102 results about "Projected area" patented technology

The invention discloses a fabric draping form three-dimensional quantification method, and belongs to the technical field of fabric draping form quantification, and the method comprises the steps: carrying out the three-dimensional scanning of a fabric sample, constructing a draping three-dimensional model of the fabric sample, determining the maximum dissectable distance of the draping three-dimensional model, selecting the sectioning step length, and calculating the number of sectioning layers. Determining the number of horizontal section cutting planes parallel to the horizontal reference plane, and dividing the three-dimensional suspension model into a plurality of suspension sub-models along the positive direction of the normal axis; calculating an orthogonal projection area and an orthogonal projection contour perimeter of each suspension sub-model on a horizontal reference plane according to the coordinates of all surface vertexes of each suspension sub-model, and further calculating a layered suspension index of each suspension sub-model; and taking the arithmetic mean value of the layered drape indexes of the drape sub-models as a drape index for quantifying the drape form of the fabric sample. According to the method, the problems of dimension deficiency and insufficient quantization precision in the prior art can be solved, and fine quantization of the drape form is realized.

This automotive rear module is an automotive rear module for reinforcing the side outer of an automobile, which is formed by hot stamping a plurality of integrated steel plates. When viewed from the vertical direction of the reference plane, the projected area is S (m 2 ), among the components of the automotive rear module, the total weight of the components is W (kg), and the total weight of the steel components with a plate thickness of 1.5 mm or less and a minimum Vickers hardness of HV230 or more is W A . When, W / S is 24 or less, and W A / W is 0.30 or more.

The invention provides a BIM model three-dimensional projection plane extraction method, electronic equipment and a medium, and the method comprises the steps: carrying out the triangularization processing of a BIM model, and obtaining a triangularization mesh model; calculating the projection area and the normal direction of the triangle in the P direction, and deleting the triangle of which the vertex is repeated and the projection area is 0 or the normal direction is opposite to the P direction; calculating a value range of coordinate values of all vertexes of the remaining triangles in the P direction, and dividing the value range into a plurality of intervals; classifying the remaining triangles into a plurality of intervals to obtain a plurality of triangle sets; for each triangle set, extracting a two-dimensional vector surface; and sorting the two-dimensional vector surfaces according to a sequence from small projection height to large projection height, and extracting to obtain a three-dimensional vector surface. According to the method, projection plane extraction is performed after triangularization based on the BIM model, the influence of a professional design software production environment and a multi-source heterogeneous storage format is eliminated, and universality is achieved; compared with two-dimensional expression, the method for extracting the three-dimensional projection surface result provides finer geometric range description, and calculation is simple.

The invention discloses a machine-made sand grading calculation method based on a double-vision compensation algorithm, and relates to the technical field of computer vision. According to the invention, through a compensation algorithm combining global and local images, the stability problem of small-particle-size particles is effectively solved. The global image provides distribution information of the whole sand grains, the local image can accurately capture details of the small grains, the instability of the small-grain-size grains is compensated through an algorithm, and the stability and the accuracy of a measurement result are ensured; according to the method, errors caused by particle shape irregularity are overcome, the mass of the particles is measured through experiments, the equivalent height is calculated by combining the projected area and density of the particles, and the method effectively avoids volume calculation deviation caused by the particle shape irregularity.

The invention provides a slope excavation engineering quantity calculation system and method based on point cloud, and the method comprises the steps: reading the slope geological data of hydropower engineering to construct an initial three-dimensional model, and collecting the multi-stage point cloud data through a three-dimensional laser scanner; performing equidistant gridding on the point clouds of the model region according to an X / Y axis, calculating the spatial similarity and color similarity of the point clouds in grids, and dividing sub-data sets according to threshold values; fitting an excavation surface through a Delaunay triangulation network, calculating an XY plane projection area, and calculating an average Z-direction distance from a subset to the surface of the initial model; the node weight of the triangulation network is corrected by fusing rock stratum interface parameters, finally, the excavation engineering amount is dynamically output through summation of the product of the projection area of each subset and the average distance, and when the deviation of adjacent stages exceeds 10%, cross validation is conducted in combination with a profile method. According to the method, the precision and the real-time performance of slope excavation engineering quantity calculation can be improved, and automatic integration of lithologic characteristics and mechanical attributes is realized.

The invention relates to a method for calculating the degree of polarization of complex space debris, in particular to a method for calculating the degree of polarization of complex space debris based on a micro-facet pBRDF model, and solves the technical problem that an existing method for calculating the degree of polarization is poor in authenticity and accuracy. According to the complex space debris polarization degree calculation method based on the micro-facet pBRDF model provided by the invention, aiming at the characteristics of multi-shape and multi-material coupling of complex space debris, on the basis of the modeling thought of complex refractive index, specular reflection, diffuse reflection and volume scattering of different structural materials of the complex space debris; the albedo projection area is adopted as a reflection contribution coefficient calculated by the total light intensity of reflected light of the complex space debris, and a micro-surface element pBRDF model of different structures and different reflection contribution coefficients of the complex space debris is established, so that the model is closer to the multi-shape and multi-material characteristics of the real space debris; and the polarization degree of the complex space debris calculated based on the micro-facet pBRDF model is more accurate.

The invention provides an acceptance method and equipment for a concrete construction joint, and the method comprises the steps: obtaining the point cloud data of the surface of the construction joint after the concrete construction joint is coated with a retarder and is subjected to roughening in a final setting stage, and reconstructing a three-dimensional surface topography model of the surface of the construction joint according to the point cloud data; performing triangular meshing on the three-dimensional surface topography model to obtain the area of each triangular mesh surface and the projection area of each triangular mesh surface on the concrete construction joint plane; the ratio of the total area and the total projection area of all the triangular mesh faces is obtained to serve as a current roughness evaluation index of the surface of the construction joint; and according to the current roughness evaluation index and a preset construction quality requirement, generating an acceptance opinion of the construction joint. The quantitative roughness evaluation index is obtained based on the point cloud data of the surface of the construction joint, and acceptance is performed according to the roughness evaluation index, so that whether the construction joint treatment meets the requirement can be quickly and accurately judged, and the construction quality of the concrete construction joint and the stability and reliability of the structural performance are ensured.

The invention is suitable for the technical field of geological exploration, and provides a method for calculating the occurrence of a certain drill hole in a concealed ore body at an ore finding position, and the method comprises the following steps: obtaining the space coordinates of a target drill hole and a plurality of adjacent drill holes at the ore finding position; calculating a spatial distance and an azimuth angle; determining a weighting function adaptively changing along with the distance, and generating a group of space coordinates of virtual points corresponding to the adjacent drill holes; connecting the virtual points in sequence to form a polygonal curved surface, calculating the horizontal projection area of the curved surface, and calculating the vertical longitudinal projection areas of the curved surface in different directions; obtaining an inclination angle according to the ratio of the maximum vertical longitudinal projection area to the horizontal projection area; and determining the direction corresponding to the maximum vertical longitudinal projection area and the opposite direction, and determining the tendency by comparing the elevation values of the virtual points closest to the two directions. According to the method, the virtual points are connected into the polygonal curved surface, the form change of the ore body in the three-dimensional space is considered, and the method can better adapt to the concealed ore body in the complex form.

The invention discloses a ROS2-based surface exposure rapid prototyping method, device and system and a medium, and relates to the technical field of additive manufacturing. The method comprises the steps that all hardware nodes are reset and initialized, a forming platform is flush with a powder laying plane, powder is supplemented, and a scraper is reset. And importing the three-dimensional model of the part to be formed into ROS2-based slicing software, generating a support structure after attitude optimization, slicing according to a preset layer thickness to obtain a slice layer, and performing rasterization processing to generate a black and white mask image. And circulating subsequent steps for each slice layer until all slice layers are completed: descending a servo motor of a forming bin according to a preset layer thickness, providing powder by a powder supply bin, and then spreading and slicking the powder. And sending the black and white mask image corresponding to the current slice layer to the DLP to execute projection. The SLM laser node performs selective laser melting according to the projected area. And a molten pool image is captured in real time and analyzed, an analysis result is input to an ROS2 decision node to dynamically adjust process parameters, and closed-loop control is achieved.

The invention discloses a flexible reconfigurable robot path planning method for three-dimensional space dynamic obstacle avoidance. The flexible reconfigurable robot path planning method comprises the following steps: 1) determining a self-adaptive grid size according to a minimum projection area of a minimum obstacle; 2) initializing a three-dimensional grid model and an obstacle recording matrix, and marking obstacle distribution in the matrix; and 3) dynamically expanding the collision detection range by combining the radius of the mechanical arm. And 4) initializing a starting point and a target point, carrying out coordinate normalization, and converting the starting point and the target point into grid indexes. And 5) pre-calculating a Dijkstra initial path to obtain a global optimal reference path. And 6) monitoring an emergent obstacle in real time, if the emergent obstacle appears, triggering a local path re-planning mechanism, performing local path correction in an affected area by applying an A * algorithm, and quickly calculating a new feasible path. And skipping to step 7). And if not, advancing according to the global optimal reference path. And 7) splicing the path obtained by the A * algorithm with the original path, advancing according to the path, and returning to the step 6) if obstacles still exist.

The invention discloses a medical image-based auricle projection area measurement method and system, and belongs to the technical field of forensic medicine. According to the method, a head CT image sequence is subjected to three-dimensional reconstruction through an improved Marking Cubes algorithm to form a high-precision head three-dimensional model, an auricle region is further extracted through fine segmentation, auricle projection areas are automatically measured at all visual angles through a dynamic angle iterative algorithm, and finally the maximum projection area value is determined. The problems that traditional manual measurement is low in precision and poor in efficiency, and the precision is affected due to the fact that modeling holes are prone to occurring in handheld three-dimensional scanning equipment are solved. The method can be applied to forensic medicine auricle defect quantitative evaluation, and a high-precision and objective basis is provided for judicial expertise.

The application discloses a kind of five-axis six-face precision machining process and equipment, belong to the field of precision machining, a kind of five-axis six-face precision machining equipment, including machine table, adjusting base, Z-axis moving module, machine head, first rotating component, second rotating component, mounting plate and clamp, the adjusting end of adjusting base is fixed with first rotating component, mounting plate is fixed in the rotating end of first rotating component, so that mounting plate is rotated around X axis under the drive of first rotating component, second rotating component is fixed to mounting plate, the rotating end of second rotating component is fixed with clamp, the rotation center of second rotating component is located at the center line of mounting plate length direction one side, so that the projection of mounting plate on clamp deviates from the central position of clamp, the projection area of mounting plate on clamp is less than the area of clamp.The application realizes five-axis six-face machining operation, and only needs once clamping, there is no cumulative error and coaxiality difficult to guarantee problem, and machining precision is extremely high.

The invention relates to the technical field of model design, in particular to a method for optimizing a three-dimensional house type model after generation based on house surveying and mapping, which comprises the following steps of: performing multi-stage combination on edge point coordinates in a weight conversion mode to obtain a combined contour edge line; analyzing the contour edge line, dividing a plurality of house units, and obtaining a logic sub-region corresponding to each house unit according to the overlapping region and the broken line region corresponding to each house unit in combination with the projection area of the contour edge line; identifying interval areas of the logic sub-regions, identifying boundary conditions of the logic sub-regions according to the interval areas, and determining target boundary conditions of the logic sub-regions; based on a target boundary condition of the logic sub-region, judging an offset region of each house unit; differential accumulation is carried out on the offset areas of the adjacent house units, and a reference model of the current three-dimensional house model is constructed according to a differential accumulation path; the optimization efficiency and the area positioning accuracy of the house model are realized.

This invention discloses a rapid calculation method for the rearward infrared radiation intensity of an S-curve nozzle, belonging to the field of infrared radiation characteristic simulation of aero-engine exhaust systems. The method comprises the following steps: determining the design parameters of the S-curve nozzle and exhaust mixer components; establishing projection models of the key shielding sections of the exhaust mixer and S-curve nozzle; calculating the projected area of ​​each component after shielding by the S-curve nozzle using an image method; calculating the flow field parameter distribution and component surface temperature of the S-curve nozzle; calculating the axial length and volume of the visible region of the exhaust gas in the S-curve nozzle; calculating the spectral transmittance and spectral radiance of the exhaust gas along the nozzle outlet centerline within the visible region of the exhaust gas, as well as the spectral radiance intensity of the exhaust gas; calculating the infrared spectral radiance intensity of the wall surface; and integrating the spectral radiance to obtain the total infrared radiation intensity. This method solves the problems of existing technologies where the simulation calculation of the infrared radiation characteristics of S-curve nozzles is complex and time-consuming, and rapid calculation methods are only applicable to axisymmetric nozzles and cannot simulate the shielding structural characteristics of S-curve nozzles.

This invention belongs to the field of image processing technology, specifically relating to an automatic measurement method and system for material quantity in a silo based on machine vision. The method includes: acquiring depth and infrared intensity images of the silo; preprocessing these images to generate a valid binary mask; determining a geometric confidence factor based on the deviation between the depth gradient and the natural angle of repose of the material being measured, as well as local curvature; and determining an environmental confidence factor by combining infrared intensity and measurement distance; repairing invalid pixels using anisotropic diffusion; predicting depth values ​​based on first-order Taylor expansion and multi-dimensional confidence weighting; converting the repaired depth image into physical height and projected area; and obtaining the total volume of material in the silo through infinitesimal element accumulation. This invention solves the problem of data loss in complex environments and improves measurement accuracy.

The invention relates to the technical field of computer aided design (CAD), in particular to an indicating surface switching method and system, and the method comprises the steps: displaying a three-dimensional model in a three-dimensional scene, and displaying an indicator used for indicating the three-dimensional model, the indicator comprises a plurality of indicating surfaces, and one indicating surface corresponds to one observation visual angle of the three-dimensional model; identifying a projection area of an orthogonal surface, facing the user, of the indicator in the current observation direction; the projection area refers to an image area formed when the orthogonal surface is projected on the projection plane along the projection direction; when the projection area is greater than or equal to a set area threshold value, newly adding an expansion surface at a position adjacent to the orthogonal surface; and when the projection area is smaller than a set area threshold value, hiding the expansion surface. Therefore, under the condition that the options are relatively limited, the number of the options can be expanded to a certain degree, and meanwhile the situation that the space is disordered due to the fact that the expansion surface is increased can be avoided.

The utility model relates to the field of bearing pre-tightening, in particular to a pre-tightening switching structure which comprises a fixing part, a supporting part, a first sliding part and a second sliding part, the supporting part is connected to the fixing part, the first sliding part is slidably connected to the fixing part, the second sliding part is slidably connected to the fixing part, and the sliding direction of the second sliding part is parallel to the sliding direction of the first sliding part. The second sliding piece is located between the supporting piece and the first sliding piece, the projection area of the second sliding piece on the face A is not equal to the projection area of the first sliding piece on the face A. The face A is perpendicular to the sliding direction of the first sliding piece, and the side, away from the second sliding piece, of the first sliding piece is used for abutting against the bearing. Under the condition that fluid is not injected, the acting force of the first sliding piece on the bearing is minimum; when the fluid pressure intensity is a fixed value, fluid is injected between the supporting piece and the second sliding piece or between the second sliding piece and the first sliding piece so as to control the change of the acting force of the first sliding piece on the bearing; and the use requirements of multiple working conditions are met.

This invention provides a method for determining the size of a pulse wind tunnel test model, comprising: determining the flow field of the nozzle and test section using numerical simulation to obtain a uniform flow field region S1 in the wind tunnel; then calibrating the uniform flow field region S2 of the nozzle and test section using a cross-shaped frame, comparing the sizes of the two uniform flow fields S1 and S2, and selecting the smaller uniform flow field region S0 as the uniform flow field region S0; scaling down the selected model under the condition of maximum test angle, with the maximum projected area M1 of the model in the direction perpendicular to the airflow occupying 60% to 65% of the cross-sectional area of ​​the uniform flow field S0; integrating the scaled-down model with the nozzle and test section into a single model, numerically simulating the entire flow process under the condition of maximum angle of attack and / or sideslip angle test angle, redetermining the model scale based on the model installation position, the shock wave position at the leading edge of the model, and the coverage of the uniform flow field, and determining the upper limit of the model length through the effective test time and the velocity of the flow field in the test section.

This invention discloses a method and system for correcting the attitude of an airborne transient electromagnetic pod coil, belonging to the field of airborne geophysical exploration. It includes: a surface-scanning industrial camera module for real-time acquisition of image information of the suspended coil; an industrial-grade integrated navigation module for outputting inertial navigation data; a time synchronization and data acquisition module for establishing a time unification mechanism; a vision processing module for extracting visual features from the images processed by the time unification mechanism; an inertial navigation calculation module for obtaining the inertial navigation state of the coil attitude angle through angular velocity integration; a data fusion and attitude estimation module for performing fusion calculations based on the combined visual features and inertial navigation state to obtain the fusion result; and a projected area and magnetic moment calculation module for calculating the coil's projected area to the ground and the effective emitted magnetic moment component based on the fusion result. This invention reduces the system complexity and electromagnetic interference risk caused by multiple inertial navigation systems, and improves the detection accuracy and stability of airborne transient electromagnetic data.

[Problem] The present invention addresses the problem that when manufacturing a bottomed rectangular cylindrical body consisting of two pairs of long sides and two pairs of short sides from a metal material, the height of an open end surface of the four sides cannot be set in an extrusion molding process. [Solution] The rectangular cylindrical metal body of the present invention is obtained by adjusting a metal material such that the cross-sectional area thereof is larger than the projected surface area of the product in a plan view, and extrusion molding the metal material.

The invention provides a ship structure sheet body model weight gravity center rapid statistical method based on a 3DE platform, and the method aims at a sheet body model which only contains material specification information and has no thickness display attribute, and comprises the steps: constructing a density configuration table of a lightweight material, responding to the selection of a user for a segment / block / whole ship node, and obtaining a density configuration table of the lightweight material; extracting all part objects and hierarchical relationships thereof under the node; for a plate part, automatically calculating a projection area based on sheet body surface geometric data, and extracting a plate thickness; for the profile part, analyzing the geometric data of the profile center line to calculate the length, and associating the section specification library to obtain the sectional area; and carrying out batch calculation on the weight and the gravity center, and generating a verifiable statistical report: outputting a detail table containing the unique ID of the part, the weight and the gravity center coordinates, and a dosage table summarized according to material types. According to the technical scheme, aiming at the problem that the original function of the 3DE platform cannot rapidly measure the weight center of gravity of the structure sheet body model, the statistical efficiency of the weight center of gravity of the structure sheet body model is improved, and the design period is shortened.

The invention relates to the technical field of hardness detection, in particular to a wear-resistant material hardness detection method and system. The method comprises the following steps: in a loading and pressure maintaining stage, irradiating an indentation area by using a multi-angle discrete spectrum light source and synchronously acquiring an image sequence; identifying a microstructure heterogeneous area based on the reflectivity difference of the image to obtain a material microstructure heterogeneous degree parameter; reconstructing the three-dimensional surface topography of the indentation area, calculating the spatial deviation between the three-dimensional surface topography and the ideal indenter model so as to determine an asymmetric distortion parameter, and obtaining a corrected indentation projection area considering the influence of the heaving or sinking of the material; a hardness value is calculated by using a hardness calculation model, a weight coefficient of the model is adjusted according to a heterogeneity parameter, and input comprises correction of an indentation projection area and an asymmetric distortion parameter. According to the scheme provided by the invention, the accuracy and representativeness of hardness detection can be improved by comprehensively quantifying the three-dimensional shape distortion and the microscopic heterogeneity.

A structural member comprising a steel plate, the structural member having a flat plate section (10a) and a bent section (10b), the bent section (10b) satisfying the following formulae (1), (2), and (3). 28 < = [square root of] area < = 45 (1) 0.17 < = r / t < = 6.90 (2) 0.22 < = n '(3) where [square root of] area is the square root [mu] m of the projected area of a minute defect on the inside of the bend of the bend section (10b), r is the minimum value [mm] of the radius of curvature on the inside of the bend of the bend section (10b), t is the thickness [mm] of the flat plate section (10a), and n' is the quartile range / average nano-hardness of the nano-hardness of the flat plate section (10a).

The present invention relates to the technical field of laser grinding of diamond composite sheets in superhard material processing, and in particular to a laser grinding control system for diamond composite sheets, wherein a partitioning module is provided to divide a processing surface into concentric ring-shaped high, low and slope grinding zones based on data from a height measuring probe; a monitoring module synchronizes laser pulses to capture spark images, quantifies the projected area ratio, the maximum spark cluster diameter and the discreteness, and binds the polar coordinate position and the grinding zone number; a control module performs the first grinding with an initial removal amount, and dynamically adjusts the subsequent removal amount of each ring zone according to the abnormal distribution of sparks; a data feedback module determines that the abnormal points are concentrated in a single grinding zone and exceed a threshold value and provides feedback, which can effectively improve the grinding quality and provide effective data feedback to relevant technical personnel to facilitate timely tracing of quality problems, and can adapt to the processing control of flat or special-shaped diamond composite sheets.

This invention relates to an inner ring guided tapered roller bearing (1), wherein the small-diameter side annular portion (6) and / or the large-diameter side annular portion (7) of the retainer (5) have flange-like portions (6a, 7a) extending from the column portion (8) via arc-shaped curved portions (6b, 7b) towards the inner diameter side, and have slit-like oil passages (10, 11) at multiple locations on the inner periphery of the flange-like portions (6a, 7a); and the dimensionless number Z, determined by the following formula, is 1.55 or more and 2.66 or less, in which the projected area of ​​the oil passages (10, 11) in the bearing axial direction is represented by (A), the radius of curvature at the center of the width direction of the oil passages (10, 11) is represented by (r), and the inner diameter of the flange-like portions (6a, 7a) is represented by (D). I This indicates that the outer diameter of the curved portions (6b, 7b) is determined by (D). O This means: Z = AD I 2 / π(D O 2 -D I 2 )r 2 .

This invention relates to the field of new materials technology, specifically to a low-optical-distortion, spotless, large-curvature tempered glass and its forming method. The glass substrate includes a glass matrix with a preset curvature and a large projected area. The surface physical tempering stress value of the glass substrate is 90MPa~150MPa, and the stress difference between different areas of its surface is controlled within 5MPa. Under anisotropic observation conditions, the glass substrate has no visible stress marks on its surface, and its transmitted optical distortion intensity is no greater than 0.05 diopter, with reflection waviness controlled within a preset extremely low threshold. By precisely controlling the surface physical tempering stress value between 90MPa and 150MPa, and creatively controlling the stress difference between different areas of its surface within 5MPa, the stress gradient approaches zero. This extreme stress uniformity fundamentally eliminates the optical birefringence phenomenon caused by local stress abrupt changes, resulting in completely no visible stress marks on the glass under anisotropic observation conditions.

A gas turbine combustor includes a plurality of narrowing parts that protrude toward the inside of a combustion liner. The center axis of the combustion liner includes an upstream center axis, which linearly extends in an upstream region of the combustion liner, and extends in an ejection part in a direction that is different from the extension direction of the upstream center axis. The combustion liner includes a first region and a second region, the first region and the second region being divided by a virtual plane which includes the center axis from the upstream region to the ejection part, and the virtual plane is orthogonal to a virtual flat plane that includes the center axis. A straight line obtained by extending the upstream center axis passes through the first region in the ejection part. The total value of projected areas of the narrowing parts present in the second region as viewed from the extension direction of the center axis is larger than the total value of projected areas of the narrowing parts present in the first region as viewed from the extension direction of the center axis.

This invention discloses a method for rapidly calculating engineering quantities using BIM modeling with standard steel structure component families. It relates to the field of steel structure BIM quantity calculation technology, including the use of part families for steel structure component families; binding relevant parameters with relevant parameters of the part families; and creating project template files. This invention achieves precise binding of part-level parameters and, ultimately, relies on preset detail tables in the integrated project template file to realize automated and standardized output from the BIM model to the bill of quantities. This ensures that key quantity calculation data such as projected area and gross weight / volume are automatically generated and updated in real time during the modeling process, avoiding manual intervention and secondary processing, and significantly improving the accuracy and efficiency of quantity calculation. The output detail tables have unified fields, standardized formats, and clear semantics, and can be directly used by cost estimators for cost accounting and bidding, effectively breaking down the data barriers between BIM design and engineering cost.

The application relates to a 3D grid model projection area calculation method, device and storage medium, the method comprising: obtaining bounding box data of a 3D grid model; calculating a set-precision projection maximum area PA on a preset projection plane according to the bounding box data of the 3D grid model; obtaining the bounding box of a 3D primitive on the projection plane according to the vertexes of the 3D primitive in the 3D grid model; obtaining the coordinates PP of the vertex on the projection plane according to the centroid coordinates and the vertex coordinates of the triangle; obtaining the offset coordinates OPP of the coordinates PP relative to the minimum value of the bounding box of the 3D grid model; calculating an actual projection maximum area A according to the bounding box data of the 3D grid model; and calculating the projection area of the 3D grid model according to the offset coordinates OPP, the actual projection maximum area A and the set-precision projection maximum area PA. Through the application, the technical problem of low accuracy of projection area calculation in the prior art is solved.

The invention discloses an eccentric wheel structure and an air compressor, and belongs to the technical field of air compressors, the eccentric wheel structure comprises a circular first mounting part (1), and a first through hole (11) is formed in the position, deviating from the circle center, in the first mounting part (1); a second through hole (212) which coincides with and communicates with the axis of the first through hole (11) is formed in the second mounting part (2), one end of the second mounting part (2) is fixedly connected with the first mounting part (1) in the axis direction of the rotor shaft, and the other end of the second mounting part (2) is fixedly connected with the third mounting part (3) in the radial direction of the rotor shaft or is integrally formed with the third mounting part (3); the third mounting part (3) is formed into a sector ring shape and is used for a counterweight part of the eccentric wheel structure; the projection area of the second installation part (2) is located on the lower portion of the first installation part (1), and the projection area of the second installation part (2) is 60%-80% of the area of the first installation part (1). The gravity center of the eccentric wheel deviates in the direction of the third installation part, the mass center of the balance weight part is farther away from the rotation center, relative rotation inertia force is increased, the inertia force is improved, preparation materials are saved, and occupied space is reduced.