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183 results about "Arc length" patented technology

Arc length is the distance between two points along a section of a curve. Determining the length of an irregular arc segment is also called rectification of a curve. The advent of infinitesimal calculus led to a general formula that provides closed-form solutions in some cases.

Vur curve determination method for centrifugal pump point-by-point integration method

The invention discloses a curve determination method for a centrifugal pump point-by-point integration method, and belongs to the technical field of centrifugal pumps. The curve determination method of the centrifugal pump point-by-point integration method is a parameterized modeling method based on an Euler equation and momentum conservation, the inlet and outlet boundaries of a vur curve are calculated according to design requirements, after a smooth transition curve is constructed in combination with runner geometry and attack angle constraint, the curve is constructed through nonlinear interpolation according to the dynamic correlation streamline arc length, and the curve is determined. The relation between the streamline arc length and the curve is established; according to the method, when the centrifugal pump blade molded line is designed, the curve can be quickly obtained through a parameterization method according to the given design condition and the streamline arc length s.
Owner:HOHAI UNIV

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

Method and device for determining catenary of mountain slope transmission system

The invention provides a mountain slope transmission system catenary determining method and device, and the method comprises the steps: obtaining the arrangement parameters of a transmission system on a mountain slope, and the arrangement parameters at least comprise the horizontal distance between two fixed points of the transmission system, the vertical height difference, and the total length of a rope of the transmission system; based on the arrangement parameters, a simultaneous equation with the catenary opening coefficient as a core unknown quantity is established, and the simultaneous equation comprises the arc length constraint of the catenary and the height difference constraint of the two end points at the same time; solving the simultaneous equation to obtain a numerical solution of the catenary opening coefficient; and determining a catenary shape and a core engineering index of the transmission system on the mountain slope under the action of gravity according to the solved catenary opening coefficient. According to the method and the device, the engineering design precision is improved, and material redundancy and adjustment cost caused by shape uncertainty are saved.
Owner:BEIJING SHIDAI CHONGSHU TECHNOLOGY CO LTD

Large-span beam formwork three-dimensional parameterization deepening design method

The invention provides a large-span beam formwork three-dimensional parameterization deepening design method, and belongs to the technical field of building construction.The method includes the steps that geometric parameters of a large-span beam three-dimensional parameterization model are obtained, and a multi-scale homogenization mechanical analysis model is established to describe nonlinear characteristics of a concrete material; an arc length control method is combined with a Newton-Raphson iterative improved algorithm to carry out large-deformation nonlinear analysis to calculate deformation control parameters, safety performance is evaluated, support structure parameters are adjusted, and a double-layer game optimization model is established to determine optimal template support system parameters. On the basis of a bending-torsion coupling analysis result, a force transmission path diagram is established through a load transmission path generation function, and an optimal force transmission path is determined by adopting a gradient optimization algorithm, so that the problems that the design of a large-span beam formwork supporting system lacks an accurate mechanical calculation basis, and structural deformation and stress distribution cannot be accurately predicted are solved; and the design of the supporting system is not reasonable.
Owner:CHINA CONSTR EIGHT ENG DIV CORP LTD +1

Movable tubular pile gas shielded welding windproof cover

The utility model discloses a movable tubular pile gas shielded welding windshield which comprises a radius adjusting cover and a perimeter adjusting block, the radius adjusting cover is of an arc-shaped structure, the inner ring of the radius adjusting cover is attached and adsorbed to the circumferential outer wall of a tubular pile, and the outer ring of the radius adjusting cover is symmetrical and is connected with a welding gun rod in an elastic tensioning mode. Perimeter adjusting blocks are telescopically inserted into two circumferential end surfaces of the arc-shaped structure of the radius adjusting cover. The windproof cover is used for covering and protecting the flame of the welding gun, can adaptively adjust the local covering radius and arc length according to the diameter of a pipe pile, can move along with the movement of the welding gun, and is simple in structure and easy to implement.
Owner:CHINA RAILWAY 18TH BUREAU GRP CO LTD +2

Tool for detecting elastic bearing body of passenger train

The invention provides a railway carriage elastic bearing body detection tool, and belongs to the technical field of bearing body detection tools. Comprising a clamping mechanism, a supporting frame body is installed on the top of the clamping mechanism, a first frame body is arranged on one side of the clamping mechanism, a second frame body is arranged at the bottom of the clamping mechanism, side bearing boxes are installed on the two sides of the top of the first frame body, and side bearing bodies are installed on the tops of the side bearing boxes; and the first outer contour measuring mechanism is used for measuring the length and the width of the side bearing box. Through the arrangement of the first outer contour measuring mechanism and the second outer contour measuring mechanism, the length and width of the outer contour of the side bearing box and the arc length and curvature of the corners of the outer contour can be rapidly measured by using the first outer contour measuring mechanism; and the length and the width of the outer contour of the side bearing body and the arc length and the curvature at the corners of the side bearing body are rapidly measured by using the second outer contour measuring mechanism.
Owner:JILIN TAIHAO RAILWAY VEHICLE EQUIP CO LTD

Variable-width volute spiral spring design method and volute spiral spring

The invention relates to a variable-width volute spiral spring design method and a volute spiral spring, and belongs to the technical field of volute spiral springs.The variable-width volute spiral spring design method comprises the steps that S1, polar angles corresponding to plane spiral lines at different arc length positions are determined; s2, determining curvature radiuses corresponding to the planar spiral lines at different polar angle positions; s3, according to different curvature radius parts, the initial section width of the volute spiral spring is designed; and S4, the initial width of the volute spiral spring is adjusted according to the ratio of the radius to the half thickness of different parts, and uniform distribution of bending stress is achieved. The core of the method is that a corresponding width change rule is designed according to a change rule of bending stress along with curvature radius disclosed by a curved beam theory. By means of the method, the maximum bending stress of all the sections can be equal, and therefore the bearing capacity and stability of the volute spiral spring are improved.
Owner:TIANJIN BAICHENG VALVE MFG CO LTD

An air spring meridian strain analysis method based on elliptic arc length piecewise integration

PendingCN122310720AAir springRubber elasticity
This invention discloses a method for analyzing the meridional strain of air springs based on piecewise integration of elliptical arc length, belonging to the technical field of vehicle suspension systems or rubber elastic elements design. The method includes the following steps: approximating the arc segment from the top of the air spring generatrix to the outermost bulge point as the first quadrant of an ellipse, determining the major and minor semi-axes of the reference and inflation states; introducing normalized coordinates to establish a linear mapping of the abscissas of the two states, constructing an elliptical arc length infinitesimal element and transforming it to the same interval for integration; dividing the interval into even-numbered equal parts, using the complex Simpson method to obtain the arc length piecewise, calculating the ratio of the inflation arc length to the reference arc length as the elongation ratio, and taking the natural logarithm to obtain the true meridional strain of each segment of the generatrix; this invention can accurately describe the non-uniform deformation of each segment of the generatrix during air spring inflation, providing a basis for strain prediction and fatigue assessment.
Owner:HARBIN INST OF TECH AT WEIHAI

Three-dimensional curved surface forming method

A three-dimensional curved surface forming method comprises the steps that stretch-forming machine stretching cylinders arranged on the two sides of the mold stretch-forming direction of a three-dimensional curved surface forming tool and stretch-forming machine stretching cylinder clamps capable of rotating around a shaft in a segmented mode move together so that bending and stretching motion loads can be applied to the two ends of a plate laid on a mold, and therefore the plate can be attached to the mold in a segmented mode; the x-direction contour section line with the largest chord height of the mold serves as a control contour section line, then stretch-forming area segmentation division is conducted on the control contour section line according to the curvature and arc length changes of the control contour section line, dispersion of the elongation of each stretch-forming area is achieved, and finally stretching is conducted according to the stretch-forming elongation of each stretch-forming area, so that the stretch-forming area is obtained. And a three-dimensional curved surface with high appearance precision is further obtained. Segmented stretch forming is provided, the elasticity and plastic deformation uniformity in the stretch forming range of each section is effectively improved, deformation uniformity of overall stretch forming is achieved, and the stretch forming precision and the stretch forming efficiency of the stretch forming process are comprehensively improved by dividing the stretch forming areas.
Owner:JIANGXI HONGDU AVIATION IND GRP

In-plane nonlinear deformation calculation method of arch structure with axis defects under rectangular coordinate system

A method for calculating the in-plane nonlinear deformation of an arch structure with axial defects in a Cartesian coordinate system is presented. This method is based on two states of the arch structure's curve element in the Cartesian coordinate system: an ideal axis and an actual axial defect. It derives the changes in the arc length and curvature of the curve element before and after deformation, obtaining expressions for the nonlinear compressive and bending strains in the in-plane of the arch structure with axial defects in the Cartesian coordinate system. The method also derives the nonlinear equilibrium differential equations in the in-plane of the arch structure with axial defects in the Cartesian coordinate system, obtaining solutions that satisfy the mechanical and geometric boundaries of the arch structure with axial defects. Finally, the method derives the nonlinear equilibrium governing equations in the in-plane of the arch structure with axial defects, ultimately obtaining the solution to the nonlinear mechanical problem in the in-plane of the arch structure with axial defects in the Cartesian coordinate system. This method can obtain the essence of the nonlinear mechanical problem of the arch structure with axial defects in the Cartesian coordinate system, filling the gap in the nonlinear strain-displacement expression for the in-plane of the arch structure with axial defects in the Cartesian coordinate system.
Owner:EAST CHINA JIAOTONG UNIVERSITY +4

An asymmetric airthoid-arc corner fairing method

The application relates to the technical field of motion planning, and discloses a corner fairing method of an asymmetric Airthoid-arc, which comprises the following steps: constructing a tool path fairing curve which is sequentially connected by a first Airthoid curve, an arc and a second Airthoid curve, and is used for fairing a corner formed by adjacent straight line segments; preliminarily setting a first transition length and a second transition length according to the lengths of the line segments on the two sides of the corner; solving the first and second tangent angles according to geometric constraints, tangential continuity, curvature continuity constraints and position continuity constraints; if there is a solution, analytically calculating a current approximate error; and finally analytically calculating the curvature extreme value and the arc length of the fairing curve. The asymmetric curve structure is adopted, the corner space is fully excavated, the curvature extreme value is small, the arc length can be analytically expressed, and the profile error is controllable, so that the numerical control machining efficiency is improved.
Owner:HEFEI UNIV OF TECH +1

A method and system for three-dimensional continuous shape estimation of a flexible robot

The application relates to a three-dimensional continuous shape estimation method and system of a flexible robot, wherein the method combines the arc length of the flexible robot and unknown external loads from the environment with a Cosserat elastic rod model and a Cosserat elastic string model to generate a Lie algebra coupled statics model representing a tendon-driven model, models the external loads as Gaussian process noise to construct a prior probability model, obtains a prior probability distribution of the flexible robot in a Lie algebra space, constructs a measurement noise model in the Lie algebra space according to discrete measurement poses captured by a sensor and measurement noise, obtains a predicted measurement value, fuses the prior probability distribution and the predicted measurement value to obtain a posterior shape estimation of the flexible robot, and calculates a continuous three-dimensional shape estimation of the flexible robot and a first credibility of the continuous three-dimensional shape estimation according to the posterior shape estimation and a Gaussian process interpolation method. Therefore, the application realizes accurate perception of the continuous three-dimensional shape of the flexible robot.
Owner:FUZHOU UNIV

Arc convolution platform attached to high-altitude bridge

The utility model relates to the technical field of high-altitude platforms, and discloses an arc convolution platform attached to a high-altitude bridge. The keel frame is fixedly connected to the side, provided with the arc-shaped plate, of the horizontal plate, the keel frame comprises a variable-curvature sector ring frame, the variable-curvature sector ring frame comprises an outer arc edge, an inner arc edge and two ring wide edges, the inner arc edge is attached to the outer edge of the arc-shaped plate, and the curvature and the arc length of the outer arc edge are larger than those of the inner arc edge; the tempered glass plate is fixedly installed on the keel frame and comprises an outer arc edge, an inner arc edge and two annular wide edges, the inner arc edge is attached to the inner arc edge, the annular wide edges are longer than the annular wide edges, the curvature of the outer arc edge is the same as that of the outer arc edge, and the arc length of the outer arc edge is larger than that of the outer arc edge; the technical problem that an existing sightseeing platform cannot be used for stage performance and cannot meet the suspension effect is solved.
Owner:GUIZHOU JIAOTONG ECONOMIC & TECHNOLOGY RESEARCH & DEVELOPMENT CO LTD +1

Gas cylinder mounting bracket

This utility model relates to the field of vehicle gas supply technology and discloses a gas cylinder mounting bracket, including a first main body and a second main body fixedly connected. The front of the first main body has an arc-shaped portion along its length, and a straight portion extends smoothly from the end of the arc-shaped portion. The shape of the arc-shaped portion is adapted to the gas cylinder, and the arc length of the arc-shaped portion satisfies the following condition: the plane where the end of the arc-shaped portion and the straight portion are located is above the plane where the lowest point of the arc-shaped portion is located and below the plane where the beginning of the arc-shaped portion is located. A first groove is provided on the back of the first main body along its length to fit the second main body into the first main body, and both ends of the second main body extend beyond the corresponding ends of the first main body. A protrusion is provided at the end of the second main body, protruding towards the front of the second main body and inclined at the top. Reinforcing members are provided at both ends of the second main body. Mounting holes are provided at least at the beginning of the second main body and the protrusion. Mounting members are provided on both sides of the first main body. This bracket meets the ground clearance requirements of existing vehicles, changes and simplifies the assembly process, optimizes overall strength, and provides high gas cylinder protection performance.
Owner:CHONGQING CHANGAN KUAYUE AUTOMOBILE

High-precision laser cutting tool and cutting method for variable-cross-section semi-cylindrical sheet metal part

The invention discloses a high-precision laser cutting tool and cutting method for a variable-cross-section semi-cylindrical sheet metal part, relates to the technical field of laser cutting, and solves the problem of cutting precision deviation of such parts. The tool designed by the invention comprises the reference plane used for drawing the arc length contour line of the part in the early stage and detecting the arc length size of the part, the whole tool is formed by splicing and welding a plurality of common steel plates, and the upper molded surface of each vertical plate is consistent with the outer surface of the part in shape, so that the effective fitting and supporting effects on the part are ensured; and the other steel plates have fixing and reinforcing effects. The cutting method comprises the steps that allowance is reserved for lineation on a sheet metal part, cutting is conducted after red light emitted by the laser device is manually adjusted and aligned with the lineation, after cutting is completed, the deviation between the actual cutting size and the expected cutting size is calculated through measurement, and then correction is conducted by adjusting the ordinate value in the cutting program. And finally, precise cutting of the variable-cross-section semi-cylindrical sheet metal part is achieved, and the high-precision size requirement of the part is met.
Owner:AEROSPACE HIWING HARBIN TITANIUM IND

Topology-Based Programming of Thermo-Active Substances

An example embodiment includes: obtaining a specification of a target deformation shape for a substance, wherein the substance has a plurality of material control points with respective curvatures and arc lengths defining the target deformation shape, and wherein the substance includes thermo-active components and non-thermo-active components; determining a set of relations between indications of presence of the thermo-active components or the non-thermo-active components, orientations of the thermo-active components, and deformation capabilities of the thermo-active components; providing, to an optimization solver application, the specification, the set of relations, and instructions to determine values of the presence of the thermo-active components or the non-thermo-active components within the locations of the target deformation shape and the orientations of the thermo-active components, such that the substance can attain the target deformation shape in response to a temperature change when in a non-deformed state; and receiving, from the optimization solver application, the values as determined.
Owner:THE BOARD OF TRUSTEES OF THE UNIV OF ILLINOIS

A method for manufacturing a titanium alloy pre-chamber forging

A manufacturing method of a titanium alloy front engine case forging, comprising designing the outer shape structure of a pre-forging blank according to the arc length of the forging; compensating the arc length value by thickening the height size of the corresponding part on the profile surface of the pre-forging blank corresponding to the outer circle of the forging; adding two trapezoidal bosses on the profile surface of the pre-forging blank corresponding to the inner circle of the forging, the positions being the two sides in the length direction; adding a boss in the middle area of the profile surface of the pre-forging blank corresponding to the outer circle of the forging; adding a boss on the profile surface of the pre-forging blank corresponding to the inner circle of the forging, which is used for positioning when the pre-forging blank is put into the die for pre-forging. The present application overcomes the shortcomings of the prior art, can effectively optimize the excess amount distribution of the forging and refine the size of the forging, thereby effectively improving the material utilization rate and effectively improving the product quality. And the lean control of the manufacturing process is strengthened, the material utilization rate is improved. The production process is simplified, and the manufacturing cycle is shortened.
Owner:BAOWU TEYE TITANIUM TECH CO LTD

Enhanced braking system for mountain rail vehicles

The application discloses a mountain rail vehicle enhanced braking system and relates to the technical field of rail vehicle braking control. The system comprises the following steps: collecting a rail position vector and an arc length, calculating rail curvature and rail slope, combining a current vehicle speed with a target speed to solve a braking demand acceleration value, generating a slope parameter and a curve parameter; adjusting a wheel-rail hydraulic braking torque value according to a braking force distribution ratio, controlling a rack rail brake engagement depth and a vibration frequency through a rack rail action instruction, generating a wheel-rail system state report and a rack rail working log; extracting a slope parameter, an actual value of adhesion force and a rack rail engagement efficiency in a braking process from the wheel-rail system state report and the rack rail working log, and combining a terrain braking curve to perform closed-loop optimization. The application performs self-learning and self-adaptive adjustment on the braking process through closed-loop feedback and parameter optimization, so that the energy utilization efficiency and the service life of key components are improved while the braking efficiency is ensured.
Owner:SICHUAN VOCATIONAL & TECHN COLLEGE OF COMM

Pipeline fixing device and water purifier

The utility model discloses a pipeline fixing device and a water purifier, the pipeline fixing device comprises a fixing body, a first clamping arm and a second clamping arm, the first side of the first clamping arm and the first side of the second clamping arm have elasticity, the first clamping arm and the second clamping arm define an arc-shaped structure, the arc-shaped structure forms a first clamping groove, the first clamping groove is arranged in an extending mode in the first direction, and the second clamping arm is arranged in the first clamping groove. The ratio of the arc length of the opening of the first clamping groove to the perimeter of the whole arc is not more than 1 / 4; the fixing piece is connected to the second side, opposite to the first side, of the fixing body, the fixing piece is provided with two or more arc-shaped second clamping grooves or fixing round holes, and the two or more second clamping grooves or fixing round holes are arranged in the second direction. A plurality of line pipes and water pipes can be fixed, so that the line pipes are neat and not messy, mounting fixing parts are saved, the opening of the first clamping groove is not larger than one fourth of the perimeter of the whole arc, and a cylindrical object can be clamped and is not prone to falling off.
Owner:NINGBO FOTILE KITCHEN WARE CO LTD

Self-adaptive road model construction method and system for vehicle backward perception

The invention provides a vehicle backward perception adaptive road model construction method and system, and the method comprises the steps: fusing a historical track, a forward road model reverse extrapolation point and a forward lane line extrapolation point under a unified road coordinate system, and constructing a road candidate point set covering a vehicle backward region; and calculating a local curvature and a curvature change rate of the candidate point set based on a sliding window to form a road complexity index sequence distributed according to the arc length. The system carries out double-index constraint on fitting quality by calculating geometric errors of sampling points and position continuity, first-order derivative continuity and second-order derivative continuity at segmented boundaries, and realizes iterative optimization by adaptively adjusting a sampling interval and a fitting order until error and smoothness requirements are met. And splicing the optimized segmented fitting curves according to an arc length sequence, constructing a self-adaptive backward road model, and outputting the self-adaptive backward road model as a unified road geometric reference for backward target detection, target tracking and risk assessment modules.
Owner:HANGZHOU HONG JING DRIVE CO LTD

Socket assembly type mechanical tunneling type shaft enclosure segment

The utility model discloses a socket assembly type mechanical tunneling type shaft enclosure segment which is a wedge-shaped segment, the shaft enclosure segment is divided into an A-type segment and a B-type segment, the arc length of the upper portion of the A-type segment is smaller than that of the lower portion of the A-type segment, the arc length of the upper portion of the B-type segment is larger than that of the lower portion of the B-type segment, and the A-type segment and the B-type segment are spliced in a staggered mode to form a segment ring; the two arc-direction side walls of the vertical shaft enclosure pipe piece are each provided with a socket female opening piece and a socket male opening piece which are oppositely arranged up and down, the arc-direction side walls of the vertical shaft enclosure pipe piece are provided with splicing notches in the upper portions or the lower portions of the socket female opening pieces, and the A-type pipe piece and the B-type pipe piece are connected through matching of the socket female opening pieces and the socket male opening pieces. The socket type female opening piece and the socket type male opening piece are fixed to the vertical shaft enclosure pipe piece through anchor bars, and an inserting groove of the socket type male opening piece and a bearing groove of the socket type female opening piece are meshed with each other. The connecting structure has the advantages that weakening of section rigidity caused by arrangement of the bolt holes is reduced, and the bearing capacity of the structure is improved.
Owner:SHANGHAI URBAN CONSTRUCTION MUNICIPAL ENGINEERING (GROUP) CO LTD

Interpolation method of workpiece profile curve, interpolation device and computing device

The application discloses a kind of workpiece profile curve interpolation method, interpolation device and computing device, method includes: obtaining the current planning speed corresponding to current interpolation point parameter;Determine next interpolation point parameter according to current interpolation point parameter and current planning speed;According to current interpolation point parameter and next interpolation point parameter, determine the curve arc length of current interpolation point to next interpolation point;Actual error value between the curve arc length and current planning displacement is calculated, whether actual error value is less than predetermined error value is judged;If not less than predetermined error value, then next interpolation point parameter is used as new current interpolation point parameter, actual error value is used as new planning speed, to determine new next interpolation point parameter, and new actual error value is calculated, whether new actual error value is less than predetermined error value is judged;If less than predetermined error value, then according to next interpolation point parameter, determine next interpolation point coordinate.According to the technical scheme of the application, the interpolation accuracy is improved.
Owner:HUNAN UNIV +1

A lightweight cable net membrane airship main envelope and method of manufacture

The application discloses a light cable net film airship main gas bag and a manufacturing method. The steps for simulating and analyzing set two-dimensional generatrix and determining the arrangement position of the circumferential reinforcing rib include: starting from the quality point of the fixed maximum cross section circumferential position, obtaining the shape after deformation, and then obtaining the quality point with the maximum transverse strain, which is the obtained arc length position of the circumferential reinforcing rib; the quality point is fixed in the next calculation to continue segmentation until the positions of the set number of circumferential reinforcing ribs are completed. The steps for determining the bulge shape after being jointly constrained by the meridian reinforcing rib and the circumferential reinforcing rib include: according to the reinforcing rib position, the reinforcing rib elastic modulus and the spherical membrane elastic modulus, simulating and calculating the spherical membrane surface, and under the condition that the airship internal and external pressure difference is a set value, the three-dimensional shape of each small bulge. The application solves the problem that it is difficult to design a polyethylene film airship main gas bag.
Owner:AEROSPACE INFORMATION RES INST CAS +1

A method for simulating post-buckling of perforating casing against external extrusion considering machining precision

This invention discloses a method for simulating the post-buckling strength of perforated casing considering machining accuracy. The method establishes a geometric model of the casing based on the machining accuracy characterized by ellipticity and eccentricity. The post-buckling behavior of the casing is obtained using the arc-length method, and the external extrusion strength of the complete casing under this machining accuracy is calculated. The results are compared with those from external extrusion strength experiments. If the error condition is met, a geometric model of the perforated casing is established based on this accuracy, and the external extrusion strength of the perforated casing is calculated using the arc-length method. This invention combines casing machining accuracy with the perforated casing stability failure method to calculate the external extrusion strength, improving the accuracy of the numerical simulation results of the perforated casing's external extrusion strength and providing a new method for simulating the external extrusion strength of perforated casing.
Owner:CNOOC TIANJIN BRANCH

Method and device for unfolding surface of three-dimensional model, electronic equipment and storage medium

The application relates to the technical field of three-dimensional model, and discloses a three-dimensional model curved surface unfolding method and device, electronic equipment and a storage medium; the method comprises the following steps: determining n intersection points of the circular hole and the circular-arc wall curved surface, wherein n is an integer greater than 1; determining the arc length of each intersection point to the same elevation of a first reference line of the circular-arc wall curved surface based on the n intersection points; displaying the n intersection points on a two-dimensional plane by taking the arc length of each intersection point as an x value and taking the distance of each intersection point from a second reference line of the circular-arc wall curved surface as a y value; and generating an edge line of the intersection of the circular hole and the circular-arc wall curved surface based on the n intersection points. The application realizes the conversion of the three-dimensional graphic data information of the circular-arc wall and the hole on the wall into a two-dimensional drawing form.
Owner:NUCLEAR POWER INSTITUTE OF CHINA +1

Intelligent anti-skid decision method and device for rail locomotive control

The application relates to an intelligent anti-skid decision method and device for track locomotive control, which comprises the following steps: collecting wheel displacement distance, track horizontal offset angle, track vertical offset angle and wheel rotation angular velocity; calculating the ideal displacement length of the wheel in the non-idling state according to the wheel displacement distance, the track horizontal offset angle, the track vertical offset angle and the wheel rotation angular velocity; calculating the wheel rotation arc length and the offset percentage of the wheel linear speed compared with the average value according to the wheel rotation angular velocity; judging the fitting degree of the wheel to the track according to the wheel displacement distance, the ideal displacement length of the wheel in the non-idling state, the wheel rotation arc length, the offset percentage of the wheel linear speed compared with the average value and the track on which the wheel travels; and adjusting the sanding opening of the sanding part according to the fitting degree of the wheel to the track. The application can realize automatic sanding according to the current locomotive state, and accidents caused by the idling of the locomotive wheel can be avoided.
Owner:STATE GRID SHANGHAI ENERGY INTERCONNECTION RES INST CO LTD

A precision turning method for complex curved surfaces with cutting length of cutting edge

This invention discloses a method for precision turning of complex curved surfaces that achieves constant cutting lengths of the cutting edge, relating to the field of turning machining technology. The method includes: planning a turning tool path on the surface to be machined and discretizing trajectory points; calculating the arc length of the turning tool path and the geometric parameters of the trajectory points; calculating the safe tool axis angle range for each trajectory point on the turning tool path; calculating the corresponding cutting edge angle range based on the safe tool axis angle range for each trajectory point; optimizing the initial cutting edge angle spline curve using a genetic algorithm to obtain a new cutting edge angle spline curve; and calculating the tool axis vector for each trajectory point from the cutting edge angle spline curve. This invention achieves constant cutting lengths of the cutting edge by adjusting the actual cutting position of the tool's cutting edge during the turning process, extending tool life, reducing machining errors caused by accelerated tool wear, and improving overall machining efficiency while avoiding the reduction in cutting efficiency due to tool changes or parameter reductions.
Owner:SUZHOU UNIV

A steel bar mesh construction quality detection method based on machine vision

PendingCN122289199AColor imageMachine vision
This invention relates to the field of construction inspection technology and discloses a machine vision-based method for inspecting the construction quality of steel mesh. The method includes: acquiring color images and depth maps of the steel mesh; locating adjacent intersection nodes and the mid-span sag points of the connecting lines; extracting depth values ​​and converting them into three-dimensional physical coordinates; setting the intersection nodes as the local coordinate origin; calculating the difference between the horizontal projected straight-line distance and the relative sag depth; using algebraic analytical methods to simultaneously solve for the coefficients of the local parabolic deflection shape; using the arc length integral analytical method based on these coefficients to obtain the true physical arc length of the steel reinforcement; and finally calculating the relative error ratio between the actual arc length and the standard spacing to output the judgment result. This invention effectively eliminates the projection shortening error caused by local steel reinforcement sag, the calculation process requires no iterative optimization, the data logic is strictly self-consistent and closed-loop, and high-precision true spacing detection is achieved.
Owner:JIANGYIN JIANXIN METAL CO LTD

Profile system

Profile system (1) comprising at least one elongated rail profile (2) extending in a longitudinal direction (L) and having a constant cross-section, and at least one retaining element (3) designed to be detachably attached to the rail profile (2), wherein the rail profile (2) in cross-section has a substantially rectangular base section (6) provided on its front face with a receiving groove (7) extending in the longitudinal direction (L) which describes a circular arc (8) extending over at least 200° with a first radius R1 and is accessible via a groove opening (9) of a predetermined groove width (B), and at least one first fastening leg (13) which is substantially flush with the rear face of the base section (6) and projects outwards from the base section (6), and wherein the retaining element (3) comprises a retaining section (15) and a retaining element (15) attached thereto.a connecting section (16) elongated and extending in the longitudinal direction (L), wherein the connecting section (16) comprises at least a web (17) extending outwards from the retaining section (15) and a cylindrically shaped joint head (18) arranged at the free end of the web (17), the lateral surface of which, viewed in cross-section, describes a circular arc with radius R2 equal to or slightly smaller than radius R1, wherein the maximum distance (a, max) between a circular chord (19) bounding the circular arc and the lateral surface is slightly smaller than the groove width (B), so that the rod end (18) can be inserted through the groove opening (9) into the receiving groove (7) in a certain pivot position of the retaining element (3) with respect to a pivot axis (20) extending in the longitudinal direction (L) and can be locked within the receiving groove (7) during a pivoting movement about the pivot axis (20), characterized in that the web (17) of the connecting section (16) projects from the retaining section (15) at an angle (β) in the range between 100° and 110°.
Owner:SCHLUTER SYST KG

Railway passenger car elastic body detection tool

The present application provides a kind of railway passenger car elastic bearing detection frock, belong to bearing detection frock technical field.The clamping mechanism is provided with support frame body on the top of the clamping mechanism, the first frame body is arranged on the side of the clamping mechanism, the second frame body is arranged on the bottom of the clamping mechanism, the first frame body is provided with the side bearing box on the top of both sides, and the side bearing body is installed on the top of the side bearing box;First outer contour measuring mechanism, the first outer contour measuring mechanism is used to measure the length and width of the side bearing box.The present application is provided with first outer contour measuring mechanism and second outer contour measuring mechanism, the length and width of the outer contour of the side bearing box can be quickly measured by using first contour measuring mechanism, and the arc length and curvature of the corner of the outer contour, and the length and width of the outer contour of the side bearing body can be quickly measured by using second contour measuring mechanism, and the arc length and curvature of the corner thereof.
Owner:JILIN TAIHAO RAILWAY VEHICLE EQUIP CO LTD