECH CO LTD

A method and system for adjusting the shape of a spherical radio telescope active reflector

The application belongs to the technical field of large radio telescope, and provides a kind of spherical radio telescope active reflecting surface shape adjusting method and system, first, the reference spherical radius and focal ratio are obtained, the coordinate system is updated, and the ideal parabolic surface of the observed celestial body is determined;Then, the coordinates of each node under the original coordinate system and the azimuth and elevation of the measured celestial body are obtained, and the position coordinates of each node under the new coordinate system are obtained through rotation transformation;The center of the ideal parabolic surface aperture is calculated, and the to-be-adjusted node is determined in combination with the reference spherical radius;Finally, the sum of the square of the distance between the coordinates of all to-be-adjusted nodes in the radial direction of the working parabolic surface and the ideal parabolic surface is minimized as the target, the target coordinates of all to-be-adjusted nodes are determined, and the extension amount of the top end of the actuator is calculated, so that the working parabolic surface is as close as possible to the ideal parabolic surface, to obtain the best receiving effect of the electromagnetic wave of the celestial body reflected by the reflecting surface.
Owner:QILU UNIVERSITY OF TECHNOLOGY (SHANDONG ACADEMY OF SCIENCES)

Method for reducing performance loss of neural network model caused by pruning

The invention discloses a method for reducing the performance loss of a neural network model caused by pruning, and the method comprises the following steps: S1, inserting a learnable orthogonal matrix into a self-attention module of a model Transform layer and an interlayer input / output end, and carrying out the rotation transformation of a weight and an input; s2, calculating importance scores corresponding to different pruning methods based on the weight and the input matrix after rotation transformation; the importance score is normalized into probability distribution, and the weight importance is concentrated on a few parameters through minimization of information entropy; fixing the weight of the original model, and training an orthogonal matrix until convergence in combination with the normalized importance score and an information entropy minimization target; s3, combining the rotation effect of the orthogonal matrix to a model weight to form an optimized weight matrix; s4, low-importance parameters are removed through an existing pruning method, and pruning operation is executed. According to the method, learnable orthogonal transformation is applied to the model weight before pruning, and the weight importance distribution is reconstructed to enhance the model pruning adaptability.
Owner:SHANGHAI JIAOTONG UNIV

A novel negative poisson's ratio spider-web dot array energy absorption structure and a design method thereof

The present application relates to the technical field of energy-absorbing lattice structure, and particularly relates to a novel negative Poisson's ratio spider-web-like lattice energy-absorbing structure and a design method thereof, which is composed of N three-dimensional negative Poisson's ratio unit structures arranged in a periodic array in a three-dimensional space, the three-dimensional negative Poisson's ratio unit structure is based on a two-dimensional negative Poisson's ratio unit structure minimum representative unit, is formed after rotation transformation and symmetric processing, and finally four structure planes with a preset included angle are constructed. The present application takes natural spider webs as a biomimetic prototype, fuses the abnormal deformation characteristics of the negative Poisson's ratio structure, constructs a lattice unit topology containing multiple types of construction points, defines key geometric parameters such as concave angles and rod diameters, and establishes a relative density calculation model to realize controllable design of the structure parameters.
Owner:QUANZHOU INST OF EQUIP MFG +1

Puncture template calibration method, device, electronic device and computer-readable storage medium

The present invention discloses a puncture template calibration method, device, electronic device and computer-readable storage medium, including: S1, fixing the puncture template with an ultrasonic probe to obtain the position of the puncture needle punctured on the puncture template; S2, obtaining a three-dimensional ultrasonic image through ultrasonic probe scanning, and obtaining the position of the puncture needle in the axial plane image; S3, calculating the rotational transformation and translational transformation between the puncture template and the axial plane image based on S1 and S2, and calculating the offset between the axis of the ultrasonic probe and the assembly center of the puncture template and the deflection angle between the scanning zero plane of the ultrasonic probe and the center line of the puncture template. The present invention can accurately calculate the positional offset between the axis of the ultrasonic probe and the assembly center of the puncture template, as well as the deflection angle between the scanning zero plane of the ultrasonic probe and the center line of the puncture template, thereby correcting the position on the puncture template and improving the puncture accuracy of the puncture device.
Owner:NANJING TUODAO MEDICAL TECHNOLOGY CO LTD

Handwritten mathematical formula identification method based on rotation position coding

The invention discloses a handwritten mathematical formula identification method based on rotation position coding, and relates to the technical field of handwritten mathematical formula identification. The method is characterized in that aiming at the problem of insufficient long-range dependence capture in long formula sequence modeling in the existing method, an end-to-end encoder-decoder framework is constructed, a rotation position encoding mechanism is introduced into a self-attention layer of a Transform decoder, and rotation transformation related to the position is applied to a query vector and a key vector, so that the long-range dependence capture in the long formula sequence modeling is realized. Enabling attention to calculate relative position information between explicit modeling symbols; and meanwhile, the attention distribution in the decoding process is constrained in combination with a coverage attention mechanism, so that repeated attention and omission of symbols are reduced. The method effectively solves the problem that long-range dependence capture is insufficient in handwritten mathematical formula long sequence modeling in an existing method, improves the recognition accuracy and robustness, and is suitable for application scenes such as mathematical formula input, intelligent education and document digitization.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

A method for estimating the angular velocity of a table tennis ball

The present invention relates to the technical field of intelligent control and discloses a method for estimating the rotational angular velocity of a table tennis ball. The method comprises the following steps: S1: obtaining two frames of camera images of a two-color table tennis ball in flight, taken before and after a net, separated by a time interval ΔT; S2: establishing a reference three-dimensional coordinate system for the two-color table tennis ball, and constructing a posture matrix R of the two-color table tennis ball in flight based on matrix rotation transformation; S3: processing the two-color table tennis ball in the two frames of camera images based on a geometric processing algorithm to obtain the corresponding actual posture matrices of the two-color table tennis ball in flight; and S4: calculating the magnitude and direction of the rotational angular velocity of the two-color table tennis ball based on the two actual posture matrices. By selecting a two-color table tennis ball, designing a reasonable camera layout, and employing an effective method for calculating the magnitude and direction of the rotational angular velocity, the present invention improves the accuracy of table tennis ball rotation estimation, saves costs, and increases practicality.
Owner:SHANGHAI UNIV OF SPORT