A method for drawing reverse curve behind turnout based on geometric constraint

Abstract

The application relates to the technical field of rail transit engineering design, and discloses a turnout rear reverse curve drawing method based on geometric constraints, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: acquiring turnout basic parameters; based on the geometric composition of the turnout rear reverse curve and the turnout basic parameters, a constraint equation set containing multiple geometric constraints is constructed; the constraint equation set is solved to obtain the coordinates of the centers of the two circular curves and the angle of the common tangent; and according to the coordinates of the centers of the two circular curves and the angle of the common tangent, the turnout rear reverse curve which is smoothly connected with the turnout side stock and the target track is generated. The method can improve the drawing precision and efficiency of the turnout rear reverse curve in the drawing design of the rail transit turnout.

Description

Technical Field

[0001] This application relates to the field of rail transit engineering design technology, and more specifically, to a method for drawing reverse curves after turnouts based on geometric constraints, a computer device, a computer-readable storage medium, and a computer program product. Background Technology

[0002] In CAD drawing design of railway and rail transit turnouts, drawing the reverse curve after the turnout is a crucial step in station layout. When a train needs to turn during operation, it needs to switch from the straight track to the side track, and finally travel along the designated track (also known as the target track). Currently, the track design between the target track and the turnout side track mainly adopts the traditional graphical method or simple trigonometric function calculation method. The core principle is to manually read the basic parameters of the turnout, manually select points to determine the centers of the two circular curves, and generate the reverse curve after the turnout by scaling and offsetting. The practical effect is greatly affected by the designer's operating experience and visual judgment, and has the following defects: (1) Unstable drawing accuracy: When manually selecting points to determine the center of two circular curves, the center position may shift due to visual errors and scaling operation deviations caused by different designers' operating habits. This results in non-integer lengths of the straight line and misalignment of curve connections, with errors reaching 3-5mm, which cannot meet the requirements of high-precision construction design. (2) Low drawing efficiency: When basic parameters such as turnout model and track spacing are changed, the original curves need to be manually deleted, parameters recalculated and drawn. Adjusting a single set of reverse curves takes 3-5 minutes, and the construction period is difficult to guarantee in the case of batch adjustment. (3) Poor compatibility with standards: It relies on designers to manually check whether the radius of the circular curve and the length of the straight line meet the engineering standards, which is prone to omissions and poses a risk of design compliance. (4) There is a certain operational threshold: the graphical method requires designers to be proficient in geometric drawing skills and understand the wiring principle. Novices need a long period of training to be competent, and manual operation is prone to repeated errors. Summary of the Invention

[0003] To address the problems of low accuracy, low efficiency, and poor standard compatibility in drawing the reverse curve of turnouts in railway and rail transit turnout design, this invention provides a geometrically constrained method for drawing the reverse curve of turnouts, a computer device, a computer-readable storage medium, and a computer program product, which can improve the accuracy and efficiency of drawing the reverse curve of turnouts.

[0004] To achieve the above objectives, according to a first aspect of the present invention, a method for drawing a turnout reverse curve based on geometric constraints is provided. The turnout reverse curve is a curve used in drawing software to connect the turnout side track to the target track. Its geometric structure includes two opposing circular curves and a straight line connecting the two circular curves. The two circular curves have the same design radius and a common tangent. The straight line is a line segment on the common tangent located between the points of tangency of the two circular curves. The straight line containing the target track is parallel to the straight line containing the turnout side track. The method includes: Obtain the basic parameters of the turnout, including the preset track spacing and the design radius of the circular curve. The track spacing is the vertical distance between the straight line where the target track is located and the straight line where the turnout side track is located. Based on the geometric structure of the turnout's reverse curve and the turnout's basic parameters, a set of constraint equations containing multiple geometric constraints is constructed. Solve the constraint equations to obtain the coordinates of the centers of the two circular curves and the angle of their common tangent. Based on the center coordinates of the two circular curves and the angle of their common tangent, a reverse curve after the turnout is generated that smoothly connects with the turnout side track and the target track.

[0005] Furthermore, the two circular curves are the first circular curve and the second circular curve. The starting point of the intersecting line is the ending point of the first circular curve, and the ending point of the intersecting line is the starting point of the second circular curve. The geometric constraints include: the perpendicular distance from the center of the first circular curve to the extension of the turnout side track is equal to the design radius; the perpendicular distance from the center of the second circular curve to the target track is equal to the design radius; the line connecting the centers of the first and second circular curves passes through the midpoint of the intersecting line; and the first circular curve is tangent to the extension of the turnout side track, and the point of tangency is the starting point of the first circular curve; the second circular curve is tangent to the target track, and the point of tangency is the ending point of the second circular curve.

[0006] Further, by solving the constraint equations, the coordinates of the centers of the two circular curves and the angle of their common tangent are obtained. This includes establishing a Cartesian coordinate system with the direction of the straight track of the turnout as the X-axis and the direction extending from the turnout center to the target track as the positive X-axis, and the direction perpendicular to the straight track as the Y-axis and pointing towards the target track as the positive Y-axis. The angle of the common tangent is defined as the angle between the intersecting line and the X-axis. The angle between the intersecting line and the X-axis and the length of the straight section after the turnout are taken as variables to be determined, while the turnout frog angle, the preset track spacing, and the design radius of the circular curve are taken as known quantities. These are substituted into the constraint equations to calculate the coordinates of the centers of the two circular curves, the length of the intersecting line, the angle between the intersecting line and the X-axis, and the length of the straight section after the turnout.

[0007] Furthermore, the basic parameters of the turnout also include the minimum length of the clamping straight line. In the process of substituting the constraint equations to calculate the coordinates of the centers of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout, the above-mentioned turnout reverse curve drawing method based on geometric constraints also includes determining whether the calculated length of the clamping straight line is not less than the minimum length of the clamping straight line; if so, the coordinates of the centers of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout are output; otherwise, at least one of the coordinates of the centers of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout is adjusted, and the calculation is recalculated.

[0008] Furthermore, the basic parameters of the turnout also include the minimum value of the length of the straight section after the turnout. In the process of substituting the constraint equations to calculate the coordinates of the center of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout, the above-mentioned turnout reverse curve drawing method based on geometric constraints also includes judging whether the calculated length of the straight section after the turnout is not less than the minimum value of the length of the straight section after the turnout; if so, the coordinates of the center of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout are output; otherwise, at least one of the coordinates of the center of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout is adjusted and recalculated.

[0009] Furthermore, obtaining the basic parameters of the turnout includes establishing a mapping table relating the turnout frog angle, the length of the straight section after the turnout, and the parameters of the reverse curve. The turnout frog angle is a fixed value, uniquely determined by the turnout model. The length of the straight section after the turnout includes both the minimum difficult value and the recommended engineering value, both of which are mandatory values ​​according to engineering specifications. The reverse curve parameters include the minimum permissible radius of the circular curve, the recommended engineering radius of the circular curve, and the minimum length of the clamping straight line, all of which are mandatory values ​​according to engineering specifications. The turnout model and the recommended engineering value of the length of the straight section after the turnout are obtained for the reverse curve after the turnout to be drawn. Based on the turnout model and the recommended engineering value of the length of the straight section after the turnout, the mapping table is queried to obtain the minimum permissible radius of the circular curve, the recommended engineering radius of the circular curve, and the minimum length of the clamping straight line in the reverse curve after the turnout to be drawn. The recommended engineering radius of the circular curve is then used as the design radius of the circular curve in the reverse curve after the turnout to be drawn.

[0010] Furthermore, the turnout basic parameters are obtained, including reading the turnout basic parameters from the drawing file through drawing software, or importing at least one set of turnout basic parameters through a table tool.

[0011] According to a second aspect of the invention, a computer device is also provided, comprising a memory, a processor, and a computer program stored in the memory, the processor executing the computer program to implement the steps of any of the methods described above.

[0012] According to a third aspect of the invention, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of any of the above methods.

[0013] According to a fourth aspect of the invention, a computer program product is also provided, comprising a computer program that, when executed by a processor, implements the steps of any of the above methods.

[0014] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: The present invention provides a method for drawing the reverse curve of a turnout based on geometric constraints. By quantifying the key steps of drawing the reverse curve of a turnout into a set of constraint equations containing multiple geometric constraints, and calculating the set of constraint equations, the coordinates of the center of the two circular curves and the angle of the common tangent are obtained. This allows for the drawing of the reverse curve of the turnout that meets the design requirements. Furthermore, the drawing error of the reverse curve can be controlled according to the requirements, thereby improving the drawing accuracy. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart illustrating a method for drawing the reverse curve after a turnout based on geometric constraints, provided in an embodiment of this application; Figure 2 A schematic diagram of a turnout reversing curve provided in an embodiment of this application; Figure 3 This is a schematic diagram of the internal structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0018] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0019] like Figure 1 As shown, a geometrically constrained method for drawing the reverse curve after a turnout is provided. This method addresses the challenge of accurately drawing the curve connecting the turnout side track and the target track in drawing software when the turnout side track and the target track are not aligned. The geometric structure of this reverse curve includes two opposing circular curves and a connecting line. The two circular curves have the same design radius and share a common tangent. The connecting line is a line segment on the common tangent located between the points of tangency of the two circular curves. The line containing the target track is parallel to the line containing the turnout side track. The vertical distance between the line containing the target track and the line containing the turnout side track is defined as the track spacing.

[0020] This method can be executed by a terminal or by a server that communicates with the terminal via a network. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, etc. The server can be a standalone server or a server cluster consisting of multiple servers. Taking the application of this method to a terminal as an example, the steps include: Step 101: Obtain the basic parameters of the turnout.

[0021] The basic parameters of the turnout include the preset track spacing and the design radius of the circular curve.

[0022] For example, the terminal can automatically read the turnout basic parameters from the drawing file using drawing software (such as CAD), or import at least one set of turnout basic parameters using a spreadsheet tool (such as an Excel spreadsheet).

[0023] Step 102: Based on the geometric structure of the turnout's reverse curve and the turnout's basic parameters, construct a set of constraint equations containing multiple geometric constraints.

[0024] Among them, the two circular curves are the first circular curve and the second circular curve, the starting point of the intersecting line is the ending point of the first circular curve, and the ending point of the intersecting line is the starting point of the second circular curve. The geometric constraints include: (1) the vertical distance from the center of the first circular curve to the extension of the turnout side track is equal to the design radius, and the vertical distance from the center of the second circular curve to the target track is equal to the design radius; (2) the line connecting the centers of the first circular curve and the second circular curve passes through the midpoint of the intersecting line; and (3) the first circular curve is tangent to the extension of the turnout side track, and the point of tangency is the starting point of the first circular curve; the second circular curve is tangent to the target track, and the point of tangency is the ending point of the second circular curve.

[0025] Step 103: Solve the constraint equations to obtain the coordinates of the center of the two circular curves and the angle of their common tangent.

[0026] For example, the terminal establishes a Cartesian coordinate system with the direction of the straight track of the turnout as the X-axis and the direction extending from the turnout center to the target track as the positive X-axis direction, and the direction perpendicular to the straight track as the Y-axis and the direction pointing to the target track as the positive Y-axis direction; the angle of the common tangent is defined as the angle between the clamping line and the X-axis; the angle between the clamping line and the X-axis and the length of the straight section after the turnout are taken as variables to be determined, and the turnout frog angle, the preset track spacing, and the design radius of the circular curve are taken as known quantities. These are substituted into the constraint equation system to calculate the coordinates of the center of the two circular curves, the length of the clamping line, the angle between the clamping line and the X-axis, and the length of the straight section after the turnout.

[0027] In one embodiment, the basic parameters of the turnout also include the minimum length of the clamping straight line. In this case, when the terminal substitutes the constraint equations to calculate the center coordinates of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight segment after the turnout, it also needs to determine whether the calculated length of the clamping straight line is not less than the minimum length of the clamping straight line. If so, the center coordinates of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight segment after the turnout are output. Otherwise, at least one of the center coordinates of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight segment after the turnout is adjusted and recalculated.

[0028] In one embodiment, the basic parameters of the turnout also include the minimum value of the length of the straight section after the turnout. In this case, when the terminal substitutes the constraint equations to calculate the coordinates of the center of the two circular curves, the length of the intersecting straight line, the angle between the intersecting straight line and the X-axis, and the length of the straight section after the turnout, it also needs to determine whether the calculated length of the straight section after the turnout is not less than the minimum value of the length of the straight section after the turnout. If so, the coordinates of the center of the two circular curves, the length of the intersecting straight line, the angle between the intersecting straight line and the X-axis, and the length of the straight section after the turnout are output. Otherwise, at least one of the coordinates of the center of the two circular curves, the length of the intersecting straight line, the angle between the intersecting straight line and the X-axis, and the length of the straight section after the turnout is adjusted and recalculated.

[0029] Step 104: Based on the center coordinates of the two circular curves and the angle of their common tangent, generate a reverse curve after the turnout that smoothly connects with the turnout side track and the target track.

[0030] For example, based on the coordinates of the two center lines and the angle of the common tangent, a reverse curve after the turnout is generated in CAD software that smoothly connects with the turnout side track and the target track.

[0031] In the above-mentioned geometric constraint-based method for drawing the reverse curve of a turnout, the key steps in drawing the reverse curve are quantified into a set of constraint equations containing multiple geometric constraints. The constraint equations are calculated to obtain the center coordinates and the angle of the common tangent of the two circular curves, thereby drawing the reverse curve of the turnout that meets the design requirements. Furthermore, the drawing error of the reverse curve can be controlled according to the requirements, thus achieving the goal of improving the drawing accuracy.

[0032] In one embodiment, step 101 above, obtaining the turnout basic parameters, includes establishing a mapping table between the turnout frog angle, the length of the straight section after the turnout, and the parameters of the reverse curve before drawing the reverse curve after the turnout. The turnout frog angle is a fixed value uniquely determined by the turnout model; the straight section after the turnout is the straight section connecting the turnout body and the reverse curve in the side track direction, and its value includes the minimum difficulty value and the recommended engineering value, both of which are mandatory values ​​in the engineering specifications; the reverse curve parameters include the minimum allowable radius of the circular curve, the recommended engineering radius of the circular curve, and the... The minimum length of the clamping straight line is a mandatory value in the engineering specifications. When it is necessary to draw the reverse curve after the turnout, obtain the recommended engineering values ​​for the turnout model and the length of the straight section after the turnout of the reverse curve to be drawn. Based on the recommended engineering values ​​for the turnout model and the length of the straight section after the turnout of the reverse curve to be drawn, query the associated mapping table to obtain the minimum allowable radius of the circular curve, the recommended engineering radius of the circular curve, and the minimum length of the clamping straight line in the reverse curve to be drawn. Then, use the recommended engineering radius of the circular curve as the design radius of the circular curve in the reverse curve to be drawn.

[0033] In this embodiment, by establishing a mapping table between different types of turnouts, the length of the straight section after the turnout, and the reverse curve parameters, it is possible to support the drawing of the reverse curves after the turnouts of multiple types of turnouts, and it can be applied to the automated drawing of the reverse curves after the turnouts in the layout of urban rail and railway stations.

[0034] In one embodiment, the above-mentioned method for drawing the reverse curve of a turnout based on geometric constraints further includes, when a change in the turnout's basic parameters is detected, re-determining the geometric constraints based on the updated turnout basic parameters and iteratively calculating the constraint equations, and outputting the updated coordinates of the center of the two circular curves and the angle of their common tangent.

[0035] In this embodiment, by automatically updating parameters, the drawing effect can be dynamically modified by humans without the need for manual redrawing, which can greatly improve the drawing efficiency of reverse curves.

[0036] In a most specific embodiment, a method for drawing the reverse curve after a turnout based on geometric constraints, based on the geometric features and engineering specification constraints of the reverse curve after the turnout, achieves accurate drawing of the reverse curve by constructing a geometric constraint model, developing a parameter linkage mechanism, and designing a CAD adaptation module. Specifically, it includes the following steps: (1) Construction of geometric constraint model like Figure 2 As shown, a rectangular coordinate system commonly used in railway design is first established: The direction of the straight track extension of the turnout is taken as the positive direction of the X-axis (i.e. Figure 2 The positive direction is from left to right. The direction perpendicular to the straight stock is the Y-axis, and the direction pointing towards the target stock is the positive direction of the Y-axis (i.e., Figure 2 (The positive direction is from top to bottom), establish a plane rectangular coordinate system.

[0037] Turnout foundation parameter extraction: Automatically reads the coordinates of the turnout center A and the straight circle point (i.e., ZY point, the end point of the turnout side track, and the starting point of the reverse curve) C from the CAD drawing, and uses the straight segment AC as the straight segment after the turnout; as well as the design input track spacing S, the design radius R of the circular curve, and the minimum length of the clamping straight line. Establish the initial parameter dataset by defining core parameters.

[0038]

[0039] Constraint equation establishment: Based on the geometric structure of the reverse curve after the turnout (two reverse circular curves tangent to each other + common tangent line connection), multiple geometric constraint equations (i.e. geometric constraint conditions) are constructed.

[0040] Specifically, the reverse curve after the turnout includes a first circular curve and a second circular curve with a common tangent and in opposite directions. The first circular curve and the second circular curve have the same design radius and are connected by a clamping straight line. The clamping straight line is the line segment between the point P where the first circular curve is tangent to the common tangent (i.e., the end point of the first circular curve) and the point Q where the second circular curve is tangent to the common tangent (i.e., the starting point of the second circular curve).

[0041] The geometric constraints include: (1) the vertical distance from the center M of the first circular curve to the extension of the turnout side track is equal to the design radius R, and the vertical distance from the center N of the second circular curve to the target track is equal to the design radius R; (2) the midpoint of the straight line PQ falls on the line MN connecting the centers of the circles; (3) the first circular curve is tangent to the extension of the turnout side track, and the point of tangency (tangency point C) is the starting point of the first circular curve; the second circular curve is tangent to the target track, and the point of tangency (tangency point E) is the ending point of the second circular curve, ensuring smooth connection of the line.

[0042] Solve the geometric constraint equations to obtain the coordinates of the circle centers M and N. The specific process is as follows: Based on the above geometric constraints, we can obtain MP=MC=R, MP⊥PQ, NQ=NE=R, NQ⊥PQ, the line connecting NM passes through the center point of PQ, MC⊥side stock, and NE⊥target stock.

[0043] Given that the side stock is parallel to the target stock, the vertical distance between the side stock and the target stock is defined as the stock line spacing S, and the side stock direction is a unit vector. =(cosα,sinα), the unit normal vector in the direction of the lateral leg (pointing downwards from the lateral leg, i.e., to the side of the center M): =( sinα, cosα), the unit vector in the direction of the line PQ: =(cosβ,sinβ) (β is the angle between PQ and the X-axis, to be determined), a unit vector perpendicular to the PQ direction (pointing towards M): =( sinβ,cosβ).

[0044] We can obtain:

[0045] in, The length of the line is the angle between the two lines. It has a minimum value. minimum value It is determined based on the track design specifications.

[0046] The coordinates of point C, the point of tangency on the extension line of the lateral thigh, are:

[0047] in, Let AC be the length of the straight section after the fork. It has a minimum value. The minimum value is determined based on track design specifications to ensure that trains can run normally.

[0048] Point C travels a length R along the direction of the lateral normal vector n to reach point M. The coordinates of point M, the center of the first circular curve, are:

[0049] The coordinates of point P, the starting point of the straight line, are:

[0050] The coordinates of point Q, the endpoint of the straight line, are:

[0051] The coordinates of the center point N of the second circular curve are:

[0052] The coordinates of the tangent point E on the target track are:

[0053] The core constraint is that the spacing S between the stock lines should be: L sin(β α)+2R cos(β α)=S Therefore, when the values ​​of R and L are both obtained and L ≥ 1, and ≥ When the minimum value is reached, all relevant coordinates and the common tangent angle value β can be obtained.

[0054] (2) Parameter linkage and dynamic calibration mechanism Parameter association mapping: Establish turnout frog angle, length of straight section after turnout, and reverse curve parameters (minimum allowable radius R of circular curve, recommended engineering radius R of circular curve, minimum length of straight section). The associated mapping table is shown in Table 1. Preset the adaptation range of reverse curve parameters for different turnout types to ensure that the drawing conforms to the above geometric constraints. The straight section after the turnout is a smooth transition section between the turnout body and the reverse curve without superelevation or gauge widening; it is a mandatory control parameter for railway / subway line design.

[0055] Table 1

[0056] Dynamic calibration trigger: When the designer modifies any turnout basic parameters (such as adjusting the track spacing S from 10m to 12m, or adjusting the design radius R of the circular curve from 200m to 250m), the system automatically triggers the calibration process, restarts the geometric constraint calculation based on the updated parameters, and synchronously corrects the center position, the corresponding common tangent direction, and the curve shape, without the need for manual deletion and redrawing.

[0057] Standard verification integration: embed engineering standard verification rules during the iteration process to automatically determine whether the curve radius meets the minimum limit and whether the straight line length meets the standard. If the parameters exceed the standard range, real-time warning prompts are output and recommended minimum compliant parameter values ​​are provided.

[0058] (3) Lightweight interaction and result output design Drag-and-drop interactive logic design: Simplifies traditional multi-step operations. Designers can adjust the position and angle of the reverse curve by dragging with the mouse, and can also precisely adjust the connection point and control data of the reverse curve by parameters. The system's background algorithm responds synchronously, realizing a lightweight design mode of "dragging to adjust, adjusting to complete the design".

[0059] Visualized output of design results: After the scheme is determined, the system automatically generates a turnout design parameter report (including core information such as turnout model, connection angle, endpoint coordinates, and association level). It also supports automatic annotation of key turnout dimensions and relationships in CAD drawings, which is convenient for designers to verify and for subsequent engineering handover.

[0060] (4) Three-dimensional scene expansion: The geometric constraint model is expanded to three-dimensional space, and the line elevation parameter constraint is added to realize the three-dimensional accurate modeling of the reverse curve after the turnout, which is compatible with the design requirements of BIM (Building Information Modeling).

[0061] The method for drawing the reverse curve after a turnout based on geometric constraints provided in the above embodiments has the following beneficial effects: (1) Significantly improved drawing accuracy: The geometric constraint algorithm controls the error of reverse curve drawing according to the requirements, with the maximum accuracy within 10^-6, completely solving the problems of center offset and curve misalignment caused by manual point selection, breaking through the accuracy bottleneck of manual point selection in traditional graphical method, and meeting the requirements of high-precision construction design.

[0062] (2) Dragging efficiency is greatly improved: the time for drawing a single set of reverse curves is reduced from 1-3 minutes to within 10 seconds. When parameters change, there is no need to manually redraw. The dynamic calibration response time is reduced to within 2 seconds. The efficiency is improved by more than 80% in batch adjustment scenarios. By establishing a dynamic linkage mechanism for parameters, iterative calibration is automatically triggered when the basic parameters change, and the curve shape and annotation are updated synchronously. There is no need to manually redraw, and the drawing effect can be dynamically modified by human interaction, which greatly improves the efficiency of design iteration.

[0063] (3) Compliance assurance: The built-in standard verification mechanism automatically avoids parameter exceeding the standard, reduces design compliance risks, and at the same time, the annotation is clear and the layers are standardized, improving the standardization level of drawings. The integrated engineering standard real-time verification function automatically avoids the risk of parameter exceeding the standard, and is adapted to the native CAD interaction logic, simplifying the operation process, reducing the dependence on the experience of designers, and realizing high-precision, standardized and automated drawing.

[0064] (4) The operating threshold is greatly reduced: designers do not need to master complex geometric drawing skills. They only need to input basic parameters to automatically complete accurate drawing. Novices can get started quickly, reducing personnel training costs and repetitive errors.

[0065] This application also provides a computer device, the internal structure diagram of which can be shown as follows: Figure 3 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides the environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a method for drawing the reverse curve after a turnout based on geometric constraints. The display unit of the computer device is used to form a visually visible image. It can be a display screen, a projection device, or a virtual reality imaging device. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0066] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0067] like Figure 3As shown, this application also provides a computer device, which includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps in the above-described method embodiments.

[0068] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described method embodiments. The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, as well as magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0069] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0070] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0071] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0072] The above description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for drawing the reverse curve after a turnout based on geometric constraints, characterized in that, The reverse curve after the turnout is a curve used in drawing software to connect the turnout side track to the target track. Its geometric structure includes two opposing circular curves and a straight line connecting the two circular curves. The two circular curves have the same design radius and a common tangent. The straight line is a line segment on the common tangent located between the points of tangency of the two circular curves. The straight line containing the target track is parallel to the straight line containing the turnout side track. The method includes: Obtain the basic parameters of the turnout, which include the preset track spacing and the design radius of the circular curve. The track spacing is the vertical distance between the straight line where the target track is located and the straight line where the turnout side track is located. Based on the geometric structure of the turnout's reverse curve and the turnout's basic parameters, a set of constraint equations containing multiple geometric constraints is constructed. Solving the constraint equations yields the coordinates of the centers of the two circular curves and the angle of their common tangent. Based on the center coordinates of the two circular curves and the angle of the common tangent, a reverse curve after the turnout is generated that smoothly connects with the turnout side track and the target track.

2. The method for drawing the reverse curve after a turnout based on geometric constraints as described in claim 1, characterized in that, The two circular curves are a first circular curve and a second circular curve. The starting point of the clamping line is the ending point of the first circular curve, and the ending point of the clamping line is the starting point of the second circular curve. The geometric constraints include: the perpendicular distance from the center of the first circular curve to the extension of the turnout side track is equal to the design radius; the perpendicular distance from the center of the second circular curve to the target track is equal to the design radius; the line connecting the centers of the first and second circular curves passes through the midpoint of the clamping line; and the first circular curve is tangent to the extension of the turnout side track, with the point of tangency being the starting point of the first circular curve; the second circular curve is tangent to the target track, with the point of tangency being the ending point of the second circular curve.

3. The method for drawing the reverse curve after a turnout based on geometric constraints as described in claim 1, characterized in that, Solving the constraint equations to obtain the coordinates of the centers of the two circular curves and the angle of their common tangent includes: A Cartesian coordinate system is established with the direction of the straight track of the turnout as the X-axis and the direction extending from the turnout center to the target track as the positive direction of the X-axis, and the direction perpendicular to the straight track as the Y-axis and the direction pointing to the target track as the positive direction of the Y-axis. The angle of the common tangent is defined as the angle between the line and the X-axis; The angle between the clamping line and the X-axis and the length of the straight section after the turnout are taken as variables to be determined. The turnout frog angle, the preset track spacing, and the design radius of the circular curve are taken as known quantities. They are substituted into the constraint equations to calculate the coordinates of the center of the two circular curves, the length of the clamping line, the angle between the clamping line and the X-axis, and the length of the straight section after the turnout.

4. The method for drawing the reverse curve after a turnout based on geometric constraints as described in claim 3, characterized in that, The turnout basic parameters also include the minimum length of the clamping straight line. In the process of substituting the constraint equations into the calculation of the center coordinates of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight segment after the turnout, the method further includes: Determine whether the calculated length of the clamping line is not less than the minimum length of the clamping line; if so, output the coordinates of the center of the two circular curves, the length of the clamping line, the angle between the clamping line and the X-axis, and the length of the straight segment after the fork; otherwise, adjust at least one of the coordinates of the center of the two circular curves, the length of the clamping line, the angle between the clamping line and the X-axis, and the length of the straight segment after the fork, and recalculate.

5. The method for drawing the reverse curve after a turnout based on geometric constraints as described in claim 3, characterized in that, The turnout basic parameters also include the minimum length of the straight section after the turnout. In the process of substituting the values ​​into the constraint equations to calculate the coordinates of the centers of the two circular curves, the length of the clamping straight line, the angle between the clamping straight line and the X-axis, and the length of the straight section after the turnout, the method further includes: Determine whether the calculated length of the straight segment after the fork is not less than the minimum value of the straight segment length after the fork; if so, output the center coordinates of the two circular curves, the length of the clamping line, the angle between the clamping line and the X-axis, and the length of the straight segment after the fork; otherwise, adjust at least one of the center coordinates of the two circular curves, the length of the clamping line, the angle between the clamping line and the X-axis, and the length of the straight segment after the fork, and recalculate.

6. The method for drawing the reverse curve after a turnout based on geometric constraints as described in claim 1, characterized in that, The acquisition of the turnout basic parameters includes: Establish a mapping table relating turnout frog angle, length of straight section after turnout, and reverse curve parameters. The turnout frog angle is a fixed value, uniquely determined by the turnout model. The length of straight section after turnout includes the minimum difficulty value and the recommended engineering value, both of which are mandatory values ​​in engineering specifications. The reverse curve parameters include the minimum allowable radius of the circular curve, the recommended engineering radius of the circular curve, and the minimum length of the straight section, all of which are mandatory values ​​in engineering specifications. Obtain the recommended engineering values ​​for the turnout type and the length of the straight section after the turnout for the reverse curve to be drawn; Based on the recommended engineering values ​​of the turnout type and the length of the straight section after the turnout in the reverse curve to be drawn, the association mapping table is queried to obtain the minimum allowable radius of the circular curve, the recommended engineering radius of the circular curve, and the minimum length of the straight section in the reverse curve after the turnout to be drawn. The recommended engineering radius of the circular curve is then used as the design radius of the circular curve in the reverse curve after the turnout to be drawn.

7. The method for drawing the reverse curve after a turnout based on geometric constraints as described in claim 1, characterized in that, The acquisition of turnout basic parameters includes: Read the turnout foundation parameters from the drawing file using drawing software, or import at least one set of turnout foundation parameters using a table tool.

8. A computer device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, It stores a computer program thereon, which, when executed by a processor, implements the steps of the method according to any one of claims 1-7.

10. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the steps of the method according to any one of claims 1-7.

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