104 results about "Cylindrical coordinate system" patented technology

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 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 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 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.

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 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 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.

The invention relates to the technical field of hydraulic machinery, in particular to a controllable radial thickening T-shaped blade top design method, an impeller and a blade. The method comprises the following steps: establishing a mapping blade of an original blade under a blade affine coordinate system; determining a closed two-dimensional geometric boundary formed by a plurality of curves in a relative circumferential-relative chordwise cylindrical surface of the mapping blade, and adjusting the closed two-dimensional geometric boundary based on a preset thickening parameter to obtain a thickened closed two-dimensional geometric boundary; and based on the thickened closed two-dimensional geometric boundary, determining a T-shaped blade top mapping blade under the blade affine coordinate system, and reflecting the T-shaped blade top mapping blade under the blade affine coordinate system to the original impeller cylindrical coordinate system to obtain a T-shaped blade top blade under the original impeller cylindrical coordinate system. By the adoption of the scheme, accurate control over the streamline normal direction can be achieved, the blade top clearance leakage vortex is restrained, and meanwhile the method has the functions of structure parameterization, control comprehensiveness and optimization flexibility.

The invention relates to the technical field of shield tunnel operation and maintenance, and discloses a three-dimensional display and positioning method for apparent diseases of a service-period shield tunnel. Comprising the following steps: establishing a three-dimensional model of a tunnel, and constructing a three-dimensional coordinate system, a cylindrical coordinate system and a conversion relation of the three-dimensional model; a panoramic image map in the tunnel is collected, a two-dimensional coordinate system is constructed, and disease information is recognized; selecting control points in the model and the image map and establishing a matching relationship; establishing a nonlinear preliminary mapping relation by using a thin-plate spline method; correcting the mapping relation through a cubic spline interpolation method to form a final mapping relation; according to the final mapping relation and the conversion relation, the image map is attached to the inner surface of the model, and disease information is marked. According to the method, the technical bottleneck of a traditional two-dimensional image in spatial expression is solved, accurate positioning of shield tunnel apparent diseases in a three-dimensional space is realized, a spatial coupling relationship between a panoramic image and a three-dimensional model is established, and a full-life-cycle data basis is provided for tunnel health monitoring, intelligent diagnosis and prevention and maintenance.

The invention discloses a method and system for determining the convection heat effect of a karst-type geothermal system, and the method comprises the steps: measuring thermophysical parameters of a rock sample from a target region, converting the thermophysical parameters into a cylindrical coordinate system, forming a rock thermophysical column, constructing a geothermal geologic model, and based on the thermophysical parameters, combining the flow characteristics and heat transfer characteristics of underground water in the target region, calculating the convection heat effect of the karst-type geothermal system. Constructing a geothermal geology mathematical model; only configuring the thermal boundary condition to the mathematical model to obtain the thermal flux at the boundary of the model; meanwhile, the thermal boundary condition and the constant pressure boundary condition are configured in a geothermal geology mathematical model, the heat flux is combined, the heat gathering effect of free convection at the boundary of the model is obtained as the free convection heat effect, and the thermal boundary condition, the constant pressure boundary condition and the water head boundary condition are further configured in the mathematical model at the same time; and in combination with the heat-gathering effect of free convection, obtaining the heat-gathering effect of forced convection at the boundary of the model as the heat-gathering effect of forced convection. The quantitative research on the heat gathering mechanism of the karst type geothermal system is realized.

This invention provides a dual-hole collaborative electromagnetic wave and laser fusion detection system for karst geological structures, belonging to the fields of precision geotechnical engineering detection and intelligent sensing technology. Based on a probe assembly, this invention heterogeneously fuses the geometric representation of laser point clouds with electromagnetic wave medium inversion data using a unified cylindrical coordinate system. The system quantifies hidden disaster-causing factors by calculating the deep karst development index and cavity volume morphology index; it uses a spatial Euclidean distance difference algorithm to calculate the minimum safe partition wall thickness, accurately locating high-risk sectors of rock wall penetration. Furthermore, the system adjusts the scanning step distance in real time based on the wave velocity gradient and generates an adaptive grouting control strategy. This invention effectively eliminates single detection blind spots, achieves three-dimensional visualization and risk quantification assessment of hidden karst, and improves the safety and scientific decision-making of pile foundation construction in complex geological environments.

The application relates to the technical field of permeability calculation, and discloses a permeability calculation method for a circular cross-section ferrite magnetic core in a toroidal inductor; when the magnetic field intensity is calculated, high-frequency analysis is carried out based on Maxwell equations, the characteristic that the magnetic field in the circular cross-section ferrite magnetic core in the toroidal inductor is uniform is used, and a virtual variable Bessel equation is derived based on a cylindrical coordinate system, and the magnetic field intensity calculation model is obtained by solving the equation, so that the limitation that the traditional measurement method needs to depend on a measuring device is broken. When the electric field intensity is calculated, the electric field intensity calculation model is obtained based on the relationship between the electric field intensity and the magnetic field intensity in the Maxwell equations. Based on the calculated magnetic field intensity and electric field intensity, the complex power of the toroidal inductor is calculated, and then the permeability prediction model is obtained in combination with an equivalent circuit model. The application is based on theoretical model calculation, is not limited by specific frequency bands and measuring instruments, is also applicable in a high-frequency range, and the predicted permeability is more accurate.

The invention relates to a pure finite element method, in particular to a pure finite element method for calculating a circumferential horizontal shear guided wave frequency dispersion curve. The method aims at solving the problems that an existing method needs complex programming and long calculation time, and consequently the solving process is complex and low in efficiency. The method comprises the following steps of: 1, adding a periodic boundary condition; establishing a finite element model of a pipeline periodic unit under the cylindrical coordinate system in finite element software; 2, parameterized scanning is carried out to solve the characteristic frequency; the invention belongs to the technical field of guided wave dispersion curve calculation.

A caving volume or caving probability 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 failure criterion. The caving analysis can then be performed using the subterranean formation parameters. The caving analysis can be performed at incremental radial distance layers into the subterrane formation from a borehole wall. The caving analysis can be performed at various measured depth layers within a depth interval of the borehole where the total caving volume is the total of the individual calculated caving volumes at each measured depth layer.

The application discloses a spacecraft single-pulse absolute reachable set solving method based on differential algebra technology and belongs to the technical field of on-orbit motion of space spacecrafts; firstly, a geocentric inertial coordinate system, a geocentric geodetic rotating coordinate system and a cylindrical coordinate system are established, and a dynamics model of on-orbit motion of the spacecraft in the cylindrical coordinate system is established; then, the earth shape perturbation, the solar pressure perturbation and the third body gravity perturbation of the sun and the moon are converted into the cylindrical coordinate system for representation, and a dynamics model considering multiple perturbation forces is obtained; finally, the absolute reachable set is solved in the dynamics model considering multiple perturbation forces based on Jet Transport technology; the dynamics model considering multiple perturbation forces is established in the cylindrical coordinate system, the absolute reachable set is solved by using Jet Transport technology based on the dynamics equation, and the absolute reachable set is simulated by using C++ and MATLAB; compared with the traditional Monte Carlo method, the solving method based on Jet Transport technology is high in accuracy and calculation efficiency.

The invention discloses a modal shape and frequency identification method for a motor stator system with an inner gear ring, and the method comprises the steps: building a shell unit and beam unit mixed analysis model of the motor stator system provided with the inner gear ring, and obtaining a total stiffness matrix and a total mass matrix under a local rectangular coordinate system through a matrix displacement method, obtaining a structural stiffness matrix and a structural mass matrix under the overall cylindrical coordinate system by using coordinate transformation; and establishing a discrete free vibration model, inputting the structural stiffness matrix and the structural mass matrix into the model, and outputting modal shapes of different orders and corresponding inherent frequencies of the motor stator system, thereby completing identification. The method comprehensively considers the influence of the stator teeth and the tooth part of the inner gear ring, helps to rapidly identify the modal shape and inherent frequency of the stator system, provides guidance for subsequent vibration acquisition and optimization, and has the advantages of simple modeling, rapid identification and high precision.

The invention relates to the technical field of hydrofracture micro-seismic event monitoring, in particular to a distributed optical fiber micro-seismic event positioning method and device, and the corresponding method comprises the steps: determining a vertical foot corresponding to a micro-seismic event according to the form of an event of the micro-seismic event in a seismic section corresponding to the micro-seismic event in a fractured well; determining the monitoring well and the perpendicular foot radius of the perpendicular foot in a cylindrical coordinate system; wherein the original point of the cylindrical coordinate system is the vertex of the event; and according to the radius of the perpendicular foot and the length of the fractured well, performing energy scanning on each grid under the cylindrical coordinate system in a plane which passes through the perpendicular foot and is perpendicular to the fractured well so as to position the microseism event. According to the method, the plane where the seismic source occurs is determined, and then seismic source scanning is performed only in the plane, so that the method has the advantages of high calculation precision and high calculation efficiency. And rapid real-time positioning of the distributed optical fiber fracturing microseism event can be ensured.

A turbocharger turbine wheel can include a hub including an axis of rotation, a back disk, and a nose, wherein the axis of rotation defines an axial coordinate (z) in a cylindrical coordinate system including a radial coordinate (r) and a azimuthal coordinate ( ) along an intended direction of rotation about the axis of rotation; and blades extending outwardly from the hub, wherein each of the blades includes a hub profile, a shroud edge, a leading edge, a trailing edge, a pressure side, and a suction side, wherein the hub profile includes a global maximum radius and a global minimum radius, and wherein, between the global maximum radius and the global minimum radius, in an axial direction from the back disk to the nose, the hub profile includes a local minimum radius at a first axial coordinate location and a local maximum radius at a second axial coordinate location.

The present application relates to the technical field of visual detection, and discloses a visual detection method and system for injection molding and bottle blowing based on quality online monitoring, which comprises the following steps: constructing a cylindrical coordinate system of a bottle body and a virtual anchor point array, obtaining a virtual anchor point reference position data set, constructing a matching template, obtaining a displacement vector set and a grid defect map; selecting a target area in the grid defect map, establishing an optical transfer function matrix and combining abnormal pixel distribution data to obtain a phase difference set and three-dimensional feature data of defects; establishing a multi-dimensional research and judgment model based on the three-dimensional feature data of defects, obtaining a key parameter set, and formulating a data detection method containing a rejection system and a self-protection system. The present application realizes adaptive identification of defects, accurate rejection of unqualified products and self-protection of equipment, and improves the real-time detection and production line efficiency. The present application solves the problems of fixed area not adapting to dynamic deformation of the bottle body, misjudgment caused by light interference and large rejection deviation in traditional detection.

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.

The invention is suitable for the technical field of heat conduction analysis, and relates to an underground granary heat insulation performance simulation method based on axisymmetric geometric analysis, which utilizes a non-uniform rational B-spline (NURBS) primary function to accurately represent a geometric shape and approximate a physical field, realizes the unification of modeling and analysis data, and improves the heat insulation performance of an underground granary. The axisymmetric characteristics and boundary conditions of the granary are fully utilized, geometric analysis system equations and solving formats such as the axisymmetric heat conduction problem are deduced in a cylindrical coordinate system from an axisymmetric steady-state heat conduction problem control equation on the basis of the variational principle, and a general three-dimensional problem is reduced into a two-dimensional problem; efficient utilization of the degree of freedom of calculation is achieved, then temperature field and heat flux density distribution characteristics of a granary body-soil body system are analyzed, the influence rule of different conditions on underground granary heat conduction is revealed through parameterization research, and a high-order continuous interpolation basis function is introduced to obtain a high-order continuous interpolation basis function; the calculation precision and calculation efficiency of underground granary temperature field analysis are effectively improved.

The invention discloses a reticulated shell structure-based prepreg yarn fiber placement trajectory tracking control method and device, and the method comprises the steps: fusing all groups of local point cloud data under multiple perspectives into a global point cloud under a unified reference coordinate system through a point cloud registration algorithm; the global point cloud is converted into a cylindrical coordinate system, and layered scanning is carried out in the axis direction of the target latticed shell structure; performing fusion noise reduction and geometric feature calculation on the point cloud data obtained by hierarchical scanning, and identifying and extracting a groove boundary curve on the target reticulated shell structure based on curvature features; converting the coordinate system of the global point cloud and the coordinate system of the groove boundary curve into an execution mechanism coordinate system, and generating a track planning result of a fiber placement path based on preset process constraints; the trajectory planning result is used for being combined with a controller of the execution mechanism to form a composite control strategy, so that tracking and dynamic error compensation are carried out on the fiber placement trajectory of the execution mechanism. And the problem of difficulty in tracking the fiber placement trajectory of the prepreg yarn is solved.