77 results about "Central line" patented technology

The invention discloses a method and device for extracting a centerline of a quasi-cylinder by using a point cloud, and the method comprises the steps: obtaining a quasi-circular target of which the centerline is to be extracted, and carrying out the three-dimensional point cloud scanning, and obtaining the three-dimensional point cloud data; point clouds of a target in the three-dimensional point cloud data are cut at equal intervals in the direction of the center line, and a plurality of annular point clouds with noise are formed; projecting the annular point cloud to a two-dimensional plane in a direction perpendicular to the center line; calculating distances from all point positions in the annular two-dimensional image to external points on the projection image; the probability of occurrence of each distance is calculated, and the position corresponding to the pixel when the probability is the maximum value is obtained as the plane center point of the annular point cloud corresponding to the two-dimensional image; associating z values of the annular point cloud during cutting in the direction of the center line to form three-dimensional coordinates of the center point; and connecting the three-dimensional coordinates of all the central points of the equally-spaced cutting annular point clouds to obtain the central line of the cylinder-like body. According to the invention, the extraction precision of the centerline of the quasi-cylinder and the extraction reliability of the centerline are improved.

The embodiment of the invention provides an underground pipeline extraction method, system and device based on point cloud and a storage medium, and belongs to the technical field of point cloud space geometry extraction. According to the scheme, underground pipeline point cloud data are obtained; segmenting the pipeline point cloud data to obtain a segmentation result; when the segmentation result is a single-pipe scene, principal component analysis and cylinder fitting are carried out based on all pipeline point cloud data to obtain a normal vector and a pipeline radius of each data point; performing plane cutting according to the normal vector to obtain a tangential plane, and obtaining a pipeline center line based on the tangential plane; determining a distance threshold parameter according to the radius of the pipeline; based on the distance threshold parameter, performing segmented straight line fitting on the pipeline center line through a random sampling consistency algorithm to obtain a center line point set; performing feature extraction on the center line point set to obtain feature points; determining a connection relationship of adjacent feature points according to the geometrical relationship; the pipeline reconstruction model obtained based on the connection relation can be suitable for complex scenes, and the calculation efficiency is improved.

The invention discloses a complex roadway network center line calculation method based on skeleton contraction, belongs to the technical field of underground mine three-dimensional modeling and point cloud data processing, is used for complex roadway network center line calculation, and comprises the following steps: establishing a neighborhood set of KDTree acquisition points for underground mine roadway point cloud data; calculating geometric features and neighborhood distances of the points according to the neighborhood point set; iteratively shrinking the underground mine roadway point cloud data; skeleton refinement is carried out according to geometric features of each shrinkage skeleton point, and discrete noise points are removed by combining an octree filtering method; processing the intersection area point set by using a principal component method and a DBScan algorithm, judging the type of the intersection, and performing center point refined calculation on each intersection; and the disordered center points are fitted into an ordered center line. According to the method, the integral roadway center line of underground mine well and roadway engineering can be accurately calculated, complex structural characteristics of crossing and staggering are overcome, and refined calculation is achieved for different roadway intersection types.

Disclosed in the present invention is a matrix transformation-based improved design method for a diffuser. Firstly, inlet and outlet position information of a diffuser is extracted, and then a double-coefficient adjustable polynomial is used to design a central line of the diffuser between the centroid of an inlet section and the centroid of an outlet section, and a change rule of the area of each section of the diffuser along the central line. In the aspect of transition of the shapes of an inlet and an outlet of the diffuser, once the inlet section and the outlet section have been mapped to a ξ-η space, a plurality of transition shapes between the inlet section and the outlet section are obtained by using a matrix transformation-based improved algorithm. The shapes of the inlet and the outlet, and each transition shape jointly form the shape of each local section of the diffuser along the central line. On the basis of the shapes of the sections, the change rule of the sectional area, and the change rule of the central line, the final three-dimensional geometry of the diffuser can be constructed under an o-xyz three-dimensional coordinate system, and the three-dimensional geometric modeling of the diffuser can be flexibly and controllably designed.

The invention provides a real-time environment construction method fusing perception and a navigation map. The method comprises the following steps: step 1, obtaining fusion perception information and navigation information; 2, obtaining semantic matching information, and dividing a scene into a road section scene and an intersection scene; step 3, respectively performing map construction according to preset construction rules; 4, acquiring navigation information of the intersection scene, and performing curve fitting; 5, calculating the cost value of the topological connection relation of the road information group; 6, calculating the cost values of the center lines of the front and rear lanes with the topological relation, and judging whether the center lines of the two lanes need to be smoothed or not; step 7, when a preset smoothing condition is satisfied, smoothing the distance X of each lane center line before and after cutting off to form a lane center line; and step 8, starting from the lane center line without the precursor relation, iteratively searching the subsequent relation until the searched object has no subsequent relation, and constructing a lane-level guide line.

The invention relates to the field of building informatization models, and discloses a linear engineering three-dimensional modeling method and system, and the method comprises the steps: S1, reading plane data of a line center line, carrying out the differential processing of a curve segment into a plurality of straight line segments, and calculating the actual length of each line segment and a stake number corresponding to each point; s2, reading the longitudinal section data of the line center line, and when the mileage and the elevation of the longitudinal section adopt different proportions, carrying out conversion to obtain converted longitudinal section data; s3, calculating coordinates of elevation inflection points according to the converted longitudinal section data, inserting the elevation inflection points into the plane data, and then calculating the elevation of each vertex by using an interpolation method to obtain three-dimensional coordinates of each vertex; and S4, drawing a three-dimensional path corresponding to the line center line according to the three-dimensional coordinate of each vertex. According to the method, the three-dimensional center line can be quickly generated through the center line and the longitudinal section of the existing two-dimensional plane graph.

The application discloses a kind of automatically generated river section and feature extraction method, comprising: by specified numerical value, along the river center line / longitudinal axis line generation point, and point is set to number along river direction, and adjacent line recursive generation center line is given to these line number;According to the order of numbering, traverse point, and make perpendicular to its adjacent line;Generation perpendicular segment and the intersection of adjacent line, and these intersection points are given the numbering value consistent with point;With intersection point along the direction of existing perpendicular segment, continue to make perpendicular to its adjacent line;Respectively, the intersection of perpendicular segment and adjacent line is solved, and these intersection points are given the numbering consistent with the starting point of perpendicular segment;Until perpendicular segment reaches river boundary;According to center line number and the intersection point number of generated perpendicular segment, line segment is generated, and automatic section establishment is completed;Information extraction point is generated by the generated section line;Extract section two / three-dimensional grid data information.The application realizes the automatic section generation and attribute extraction of river with relatively severe width and curvature variation.

The present invention relates to a method for simulating and modeling the projection of the automatic fiber placement trajectory of a composite material. The method includes the following steps: obtaining the center point coordinates by averaging the coordinates of all nodes of the calculation unit; making a perpendicular projection point from the center point coordinates to the center lines of all tow trajectories of the currently selected ply, calculating the shortest distance from the center point to the center lines of all tow trajectories of the selected ply using the distance formula after obtaining the projection point coordinates, and selecting its tow trajectory by comparing all the above shortest distances; making a tangent to the selected tow trajectory such that the tangent passes through the projection point; calculating the dot product of the tangent vector and the ply coordinate system of the calculation unit to obtain the true ply angle of the single layer of the selected calculation unit, and replacing the theoretical ply angle of the single layer of the selected calculation unit with the true ply angle. The present invention obtains an accurate and true ply angle and can accurately simulate the structural performance of the actual automatic fiber placement.

The invention discloses an AUV underwater local path planning method and system based on an improved VFH algorithm, and the method comprises the steps: converting the environment where an AUV is located into a three-dimensional grid map, obtaining the distance data of the surrounding environment of the AUV, processing the data, setting the advancing direction, dividing a space into beta * omega spherical sectors according to the resolution alpha, and carrying out the calculation of the beta * omega spherical sectors; calculating an obstacle strength value and determining a sector to which each grid belongs, constructing a sector strength matrix graph for the three-dimensional grid map, setting a threshold value and screening passable sectors, combining adjacent passable sectors and selecting reserved wide valleys, and calculating cost by adopting an improved cost function; the method comprises the following steps: selecting a geometric center line direction with minimum cost and reserved wide valley as a moving direction, constructing a three-dimensional dynamic situation field, calculating a step length base value according to a potential field gradient and an adaptive step length formula, performing correction and dynamic adjustment processing, then determining a final step length, moving the AUV according to the final step length, updating the state, and circulating until the AUV reaches a target. And safe and efficient path planning of the AUV is realized.

The invention relates to a torsion angle description and analysis method of a sectional material bending and torsion component, and relates to the field of advanced manufacturing of complex sectional material bending components. The method comprises the following steps: respectively extracting NURBS parameters on edges and a center line of a section bending and twisting component, carrying out parameterized point distribution according to an arc length to obtain curvatures and coordinates of all points on a curve, and finally calculating section torsion angles at different positions on the center line by constructing a torsion vector and a projection plane and combining matrix transformation. Under the condition, a torsion angle parameter analysis method is provided for manufacturing the section bending and twisting component through the six-axis free bending and twisting technology, the torsion angle change of the section bending and twisting component along all the sections of the axis can be accurately described, and the manufacturing precision of the six-axis free bending and twisting technology is further improved; in addition, the method is simple, feasible and high in analysis efficiency, and has important engineering application value and obvious economic benefits in the fields of aerospace and new energy automobiles.

The invention relates to a triangular indexable blade clamping phase error measuring method, and belongs to the technical field of machine tool blade machining. According to the method, a triangular indexable blade blank is clamped on a workpiece clamp of a peripheral edge grinding numerical control machine tool, and according to the machined triangular indexable blade blank and actual geometric characteristics of the machined triangular indexable blade blank on the machine tool, the included angle of the center lines of a triangle A0B0C0 clamped without eccentric errors and a triangle ABC actually clamped is obtained, namely the phase error. The method is input into a machine tool, and phase errors generated by blade clamping can be measured and eliminated. The method has the characteristics of high efficiency, high accuracy, wide applicability and the like.

The invention relates to a method, device and equipment for positioning channels and collaterals based on three-dimensional point cloud information, and the method comprises the steps: generating a pseudo-color space through extracting depth information according to human body three-dimensional point cloud data, extracting a human body foreground region in the pseudo-color space, and segmenting and projecting the human body foreground region according to a human body proportion and a topological relation. Generating central coordinates of each region of the human body, obtaining a human body center line, and generating human body back meridians according to the human body center line and the human body foreground region through a traditional Chinese medicine meridian equal-body-cun theory. According to the method, multi-layer grid aggregation calculation can be adopted, point cloud noise interference is effectively suppressed, and the stability of generated coordinates is improved; based on the equal-body-size principle of traditional Chinese medicine, different human body shapes are automatically adapted through percentage grid positioning; and a center line among the head, the neck and the waist can be accurately obtained, and a reliable reference is provided for calculation of human body back meridians and collaterals.

A road center line determination method, device, equipment and storage medium are disclosed. The method comprises: acquiring a first boundary contour line and a second boundary contour line on both sides of a target road; determining an outer bounding rectangle of the boundary contour line and a projection point of each boundary point on the outer bounding rectangle; extending a connecting line between each boundary point and the corresponding projection point, determining a first associated point intersecting the contour line, and taking a midpoint between each boundary point and the corresponding associated point as a feature point corresponding to the boundary point; based on the change direction of the boundary contour line, sorting each first feature point and each second feature point, and based on the sorted feature point sequence, determining a center line corresponding to the target road. Through the technical scheme of the embodiment of the present application, the determination efficiency and accuracy of the road center line can be improved, and the combined center line can perfectly retain the geometric shape of the original two lines.

The embodiment of the present application provides a method, system, device and storage medium for underground pipeline extraction based on point cloud, which belongs to the field of point cloud spatial geometry extraction technology. The solution obtains underground pipeline point cloud data; segments the pipeline point cloud data to obtain segmentation results; when the segmentation result is a single-pipe scene, principal component analysis and cylinder fitting are performed based on all pipeline point cloud data to obtain the normal vector and pipeline radius of each data point; plane cutting is performed according to the normal vector to obtain a tangent plane, and the pipeline centerline is obtained based on the tangent plane; the distance threshold parameter is determined according to the pipeline radius; based on the distance threshold parameter, the pipeline centerline is segmented and fitted with a straight line by a random sampling consistency algorithm to obtain a centerline point set; feature extraction is performed on the centerline point set to obtain feature points; the connection relationship between adjacent feature points is determined according to the geometric relationship; the pipeline reconstruction model is obtained based on the connection relationship, which can be applied to complex scenes and improve computational efficiency.

The present application belongs to the field of mechanical design, and particularly relates to a method for extracting a center line of a rod body based on internal point array information of a three-dimensional model. The method comprises the following steps: S1, extracting an outer surface and a bounding box information of a rod body model with a cross-sectional radius R of the rod body; S2, generating an initial point array in the bounding box; S3, extracting a point inside the rod body model and a nearest point of the point to the outer surface of the rod body model; S4, calculating coordinates of a center O of a rod body cross section corresponding to each point in a point array sub-set extracted in step S3; and S5, performing curve fitting on all points O to obtain a center line of the rod body model. The present application can realize fast extraction of a center line of a non-straight rod body three-dimensional model, and is particularly suitable for application in a rod body design environment with a relatively complex shape.

The present invention discloses a method for measuring the angle of a probe of a three-dimensional coordinate measuring machine, belonging to the technical field of three-dimensional coordinate measuring machines, comprising: measuring the pitch angle of the probe: obtaining the center point O of the Z axis; when the probe swings during the process of measuring a workpiece, obtaining the center point B of the probe at this time; obtaining a perpendicular line between point B and the center line of the Z axis, and the intersection of the perpendicular line and the center line of the Z axis is recorded as point C; obtaining the straight-line distance S1 between point O and point B, obtaining the distance H1 between point O and point C, obtaining the distance L1 between point B and point C, and using inverse trigonometric functions to determine the angle θ between straight line S1 and straight line H1. The present invention collects the probe signal of the three-dimensional coordinate measuring machine in real time, and the signal from the edge sensor of the turntable in real time. By collecting the probe signal and the sensor signal, the position relationship is determined by using the three-point plane, and a related calculation method is constructed to obtain the rotation angle and the pitch angle, which is conducive to improving the measurement accuracy of the workpiece.

The invention provides a baseline iteration adjustment method of a tunnel three-dimensional model, and belongs to the technical field of tunnel modeling. The method comprises the steps of obtaining a three-dimensional model of a tunnel through photogrammetry; according to the center line of the tunnel and the section information of the tunnel, the first discrete points in the center line are shifted to the side walls of the tunnel, so that coordinates of the second discrete points on the design lines of the side walls on the two sides of the tunnel are obtained. In the extending direction of the three-dimensional model, a plurality of first feature points are marked at the corresponding hole openings in the three-dimensional model, and a plurality of second feature points are marked in the corresponding hole bodies in the three-dimensional model. And endowing the coordinates of a second discrete point at the portal of the tunnel to the first feature point to obtain the coordinates of a second feature point. And correcting the coordinate of the second feature point through the accumulated chord length of the second feature point in the extension direction of the three-dimensional model. And correcting the coordinates of the second feature point again by calculating the shortest distance from the second feature point to the design line. According to the adjusting method, the precision of tunnel three-dimensional modeling can be improved.

The invention provides an airway geometric parameter measurement method and system, and relates to the technical field of medical image processing, and the method comprises the steps: obtaining airway foreground voxel data corresponding to a chest CT, and converting a voxel index coordinate into a world physical coordinate according to image space meta-information; obtaining a center line point set through three-dimensional skeletonization, establishing candidate connecting edges in a preset neighborhood, generating a topological tree based on a strategy with branch penalty terms, and completing branch segmentation and generation coding; the method comprises the steps that firstly, a tail end branch meeting a preset condition serves as a starting point for backtracking, the section area and the section equivalent diameter of each node slice are calculated, branch node direction vector score cross angle parameters are fitted, finally, a structured file is summarized and output according to algebraic labels and other dimensions, and stable measurement and standardized output of airway multi-scale geometric parameters can be achieved. And the comparability and repeatability of group scale analysis are improved.

The utility model provides a plotter for mathematics, which relates to the technical field of plotters and comprises a fixing seat, a sliding groove is arranged at the top of the fixing seat, a rotating ring is arranged in the sliding groove, a top plate is fixedly connected to the top of the rotating ring, and a center line is fixedly connected between the inner walls of the top plate. According to the drawing device, the drawing device is placed on the blackboard, the drawing device can be adsorbed to the blackboard through the suction cup, fatigue caused by long-time supporting of a worker is avoided, the ruler is manually pulled to move left and right, the center line and the scale line serve as reference, the radius of a graph is determined accordingly, the ruler is fixed by tightening the first locking bolt, and the drawing device is convenient to use. The straight ruler is made of transparent acrylic plate materials, the relative position between the pointer and the angle line is observed through the straight ruler, accordingly, the included angle of the circle center of the arc is determined, and the drawing efficiency is greatly improved.

The application discloses a center line to inner hole bottom surface vertical distance gauge for a reducer shell bearing hole, which comprises a base unit, a calibration unit, an auxiliary unit and a measuring unit; the measuring unit comprises a measuring table and a table seat for mounting the measuring table; the calibration unit comprises a calibration piece arranged on the plane of the base unit, and the height of the calibration piece is designed as the standard vertical distance between the lowest point of the bearing hole and the inner hole bottom surface minus the radius of the bearing hole; the auxiliary unit comprises an auxiliary base, and the calibration part of the auxiliary base is tightly attached to the plane of the base unit; the table seat is arranged on the auxiliary base; the mechanical reference conversion of the calibration piece and the auxiliary base converts the complex three-dimensional space measurement into simple height difference comparison, the single measurement time is greatly shortened, the efficiency is improved compared with the traditional three-coordinate measurement, the cost of the gauge is reduced, the enterprise cost is significantly reduced, and the operation is simple, so that workers can quickly and simply start and complete standardized detection.

The invention provides an automatic calculation method for a rail transit shield interval evacuation platform, and the method comprises the steps: opening a plane design scheme file after an AutoCAD secondary development program is operated, and reading road design scheme data and tunnel inner diameter data; the method comprises the following steps: inputting and storing a rail transit shield interval tunnel rail ultrahigh value, a rail structure height, a center line offset and a corresponding mileage range, setting design parameters of an evacuation platform, determining a platform design range, segmenting the evacuation platform, and calculating the distance between the outer side of the evacuation platform and a line center line in a segmented manner; calculating the clear distance from the center line of the shield interval tunnel line to the evacuation platform, and determining the width of the evacuation platform; the digital and intelligent level is greatly improved, the data accuracy is 100%, and compared with a traditional manual calculation mode, the calculation efficiency and the calculation precision are greatly improved.

The invention discloses a device for acquiring a center line of a tubular substructure and marking the tubular substructure and equipment for analyzing a medical image. The device comprises a trained backbone unit which extracts semantic information and depth information of the medical image; the trained centrality head is used for receiving the semantic information and the depth information and predicting the centrality of the tubular substructure; a trained landmark header which receives the semantic information and the depth information and predicts a starting point and an ending point of the tubular substructure; and the information integration unit is used for extracting center lines of the tubular substructures according to the starting point and the ending point by using a tracking algorithm and taking the centrality as a loss field, and the information integration unit sorts the center lines and marks the tubular substructures according to the center lines. The device for acquiring the central line of the tubular substructure from the medical image and marking the tubular substructure and the equipment for analyzing the medical image have higher robustness.

Proposed are a method and an apparatus for detecting the diameter of a tubular structure in a medical image. The apparatus may identify the tubular structure in a two-dimensional or three-dimensional medical image, and calculate a distance map indicating a distance from each point inside the tubular structure to a boundary of the tubular structure. The apparatus may also calculate central points, based on a gradient of a distance value in the distance map, and connect the central points to create a center line. The apparatus may further obtain the diameter of the tubular structure for each location by determining a distance between the center line and the boundary of the tubular structure in a direction perpendicular to the center line.

To provide a ball screw design method and a ball screw that can secure smooth ball movement and cope with high speed movement.SOLUTION: In a ball screw design method, when a ball diameter is represented as Da, the length of a straight line between two curved lines as L, a ball pitch angle on the curved line as θb, and a central angle of the curved line as θr in the case where there exists a straight line between the two curved lines whose radiuses are the same as a central line of a circuit, an angle ratio of the curved lines is defined as θr / θb, and the θr / θb is determined as (A) θr / θb≒n+0.25 (n being an optional integer), or (B) when θr / θb≒n+0.25 is not satisfied, the value of L is set so as to satisfy formulas (1) and (2): (1) L / Da+θr / θb≒n+0.5 (n being an integer), (2) L≒(n+0.5-(θr / θb))×Da.SELECTED DRAWING: Figure 4

The invention belongs to the field of general drawing design and construction management of industrial enterprises, particularly relates to a statistical calculation method, system and equipment for the road area of an industrial enterprise, and aims to solve the problems of tedious operation, low efficiency and high error rate in the prior art. The method comprises the following steps: acquiring a road drawing of which the area is to be calculated, acquiring side lines and a center line in the road drawing, and establishing a side line set and a center line set; any graph line in the sideline set is obtained, and whether the graph line is a straight line or an arc line is judged; virtual points and virtual line segments are obtained based on the straight lines and the arc lines, all blocks are obtained by combining the center lines, and the road area is obtained by accumulating the areas of all the blocks. According to the method, the work of copying road side lines, enclosing boundaries, modifying and filling and the like is omitted, a large amount of time is saved, and compared with the background technology, the work efficiency is greatly improved.

The application discloses a complex conduit first-order continuous center line reconstruction method based on scanning point cloud data and belongs to the field of engine geometric parameter digitization detection. After obtaining scanning point cloud data of an outer surface of a conduit, straight pipe data and curved pipe data of the complex conduit are segmented. For the segmented straight pipe and curved pipe data, random sampling cylinder fitting and circle fitting operation based on intersection of a vector point and a main plane are respectively performed to obtain trend lines of the straight pipe and the curved pipe. For the trend lines of the straight pipe and the curved pipe, center points of different pipe sections based on equally-spaced vertical section planes are solved, and linear fitting is respectively performed on the center points of the different pipe sections to obtain a plurality of discontinuous center line sections of the complex conduit. A cubic spline curve is adopted to perform first-order derivative interpolation fitting between adjacent straight line sections and circular arc section center lines to obtain a complex conduit first-order derivative continuous center line. The reconstructed center line is used as a reference for calibration of a pipe special-purpose measuring device measuring capacity.

This invention relates to a rapid method for determining conical field-of-view occlusion, comprising: S1, setting Δ blk Let the occlusion triangle be represented by its three vertices A, B, and C, and the center line of the conical field of view. Determine the occlusion triangle Δ. blk Does the plane S containing the antenna reflector aperture intersect with the conical field of view? If they intersect, then the Δ on the upper part of plane S... blk Divided into (Δ blk )1、(Δ blk S2; Determine whether it is consistent with (Δ) blk S1. Intersect; S3. Determine if any of A, B, and C is inside the conical field of view; S4. Determine Δ blk Does there exist an edge that intersects the conical field of view? S5, If (Δ blk If 2 is not empty, then for (Δ) blk 2. Repeat steps S2 to S4; traverse the triangular mesh of all obstructions; traverse the azimuth of all conical fields of view to determine the azimuth of the obstructed conical fields of view. This invention enables rapid and quantitative calculation of the spatial distribution of the azimuth of a two-axis rotatable point beam antenna when it is obstructed by a star.

The application discloses a tunnel three-dimensional center line extraction method based on octree occupancy map and distance transformation, which takes tunnel scene point cloud sequences registered to the same global coordinate system as input, incrementally constructs a global octree occupancy map to obtain an occupancy leaf voxel center point set, extracts a candidate occupancy voxel center point set and performs three-dimensional principal component analysis to obtain a stable axial direction, constructs a cross-section plane along the stable axial direction, extracts a point set within the slice thickness range, projects the point set to a two-dimensional coordinate system, rasterizes a cross-section obstacle grid, performs two-dimensional distance transformation, takes a point corresponding to a maximum value of a distance field as a maximum inscribed circle center, and back-projects the point to obtain a slice center point and a clear radius, accumulates continuous effective center points, applies a maximum turning angle constraint, and outputs a tunnel three-dimensional center line. The application does not require strict alignment of the input tunnel coordinate system Z-axis with the gravity direction, and does not depend on an odometer trajectory or a platform attitude estimation axial direction, and is suitable for straight or curved tunnel structures with longitudinal slopes.

The application discloses a shot specimen deformation analysis method, device, equipment and storage medium. The principal component analysis of point cloud data can determine the geometric center, major axis, minor axis and minor axis, automatically adapt the specimen placing posture and eliminate the influence caused by the position deviation. The point cloud projection based on the feature data can simplify the three-dimensional data into two-dimensional data, reduce the subsequent processing complexity while retaining the key deformation features. The preprocessing of the projected point cloud can improve the point cloud continuity, eliminate noise and void, generate a clear and stable optimized image, and ensure the accuracy of the subsequent center line extraction. The extraction of the center line corresponding to the optimized image and the back projection can obtain an accurate and continuous three-dimensional center line point cloud, avoiding the deviation caused by manual intervention. The deformation analysis of the shot specimen based on the center line point cloud can realize the accurate calculation of the curvature and the equivalent arc height and the automatic verification of the simulation model, and comprehensively improves the reliability and efficiency of the deformation evaluation.

This invention discloses a design method for a volute, a volute itself, a volute assembly, and a range hood. The design method includes: determining the base circle diameter of the volute and drawing the base circle; drawing N center lines based on the center of the base circle, each center line passing through the center of the circle, and the angle between any two adjacent center lines being a preset angle; selecting one center line as the 0° center line, and determining the position of the first main spiral control point on the 0° center line, setting a second main spiral control point on the 90° center line, and setting a third main spiral control point on the 270° center line; determining the position of the spiral control points on the remaining center lines based on the spiral radii of the spiral control points on the N center lines forming a second-order arithmetic sequence; and obtaining a complete spiral by connecting the positions of the N spiral control points using spline curves. This volute design method is simple and reliable, and can quickly design volutes suitable for large airflow conditions.