Torsion angle description and analysis method of profile bending and torsion component

Abstract

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

Description

Technical Field

[0001] The present application relates to the technical field of advanced manufacturing of complex profile bending components, and in particular to a method for describing and analyzing the torsion angle of a profile bending-torsion component. Background Art

[0002] Profile bending and torsion components are widely used in aerospace, automobile, rail transportation and other fields. In order to meet the requirements of reasonable layout of key load-bearing components in the space of equipment and close fit with other sheet metal surfaces, such components often have complex characteristics such as multiple bends in space, continuous changes in curvature, and even cross-sectional torsion.

[0003] At present, although the six-axis free bending and twisting process and technology can realize the integral forming of profile bending and twisting components, the existing free bending and twisting process analytical algorithm still has the following defects when processing the section torsion angle:

[0004] (1) Compared with circular tubes, the geometric configuration of profile bending-torsion components not only includes the spatial variable curvature of the three-dimensional bending tube, but also incorporates the continuous or discontinuous torsion changes of the cross section along the axial direction. The existing technology usually relies on empirical estimation or simple geometric measurement, which makes it difficult to accurately describe the torsion angle changes at various locations on the complex spatial curve.

[0005] (2) When the bending and torsion features of a component are formed, the analytical method not only needs to accurately calculate the bending parameters of the segment, but also needs to simultaneously assign the value of the torsion angle on the bending segment. The algorithm in the prior art only focuses on the influence of torsion on the shape of the circular tube axis, and does not consider the torsion requirement in the cross-sectional direction of the profile. Summary of the invention

[0006] The purpose of this application is to provide a method for describing and analyzing the torsion angle of a profile bending-torsion member to solve the problems existing in the above-mentioned prior art.

[0007] To achieve the above purpose, the technical solution adopted in this application is:

[0008] In a first aspect, the present application provides a method for describing and analyzing the torsion angle of a profile bending-torsion member, the method comprising:

[0009] Obtain the control points on the center line and edge of the profile bending and torsion member {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e};

[0010] Determine the n uniformly distributed parameter values ​​{u i}, where (i = 1, 2, ..., n); the value of n is determined by the minimum radius R on the profile bending and torsion member min , the corresponding relationship between the total arc length S and the forming area length A;

[0011] Based on the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i} Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (u i );

[0012] According to the parameter value {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determine the first-order derivative of each point on the NURBS curve and the coordinate point and corresponding weight of the first-order derivative;

[0013] In response to matching the weight of the center line with the coordinate point, determining a first-order derivative vector C1;

[0014] Determine the radius of curvature R of each point on the center line i And the corresponding curvature radius R i Required eccentricity U i ;

[0015] Construct the twist vector t i , and define the end section of the profile bending-torsion member as a projection plane, and determine the normal vector Q of the projection plane;

[0016] Based on the torsion vector t i and the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i And the cross-sectional torsion angle γi at different positions on the profile bending-torsion member.

[0017] In a possible implementation, the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {ka} and {k e} is obtained from the default global coordinate system (O-XYZ) of the 3D software; the control point {P a} and {P e},include:

[0018]

[0019] In a possible implementation, the minimum radius R on the profile bending and torsion member is min , the corresponding relationship between the total arc length S and the forming zone length A, including:

[0020]

[0021] In a possible implementation, the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i} Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (u i ),include:

[0022]

[0023] In a possible implementation, the parameter value {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determining the first-order derivative at each point on the NURBS curve and the coordinate points and corresponding weights on the first-order derivative, including:

[0024]

[0025] In a possible implementation, the step of determining the first-order derivative vector C1 in response to matching the weight of the center line with the coordinate point includes:

[0026] C1=[p a 1-(w1 / w n )×p ai ] / w n .

[0027] In one possible implementation, the curvature radius R of each point on the center line is determined. i ,include:

[0028]

[0029] In a possible implementation, the construction of the torsion vector t i , and define the end section of the profile bending-torsion member as a projection plane, and determine the normal vector Q of the projection plane, including:

[0030]

[0031] In a possible implementation, the torsion vector t i and the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i and the cross-sectional torsion angle γ at different positions on the profile bending-torsion member i ,include:

[0032]

[0033] In a second aspect, the present application provides a device for describing and analyzing the torsion angle of a profile bending and torsion member, the device comprising:

[0034] The acquisition module is used to obtain the control points on the center line and edge of the profile bending and torsion member {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e};

[0035] Determination module, used to determine n uniformly distributed parameter values ​​{u i};

[0036] The determining module is also used to determine the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i} Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (ui );

[0037] The determining module is further configured to determine the value of the parameter {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determine the first-order derivative of each point on the NURBS curve and the coordinate point and corresponding weight of the first-order derivative;

[0038] The determination module is further configured to determine a first-order derivative vector C1 in response to matching the weight of the center line with the coordinate point;

[0039] The determination module is also used to determine the curvature radius R of each point on the center line. i And the corresponding curvature radius R i Required eccentricity U i ;

[0040] Building blocks for constructing the twist vector t i , and define the end section of the profile bending-torsion member as a projection plane;

[0041] The determination module is further used to determine the normal vector Q of the projection plane;

[0042] The determining module is further configured to determine the torsion vector t i and the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i and the cross-sectional torsion angle γ at different positions on the profile bending-torsion member i .

[0043] In the third aspect, the present application provides a computer device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the processor can load and execute at least one instruction, at least one program, a code set or an instruction set to implement the torsion angle description and analysis method of the profile bending and torsion component provided above.

[0044] In a fourth aspect, the present application provides a computer-readable storage medium, which stores at least one instruction, at least one program, code set or instruction set. The processor can load and execute at least one instruction, at least one program, code set or instruction set to implement the torsion angle description and analysis method of the profile bending and torsion component provided above.

[0045] In a fifth aspect, the present application provides a computer program product or a computer program, the computer program product or the computer program comprising computer program instructions, the computer program instructions being stored in a computer-readable storage medium. A processor reads the computer instructions from the computer-readable storage medium and executes the computer instructions, so that the computer device executes the torsion angle description and analysis method of the profile bending and torsion member provided above.

[0046] The beneficial effects of the technical solution provided by this application include at least:

[0047] By extracting the NURBS parameters on the edges and center lines of the profile bending and torsion components respectively, and then performing parameterized point distribution according to the arc length, the curvature and coordinates of each point on the curve are obtained, and by constructing the torsion vector and the projection plane and combining the matrix transformation, the cross-sectional torsion angle at different positions on the center line is finally calculated. In this case, the present application adopts the six-axis free bending and torsion technology to manufacture profile bending and torsion components, and provides an analytical method for torsion angle parameters, which can accurately describe the torsion angle changes of the cross sections of the profile bending and torsion components along the axis, and further improve the manufacturing accuracy of the six-axis free bending and torsion technology; in addition, the method is simple and feasible, with high analytical efficiency, and has important engineering application value and obvious economic benefits in the fields of aerospace and new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. They are used to explain the present application together with the embodiments of the present application and do not constitute a limitation of the present application.

[0049] Figure 1 and Figure 2 A flow chart of a method for describing and analyzing the torsion angle of a profile bending-torsion member provided by an exemplary embodiment of the present application is shown.

[0050] Figure 3 A schematic diagram of a cross section and coordinate system division of a profile bending-torsion member is shown, which illustrates a method for describing and analyzing the torsion angle of a profile bending-torsion member provided by an exemplary embodiment of the present application.

[0051] Figure 4 A schematic diagram of torsion angle parameter calculation for a torsion angle description and analytical method of a profile bending-torsion member provided by an exemplary embodiment of the present application is shown.

[0052] Figure 5 A schematic structural diagram of a typical profile bending and torsion member provided in a specific embodiment of the present application is shown.

[0053] Figure 6 A structural block diagram of a torsion angle description and analysis device for a profile bending-torsion member provided by an exemplary embodiment of the present application is shown.

[0054] Figure 7 A schematic diagram of the structure of a computer device for executing a method for describing and analyzing the torsion angle of a profile bending-torsion member provided by an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] First, a brief introduction to NURBS involved in this application:

[0057] NURBS (Non-Uniform Rational B-Splines) is a mathematical model widely used in computer graphics and engineering design to represent curves and surfaces. NURBS combines the flexibility of B-spline with the accuracy of rational polynomials, and can accurately represent various geometric shapes, including straight lines, circles, ellipses, etc. The following is a detailed explanation of NURBS:

[0058] Control Points are a set of points that define the shape of a NURBS. These points do not necessarily lie on the final curve, but they have a direct effect on the shape of the curve.

[0059] Weights: Each control point is associated with a weight that determines the degree of influence of the control point on the final shape. The larger the weight, the greater the influence of the control point on the curve or surface. Weights can be used to accurately represent certain special geometric shapes, such as circles and ellipses.

[0060] Knot Vector is a non-decreasing sequence of values ​​used to define the parameter interval of a curve or surface.

[0061] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0062] Figure 1 A method for describing and analyzing the torsion angle of a profile bending-torsion member provided by an exemplary embodiment of the present application is shown, and the method includes:

[0063] Step 101, obtaining the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}.

[0064] In the embodiment of the present application, the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e} is obtained from the default global coordinate system (O-XYZ) of the 3D software; the above control points {P a} and {P e},include:

[0065]

[0066] Optionally, the 3D software includes at least one of UG, ZW3D, and CATIA.

[0067] Step 102, determine n uniformly distributed parameter values ​​{u i}, where (i = 1, 2, ..., n); the value of n is determined by the minimum radius R on the profile bending-torsion member min , it is determined by the corresponding relationship between the total arc length S and the forming area length A.

[0068] In the embodiment of the present application, the minimum radius R on the above-mentioned profile bending and torsion member is min , the corresponding relationship between the total arc length S and the forming zone length A, including:

[0069]

[0070] In the embodiments of the present application, parametric space is an important concept in computer graphics and geometric modeling. Especially when dealing with curves and surfaces, parametric space provides a method to map geometric objects to a parameter domain, so that these objects can be more easily described and operated mathematically.

[0071] Step 103, based on the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i The Cartesian coordinates C of the points on the center line and edge of the corresponding profile bending and torsion member a (u i) and C e (u i ).

[0072] In the embodiment of the present application, based on the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i The Cartesian coordinates C of the points on the center line and edge of the corresponding profile bending and torsion member a (u i ) and C e (u i ),include:

[0073]

[0074] In the embodiment of the present application, the weighted homogeneous coordinates of each control point are calculated in the NURBS basis function M(u i ), and then find the Cartesian coordinates C of the points on the center line and edge line corresponding to the parameter value a (u i ) and C e (u i ).

[0075] Step 104, according to the parameter value {u i The Cartesian coordinate C of the point on the center line of the corresponding profile bending and torsion member a (u i ), determine the first-order derivative of each point on the NURBS curve as well as the coordinate points and corresponding weights of the first-order derivative.

[0076] In the embodiment of the present application, the above-mentioned parameter value {u i The Cartesian coordinate C of the point on the center line of the corresponding profile bending and torsion member a (u i ), determine the first-order derivative at each point on the NURBS curve and the coordinate points and corresponding weights on the first-order derivative, including:

[0077]

[0078] Step 105, in response to matching the weight of the center line with the coordinate point, expanding it into a three-element column and converting it into a three-dimensional coordinate form to determine the first-order derivative vector C1.

[0079] In the embodiment of the present application, the above response, after matching the weight of the center line with the coordinate point, determines the first-order derivative vector C1, including:

[0080] C1=[p a 1-(w1 / w n )×p ai ] / w n .

[0081] In the embodiment of the present application, w n Represents the weight of the current point, and w1 represents the first-order derivative of the weight.

[0082] Step 106, determine the radius of curvature R of each point on the center line i And the corresponding curvature radius R i Required eccentricity U i .

[0083] In the embodiment of the present application, the curvature radius R of each point on the center line is determined by the curvature definition formula: i According to the principle of free bending, the eccentricity U required for the corresponding radius can be calculated i .

[0084] In the embodiment of the present application, the radius of curvature R of each point on the center line is determined as follows: i ,include:

[0085]

[0086] Step 107, construct the torsion vector t i , and define the end section of the profile bending-torsion member as the projection plane, and determine the normal vector Q of the projection plane.

[0087] In the embodiment of the present application, the above-mentioned construction of the torsion vector t i , and define the end section of the profile bending-torsion member as the projection plane, and determine the normal vector Q of the projection plane, including:

[0088]

[0089] In the embodiment of the present application, t1 represents the initial torsion vector on the end section.

[0090] It is worth mentioning that see Figure 3 , set the end points at both ends of the center line, evenly select n bending sections in the middle of the profile bending and torsion member, take the intersection of the end section of the profile and the center line as the origin O, the end surface as the XY plane, establish the initial local coordinate system O0-x0y0z0, and define the angle α between the bottom edge of the end section and the y0 axis as the initial section direction angle; for each section, take the intersection of each section and the center line as the origin, and the tangent line of the curve passing through this point is z i axis, and establish the y axis according to the angle α with the bottom edge of the curved section i Axis, forming a new local coordinate system O i -xi y i z i ; Connect the corresponding coordinate points on the center line and edge of the profile bending and torsion member in sequence to form a torsion vector t i .

[0091] Step 108, see Figure 4 , based on the torsion vector t i and the normal vector Q of the projection plane, and determine the torsion vectors t on the profile bending and torsion member in turn i Projection t′ on the end section i And the section torsion angle γ at different positions on the profile bending-torsion member i .

[0092] In the embodiment of the present application, the end section of the profile bending-torsion member is defined as a projection plane, and the normal vector Q of the projection plane can be obtained by taking any point (a, b, c) on the plane that is not colinear with the torsion vector t1.

[0093] In the embodiment of the present application, the above-mentioned torsion vector t i and the normal vector Q of the projection plane, and determine the torsion vectors t on the profile bending and torsion member in turn i Projection t′ on the end section i And the section torsion angle γ at different positions on the profile bending-torsion member i ,include:

[0094]

[0095] Figure 5 A schematic diagram of the structure of a typical profile bending-torsion member provided by a specific embodiment of the present application is shown. In a specific embodiment, a method for describing and analyzing the torsion angle of a profile bending-torsion member includes the following steps:

[0096] Step 501, using 3D modeling software to extract the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}:

[0097]

[0098] Step 502, by measuring the center line of the profile bending and torsion member, the minimum bending radius R min The arc length is 808mm, the total arc length is 967mm, and the forming zone length A is set to 150mm during six-axis free bending and torsion forming, so the value of n is 17:

[0099]

[0100] Step 503: Substitute the values ​​of the control points, weights and node vectors extracted in step 501 to calculate the Cartesian coordinates C of the points on the center line and edge line corresponding to each parameter value. a (u i ) and C e (u i ):

[0101]

[0102] Step 504, combining the coordinates of the center line obtained in step 503 and the weight obtained in step 501, respectively calculate the first-order derivative vector C1:

[0103]

[0104] Step 505: Combine step 504 and step 501 to calculate the curvature radius R of each point on the center line through the curvature definition formula. i :

[0105]

[0106] Step 506: According to the principle of free bending, the eccentricity U required for the corresponding radius in step 505 can be calculated. i :

[0107]

[0108] Step 507, set the end points at both ends of the center line, and take n curved sections in the middle, take the intersection of the end section of the profile and the center line as the origin O, the end surface as the XY plane, establish the initial local coordinate system O0-x0y0z0, and define the angle α between the bottom edge of the end section and the y0 axis as the initial section direction angle; for each section, take the intersection of the end section and the center line as the origin, and take the tangent line of the curve passing through the point as the z i axis, and establish the y axis according to the angle α with the bottom edge of the curved section i Axis, forming a new local coordinate system O i -x i y i z i .

[0109] Step 508, sequentially connect the corresponding coordinate points on the center line and edge line of the profile bending and torsion member in step 503 to form a torsion vector t i ;

[0110]

[0111] Step 509, define the end section of the profile bending-torsion member as the projection plane, and take any point (473, -719, 1407) on the plane that is not collinear with the torsion vector t1, and the normal vector Q of the projection plane can be obtained:

[0112]

[0113] Step 510, combining step 508 and step 509, can calculate the torsion vectors t on the profile bending and torsion member. i Projection t′ on the end section i , and then calculate the section torsion angle γ at different positions on the profile bending-torsion member i :

[0114]

[0115] Therefore, through the above analytical steps, the corresponding local torsion angle of the six-axis free bending and torsion forming process with different eccentricity settings can be obtained:

[0116]

[0117] Figure 6 A structural block diagram of a device for describing and analyzing the torsion angle of a profile bending and torsion member provided by an exemplary embodiment of the present application is shown, and the device includes:

[0118] The acquisition module 601 is used to obtain the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e};

[0119] Determination module 602, used to determine n uniformly distributed parameter values ​​{u i};

[0120] The determination module 602 is also used to determine the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i The Cartesian coordinates C of the points on the center line and edge of the corresponding profile bending and torsion member a (u i ) and C e (u i );

[0121] The determination module 602 is further configured to determine the value of the parameter {u i The Cartesian coordinate C of the point on the center line of the corresponding profile bending and torsion member a (u i ), determine the first-order derivative of each point on the NURBS curve as well as the coordinate points and corresponding weights of the first-order derivative;

[0122] The determination module 602 is further configured to determine a first-order derivative vector C1 in response to matching the weight of the center line with the coordinate point;

[0123] The determination module 602 is also used to determine the curvature radius R of each point on the center line. i And the corresponding curvature radius R i Required eccentricity U i ;

[0124] Construction module 603, used to construct the torsion vector t i , and define the end section of the profile bending-torsion member as the projection plane;

[0125] The determination module 602 is further used to determine the normal vector Q of the projection plane;

[0126] The determination module 602 is further configured to determine the torsion vector t i and the normal vector Q of the projection plane, and determine the torsion vectors t on the profile bending and torsion member in turn i Projection t′ on the end section i And the section torsion angle γ at different positions on the profile bending-torsion member i .

[0127] In a possible implementation, the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e} is obtained from the default global coordinate system (O-XYZ) of the 3D software; the control point {P a} and {P e},include:

[0128]

[0129] In a possible implementation, the minimum radius R on the profile bending and torsion member is min , the corresponding relationship between the total arc length S and the forming zone length A, including:

[0130]

[0131] In a possible implementation, the control points {P a} and {P e}, weight {w a} and {w e}、Node vector {k a} and {k e}, determine the parameter value {u i} Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (u i ),include:

[0132]

[0133] In a possible implementation, the parameter value {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determining the first-order derivative at each point on the NURBS curve and the coordinate points and corresponding weights on the first-order derivative, including:

[0134]

[0135] In a possible implementation, the step of determining the first-order derivative vector C1 in response to matching the weight of the center line with the coordinate point includes:

[0136] C1=[p a 1-(w1 / w n )×p ai ] / w n .

[0137] In one possible implementation, the curvature radius R of each point on the center line is determined. i ,include:

[0138]

[0139] In a possible implementation, the construction of the torsion vector t i , and define the end section of the profile bending-torsion member as a projection plane, and determine the normal vector Q of the projection plane, including:

[0140]

[0141] In a possible implementation, the torsion vector t iand the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i and the cross-sectional torsion angle γ at different positions on the profile bending-torsion member i ,include:

[0142]

[0143] It should be noted that the torsion angle description and analysis device of the profile bending and torsion member provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be distributed and completed by different functional modules as needed, that is, the internal structure of the equipment can be divided into different functional modules to complete all or part of the functions described above.

[0144] Figure 7 A schematic diagram of the structure of a computer device for performing a method for describing and analyzing the torsion angle of a profile bending and torsion member provided by an exemplary embodiment of the present application is shown, and the computer device includes:

[0145] The processor 701 includes one or more processing cores. The processor 701 executes various functional applications and data processing by running software programs and modules.

[0146] The receiver 702 and the transmitter 703 can be implemented as a communication component, and the communication component can be a communication chip. Optionally, the communication component can be implemented to include a signal transmission function. That is, the transmitter 703 can be used to transmit a control signal to the image acquisition device and the scanning device, and the receiver 702 can be used to receive the corresponding feedback instruction.

[0147] The memory 704 is connected to the processor 701 via a bus 705 .

[0148] The memory 704 may be used to store at least one instruction, and the processor 701 may be used to execute the at least one instruction to implement each step in the above method embodiment.

[0149] An embodiment of the present application also provides a computer-readable storage medium, which stores at least one instruction, at least one program, code set or instruction set, which is loaded and executed by a processor to implement the above-mentioned torsion angle description and analysis method of the profile bending and torsion component.

[0150] The present application also provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the torsion angle description and analysis method of the profile bending and torsion member described in any of the above embodiments.

[0151] Optionally, the computer readable storage medium may include: a read-only memory (ROM), a random access memory (RAM), a solid state drive (SSD), or an optical disk. Among them, the random access memory may include a resistance random access memory (ReRAM) and a dynamic random access memory (DRAM). The serial numbers of the above embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0152] It should be understood that the specific examples herein are only intended to help those skilled in the art to better understand the present disclosure, rather than to limit the scope of the present invention.

[0153] It is understood that in the various implementations of this specification, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the present disclosure.

[0154] It can be understood that the various implementation modes described in this specification can be implemented individually or in combination, and the present disclosure is not limited to this.

[0155] Unless otherwise stated, all technical and scientific terms used in this disclosure have the same meaning as those generally understood by those skilled in the art of the technical field of this specification. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the scope of this specification. The term "and / or" used in this specification includes any and all combinations of one or more related listed items. The singular forms of "a", "above", and "the" used in this disclosure and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0156] It can be understood that the processor of the present disclosure can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method implementation method can be completed by the hardware integrated logic circuit or software instructions in the processor. The above processor can be a general processor, a digital signal processor (DigitalSignalProcessor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the present disclosure can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the present disclosure can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined to perform. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0157] It is understood that the memory in the present disclosure may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (programmable ROM, PROM), an erasable programmable read-only memory (erasable PROM, EPROM), an electrically erasable programmable read-only memory (EEPROM) or a flash memory. The volatile memory may be a random access memory (RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0158] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this specification.

[0159] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method implementation methods and will not be repeated here.

[0160] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0161] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0162] In addition, each functional unit in each embodiment of the present specification may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0163] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this specification, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of this specification. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0164] The above is only a specific implementation of this specification, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in this specification, which should be included in the protection scope of this specification. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for describing and analyzing the torsion angle of a profile bending-torsion member, characterized in that: The method comprises: Obtain the control points on the center line and edge of the profile bending and torsion member {P a } and {P e }, weight {w a } and {w e }、Node vector {k a } and {k e }; Determine n uniformly distributed parameter values ​​{u i }, where (i = 1, 2, ..., n); the value of n is determined by the minimum radius R on the profile bending and torsion member min , the corresponding relationship between the total arc length S and the forming area length A; Based on the control points {P a } and {P e }, weight {w a } and {w e }、Node vector {k a } and {k e }, determine the parameter value {u i } Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (u i ); According to the parameter value {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determine the first-order derivative of each point on the NURBS curve and the coordinate point and corresponding weight of the first-order derivative; In response to matching the weight of the center line with the coordinate point, determining a first-order derivative vector C1; Determine the radius of curvature R of each point on the center line i And the corresponding curvature radius R i Required eccentricity U i ; Construct the twist vector t i , and define the end section of the profile bending-torsion member as a projection plane, and determine the normal vector Q of the projection plane; Based on the torsion vector t i and the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i and the cross-sectional torsion angle γ at different positions on the profile bending-torsion member i .

2. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: The control points {P a } and {P e }, weight {w a } and {w e }、Node vector {k a } and {k e } is obtained from the default global coordinate system (O-XYZ) of the 3D software; the control point {P a } and {P e }, include:

3. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: The minimum radius R on the profile bending and torsion member min , the corresponding relationship between the total arc length S and the forming zone length A, including:

4. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: The control points {P a } and {P e }, weight {w a } and {w e }、Node vector {k a } and {k e }, determine the parameter value {u i } Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (u i ),include:

5. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: According to the parameter value {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determining the first-order derivative at each point on the NURBS curve and the coordinate points and corresponding weights on the first-order derivative, including:

6. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: The step of determining a first-order derivative vector C1 in response to matching the weight of the center line with the coordinate point comprises: C1=[p a 1-(w1 / w n )×p ai ] / w n .

7. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: Determine the curvature radius R of each point on the center line i ,include:

8. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: The torsion vector t is constructed i , and define the end section of the profile bending-torsion member as a projection plane, and determine the normal vector Q of the projection plane, including:

9. The method for describing and analyzing the torsion angle of a profile bending-torsion member according to claim 1, characterized in that: The twist vector t i and the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i and the cross-sectional torsion angle γ at different positions on the profile bending-torsion member i ,include:

10. A device for describing and analyzing the torsion angle of a profile bending-torsion member, characterized in that: The device comprises: The acquisition module is used to obtain the control points on the center line and edge of the profile bending and torsion member {P a } and {P e }, weight {w a } and {w e }、Node vector {k a } and {k e }; Determination module, used to determine n uniformly distributed parameter values ​​{u i }; The determining module is also used to determine the control points {P a } and {P e }, weight {w a } and {w e }、Node vector {k a } and {k e }, determine the parameter value {u i } Corresponding to the Cartesian coordinates C of the points on the center line and edge of the profile bending and torsion member a (u i ) and C e (u i ); The determining module is further configured to determine the value of the parameter {u i The Cartesian coordinate C corresponding to the point on the center line of the profile bending and torsion member a (u i ), determine the first-order derivative of each point on the NURBS curve and the coordinate point and corresponding weight of the first-order derivative; The determination module is further configured to determine a first-order derivative vector C1 in response to matching the weight of the center line with the coordinate point; The determination module is also used to determine the curvature radius R of each point on the center line. i And the corresponding curvature radius R i Required eccentricity U i ; Building blocks for constructing the twist vector t i , and define the end section of the profile bending-torsion member as a projection plane; The determination module is further used to determine the normal vector Q of the projection plane; The determining module is further configured to determine the torsion vector t i and the normal vector Q of the projection plane, and successively determine the torsion vectors t on the profile bending-torsion member i Projection t′ on the end section i and the cross-sectional torsion angle γ at different positions on the profile bending-torsion member i .

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