26 results about "Surface equation" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The application discloses a kind of flow characteristics analysis method and system of axial quantitative vane pump, method includes: constructing the stator cam surface equation and blade cam surface equation of axial quantitative vane pump, determine parameter and draw to obtain blade three-dimensional model and stator cam surface model;Assembled model obtains blade-stator kinematic pair, calculates the volume of axial quantitative vane pump;Determine the working state and movement stage of axial quantitative vane pump, draw the two-dimensional model of blade-stator kinematic pair;Calculate the displacement of different movement states and movement stages, construct displacement mathematical calculation model and instantaneous flow and pulsation rate calculation model, establish the lumped parameter model of axial quantitative vane pump, carry out flow characteristic analysis to axial quantitative vane pump.By the technical scheme of the application, the derivation, simplification and calculation process are simplified, the flow characteristic parameters of axial quantitative vane pump can be quickly and accurately calculated, which provides a basis for optimizing the structure and performance parameters of axial quantitative vane pump.

The present application provides a kind of particle swarm optimization method based on optimal loading contact area of planetary modified gear, mainly including the steps of establishing planetary gear comprehensive modified gear surface equation, calculating modified gear surface contact area and establishing optimization model and solving etc.The present application is based on particle swarm algorithm, and the tooth profile design of planetary gear mechanism is optimized to improve its gear surface contact area, and then improve carrying capacity.Particle swarm algorithm can provide efficient, accurate and easy-to-implement design method for the tooth profile modification of planetary mechanism, so as to improve the quality and performance of gear products, meet the demand of modern mechanical transmission system for high-performance gears.

The application discloses a hypoid gear digital design method and system, and is applied to the technical field of gear design and manufacturing. The method comprises the following steps: according to initial design parameters, solving the gear blank parameters of a hypoid gear pair, the forming method machining parameters of a large gear and the cutter tilt method machining parameters of a small gear; based on gear machining principles and space meshing principles, establishing the large gear tooth surface equation and the small gear tooth surface equation, determining the theoretical boundary of the rotary projection tooth surface, and dividing discrete grid nodes; constructing an objective function for iterative solving, obtaining tooth surface discrete point cloud data; constructing a cubic spline curve, reconstructing the tooth surface spline surface; establishing a gear blank solid model, cutting the gear blank by using the reconstructed tooth surface through Boolean operation, and generating a hypoid gear three-dimensional entity model. The application overcomes the disadvantages of the traditional design method, such as design and modeling simulation fragmentation, low efficiency of artificial optimization iteration, and greatly improves the design efficiency through full-automatic modeling process and fast design optimization response.

The application discloses a kind of based on flexible clamp rack digital shaping error evaluation method and correction method, including the following steps: the final support position of support column numerical model capable of supporting skin numerical model is generated, and the surface equation of current skin numerical model is obtained;According to the final support position coordinate data of support column numerical model, the support column on rack is controlled to move to corresponding position;The motion position of each support column on rack and the position coordinate of the end of each current support column are obtained, the support surface equation of support column is fitted, the straight line equation of straight line through the end position coordinate point of each support column and perpendicular to the plane where rack is located;The skin degree of the surface equation between skin numerical model and support surface is calculated, and the error of rack shaping is evaluated according to skin degree. The shape error of support surface of rack is evaluated by using the skin degree of shape formed by the end of support column of rack and actual numerical model surface shape, so that the quality of rack shaping is guaranteed.

The invention discloses a hypoid gear digital design method and system, and is applied to the technical field of gear design and manufacturing. The method comprises the following steps that according to initial design parameters, gear blank parameters, large wheel forming method machining parameters and small wheel cutter inclination method machining parameters of the hypoid gear pair are solved; based on a gear machining principle and a space meshing principle, establishing a large gear tooth surface equation and a small gear tooth surface equation, determining a theoretical boundary of a rotary projection tooth surface, and dividing discrete grid nodes; constructing an objective function for iterative solution to obtain tooth surface discrete point cloud data; constructing a cubic spline curve, and reconstructing a tooth surface spline surface; and establishing a gear blank solid model, cutting the gear blank by utilizing the reconstructed tooth surface through Boolean operation, and generating a hypoid gear three-dimensional solid model. According to the method, the defects that in a traditional design method, design and modeling simulation are separated, and manual optimization iteration efficiency is low are overcome, and the design efficiency is greatly improved through a full-automatic modeling process and rapid design optimization response.

The application discloses a kind of indentation test method and system suitable for complex curved surface parts, it is related to the technical field of material mechanical property test, the method comprises: confirming initial space coordinate system;The surface of the part to be tested is scanned by three-dimensional profilometer, three-dimensional topography data is obtained, curved surface equation is obtained, and tangent plane equation at target measuring point on the part to be tested is calculated;Confirm the angle between the plane intersection line of tangent plane and the initial space coordinate system and horizontal plane, and according to the angle and the preset interval between the telescopic rod, two telescopic rods are calculated and controlled to move;The center point coordinate of spherical hinge moving assembly, the projection point coordinate of vertical projection on the plane where the positioning table is located is calculated to calculate the coordinate of the center of positioning table, and the coordinate difference between projection point coordinate and the center coordinate is calculated to carry out indentation test to the target measuring point, the application can quickly, accurately and non-destructively carry out indentation test to complex curved surface parts.

The invention discloses a multi-spherical-pair self-adaptive palm structure and a shape sensing method and system thereof, and relates to the technical field of robot tactile perception, and the method comprises the steps: firstly obtaining the position and normal vector of an object surface contact point through kinematics modeling; selecting a hyper-quadratic surface equation as a parameterized model; constructing an optimization objective function fusing the position error and the normal deviation; a least square method optimizer capable of being iteratively reconstructed is used for solving, in each iteration, balance factors are adaptively updated according to error statistical distribution of all contact points so as to balance contribution of two kinds of heterogeneous errors, and a dynamic weight is calculated for each contact point so as to suppress noise and abnormal points; and finally, outputting a fitted hyper-quadric surface parameter. According to the method, the problems that multi-source errors are difficult to balance and are sensitive to measurement noise in shape perception are solved, and high-precision and high-robustness online object shape estimation is realized.

This invention discloses a method for analyzing the cracking risk of concrete dams based on a response surface surrogate model. The method includes: treating factors influencing the temperature and stress fields of the concrete dam as random variables and statistically analyzing their distribution characteristics; generating random variable input samples, importing them into a temperature-stress finite element model, extracting tensile stress values ​​at characteristic points, and normalizing the data; optimizing the support vector machine, establishing a mapping relationship between the output response and input variables, obtaining the response surface equation between the random variables and tensile stress, and using this equation as a surrogate model for finite element simulation; constructing a cracking risk function; solving for the failure probability and reliability index using the Monte Carlo method based on Latin hypercube sampling; and evaluating the cracking risk of the proposed structure based on the failure probability and reliability index, obtaining the evaluation results. This method enables pre-assessment of the cracking risk of the proposed structure and scientifically quantifies the cracking risk using reliability indices, which has significant theoretical implications.