Method for representing arcs for assisting in panel processing of a ship hull structure

Abstract

The application discloses an arc expression method for assisting ship body structure panel processing, and comprises the following steps: S1, obtaining ship body structure panel processing arc lines and curve data of the arc lines, wherein the curve data comprises arc length, radius and deflection angle of the arc segments; S2, determining inflection points in the structure panel processing arc lines; S3, detecting whether the arc segments on both sides of the inflection points are suitable for small-radius arc fitting, if the detection result is yes, then small-radius arc fitting is performed on the arc segments suitable for small-radius arc fitting, the end points of the remaining arc segments are connected to form a chord, and the chord height of the point on the arc segment is marked. According to the bending characteristics of the arc lines, the arc lines are segmented and simplified, for example, the arc lines are separated at the inflection points, the arc segments with large radius R values and slow bending are expressed by equidistant chord heights of the connecting lines of the end points of the arc lines, and the arc segments with small radius R values and fast bending are replaced by a small radius R value, and the arc length of the arc segment is marked, so that the actual processing arc lines can be accurately drawn by the on-site construction personnel.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ship structure panel processing, and more particularly, the present application relates to an arc expression method for assisting ship structure panel processing. BACKGROUND

[0002] The ship body is a plate frame structure composed of steel plates and skeletons, specifically, the deck, the side plate, the bilge plate, the bottom plate and the tail plate form an external closed boundary (spliced by steel plates), and the internal longitudinal and transverse bulkheads divide the ship body into various functional cabins, and these external closed boundaries and internal longitudinal and transverse bulkheads are supported by respective skeletons to form a firm ship structure. The skeleton is divided into rolled sections (such as angle steel and flat steel) and combined sections (T-shaped section), and the T-shaped strong skeleton (strong rib, side longitudinal girder, rib plate and bottom keel) of the main ship plate needs to be processed into the required arc shape in advance and then assembled and welded with the T-shaped strong skeleton web plate.

[0003] Modern shipbuilding has completely abandoned the previous 1:1 floor lofting due to the use of three-dimensional modeling software, and the curved panel data required for processing can be automatically extracted by the software, such as the data provided by the regular manhole reinforcement ring, which can clearly express the required shape, such as Figure 1 、 Figure 2 In the figure, CUR- represents an arc segment, and STR- represents a straight line segment. The data starts from "END 1" and expresses the changing arc segment characteristics in sequence to the other end.

[0004] Figure 1 The arc radius has no continuous change and the radius value is also within the range of the measurable line in the field, and the arc direction angle is also a regular value, so the processing template of the arc can be accurately copied in the field. Figure 2 The arc is a typical processing data of the reinforcement panel of the waist round opening edge on the ship structure, and such template data can also be accurately copied by the field construction personnel.

[0005] There is also a T-shaped section panel (strong rib, side longitudinal girder, bottom keel, etc.) following the irregular (variable radius arc) line of the ship plate, and the processing data automatically separated by the three-dimensional software is difficult to accurately copy by the field construction personnel, such as Figure 3 . Figure 3 As can be seen from the right figure, the T-shaped section panel is an irregular arc, the arc radius value and the direction angle change constantly, the maximum radius value is 7586mm, and the field construction personnel cannot accurately draw the actual processing arc. SUMMARY

[0006] The present application provides an arc expression method for assisting ship structure panel processing, which aims to improve the operability of variable radius bending arc processing data.

[0007] The present application is achieved, a kind of auxiliary ship body structure panel processing arc expression method, the method specifically includes the following steps:

[0008] S1, obtain ship body structure panel processing arc and the curve data of arc, curve data includes the arc length of arc segment, radius and deflection angle;

[0009] S2, determine the inflection point in structure panel processing arc;

[0010] S3, detect whether the arc segment of the two sides of inflection point is suitable for small radius arc fitting, if the detection result is yes, then the arc segment suitable for small radius arc fitting is fitted with small radius arc, the end point of the remaining arc segment is connected to form chord, and the chord height of the point on arc segment is marked.

[0011] Further, the determination method of inflection point is specifically as follows:

[0012] detect whether the direction of current arc segment is opposite to the direction of previous arc segment, if the detection result is yes, then the end point of last arc segment is taken as the inflection point of the start point of current arc segment.

[0013] Further, detect whether the deflection direction of the deflection angle of current arc segment is same with the deflection direction of the deflection angle of previous arc segment, if not same, then the direction of current arc segment is opposite to the direction of previous arc segment.

[0014] Further, small radius arc fitting is suitable for at least one arc segment, and the arc segment needs to meet the following conditions:

[0015] The radius of arc segment is less than radius threshold value, the deflection direction of arc segment deflection angle is same, and the total deflection angle of arc segment is less than deflection angle threshold value.

[0016] Further, the radius threshold value is 2m, and the deflection angle threshold value is 45 degrees.

[0017] Further, if the arc segment of the two sides of inflection point is not suitable for small radius arc fitting, then the end point of all arc segments is connected to form chord, and the chord height of the point on arc segment is marked.

[0018] Further, the fitting method of small radius arc is specifically as follows:

[0019] Sampling fitting point for small radius arc fitting on the continuous arc segment to be fitted, and fitting small radius arc based on fitting point.

[0020] Further, the fitting point includes: the start point, midpoint and end point of the continuous arc segment to be fitted.

[0021] Further, the curve data of ship body structure panel processing arc and arc is separated from three-dimensional modeling software TRIBON.

[0022] Based on the curvature characteristics of the arc, the arc segments are simplified. For example, the arc is separated at the inflection point. For arc segments with a larger radius R value and a slow curvature, the arc data is expressed by the equidistant chord height of the line connecting the ends of the arc. For arc segments with a smaller radius R value and a fast curvature, a uniform small radius R value can be marked to replace it, and the arc length of this arc segment is marked to help on-site construction personnel accurately draw the actual processing arc. Attached Figure Description

[0023] Figure 1 This invention provides processing data for small-radius curved panels in embodiments of the invention.

[0024] Figure 2 Processing data for regular curved panels provided in embodiments of the present invention;

[0025] Figure 3 Data for processing the hull T-shaped composite material panel provided in the embodiments of the present invention;

[0026] Figure 4 This is a schematic diagram of the arc length and tilt angle of the curved data provided in an embodiment of the present invention;

[0027] Figure 5 Provided for embodiments of the present invention Figure 3 A schematic diagram illustrating the representation of processing data for the middle panel;

[0028] Figure 6 A flowchart illustrating the arc representation method for auxiliary hull structure panel processing provided in this embodiment of the invention. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0030] Based on the curvature characteristics of the arc, the arc segments are simplified. For example, the arc is separated at the inflection point. For arc segments with a larger radius R value and a slow curvature, the arc data is expressed by the equidistant chord height of the line connecting the ends of the arc. For arc segments with a smaller radius R value and a fast curvature, a uniform small radius R value can be marked to replace it, and the arc length of this arc segment is marked to help on-site construction personnel accurately draw the actual processing arc.

[0031] Figure 6 A flowchart illustrating the method for representing arcs in the auxiliary hull structure panel processing provided in this embodiment of the invention. The method specifically includes the following steps:

[0032] S1, separate the hull structure panel processing arc and the cam data of the arc from the three-dimensional modeling software TRIBON, the cam data includes: the arc length, the radius and the deflection angle of the arc segment, the deflection angle refers to the deflection angle of the tangent direction of the end point of the arc segment relative to the tangent direction of the starting point, the cam data of the structure panel processing arc is shown on the right side in Figures 1 to 4 , the angle in the cam data is the deflection angle of the arc segment in the application.

[0033] S2, determine the inflection point in the hull structure panel processing arc, wherein the determination method of the inflection point is as follows:

[0034] Detect whether the direction of the current arc segment is opposite to that of the previous arc segment, if the detection result is yes, the end point of the previous arc segment, that is, the starting point of the current arc segment, is taken as the inflection point. In the embodiment of the application, if the detection of the inflection point is based on the deflection angle of the arc segment, the detection method is as follows:

[0035] Detect whether the deflection angle of the current arc segment is the same as the deflection direction of the deflection angle of the previous arc segment, if not, the direction of the current arc segment is opposite to that of the previous arc segment, the end point of the previous arc segment, that is, the starting point of the current arc segment, is taken as the inflection point, if yes, the direction of the current arc segment is the same as that of the previous arc segment.

[0036] In the embodiment of the application, the "angle" value of each arc segment in the "cam data", that is, the angle of the tangent direction of the end point of each arc from the tangent direction of the starting point of the arc, the deflection direction is counterclockwise positive and clockwise negative, details are shown in Figure 4 ; for a continuous arc, when the deflection angle of the "cam data" changes from "positive" to "negative", or from "negative" to "positive", the end point of the previous arc is judged as the "inflection point" of the continuous arc. From Figure 3 , it is not difficult to see from the "cam data" on the right side that the end point (right side) of a segment with an arc length of 144mm is an "inflection point" of the continuous arc, details are shown in Figure 5 .

[0037] S3, detect whether the arc segments on both sides of the inflection point are suitable for small radius arc fitting, if the detection result is yes, the arc segments suitable for small radius arc fitting are subjected to small radius arc fitting, the end points of the remaining arc segments are connected to form a chord, and the chord height of the point on the arc segment is marked, if the detection result is no, the end points of all arc segments are connected to form a chord, and the chord height of the point on the arc segment is marked.

[0038] In the embodiment of the present application, the small-radius arc fitting is applicable to one arc segment or a plurality of continuous arc segments, and the small-radius arc fitting applicable to one arc segment needs to meet the following conditions: the radius of the arc segment is smaller than the radius threshold, and the deflection angle of the arc segment is smaller than the deflection angle threshold; the small-radius arc fitting applicable to a plurality of continuous arc segments needs to meet the following conditions: the radius of all the arc segments is smaller than the radius threshold, and the deflection directions of the deflection angles of all the arc segments are the same, and the total deflection angle of all the arc segments is smaller than the deflection angle threshold.

[0039] In the embodiment of the present application, if the radius of the arc is too large, not only the required construction site is large, but also it is difficult to accurately determine the center and the radius, based on this, the above-mentioned radius threshold is generally 2m, in addition, the above-mentioned deflection angle threshold is 45 degrees.

[0040] In the embodiment of the present application, the method for small-radius arc fitting is specifically as follows:

[0041] In the n(n≥1) continuous arc segments to be fitted, the fitting points for small-radius arc fitting are used, the fitting points include the starting points, the middle points and the ending points of the n continuous arc segments, the small-radius arc fitting is performed based on the fitting points, and there is a certain deviation between the fitted arc and the actual arc segment, in the actual assembly process, the deviation within 5mm from the actual position can meet the assembly requirements of the panel.

[0042] In combination with Figure 5 It is described that the arc segment on the right side of the inflection point is fitted with a small-radius arc, and all the arc segments on the left side are marked with chord heights. As shown in Figure 5 , three continuous arc segments are identified as one large arc segment, the starting point and the ending point of the large arc segment form a chord, or each arc segment independently forms a chord, and then the heights of the points on the arc segment to the chord are marked.

[0043] The present application is described by way of example, and obviously the specific implementation of the present application is not limited by the above-mentioned manner, as long as various non-essential improvements are made by using the method concept and technical scheme of the present application, or the concept and technical scheme of the present application are directly applied to other occasions without improvement, all of which are within the protection scope of the present application.

Claims

1. A method for expressing arcs in auxiliary hull structure panel processing, characterized in that, The method specifically comprises the following steps: S1, obtaining the processing arc line of the hull structure panel and the curve data of the arc line, the curve data comprising the arc length, radius and deflection angle of the arc segment; S2, determining the inflection point in the processing arc line of the structure panel; S3, detecting whether the arc segments on both sides of the inflection point are applicable to small-radius arc fitting, if the detection result is yes, performing small-radius arc fitting on the arc segments applicable to small-radius arc fitting, connecting the end points of the remaining arc segments to form a chord, and marking the chord height of the point on the arc segment; The small-radius arc fitting is applicable to at least one arc segment, and the arc segment needs to satisfy the following conditions: The radius of the arc segment is smaller than the radius threshold value, the deflection direction of the deflection angle of the arc segment is the same, and the total deflection angle of the arc segment is smaller than the deflection angle threshold value.

2. The method of representing an arc for assisting in the processing of panels for a ship structure as defined in claim 1, wherein, The determination method of the inflection point is specifically as follows: Detecting whether the direction of the current arc segment is opposite to that of the previous arc segment, if the detection result is yes, taking the end point of the previous arc segment as the start point of the current arc segment as the inflection point.

3. The method of claim 2, wherein the arc representation is a spline. Detecting whether the deflection direction of the deflection angle of the current arc segment is the same as that of the previous arc segment, if not, the direction of the current arc segment is opposite to that of the previous arc segment.

4. The method of representing curves for assisting in the processing of panels for ship construction as defined in claim 1, wherein, The radius threshold value is 2m, and the deflection angle threshold value is 45 degrees.

5. The method of claim 1, wherein the method further comprises: determining a plurality of points on the curved line; and determining a plurality of points on the curved line by interpolating between the plurality of points on the curved line. If the arc segments on both sides of the inflection point are not applicable to small-radius arc fitting, connecting the end points of all the arc segments to form a chord, and marking the chord height of the point on the arc segment.

6. The method of representing curves for assisting in the processing of panels for ship construction as defined in claim 1, wherein, The fitting method of the small-radius arc is specifically as follows: Sampling the fitting points for small-radius arc fitting on the to-be-fitted continuous arc segment, and fitting the small-radius arc based on the fitting points.

7. The method of representing an arc according to claim 6, wherein the arc is represented by a plurality of straight line segments. The fitting points comprise the start point, middle point and end point of the to-be-fitted continuous arc segment.

8. The method of representing curves for assisting in the processing of panels for ship construction as defined in claim 1, wherein, The curve data of the processing arc line of the hull structure panel and the arc line are separated from the three-dimensional modeling software TRIBON.

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