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41 results about "Surface equation" patented technology

Thermal-mechanical coupling simulation-based method for evaluating thermal insulation property of light regenerated building block

The invention relates to a thermal insulation evaluation method for a light recycled building block based on thermal coupling simulation, which comprises the following steps: modeling the recycled building block into a heterogeneous multiphase complex, and introducing a three-layer structure field of micro pores, mesoscopic aggregates and macroscopic blocks; a partition coupling strategy is adopted, a microstructure variability-heat flux density disturbance-stress field reconstruction causal chain is constructed, and macroscopic thermal insulation performance fluctuation caused by thermal deformation is captured; tracking a thermal stress concentration area caused by temperature difference change through thermal and force coupling simulation; analyzing the influence of a thermal stress migration path on local structure integrity, pore change and crack evolution; constructing a thermal stress and structure disturbance factor framework, and evaluating the influence degree of the structure local deformation on the thermal resistance; extracting high-dimensional feature data; establishing a heat and force characteristic space; constructing a response surface equation, and mapping a change track of the thermal insulation performance in a heat and force coupling response space; a time and structure response composite scoring system is formed, real coupling of multiple physical fields is achieved, and limitation of traditional evaluation is broken through.
Owner:CHINA CONSTR FIFTH ENG DIV CORP LTD

Workpiece polishing track generation method and device

The invention relates to a workpiece polishing track generation method and equipment, and the method comprises the steps: collecting a current workpiece surface point cloud, carrying out the plane fitting, obtaining an upper surface equation and an upper surface point cloud, projecting the upper surface point cloud to the upper surface equation, obtaining a two-dimensional projection drawing, obtaining the template workpiece contour of each type of template workpiece, and carrying out the polishing of the workpiece. And calculating the polishing track points of each type of template workpiece, matching the two-dimensional projection drawing with the contour of the template workpiece to obtain the corresponding polishing track points, and back-projecting the polishing track points to the three-dimensional space to obtain the three-dimensional polishing track of the current workpiece. The problem that the workpiece surface polishing track cannot be quickly and effectively recognized in the prior art is solved.
Owner:SPEEDBOT ROBOTICS CO LTD

Flame surface database construction method and device, equipment and storage medium

The invention discloses a flame surface database construction method and device, equipment and a storage medium, and relates to the technical field of database management. Comprising the steps of performing data partitioning processing on a discrete post-mixed score space and a scalar dissipation rate in a target thermodynamic system based on a preset data partitioning method so as to obtain a data base point formed by a partitioned post-mixed score and a partitioned post-scalar dissipation rate; determining a constraint value set corresponding to the data base point according to a constraint flame surface equation corresponding to each constraint in the target thermodynamic system; solving the constraint potential energy form equation of each constraint in the constraint value set to obtain a corresponding constraint potential energy value, and determining the mass fraction distribution of each component corresponding to the data base point in the target thermodynamic system based on the constraint potential energy value, so as to construct a target flame surface database based on the temperature distribution and the mass fraction distribution corresponding to the data base point. In this way, the dimensionality of solving the equation set is reduced by reducing the number of the components of the control equation for describing the system to the number of the constraints.
Owner:SICHUAN TIANFU FLUID BIG DATA RES CENT

Five-axis machining tool path planning method for complex curved surface

The invention discloses a five-axis machining tool path planning method for a complex curved surface, and relates to the technical field of numerical control machining. Subregions are divided based on the Gaussian curvature of a curved surface model, and a region equation is fitted; projecting the sub-regions and screening to obtain a boundary point set, fitting a curved surface equation by adopting cubic NURBS, and performing normal vector and curvature constraint optimization to splice an optimal curved surface equation; setting a section plane, calculating a section curve, calculating an arc length based on a Simpson formula, and planning a track point coordinate sequence according to the curvature; constructing a spiral equation of adjacent section planes, calculating a spiral step length based on a Simpson formula according to a position and tangent continuous constraint solving coefficient, and generating a cross-plane track point sequence; in the section plane, based on lossless and cutting direction constraints, an optimal angle sequence is obtained through optimization of a genetic algorithm, and a cross-plane angle sequence is obtained through cosine interpolation; and a machining pose sequence is generated through integration, and high-precision machining of the complex curved surface is achieved.
Owner:信阳星原智能科技有限公司

Slope three-dimensional finite element analysis-based safety coefficient prediction method and application

The invention provides a safety coefficient prediction method based on slope three-dimensional finite element analysis and application, and relates to the field of hydraulic geotechnical engineering. Comprising the following steps: inputting a finite element grid, and calculating a geometric topological relation of the three-dimensional finite element grid; the method comprises the following steps: inputting position information and mechanical parameters of a bottom sliding surface and a side sliding surface of a possible sliding block, calculating to obtain a description equation of the possible sliding block, performing cutting calculation by utilizing a sliding surface equation and geometry of a finite element grid to obtain polygons of a boundary surface of the sliding block, decomposing each polygon into triangular grids, and analyzing a stress result based on a slope finite element to obtain a stress result of the boundary surface of the possible sliding block. Calculating stress values of triangular mesh nodes of the boundary surface through line interpolation; integration is carried out on the sliding force and the anti-sliding force of the boundary surface, and the safety coefficient of the possible sliding block body is calculated; according to the method, efficient intersection of the sliding surface and the finite element grid is achieved, geometric processing efficiency is improved, calculation efficiency and calculation accuracy are improved, and the method is suitable for three-dimensional irregular sliding block analysis in the fields of water conservancy, mines and the like.
Owner:CHINA YANGTZE POWER

Rock quality index calculation method, system, equipment and medium

The invention discloses a rock quality index calculation method, system and device and a medium, and the method comprises the steps: determining a three-dimensional point cloud in response to a rock mass quality index calculation request; determining three-dimensional point cloud reconstruction data based on the distance between the three-dimensional point cloud and the fitting plane, and generating a three-dimensional point cloud image based on the three-dimensional point cloud reconstruction data; segmenting a surrounding rock structural surface of the three-dimensional point cloud picture; constructing a first roadway surrounding rock three-dimensional body which does not contain a surrounding rock structural surface; determining a second area corresponding to the surrounding rock structural plane in the three-dimensional point cloud reconstruction data according to the first area of the surrounding rock structural plane in the three-dimensional point cloud picture, and fitting the three-dimensional point cloud reconstruction data of the second area to form a structural plane equation; segmenting the first roadway surrounding rock three-dimensional body for the first time according to a structural plane equation to obtain a second roadway surrounding rock three-dimensional body containing a surrounding rock structural plane; the second roadway surrounding rock three-dimensional body is subjected to second segmentation, the rock mass quality index is calculated according to the second segmentation result, and high efficiency and lossless measurement of the rock mass quality index can be achieved.
Owner:CINF ENG CO LTD

Method and device for compensating dispensing height through curved surface fitting

The invention discloses a method and device for compensating the dispensing height through curved surface fitting. The method comprises the steps that three-dimensional coordinate point information of a plurality of discrete sampling points on the surface of a to-be-dispensed target is collected; building a polynomial of a curved surface model for compensating dispensing according to the number of the sampling points; constructing a matrix, and constructing a linear equation set based on the primary function; and the weight coefficient of the linear equation set is solved through a Gaussian elimination method, a fitted quadric surface equation after interpolation calculation is obtained, and the dispensing height is compensated based on the quadric surface equation. According to the method, the polynomial is fitted through the three-dimensional coordinate point information, the linear equation set is constructed, the predicted compensation value is obtained after interpolation calculation is carried out according to the fitting result so as to compensate the dispensing height, the high-precision continuous curved surface model can be constructed by collecting discrete sampling points, real-time interpolation calculation of any coordinate is supported, and the precision of the dispensing height is improved. The method can solve the problem of insufficient fitting precision of dispensing height compensation based on a single plane.
Owner:SHENZHEN TENSUN IND EQUIP

Optimization-based three-dimensional model complex gap repairing method

The invention discloses a method for repairing a complex gap based on an optimization three-dimensional model. The method comprises the steps that a B-Rep model of a product needing to be repaired is obtained through modeling in a computer, then all edges of the B-Rep model are traversed to obtain gap edges, a connection relation graph of all the gap edges is constructed according to the gap edges, the connection relation graph is searched to obtain all ring structures, and the ring structures of the product needing to be repaired are obtained. The method comprises the following steps: processing according to a ring structure to obtain all edge pairs meeting conditions, sampling the obtained edge pairs, processing all sampling points obtained by sampling to obtain an overall optimization error of the edge pairs, and continuously optimizing the edge pairs according to the overall optimization error to finally obtain a repaired curved surface equation. And finally, repairing the B-Rep model of the to-be-repaired product according to the obtained repairing curved surface equation so as to manufacture a repaired product. According to the method for automatically repairing the complex gap based on optimization, the model repairing capability and effectiveness can be effectively improved.
Owner:ZHEJIANG UNIV

A method and apparatus for shallow foundation reliability analysis

The application discloses a shallow foundation reliability analysis method and device. The method comprises the following steps: selecting a deterministic bearing capacity envelope surface equation of a shallow foundation according to requirements; obtaining a probability single-axis bearing capacity sample set; converting the deterministic bearing capacity envelope surface by using the probability single-axis bearing capacity sample to generate a large number of probability bearing capacity envelope surface samples; setting a load combination sample according to requirements, comparing the load combination sample with the bearing capacity envelope surface sample, and carrying out reliability analysis by combining a performance function and a Monte Carlo simulation. The core of the application is to solve the probability single-axis bearing capacity, combine the deterministic bearing capacity envelope surface equation, construct the probability bearing capacity envelope surface, and carry out the shallow foundation reliability analysis by using the Monte Carlo simulation. The method avoids numerical analysis for different load combinations respectively, greatly improves the calculation efficiency, and is simple in principle and convenient to use, thereby providing an efficient and practical tool for the shallow foundation reliability analysis under complex geological and load conditions.
Owner:SOUTH CHINA UNIV OF TECH

Quadratic surface fitting method, model training method, model reasoning method and equipment

The embodiment of the invention provides a quadric surface fitting method, a model training method, a model reasoning method and equipment, and relates to the technical field of computer vision, and the quadric surface fitting method comprises the steps: determining a local PCA coordinate system corresponding to a local curved surface where a target point is located through a PCA method; and then, converting a Mongolian equation corresponding to a local curved surface where the target point is located into a local PCA coordinate system to obtain an implicit curved surface equation. Then, solving the implicit curved surface equation according to the position information of the target point cloud block in the local PCA coordinate system, and obtaining the value of an item to be solved; and finally, according to the value of the item to be solved, obtaining a differential characteristic parameter of the local curved surface. According to the technical scheme, the quadric surface fitting precision can be improved, and more accurate differential characteristic parameters can be obtained.
Owner:ALIBABA (CHINA) CO LTD +1

A parametric modeling method for modified helical gears

A parametric modeling method for modified helical gears, wherein the modified gear involute is obtained by rotating the standard gear involute around the center of a base circle by σ radians, and the homogeneous coordinate transformation method and the scanning and cutting operation of the three-dimensional CAD software are adopted. The modeling of the modified helical gear tooth surface utilizes the scanning and cutting operation of the three-dimensional CAD software, the scanning path is the tooth modification curve, and the scanning profile is the tooth profile modification curve, and the method includes the following steps: (1) calculating the tooth profile modification curve and the surface equation; (2) establishing a two-dimensional sketch of the tooth profile of the modified helical gear; (3) calculating the tooth modification curve and the surface equation; (4) performing the scanning and cutting operation along the tooth modification curve and creating a three-dimensional geometric model of the modified helical gear. The invention solves the problem of establishing models of modified helical gears of different modification types, and the modeling process is simple, the modeling difficulty is reduced, and the modeling accuracy is improved.
Owner:SHANDONG UNIV

Planetary roller screw pair axial clearance calculation method, device, equipment and system

The invention discloses a planetary roller screw pair axial clearance calculation method, device, equipment and system, and belongs to the field of axial clearance calculation. The method comprises the following steps: constructing an ideal section coordinate system of actual meshing points of a lead screw, a roller and a nut under the condition of no machining error; actual machining errors of the lead screw, the roller and the nut are obtained respectively, and an actual spiral curved surface equation is obtained based on the machining errors; a meshing equation is obtained based on the spiral curved surface equation; and finally obtaining the axial clearance based on the meshing equation. According to the scheme, the screw rod, the pin roller and the nut are constructed into the spiral curved surface model containing various machining errors, the five-element nonlinear meshing equation set is established based on the position consistency and the normal consistency, the actual meshing point and the normal gap under the error condition are obtained through solving, then the actual meshing point and the normal gap are converted into the axial gap, and therefore the machining precision of the screw rod is improved. And accurate gap calculation under error coupling is realized.
Owner:INNER MONGOLIA UNIV OF TECH

Shallow foundation reliability analysis method and device

The invention discloses a shallow foundation reliability analysis method and device. The method comprises the steps that a deterministic bearing capacity envelope surface equation of the shallow foundation is selected according to requirements; obtaining a probability uniaxial bearing capacity sample set; converting the deterministic bearing capacity envelope surface by utilizing the probability uniaxial bearing capacity sample to generate a large number of probability bearing capacity envelope surface samples; setting a load combination sample according to requirements, comparing the load combination sample with a bearing capacity envelope surface sample, and carrying out reliability analysis in combination with a performance function and Monte Carlo simulation. The core of the method is that the probability bearing capacity envelope surface is constructed by solving the probability uniaxial bearing capacity and combining a deterministic bearing capacity envelope surface equation, and the reliability analysis of the shallow foundation is carried out by adopting Monte Carlo simulation. According to the method, the situation that numerical analysis is conducted on different load combinations is avoided, the calculation efficiency is greatly improved, the principle is simple, use is convenient, and an efficient and practical tool is provided for shallow foundation reliability analysis under the complex geology and load conditions.
Owner:SOUTH CHINA UNIV OF TECH

Method for determining parameters of grinding tool for accurate grinding and polishing of aspherical mirror

The invention provides a method for determining parameters of an accurate grinding and polishing grinding tool for an aspherical mirror. The method comprises the following steps: acquiring a surface shape equation of the aspherical mirror; based on the surface shape equation, calculating the curvature radius of a plurality of points on the aspherical mirror, and taking the curvature radius as a first curvature radius; the curvature radius of the grinding tool is determined according to the minimum value of the first curvature radiuses of the multiple points and serves as a second curvature radius; wherein the second curvature radius is smaller than or equal to the minimum value in the first curvature radiuses; the contact condition of the grinding tool and the aspherical mirror is analyzed, and the polishing pad material type of the grinding tool is selected based on the contact condition. According to the method, the radius of the grinding tool is determined to be not greater than the minimum radius of curvature by calculating the radius of curvature of each point of the aspheric surface, so that the curvature of the grinding tool is matched with the aspheric surface, and interference is avoided during processing; by means of the method, the diameter of the grinding disc can be maximized and is two times of the minimum curvature radius, and the grinding efficiency can be greatly improved; the limitation of traditional experience dependence is broken through, and efficient aspheric surface machining can be guided.
Owner:TIANJIN JINHANG INST OF TECH PHYSICS

Method and device for identifying central axis of cylindrical surface based on local measurement data

The present invention relates to the field of reverse engineering technology, and discloses a method and device for identifying the central axis of a cylindrical surface based on local measurement data. The method comprises the following steps: obtaining original point cloud data of local measurement of the cylindrical surface to obtain point cloud data to be processed; randomly selecting two initial fitting points to fit the cylindrical surface equation and the linear equation to obtain an initial fitting radius, an initial central axis linear direction vector, and an initial central axis linear equation; updating the central axis linear direction vector, and iteratively fitting the cylindrical surface equation and the central axis linear equation by selecting points other than the fitted points according to a preset rule; determining the effective point cloud data required for optimizing the cylindrical surface radius, and optimizing to obtain the optimal cylindrical radius; and evaluating the deviation of the updated central axis linear equation. If the evaluation is qualified, the central axis determined by the central axis linear equation is used as the final identified cylindrical surface central axis. The present invention improves the fitting accuracy based on local measurement data and reduces the difficulty of identifying the optimal central axis.
Owner:XIAN THERMAL POWER RES INST CO LTD

Flow characteristic analysis method and system for axial constant flow vane pump

The invention discloses a flow characteristic analysis method and system for an axial constant flow vane pump, and the method comprises the steps: constructing a stator curved surface equation and a vane curved surface equation of the axial constant flow vane pump, determining parameters, and drawing to obtain a vane three-dimensional model and a stator curved surface model; assembling the model to obtain a blade-stator kinematic pair, and calculating the volume of the axial quantitative vane pump; determining a working state and a motion stage of the axial constant flow vane pump, and drawing a two-dimensional model of a vane-stator motion pair; the displacement of different motion states and motion stages is calculated, a displacement mathematical calculation model and an instantaneous flow and pulsation rate calculation model are constructed, a lumped parameter model of the axial constant displacement vane pump is established, and flow characteristic analysis is conducted on the axial constant displacement vane pump. According to the technical scheme, derivation, simplification and calculation processes are simplified, the flow characteristic parameters of the axial constant displacement vane pump can be rapidly and accurately calculated, and a basis is provided for optimizing the structure and performance parameters of the axial constant displacement vane pump.
Owner:BEIJING UNIV OF TECH

Facade projection intelligent detection method based on multi-sensor tight coupling

The invention discloses a multi-sensor tight coupling-based facade projection intelligent detection method, which comprises the following steps of: acquiring multi-modal data including point clouds and images of a to-be-detected facade, performing panoramic segmentation on the images to obtain semantic information, and transmitting the semantic information to the point clouds; carrying out downsampling on the point cloud, carrying out density clustering in combination with semantic information, calculating a projection confidence vector, calculating an equation of a plane where a vertical face is located by using a random sampling consistency algorithm, calculating a bounding box for a projection, and completing rough estimation of the projection based on the point cloud; calculating a surface equation of the projection by using a point cloud, converting the surface equation of the projection into a camera coordinate system, and fitting the boundary of the projection in the space by using the pixel position of the projection in the image and combining a facade equation; and adjusting a coarse estimation result of the point cloud and a boundary based on image fitting according to the projection confidence vector, and carrying out combined filtering on the two types of results for coupling to finish accurate detection of the projections to obtain a projection queue.
Owner:CENT SOUTH UNIV

Method for calculating shortest contact line length of incomplete gear pair of planetary roller screw

The invention provides a method for calculating the shortest contact line length of an incomplete gear pair of a planetary roller screw, and the method comprises the steps: building a meshing curved surface equation of the incomplete gear pair based on basic geometric parameters, calculating the contact point coordinates of the gear pair according to the meshing curved surface equation, constructing a contact thread section according to the calculated or preset meshing radius of the incomplete gear pair, and obtaining the shortest contact line length of the incomplete gear pair. And the shortest contact line length value of the incomplete gear pair is obtained through contact thread section calculation. According to the method, a traditional process depending on finite element simulation or complex modeling is simplified, the length of the contact line is directly solved through a mathematical formula, and resource consumption and a design period are reduced; a uniform meshing curved surface equation and a coordinate transformation matrix are utilized to accurately describe the dynamic meshing state of the gear pair, and tedious iterative analysis is avoided. According to the method, both precision and convenience are considered, the technical threshold of front-line personnel is greatly reduced, and efficient and reliable theoretical support is provided for optimization design and engineering application of the planetary roller screw.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Method, device and storage medium for predicting geological structure ahead of tunnel face

The present invention relates to the field of geological engineering and digital modeling technology, and provides a method, device, and storage medium for predicting geological structures in front of a tunnel face. By drawing geological element objects on a registered real-life three-dimensional model, constructing various surface equations of a cavern BIM model, solving the spatial intersection line parameters between the fitted plane equation and the surface equation, and obtaining the spatial Boolean operation results of the surface equation with the cavern BIM model, all geological element objects and spatial intersection line expressions and their corresponding starting point parameters that intersect with the cavern BIM model are obtained. The range of the cavern pile number segment to be blasted in front of the tunnel face is obtained according to the pile number of the tunnel face, and all geological element objects within the cavern pile number segment that intersect with the underground cavern are searched and used as the geological structure element set to be predicted. The present application has the advantages of high efficiency, high precision, and three-dimensional visualization, and realizes the dynamic prediction of geological structures in front of the tunnel face.
Owner:POWERCHINA ZHONGNAN ENG

Indentation test method and system suitable for complex curved surface part

The invention discloses an indentation testing method and system suitable for a complex curved surface part, and relates to the technical field of material mechanical property tests.The method comprises the steps that an initial space coordinate system is confirmed; scanning the surface of the to-be-measured part through a three-dimensional contourgraph to obtain three-dimensional shape data and a curved surface equation, and calculating a tangent plane equation at a target measuring point on the to-be-measured part; determining an included angle between a plane intersection line between a tangent plane and the initial space coordinate system and a horizontal plane, and calculating and controlling the two telescopic rods to move according to the included angle and a preset interval between the telescopic rods; and calculating a central point coordinate of the spherical hinge moving assembly and a projection point coordinate of vertical projection on the plane where the positioning table is located so as to calculate a coordinate of the center of the positioning table, and calculating a coordinate difference between the projection point coordinate and the central coordinate so as to carry out indentation testing on the target measuring point. According to the invention, the indentation test can be rapidly, accurately and non-destructively carried out on the complex curved surface part.
Owner:CHANGCHUN UNIV OF TECH +1

Design and forming method of streamline tunnel type rotating fluid machinery flow channel

ActiveCN111881532Breduce flow lossCurvature changes gentlyGeometric CADPump componentsPhase mixingMachine
The present invention discloses a streamline tunnel type rotating fluid machinery flow channel design and forming method and includes the following steps: S1: obtain the relevant constraint parameters obtained by one-dimensional design; S2: obtain the center line expansion projection curve and construct it as a cubic Hermite curve; S3: after obtaining the center line expansion projection curve, restore the expansion plane to a cylinder, and obtain the equation of the cylindrical projection curve; S4: if the meridian form is known, it is easy to obtain the equation of the torus where the center line is located; S5: combine the above-mentioned cylindrical projection curve and the torus equation to obtain the equation of the actual flow channel center line; S6: according to the flow characteristics and speed conditions of the rotating machinery, the flow channel inlet and outlet areas are obtained, thereby forming a complete flow channel. The present invention can be easily expanded to the streamline design of more fluid machinery through the combined equation method, and is suitable for media such as gas, liquid, solid powder and multiphase mixed fluid, forming a design system from streamline to flow channel, low dimension to high dimension, and can make a more reasonable prediction of mechanical performance.
Owner:KORUO TAIBO (BEIJING) TECH CO LTD

A five-axis machining tool path planning method for complex curved surfaces

The application discloses a five-axis machining tool path planning method for complex curved surfaces, and relates to the technical field of numerical control machining.The method comprises the following steps: dividing a sub-region based on a Gaussian curvature of a curved surface model and fitting a regional equation; projecting the sub-region and screening to obtain a boundary point set; fitting a curved surface equation by adopting a cubic NURBS; optimizing splicing into an optimal curved surface equation through a normal vector and curvature constraint; setting a cutting plane and calculating a cross curve; calculating an arc length based on a Simpson formula and planning a coordinate sequence of a trajectory point according to the curvature; constructing a helical equation of adjacent cutting planes, solving coefficients according to position and tangent continuous constraint, calculating a helical step length based on the Simpson formula, and generating a cross-surface trajectory point sequence; in the cutting plane, based on lossless and cutting direction constraint, optimizing an optimal angle sequence by a genetic algorithm, and generating a cross-surface angle sequence through cosine interpolation; and integrating a machining pose sequence to realize high-precision machining of the complex curved surface.
Owner:信阳星原智能科技有限公司

A flame surface database construction method, device, equipment and storage medium

The present application discloses a flame surface database construction method, device, equipment and storage medium, which relates to the technical field of database management, including: based on a preset data segmentation method, respectively performing data partition processing on the discrete post-mixing fraction space and scalar dissipation rate in the target thermal system to obtain a data base point composed of the post-partitioning mixing fraction and the post-partitioning scalar dissipation rate; determining the constraint value set corresponding to the data base point according to the constraint flame surface equation corresponding to each constraint in the target thermal system; solving the constraint potential energy form equation of each constraint in the constraint value set to obtain the corresponding constraint potential energy value, and determining the mass fraction distribution of each component corresponding to the data base point in the target thermal system based on the constraint potential energy value, so as to construct the target flame surface database based on the temperature distribution and mass fraction distribution corresponding to the data base point. In this way, by reducing the dimension of the control equation describing the system from the number of components to the number of constraints, the dimension of the equation group to be solved is reduced.
Owner:SICHUAN TIANFU FLUID BIG DATA RES CENT

Five-axis machining cutter contact track optimization and nonlinear error control method based on cutting contour surface

The invention discloses a five-axis machining cutter contact track optimization and nonlinear error control method suitable for various cutters. According to the method, a five-axis numerical control machine tool kinematics model and a five-axis linear interpolation trajectory equation are established, and interpolation tool nose point and tool axis vector data are calculated. Based on a cutter cutting contour surface equation, accurate cutter contact position coordinates are deduced, a parameter iterative algorithm is provided, and the maximum nonlinear error in a cutter contact track is searched and compensated. By constructing an error solution and compensation model, a path track in five-axis machining of the cutter is optimized, the size of a nonlinear error is effectively controlled, and then the machining precision and the surface quality of a complex curved surface are improved. The method has the advantages of high real-time performance, high compensation precision, high adaptability and the like, and is suitable for a high-precision five-axis machining scene.
Owner:GUILIN UNIVERSITY OF TECHNOLOGY

A complex gap repair method for 3D models based on optimization

The present invention discloses a method for repairing complex gaps in a three-dimensional model based on optimization. The method includes obtaining a B-Rep model of a product to be repaired through modeling within a computer, then traversing all edges of the B-Rep model to obtain gap edges, constructing a connection relationship graph of all gap edges based on the gap edges, searching the connection relationship graph to obtain all ring structures, processing the ring structures to obtain all qualified edge pairs, then sampling the obtained edge pairs, processing all sampled points to obtain the overall optimization error of the edge pairs, continuously optimizing the edge pairs based on the overall optimization error to ultimately obtain a repair surface equation, and finally repairing the B-Rep model of the product to be repaired based on the obtained repair surface equation, thereby producing a repaired product. The present invention is based on an optimized method for automatically repairing complex gaps, which can effectively improve the ability and effectiveness of model repair.
Owner:ZHEJIANG UNIV

On-machine measurement method of face gear pitch error based on CNC worm wheel gear grinding machine

The present invention discloses an on-machine measurement method for the pitch error of a face gear based on a numerically controlled worm wheel gear grinding machine, comprising the following steps: Step 1: planning of gear tooth surface measurement points: 11) establishing the tooth surface equation of the face gear: constructing the tooth surface equation of the face gear according to the homogeneous transformation matrix between the gear cutter coordinate system and the face gear coordinate system and the meshing relationship between the gear cutter and the face gear; 12) planning the tooth surface measurement points with the center point of the tooth surface of the face gear according to the constructed tooth surface equation of the face gear; 13) solving the coordinates and normal direction of each tooth surface measurement point; Step 2: on-machine measurement of the face gear: measuring all side measurement points on the machine. The present invention is based on the on-machine measurement method for the pitch error of a face gear based on a numerically controlled worm wheel gear grinding machine. By measuring the pitch error of the face gear on the machine, it is possible to avoid repeated installation of the face gear due to detection, and changes in the installation reference affecting the tooth surface measurement accuracy, tooth surface processing accuracy and tooth surface processing efficiency.
Owner:CHONGQING UNIV

Method, device and storage medium for processing a round tube intersecting line weld

This application discloses a method, apparatus, and storage medium for processing intersecting weld seams of circular pipes. The method acquires three-dimensional point cloud data of a first and a second circular pipe using a pre-scanning mode. The acquired three-dimensional point cloud data is preprocessed, and the cylindrical surface equations of the first and second circular pipes are fitted using this data. Then, a projection method is used to project the bottom circle of the second circular pipe cylinder onto the axis vector of the first circular pipe to obtain the intersecting weld seam data. The intersecting weld seam processing method provided in this application solves the problem in the prior art where, when obtaining the intersecting weld seam trajectory by teaching key points on the intersecting weld seam, the accuracy of the generated weld seam trajectory is low due to human error, thus affecting the welding formation effect and welding quality. This method only requires setting the scanning range to quickly and accurately calculate the intersecting weld seam data and allows for corresponding welding process adjustments based on actual conditions to improve the welding formation effect.
Owner:WUXI LICHENG INTELLIGENT EQUIP CO LTD

Continuous ship unloader material flow stable control system and method

The invention provides a material flow stability control system and method for a continuous ship unloader, and the method comprises the following steps: S1, recognizing the contour of a material in each chain bucket which is continuously lifted, and obtaining material morphology point cloud data; s2, de-noising the material morphology point cloud data by adopting a statistical filtering method; s3, performing plane fitting on the de-noised material morphology point cloud data by adopting a least square method to obtain a plane equation of the material surface; s4, performing curved surface integral on the plane equation of the material surface and a pre-obtained chain bucket bottom surface equation to obtain a material volume; s5, obtaining the material load in the chain bucket according to the material volume and the specific gravity, and calculating the instantaneous material flow value of the system according to the parameters such as the current chain bucket lifting rate; and S6, comparing the instantaneous material flow with a preset material flow, and timely adjusting a material taking process strategy. According to the method, the material taking strategy is dynamically adjusted, and it is ensured that the ship unloader efficiently carries out ship unloading operation under stable material flow.
Owner:DALIAN HUARUI HEAVY IND GRP CO LTD

Hydrostatic guide rail bearing performance calculation method for realizing fluid-structure interaction based on thick plate theory

The invention discloses a static pressure guide rail bearing performance calculation method for realizing fluid-structure interaction based on a thick plate theory, which comprises the following steps of: 1, calculating the deflection of a cantilever thick plate under the action of concentrated force based on a work interoperability theorem, establishing a deflection surface equation and a stress formula of the cantilever thick plate, solving unknown parameters through a Gaussian iteration method, and calculating the deflection of the cantilever thick plate under the action of concentrated force; and the deformation condition of the thick plate under the action of concentrated force is obtained. And 2, discretizing the Reynolds equation by using a finite difference method, establishing an iterative equation of oil film pressure distribution, and solving the pressure distribution of the rectangular oil pad under set boundary conditions by using a Gaussian-Seidel iterative method. And step 3, comprehensively considering the influence of the pressure plate deformation on the oil film thickness and the pressure distribution through iterative coupling calculation, repeatedly iterating until the tolerance requirement is met, and finally obtaining the pressure plate deformation and the oil film pressure distribution under the consideration of the fluid-solid coupling effect. According to the calculation method, the bearing capacity of the hydrostatic guideway under the actual working condition can be evaluated more accurately.
Owner:BEIJING UNIV OF TECH

Error evaluation method and correction method based on digital shape adjustment of flexible clamp bent frame

The invention discloses an error evaluation method and correction method based on digital shape adjustment of a flexible clamp bent, and the method comprises the following steps: generating a final supporting position of a supporting column digital model capable of supporting a skin digital model, and obtaining a curved surface equation of the current skin digital model; according to the final supporting position coordinate data of the supporting stand column digital model, controlling the supporting stand columns on the bent frame to move to corresponding positions; the method comprises the following steps: acquiring the movement position of each supporting column on a bent and the position coordinate of the tail end of each current supporting column, and fitting to generate a supporting curved surface equation of the supporting columns and a linear equation of a straight line passing through the position coordinate point of the tail end of each supporting column and perpendicular to the plane where the bent is located; and calculating the model fitting degree between the skin digital-analog curved surface and the supporting curved surface, and evaluating the shape adjusting error of the bent frame according to the model fitting degree. The shape error of the bent support curved surface is evaluated by adopting the model fitting degree of the shape formed at the tail end of the support upright post of the bent and the actual digital-analog curved surface shape, so that the shape adjusting quality of the bent is ensured.
Owner:CHENGDU AIRCRAFT INDUSTRY GROUP