152 results about "Cylindrical coordinate system" patented technology

The present invention relates to the technical field of coastal engineering, and disclosed is a method for evaluating a radiation hydrodynamic force for a concentric cylindrical structure, comprising the following steps: S1, coordinate system establishment: establishing a cylindrical coordinate system orθz and a Cartesian coordinate system oxyz by taking the intersection of the center of a concentric cylindrical structure and a still water surface as the origin, where the z-axis is vertically upward; S2, flow field division: dividing the entire flow field into an outer domain and an inner domain; S3, perforated boundary condition assumption; S4, determining radiation velocity potentials of the inner domain and the outer domain by means of governing equations and boundary conditions; and S5, by means of the expressions of velocity potential functions of the inner and outer domains, determining first-order radiation forces, added masses and damping coefficients generated by the vibration of an inner cylinder and an outer cylinder. The method takes into account both the effects of seismic and radiation hydrodynamic forces, provides accurate structural response prediction, fills the technological gap in the field of seismic analysis of concentric cylindrical structures as breakwater units, and provides a reliable basis for engineering design.

The invention belongs to the technical field of meteorological radars, and particularly relates to an airship-borne meteorological radar three-dimensional wind field inversion method based on multi-angle asymmetric coplanar analysis, and the method specifically comprises the steps: enabling an airship to fly linearly in a certain direction, and carrying out the volume scanning, doppler radial velocity and radar scanning information of a target observed at each parking position of the airship-borne meteorological radar are acquired, and the position and slant distance of the target are calculated; dividing every two parking position observation results into one group, and selecting a combination meeting performance optimization conditions based on the performance optimization conditions of the MA-ASCAT model; on the basis of an inversion formula of an MA-ASCAT model, first two dimensions under a cylindrical coordinate system are obtained through inversion by utilizing the screened combination, and a third dimension is solved according to the wind speeds of the first two dimensions on the basis of an incompressible mass continuity equation; and converting the three-dimensional wind speed under the cylindrical coordinate system into a Cartesian coordinate system, so that the three-dimensional wind field inversion method is completed.

The invention discloses a low-frequency sound propagation loss forecasting method suitable for a polar region sea area, and the method comprises the steps: building a two-dimensional ice layer model of a forecast sea area according to remote sensing data based on the setting that sea ice of the polar region sea area is a uniform elastic medium; calculating hydrological conditions of the ocean sound channel of the polar sea area; establishing a forecast sea area two-dimensional seabed model according to the seabed topography sediment database; an under-ice sound field model is constructed based on a three-dimensional cylindrical coordinate system, sound pressure from unit intensity sound sources with different sizes and depths to a receiving point in a forecast sea area is calculated through a frequency domain finite element method in combination with a PML technology, and sound propagation loss of a needed position is obtained through calculation. According to the method, the application limitation of traditional ray and normal wave theories under complex boundary conditions is broken through through a finite element method, a synergistic effect mechanism of actual ice layer parameter space change, submarine topography fluctuation and sound velocity profile gradient characteristics is systematically analyzed, and sound field modeling is more accurately carried out on different ice layers and submarine topographies in the Chukong sea region all year round; the influence of sound wave propagation is simulated.

The invention relates to the technical field of oil exploration and development, and particularly provides a numerical simulation method for CO2 storage and oil displacement development effect evaluation. The method comprises the following steps: constructing a flow state physical model after CO2 enters a reservoir; according to the flow state physical model, a seepage model of CO2 entering the reservoir is established by combining the Darcy seepage theory and the mass conservation theory, and an oil phase formula, a water phase formula and a CO2 gas phase formula are obtained in a radial one-dimensional cylindrical coordinate system; dividing a calculation area into differential grids according to an oil phase formula, a water phase formula and a CO2 gas phase formula to obtain a limited number of grid nodes, and replacing a continuous solution domain with the limited number of grid nodes; according to the solution domain, calculating to obtain a relation expression of CO2 saturation changing along with radius and time; a prediction model is formed through the change relational expression, the CO2 storage or oil displacement state is predicted, the CO2 storage and oil displacement process is accurately simulated, and the CO2 emission reduction effect and potential can be effectively improved.

The invention discloses a fan-shaped blade grid test piece inlet section design method, which is used for designing an inlet section for connecting a transition section and a test section, and the inlet section comprises an upper curved surface, a lower curved surface and two side end surfaces. The method comprises the following steps: determining an airflow angle beta 1; selecting one curve of the side end face, and converting point coordinates on the curve between a Cartesian coordinate system and a cylindrical coordinate system; selecting a curve configuration style by combining the rotation angle beta 2; repeatedly designing curves with different radial heights on the side end surface; a side end surface is formed through curved surface stacking; rotating the curve of the maximum radial height and the curve of the minimum radial height to form an upper curved surface and a lower curved surface; and the array side end surface completes the integral design of the inlet section. According to the invention, a cylindrical coordinate system and Cartesian coordinate system conversion and curved surface stacking technology is adopted, high-precision curved surface configuration can be carried out on the inlet section of the fan-shaped blade grid test piece, accurate control of an airflow angle is realized, and the stability of a flow field of the inlet section of the fan-shaped blade grid test piece is effectively improved.

The embodiment of the invention discloses an electromagnetic wave logging detection depth determination method and device, a medium and a program product. The method comprises the steps that a conductivity disturbance stratum model under the homogeneous medium background condition is established, a multi-component transmitting and receiving antenna combination mode is simulated, a lower step signal source serves as an excitation source of transient electromagnetic wave logging, and a homogeneous medium transient electromagnetic wave logging response model is determined; according to the electromagnetic wave logging response perturbation model and the uniform medium transient electromagnetic wave logging response model, a sensitivity function of induced electromotive force is determined; determining a radial integral sensitivity function under a cylindrical coordinate system according to the sensitivity function of the induced electromotive force; and determining the detection depth of transient electromagnetic wave logging in the target time range according to the radial integral sensitivity function. According to the scheme, specific analysis can be carried out in combination with instrument parameters and signal definition, the detection performance evaluation problem of time domain signals measured in a well is solved, and the detection depth of transient electromagnetic wave logging equipment is accurately determined.

The invention discloses a method and system for detecting the position of an insulating partition plate in a transformer, and relates to the field of transformer detection, and the method comprises the steps: determining an ultrasonic detection device; the ultrasonic detection device comprises a mechanical arm, a fixed bracket and an ultrasonic probe, scanning the curved surface of the transformer shell by using an ultrasonic detection device to obtain an ultrasonic signal; performing sound velocity compensation on the ultrasonic signal according to the propagation time and propagation velocity of the ultrasonic signal in different media between the transformer shell and the position of the insulating partition plate; performing three-dimensional imaging coordinate conversion according to the data after sound velocity compensation; converting a three-dimensional imaging coordinate into a cylindrical coordinate system from a Cartesian coordinate system; generating a three-dimensional image according to the data after the three-dimensional imaging coordinate conversion; and determining the position of the insulating separator according to the generated three-dimensional image. According to the invention, accurate and non-intrusive detection of the geometric position of the insulating separator in the ultrahigh-voltage transformer can be realized, and the efficiency and precision of position detection of the insulating separator are improved.

The invention relates to the technical field of artificial intelligence, and discloses an eggshell crack detection method and system based on a convolutional neural network. The method comprises the following steps: synchronously obtaining multi-modal data of an egg through multispectral transmission imaging and three-dimensional structured light measurement; performing rigid registration and expansion on the data under a cylindrical coordinate system to generate a multi-channel fusion feature map with space alignment; inputting into a convolutional neural network of an encoder-decoder structure to carry out pixel-level crack segmentation, and outputting a crack probability graph; and after thresholding and connected domain analysis, judging whether the egg contains cracks or not according to a geometrical characteristic judgment criterion. The system comprises a multi-modal image acquisition module, a data preprocessing and fusion module, a crack feature extraction and classification module and a decision execution module. According to the method, through cooperation of multi-modal information fusion and the deep learning model, the accuracy and robustness of crack detection are remarkably improved, and the method is suitable for a high-speed automatic sorting scene.

The invention discloses a cement production equipment fault early warning method and system, and relates to the technical field of cement production equipment health monitoring, and the method comprises the steps: building a cylindrical coordinate system on the surface of a rotary kiln cylinder, and dividing the cylindrical coordinate system into a plurality of independent visual monitoring surface elements; collecting infrared and visible light image sequences in multiple working conditions and multiple continuous rotation periods for each visual monitoring surface element in a healthy state, and constructing a healthy visual fingerprint reference library representing stable state characteristics of the visual monitoring surface element; according to the method, the rotary kiln cylinder visual monitoring surface elements are divided, the healthy visual fingerprint reference library is constructed, real-time accurate comparison is achieved in combination with the twin neural network, cylinder state monitoring can be comprehensively covered, and limitation of local monitoring is avoided; and through time sequence deviation degree calculation and spatial correlation analysis, the deterioration trend and spatial correlation characteristics of the fault precursor can be captured in an early stage, and the early warning timeliness is greatly improved.

The invention discloses a voiceprint analysis-based power transmission structure foundation construction quality monitoring method and a voiceprint analysis-based power transmission structure foundation construction quality monitoring system, and relates to the technical field of the voiceprint analysis-based power transmission structure foundation construction quality monitoring method and the voiceprint analysis-based power transmission structure foundation construction quality monitoring system. Calculating a wind field stability index in each direction corresponding to each monitoring section of the power transmission structure; establishing a wind load influence model of the power transmission structure, and obtaining a wind load intensity index corresponding to each monitoring section of the power transmission structure according to the wind field all-directional stability index corresponding to each monitoring section of the power transmission structure, the cylindrical coordinate system coordinate data and the wind field radial wind speed data; inputting the wind load intensity indexes corresponding to the monitoring sections of the power transmission structure into the power transmission structure dynamic stability analysis model, evaluating the dynamic safety domain index of the power transmission structure, and performing operation stability early warning of the power transmission structure according to the dynamic safety domain index of the power transmission structure. And the foundation construction quality monitoring accuracy and effectiveness of the power transmission structure in severe convection weather are ensured.

The invention discloses an expansion flange laser detection system and a method thereof. The expansion flange laser detection system comprises a power supply module; the system comprises a laser, a microcontroller module, a laser measurement module and a servo driving module, and the spatial position and the incident angle of the laser are accurately adjusted by driving a plurality of motors. The invention discloses a data processing method of an expansion flange laser detection system. The data processing method comprises the following steps: (1) surface modeling and deformation analysis; (2) laser attitude control; (3) scanning detection; (4) signal processing and feature extraction; and (5) real-time control. The expansion flange laser detection system has the following beneficial effects that the expansion flange laser detection system can automatically adjust the laser incident angle, and high-precision detection of inner hole deformation is realized through a mathematical model and a control algorithm. The system establishes an inner hole surface model in a three-dimensional cylindrical coordinate system, and a real-time adaptive control strategy is adopted to ensure that a laser beam always keeps an optimal incident angle with a detection surface.

The invention provides a method and device for analyzing torsional vibration of a pipe pile in transverse isotropic unsaturated soil based on a fractional derivative model and electronic equipment. The method for analyzing the torsional vibration of the tubular pile in the transverse isotropic unsaturated soil based on the fractional derivative model comprises the following steps of: setting assumed conditions, introducing transverse isotropic and fractional derivative Kelvin viscoelastic models, constructing a three-dimensional constitutive relationship between pile peripheral soil and pile core soil, and constructing a torsional vibration model of the tubular pile in the transverse isotropic unsaturated soil. Obtaining a motion equation of the transverse isotropic unsaturated viscoelastic soil under the cylindrical coordinate system; deducing a seepage continuity equation of the transverse isotropic unsaturated soil; establishing a power control equation of the transverse isotropic unsaturated soil body; a tubular pile torsional vibration control equation based on an Euler-Bernoulli rod is established; deducing the torsion dynamic response of the pipe pile in the frequency domain; and the torsional vibration of the pipe pile is analyzed, and an analysis result is obtained. The purpose of improving the prediction precision of the dynamic response of the tubular pile under the complex soil body condition is achieved.

The invention discloses a metamorphic rock buried hill fractured reservoir imbibition characteristic curve calculation method. The method comprises the steps that samples of different matrix rock mass types in a target area are collected; the novel reverse imbibition experiment device is used for carrying out an imbibition experiment; drawing an experimental imbibition recovery ratio change scatter diagram; establishing an oil and water relative permeability and capillary pressure curve representation function; establishing an imbibition mathematical model under the cylindrical coordinate system, and calculating a theoretical imbibition recovery ratio; fitting by adopting a least square method and a genetic algorithm to obtain imbibition characteristic parameters; drawing imbibition characteristic curves of different types of matrix rock blocks; establishing a geologic model; and carrying out numerical simulation by adopting a relative permeability zoning mode, and the like. The method is reliable in technical principle and clear in logic, prediction of the relative permeability curve and the capillary force curve of the matrix rock core is more accurate, and the method has important significance in research on fine numerical simulation, remaining oil prediction, water injection strategy optimization and the like of a double-hole single-permeability oil reservoir.

The invention relates to an equivalent magnetic network modeling solving method for a planar induction motor. The method comprises the following steps: dividing an electromagnetic field solving area of the planar induction motor; giving size structure parameters and input parameters of the planar induction motor, and establishing an axial magnetic flux three-dimensional cylindrical coordinate system; establishing a preliminary magnetic network model, determining position angle information of grid nodes, and performing numerical solution of a cross-shaped magnetic conductance unit; according to the air gap layer connection node position angle information, adaptively connecting an air gap dynamic node; carrying out cubic spline interpolation solution on the magnetic conductivity of the nonlinear magnetic conductance unit based on a nonlinear ferromagnetic material B-H curve, and carrying out iterative solution through a relaxation coefficient method; and after iteration is completed, air gap flux density solving is realized.

The invention discloses a three-dimensional surface reconstruction method and system based on single-frame real-time point cloud. The method comprises the following steps: collecting material surface point cloud data in real time; transferring the collected point cloud data from a laser radar coordinate system to a getting-off coordinate system, and filtering interference point cloud to obtain first point cloud data; converting the first point cloud data into a cylindrical coordinate system from a getting-off coordinate system, dividing the selected material area into a plurality of fan-shaped grids in the cylindrical coordinate system, and projecting the first point cloud data into each fan-shaped grid; calculating centroids of all points in each grid as grid sampling points; if the point set in the grid is empty, carrying out sampling point supplement on the empty grid; and constructing a quadrilateral grid based on the complemented grid sampling points and the grid indexes to which the grid sampling points belong, and rendering the quadrilateral grid to obtain a three-dimensional reconstruction result of the material surface. According to the method, the overall estimation value of the material area is completed on the basis of the data of the single-frame point cloud, and the timeliness and the construction quality of excavator construction are effectively improved.

The invention discloses a map construction method fusing laser radar inertial navigation satellite navigation multi-modal data, and relates to the technical field of vehicle autonomous positioning and high-precision map construction. The method comprises the steps of obtaining multi-source original data of a laser radar point cloud, and performing preprocessing; sequentially constructing a laser speedometer constraint, an inertia pre-integration constraint, a loopback detection constraint and a global satellite navigation system constraint based on the preprocessed data, and constructing a factor graph optimization framework according to each constraint; in the loopback detection constraint, a point cloud descriptor construction method based on vertical layering of a cylindrical coordinate system is adopted, and a low-dimensional global descriptor with discrimination capability is formed by performing space division on a point cloud and extracting local height features; a delay switching strategy between a laser inertial system and a satellite inertial system is adopted in the factor graph optimization framework; and carrying out positioning and mapping service based on the factor graph optimization framework. According to the method, the precision and reliability of map construction in a complex environment can be remarkably improved.

The invention belongs to the technical field of high-frequency electromagnetic devices, and particularly relates to a circular litz wire alternating current resistance coefficient optimization calculation method based on a winding shape, which comprises the following steps of: 1, fitting a winding external magnetic field analytical expression of a circular litz wire under a rectangular coordinate system according to the winding shape; 2, converting the winding external magnetic field analytical expression under the rectangular coordinate system into a cylindrical coordinate system for expression; 3, deriving an external proximity effect loss analytical expression of the single-turn circular litz wire by adopting a winding external magnetic field analytical expression under a cylindrical coordinate system; 4, deriving a winding alternating-current resistance coefficient analytical expression corresponding to the external proximity effect of the circular litz wire winding by adopting a single-turn circular litz wire external proximity effect loss analytical expression; and 5, superposing the alternating current resistance coefficient analytical expressions corresponding to the external proximity effect of the winding, the skin effect and the internal proximity effect to form an alternating current resistance coefficient analytical calculation improved formula of the circular litz wire winding.

This invention relates to a method for analyzing large deformations of saturated soil and structures based on a semi-implicit material point method, comprising: decoupling pore pressure and motion variables using an incremental step method; introducing a penalty function for an enhanced frictional contact algorithm; introducing an artificial compressibility parameter into the pressure Poisson equation; employing the B-bar technique to reduce volume lock-in effects; using an affine particle cell method; modifying the calculation formula for axisymmetric problems, considering volume integrals and gradient evaluation in cylindrical coordinates; and conducting verification. The beneficial effects of this invention are: by employing an incremental step method, artificial fluid compressibility, and the B-bar technique, this invention avoids numerical instability caused by coupling problems in traditional methods, ensures the convergence of the simulation process, and avoids non-physical stress oscillations.

The invention discloses a surface damage positioning method suitable for an ultrahigh-strength concrete wind power mixing tower. The surface damage positioning method comprises the steps that benchmark identification pieces containing radio frequency chips and visual recognition patterns are annularly arranged at the preset height of a tower at intervals; the inspection equipment carries a millimeter wave radar, a binocular vision camera and a radio frequency identification module to spirally cruise along the tower drum, and synchronously obtains initial coordinates, real-time image streams and radar reflection signals; correcting the image flow and extracting features, establishing pixel and physical space mapping in combination with the size of the reference identifier, and generating an initial three-dimensional grid model; radar signals are analyzed, mutation feature points are extracted, and a suspected damage area is preliminarily positioned in combination with a three-dimensional grid; controlling equipment to perform fixed-point shooting, extracting damage contour features and calculating actual geometric parameters; the parameters and the physical coordinates are imported into a cylindrical coordinate system conversion model, the damage height, the circumferential angle and the distance between the damage height and the nearest reference identification piece are output, and accurate positioning is achieved; and reliable data support is provided for operation and maintenance of the wind power mixed tower.

A machining shape simulation device (100) for generative gear cutting comprises: a cylindrical coordinate system lattice prescribing unit (111) that prescribes a cylindrical coordinate system lattice that comprises a radial distance R component, an axial coordinate Z component, and an azimuth angle θ component and in which the lattice pitch of the radial distance R is set; a workpiece shape model prescribing unit (120) that prescribes a workpiece shape model defined by the axial direction as the axial coordinate Z direction in the cylindrical coordinate system lattice and the azimuth angle θ specified with respect to the radial distance R and the axial coordinate Z; a tool shape model prescribing unit (121); an interference region calculation unit (130) that calculates, on the basis of the workpiece shape model, a tool shape model, and the trajectory of relative movement of the tool and the workpiece, an interference region between the tool shape model and the workpiece shape model during generative gear cutting; and a machining result prediction unit (190) that predicts the machining result of the workpiece on the basis of the calculation result of the interference region calculation unit.

The present application provides a method, apparatus, and electronic device for analyzing the geometric features of a pipeline. The method for analyzing the geometric features of the pipeline includes: using three-dimensional laser scanning technology to obtain point cloud data of the surface of the target pipeline, where the point cloud data includes the three-dimensional coordinate information of multiple sampling points; preprocessing the three-dimensional coordinate information of the multiple sampling points to obtain the corrected three-dimensional coordinate information of the multiple sampling points; converting the corrected three-dimensional coordinate information into cylindrical coordinate information; performing fitting processing on the cylindrical coordinate information in the cylindrical coordinate system to obtain a first surface; deleting the surface part corresponding to the weld on the first surface, and supplementing a target surface in the area of the surface part to obtain a second surface; determining the distribution range of the axial straightness and / or the distribution range of the circumferential non-circularity of the target pipeline according to the second surface, which can improve the analysis efficiency and analysis accuracy of the geometric features of the target pipeline.

The invention discloses a fire source positioning method and system based on combination of thermal imaging and laser ranging, and relates to the field of fire prevention and control. Acquiring a thermal image, an original image and point cloud data of a target area, identifying a fire source candidate area, constructing a cylindrical coordinate system taking one end of a central axis of the fire source candidate area as an original point, and generating a three-dimensional model containing fire source space attitude and obstacle information; adjusting the shooting angle of the thermal imager in combination with the three-dimensional model, and planning a surrounding path containing an effective detection point location; the mobile carrier is controlled to move along the path, and a three-dimensional space constraint matrix is generated; performing Lie algebraic fusion on the thermal imaging signal features and a three-dimensional space constraint matrix in a symplectic geometric space, dynamically adjusting a laser ranging covariance weight through a confrontation recognition model, and mapping the laser ranging covariance weight into a space coordinate of a fire source in a cylindrical coordinate system; and calculating the Riemannian manifold distance between the positioning coordinate and the pre-path data, and when the Riemannian manifold distance exceeds a threshold value, re-sampling the data, updating the model weight and re-positioning. According to the invention, the fire source positioning precision is greatly improved.

The invention discloses a turbine blade flutter evaluation method adopting a single-channel harmonic balance model. The method comprises the following steps: 1, carrying out structural grid division on a turbine blade to obtain a vibration mode, a vibration frequency and a vibration pitch diameter of a vibration blade; 2, performing fluid grid division on the turbine blade to obtain grid coordinates under a cylindrical coordinate system; 3, aligning the coordinates of the structural grid and the fluid grid to obtain a vibration mode of the fluid grid; 4, adopting a Doppler frequency shift effect to obtain blade vibration frequencies, vibration pitch diameters and inter-blade phase angles of other blade rows except the blade row where the vibration blades are located; 5, realizing mutual transmission of upstream information and downstream information of the rotor-stator interface; 6, single-channel unsteady harmonic balance analysis is achieved; and step 7, evaluating the stability of the turbine blade flutter system. According to the method, the flutter of the multiple rows of turbine blades is evaluated, and the method has the characteristics of low calculation cost and high evaluation accuracy.

The invention discloses an intelligent ship 360-degree horizontal panoramic image stitching method, which comprises the following steps: acquiring all sequence frame images corresponding to each camera video according to a camera array, and traversing each pixel point in a corresponding initial stitching panoramic image by constructing a panoramic image hash mapping function according to a set panoramic image width to obtain a panoramic image sequence; performing projection processing on each pixel point in the cylindrical coordinate system to obtain a three-dimensional projection coordinate point, projecting the camera internal reference to an image pixel coordinate system to obtain an image pixel point, and determining a pixel contribution weight of the camera in an image area in the corresponding panorama based on the image pixel point; according to the pixel contribution weight and the three-dimensional projection coordinate point, a hash key value pair is inserted in combination with a panorama hash mapping function so as to fill panorama pixels, and a horizontal panorama of the corresponding sequence frame is acquired; according to the invention, the problems of insufficient resolution, dynamic adaptability, real-time performance, maritime environment applicability, intelligent navigation information perception capability and the like of the existing panoramic splicing scheme are solved.

The application belongs to the technical field of magnetic parameter measurement, and discloses a device and a calculation method for testing magnetic force in each direction between permanent magnets. The device uses an electric sliding table and a vertical sliding table to construct a three-dimensional motion platform, and collects the magnetic force of a tile-shaped permanent magnet under different spatial displacements in real time through a sensor. The device can not only meet the force testing needs of the inner / outer rotor permanent magnet under the axial, radial and tangential misalignment states, but also can adapt to different sizes of the inner / outer rotor permanent magnet by adjusting the clamp. Meanwhile, the magnetic force calculation method proposed by the application takes the equivalent magnetic charge model under the cylindrical coordinate system as the theoretical basis, and accurately solves the three-dimensional magnetic force of the inner / outer rotor permanent magnet under any spatial relative position through quadruple integration. With the help of the testing device and the calculation model proposed by the application, the precise measurement and theoretical verification of the magnetic force in each direction of the permanent magnet can be realized, the calculation is simple, and the degree of coincidence is high. The testing and calculation method has engineering universality and convenience.

A borehole stability index can be determined by using received user inputs and received subterranean formation characteristics. The portion of the subterranean formation characteristics that represent the rock stresses can be transformed to a coordinate system, such as a cylindrical system. Subterranean formation parameters can be calculated from the transformed characteristics. A lithology-specific algorithm can be applied to the subterranean formation parameters to generate a borehole stability index. The borehole stability analysis can then be performed using the subterranean formation parameters. The borehole stability analysis can be performed at incremental radial distance layers into the subterrane formation from a borehole wall. The borehole stability analysis can be performed at various measured depth layers within a measured depth interval of the borehole where the borehole stability index is the algorithmic combination of the individual calculated borehole stability indexes at each measured depth layer.

This invention discloses a system and method for locating corona discharge in generator stator windings. The system includes a track, two symmetrical supports, and a controller. The supports are I-shaped with adjustable support rod height. A movable crossarm slider is mounted on the crossarm rod, with both ends fixed to the crossarm slider. A track slider is fitted onto the track, enabling circumferential rotation and axial stepping movement. A laser mapping and modeling device and a corona discharge detection device are fixed opposite to each other on the track slider. The method includes: system layout; track center calibration; laser mapping and modeling to establish a cylindrical coordinate system; background noise detection; abnormal discharge detection under rated voltage; and data comparison to screen for true discharge points. This invention achieves blind-spot-free detection throughout the entire stator winding. By establishing a dedicated coordinate system through laser mapping and modeling, combined with ultraviolet and acoustic fingerprint detection methods and background noise comparison, it achieves precise coordinate positioning of corona discharge points, adapting to different generator models and automating operation.

The present invention specifically discloses a method and device for detecting the speed domain of a liquid-viscous clutch based on dynamic solution, wherein the method obtains the fluid Reynolds equation considering the influence of centrifugal force in a cylindrical coordinate system; introduces a pressure flow factor and a shear flow factor into the fluid Reynolds equation to correct the error generated when solving the lubrication of a rough surface; describes the rough surface profile, establishes an M-B fractal contact model to simulate the contact state between micro-convex peaks, and obtains the friction pair gap flow field characteristic parameters; discretizes the friction pair gap flow field characteristic parameters, constructs a liquid-viscous clutch flat-torsion coupling dynamic model, obtains the friction pair gap oil film viscous torque and power transmission mechanism, proposes a discretized numerical solution method for the friction pair gap flow field characteristic parameters, and obtains the output speed and / or output speed range of the load end. The technical solution is adopted to clarify the contact mechanism between the gap fluid and the micro-convex peaks under discrete distribution, and obtain the dynamic mapping relationship between the load end and the input end speed transmission.

The invention relates to the field of optical fiber preforms, in particular to an optical fiber preform stretching process simulation method which comprises the following steps: performing grid division on a two-dimensional cylindrical coordinate system; the grids are clustered to obtain a plurality of clusters, and segmentation and filling are carried out; obtaining a new axial length, similarly obtaining a new radial length, adjusting the first area according to the new axial length and the new radial length to obtain second areas, taking an area formed by all the second areas as a third area, and calculating the important degree of axial heat conduction and the important degree of radial heat conduction of the third area; and obtaining a temperature field, constructing a viscosity field and a velocity field based on the temperature field, and completing process simulation. Through the technical scheme of the invention, the accuracy of a simulation result can be improved.

The application discloses a gesture point selection and distance measurement method in a three-dimensional point cloud perspective display mode, comprising the following steps: obtaining two-dimensional coordinates of a user gesture by using a touch screen of a smart mobile device, mapping the two-dimensional coordinates into a ray endpoint in a three-dimensional space coordinate system through normalization conversion and inverse matrix operation, converting the ray endpoint into actual three-dimensional coordinates, converting three-dimensional point cloud data from a Cartesian coordinate system into a cylindrical coordinate system, judging whether the ray intersects with a cylinder through a ray equation, screening intersection points meeting the conditions, calculating the shortest distance between the ray and the central axis of the cylinder, and determining whether a target point is selected through a distance threshold value. The application effectively avoids misoperation through minimum distance judgment and screening, improves the user's interactive experience, is suitable for various application scenarios such as augmented reality and virtual reality, optimizes the coordinate conversion and ray projection algorithm, and improves the response speed and accuracy of the system.