A two-dimensional irregular parts layout method based on relational rectangles

Abstract

The present invention provides a two-dimensional irregular part nesting method based on relationship rectangles, comprising the following steps: inputting the contour information of the part to be nested and the contour information of all nested parts in a nested state; calculating all the relationship rectangles of the contour of the part to be nested in a certain direction, and then obtaining all the nesting relationship contours of the contour of the part to be nested in this direction; calculating the maximum non-overlapping nesting distance between the contour of the part to be nested and all the nesting relationship contours, selecting the minimum value of all the maximum non-overlapping nesting distances as the nesting distance d of the contour of the part to be nested in this direction; translating the contour of the part to be nested in this direction by the nesting distance d to complete the nesting in this direction; and outputting the contour information of the part to be nested after the nesting. The local nesting in the nesting process based on the blank discretization method can be completed efficiently and accurately, shortening the time required for the overall nesting process, and improving the utilization rate of the plate.

Description

Technical Field

[0001] The present invention relates to the field of intelligent optimization layout in a mechanical processing production process, and more specifically, to a two-dimensional irregular parts layout approach method for completing local abutment in a layout process based on a blank discretization method. Background Art

[0002] Two-dimensional irregular parts nesting is widely used in many industries such as industrial metal sheet cutting, leather cutting in the clothing industry, and furniture wood cutting. A well-designed intelligent nesting system can greatly improve the utilization rate of materials and shorten the time required for nesting, thereby saving the company's production costs and improving production efficiency. As a type of intelligent nesting algorithm, the nesting algorithm based on the blank discretization method has been widely studied and applied because of its easy implementation and good nesting effect. As one of the key methods in the nesting algorithm based on the blank discretization method, the nesting contour docking method plays an important role in reducing the gap between the nesting contours and thus improving the blank utilization rate. A well-designed contour docking method can efficiently achieve the docking of the nesting contours.

[0003] In the existing research on the layout algorithm based on the blank discretization method, the layout contour docking process is realized by the advance and retreat method. The basic principle of the advance and retreat method is as follows: Figure 6 As shown. Figure 6 It can be seen that the docking accuracy based on the advance and retreat method is determined by the error. The smaller the error, the higher the docking accuracy, and the more advance and retreat times are required. And each advance and retreat needs to complete the overlap detection of the contour to be arranged with all the arranged contours and the blank boundary. When there are many arrangement contours, the overlap detection between the arrangement contours requires a lot of computing time, which seriously affects the overall arrangement efficiency of the algorithm.

[0004] Although CN 110059864 A discloses a method and system for intelligent rectangular layout based on knowledge transfer, the method can improve the utilization rate of plates and the speed of solution, and has good practicality in solving large and medium-sized rectangular layout problems. However, in production practice, layout problems often appear in the form of irregular contours. Compared with rectangular layout problems, the contour positioning process is more complicated in irregular contour layout problems. The existing advance and retreat docking method involves a large number of overlapping detections, and the required calculation time is too long, which seriously affects the overall efficiency of layout. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a two-dimensional irregular parts nesting and docking method based on relationship rectangles, which is used to complete the local docking in the nesting process based on the blank discretization method, and belongs to the field of intelligent optimization nesting in mechanical processing production processes; by adopting this method, the local docking in the nesting process based on the blank discretization method can be completed efficiently and accurately, shortening the overall time required for the nesting process and improving the utilization rate of the plate.

[0006] In order to realize the above technical features, the object of the present invention is achieved as follows: a two-dimensional irregular parts arrangement and docking method based on relationship rectangles, comprising the following steps:

[0007] Step 1: Input the contour information of the part to be nested and the contour information of all nested parts in the docking state, wherein the part contour information includes the vertex coordinates of the polygon corresponding to the part contour at the current position and the vertex coordinates of the real-time rectangle corresponding to the part contour;

[0008] Step 2: Calculate all the relationship rectangles of the contour of the part to be arranged in a certain direction, and then obtain all the adjacent relationship contours of the contour of the part to be arranged in this direction;

[0009] Step 3: Calculate the maximum non-overlapping distance between the contour of the part to be arranged and all contours in the arrangement relationship, and select the minimum value of all maximum non-overlapping distances as the distance d of the contour of the part to be arranged in this direction;

[0010] Step 4: The contour of the part to be arranged is translated in this direction by a distance d to complete the docking in this direction;

[0011] Step 5: Output the contour information of the parts to be nested after docking.

[0012] The specific process of step 1 is as follows:

[0013] The blank discretization method is to discretize the blank into a series of sampling points according to the discrete precisions px and py, and these sampling points are stored in a container according to the principle of the leftmost and the bottommost; in the sampling process, the contour of the part to be sampled will shift the center of gravity to each sampling point position in turn until the first selectable sampling point position is found; the first selectable sampling point refers to the sampling point where the contour of the part to be sampled does not overlap with the contour of the already sampled part and the blank contour after the center of gravity of the contour of the part to be sampled is shifted to the position corresponding to the point.

[0014] The waiting docking state of the contour of the part to be arranged in step 1 refers to the state in which the contour of the part to be arranged is not docked to the boundary of the contour of the arranged part or the blank after the center of gravity of the contour of the part to be arranged is translated to the optional arrangement point position, and at this time, there is a gap between the contours;

[0015] The real-time rectangle definition of the part contour described in step 1: suppose the maximum value of the x coordinate among all vertices of the polygon corresponding to the part contour is max_x, and the minimum value is min_x, the maximum value of the y coordinate among all vertices is max_y, and the minimum value is min_y, then the real-time rectangle of the part contour is defined as a rectangle with 4 vertices, namely (min_x, min_y), (max_x, min_y), (max_x, max_y), and (min_x, max_y).

[0016] After the nesting contour is translated, the corresponding real-time rectangle is translated in the same direction and distance, and there is no need to regenerate the real-time rectangle of the nesting contour; after the nesting contour is rotated, it is necessary to regenerate the real-time rectangle of the rotated nesting contour. By comparing the relative positions of the real-time rectangles of the nesting part contours, the relative positions between the nesting part contours can be quickly pre-judged, thereby improving the efficiency of overlapping judgment between the nesting contours during the nesting process.

[0017] The specific process of step 2 is:

[0018] All the relationship rectangles in a certain direction of the contour of the part to be arranged in step 2 include two types: x-negative direction relationship rectangles and y-negative direction relationship rectangles, which are used to achieve the contour of the part to be arranged to be connected in the x-negative direction and the y-negative direction respectively;

[0019] Definition of the x-negative direction relationship rectangle of the part contour to be arranged: After the left side of the real-time rectangle of the contour A to be arranged is offset by px units in the x-negative direction, the rectangle formed is called the x-negative direction contact pre-judgment rectangle, and the real-time rectangle of the arranged part contour that overlaps with the x-negative direction contact pre-judgment rectangle is called the x-negative direction relationship rectangle of the part contour to be arranged, such as: the real-time rectangle of the arranged part contours B and D, the arranged part contours B and D are called the x-negative direction contact relationship contours of the part contour A to be arranged;

[0020] Definition of the negative y direction relationship rectangle of the part contour to be arranged: After the bottom side of the real-time rectangle of the contour A to be arranged is offset py units in the negative y direction, the rectangle formed is called the negative y direction abutment pre-judgment rectangle, and the real-time rectangle of the arranged part contour that overlaps with the negative y direction abutment pre-judgment rectangle is called the negative y direction relationship rectangle of the part contour to be arranged, such as: the real-time rectangle of the arranged part contours B, E and F, the arranged part contours B, E and F are called the negative y direction abutment relationship contours of the part contour A to be arranged.

[0021] In the nesting process based on the blank discretization method, the maximum contact distances in the negative x direction and the negative y direction during the abutment process of the contour of the part to be nested are px and py respectively, otherwise the contour of the part to be nested will overlap with the contour of the already nested part or the contour of the blank. Based on the above analysis, it can be seen that the pre-judgment rectangle for abutting in the negative x direction obtained by offsetting the left side of the real-time rectangle of the contour of the part to be nested by px units can fully detect all the contours of the already nested parts that may overlap with the contour of the part to be nested in the negative x direction; similarly, the pre-judgment rectangle for abutting in the negative y direction of the contour of the part to be nested can also fully detect all the contours of the already nested parts that may overlap with the contour of the part to be nested in the negative y direction.

[0022] The specific process of step 3 is as follows:

[0023] The x-negative direction abutment of the contour of the part to be arranged. After obtaining all the x-negative direction abutment relationship contours of the contour of the part to be arranged in step 2, it is necessary to calculate the maximum non-overlapping abutment distance between the contour of the part to be arranged and all the x-negative direction abutment relationship contours. The ray method is used to calculate the maximum non-overlapping abutment distance between the contour of the part to be arranged and the x-negative direction abutment relationship contours;

[0024] The negative y direction contact of the contour of the part to be arranged is obtained. After all the negative y direction contact relationship contours of the contour of the part to be arranged described in step 2 are obtained, it is necessary to calculate the maximum non-overlapping contact distance between the contour of the part to be arranged and all the negative y direction contact relationship contours. The ray method is used to calculate the maximum non-overlapping contact distance between the contour of the part to be arranged and the negative y direction contact relationship contours.

[0025] In the specific process of the ray method, taking polygon A located in the positive x direction of polygon B and calculating the maximum non-overlapping distance of polygon A translated in the negative x direction as an example, rays are drawn in the negative x direction with each vertex of polygon A as endpoints, and the intersection points of each ray with the vertex of A as endpoints and the edge of polygon B are obtained, and then the distances between each endpoint of the ray and its corresponding intersection points are obtained, and the minimum value of all the obtained distances is used as the alternative maximum non-overlapping distance 1 from polygon A to polygon B; similarly, rays are drawn in the positive x direction with each vertex of polygon B as endpoints, and the intersection points of each ray with the vertex of B as endpoints and the edge of polygon A are obtained, and then the distances between each endpoint of the ray and its corresponding intersection points are obtained, and the minimum value of all the obtained distances is used as the alternative maximum non-overlapping distance 2 from polygon A to polygon B; finally, the minimum value of the alternative maximum non-overlapping distance 1 from polygon A to polygon B and the alternative maximum non-overlapping distance 2 from polygon A to polygon B is used as the maximum non-overlapping distance from polygon A to polygon B;

[0026] The ray method used to calculate the maximum non-overlapping distance in the y direction is similar to the ray method used to calculate the maximum non-overlapping distance in the x direction, except that the ray in the x direction is replaced by a ray in the y direction.

[0027] The present invention has the following beneficial effects:

[0028] 1. The present invention analyzes the relative position relationship between the contour of the part to be arranged and the contour of the arranged part before docking, proposes the definition of the real-time rectangle of the part contour, and uses the real-time rectangle of the part contour as an attribute of the part contour object to represent the position of the part contour in the blank; on the basis of the definition of the real-time rectangle of the part contour, combined with the discrete accuracy of the blank discretization method, the definition of the relationship rectangle of the contour of the part to be arranged is proposed, which is used to calculate all the contours of the arranged parts that may overlap with the contour of the part to be arranged during the docking process, that is, the docking relationship contour; the maximum non-overlapping docking distance between the contour of the part to be arranged and each docking relationship contour is calculated by the ray method, and the minimum value of all the maximum non-overlapping docking distances is the docking distance of the contour of the part to be arranged in this direction; the contour of the part to be arranged is translated in this direction by the docking distance to complete the docking in this direction. The two-dimensional irregular part arrangement docking method based on the relationship rectangle of the present invention can efficiently and accurately complete the local docking in the arrangement process based on the blank discretization method, shorten the overall time required for the arrangement process, and improve the utilization rate of the plate.

[0029] 2. The present invention reduces the number of related outlines of already arranged parts in the docking process by calculating all relationship rectangles of the outlines of the parts to be arranged, thereby improving the calculation efficiency of the subsequent steps; compared with the approximate docking method with a given docking accuracy error in the advance and retreat method, the present method uses the ray method to accurately calculate the maximum non-overlapping docking distance of the outlines of the parts to be arranged, which is a precise docking method. At the same time, it avoids the process of multiple overlapping judgments required in the advance and retreat method, greatly shortens the time required for the docking process, and thus improves the overall calculation efficiency of the arrangement algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] Figure 1 The present invention is a flow chart of the operation of a two-dimensional irregular parts arrangement and docking method based on relationship rectangles.

[0032] Figure 2 It is a schematic diagram of the docking state of the present invention.

[0033] Figure 3 It is a real-time rectangular schematic diagram of the present invention.

[0034] Figure 4 It is a schematic diagram of the rectangular relationship in the negative x direction of the present invention.

[0035] Figure 5 It is a schematic diagram of the rectangular relationship in the negative y direction of the present invention.

[0036] Figure 6 It is a schematic diagram of the ray method of the present invention.

[0037] Figure 7 It is a flow chart of the advance and retreat method of the present invention.

[0038] Figure 8 This is the calculation process of the negative y direction relationship rectangle of the present invention.

[0039] Fig. 9 This is the calculation process of the abutment distance in the negative y direction of the present invention.

[0040] Fig.10 This is the calculation process of the negative x direction relation rectangle of the present invention.

[0041] Fig.11 This is the calculation process of the abutment distance in the negative x direction of the present invention. DETAILED DESCRIPTION

[0042] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0043] Embodiment 1:

[0044] See also Figure 1-5 A two-dimensional irregular parts arrangement and docking method based on a relational rectangle comprises the following steps:

[0045] Step 1: Input the contour information of the part to be nested and the contour information of all nested parts in the docking state, wherein the part contour information includes the vertex coordinates of the polygon corresponding to the part contour at the current position and the vertex coordinates of the real-time rectangle corresponding to the part contour;

[0046] Step 2: Calculate all the relationship rectangles of the contour of the part to be arranged in a certain direction, and then obtain all the adjacent relationship contours of the contour of the part to be arranged in this direction;

[0047] Step 3: Calculate the maximum non-overlapping distance between the contour of the part to be arranged and all contours in the arrangement relationship, and select the minimum value of all maximum non-overlapping distances as the distance d of the contour of the part to be arranged in this direction;

[0048] Step 4: The contour of the part to be arranged is translated in this direction by a distance d to complete the docking in this direction;

[0049] Step 5: Output the contour information of the parts to be nested after docking.

[0050] Furthermore, the specific process of step 1 is as follows:

[0051] See also Figure 2 The blank discretization method is to discretize the blank into a series of sampling points according to the discrete precisions px and py, and these sampling points are stored in a container according to the principle of the leftmost and the bottommost; in the sampling process, the contour of the part to be sampled will shift the center of gravity to each sampling point position in turn until the first selectable sampling point position is found; the first selectable sampling point refers to the sampling point where the contour of the part to be sampled does not overlap with the contour of the already sampled part and the blank contour after the center of gravity of the contour of the part to be sampled is shifted to the position corresponding to the point.

[0052] The waiting docking state of the contour of the part to be arranged in step 1 refers to the state in which the contour of the part to be arranged is not docked to the boundary of the contour of the arranged part or the blank after the center of gravity of the contour of the part to be arranged is translated to the optional arrangement point position. At this time, there is a gap between the contours; for example, Figure 2 In the figure, it is assumed that contour B is the contour of the part to be arranged in the state of being abutted, and contour A is the contour of the arranged part. In order to make the utilization rate of the blank as high as possible, the center of gravity of the contour B of the part to be arranged should be as low as possible, and at the same time, it should be translated to the left as much as possible to make the arrangement of the arrangement contours more compact. Based on the principle that the center of gravity is the leftmost and the lowest, it can be seen that there is a gap between the contour B to be arranged and the contour A that has been arranged in the x direction and the y direction. By abutting contour B in the negative x direction and the negative y direction, the part contours can be arranged more compactly, thereby improving the utilization rate of the blank.

[0053] See also Figure 3 , the real-time rectangle definition of the part contour described in step 1: suppose the maximum value of the x coordinate of all vertices of the polygon corresponding to the part contour is max_x, the minimum value is min_x, the maximum value of the y coordinate of all vertices is max_y, and the minimum value is min_y, then the real-time rectangle of the part contour is defined as a rectangle with 4 vertices (min_x,min_y), (max_x,min_y), (max_x,max_y), (min_x,max_y) in sequence.

[0054] After the nesting contour is translated, the corresponding real-time rectangle is translated in the same direction and distance, and there is no need to regenerate the real-time rectangle of the nesting contour; after the nesting contour is rotated, it is necessary to regenerate the real-time rectangle of the rotated nesting contour. By comparing the relative positions of the real-time rectangles of the nesting part contours, the relative positions between the nesting part contours can be quickly pre-judged, thereby improving the efficiency of overlapping judgment between the nesting contours during the nesting process.

[0055] Furthermore, the specific process of step 2 is as follows:

[0056] All the relationship rectangles in a certain direction of the contour of the part to be arranged in step 2 include two types: x-negative direction relationship rectangles and y-negative direction relationship rectangles, which are used to achieve the contour of the part to be arranged to be connected in the x-negative direction and the y-negative direction respectively;

[0057] The x-negative direction relationship rectangle of the part contour to be nested is defined as: Figure 4 As shown in the dotted rectangle, after the left side of the real-time rectangle of the contour A to be arranged is offset by px units in the negative x direction, the rectangle formed is called the negative x direction contact pre-judgment rectangle, and the real-time rectangle of the arranged part contour that overlaps with the negative x direction contact pre-judgment rectangle is called the negative x direction relationship rectangle of the contour of the part to be arranged, as shown in 4: the real-time rectangle of the arranged part contours B and D, the arranged part contours B and D are called the negative x direction contact relationship contours of the contour A of the part to be arranged;

[0058] The negative y-direction relationship rectangle of the part contour to be nested is defined as: Figure 5 As shown in the dotted rectangle, after the bottom side of the real-time rectangle of the contour A to be arranged is offset py units in the negative y direction, the rectangle formed is called the negative y direction abutment pre-determination rectangle, and the real-time rectangle of the arranged part contour overlapping with the negative y direction abutment pre-determination rectangle is called the negative y direction relationship rectangle of the part contour to be arranged, as shown in 5: the real-time rectangles of the arranged part contours B, E and F, the arranged part contours B, E and F are called the negative y direction abutment relationship contours of the part contour A to be arranged.

[0059] Furthermore, in the nesting process based on the blank discretization method, the maximum contact distances in the negative x direction and the negative y direction during the abutment process of the contour of the part to be nested are px and py respectively, otherwise the contour of the part to be nested will overlap with the contour of the already nested part or the contour of the blank. Based on the above analysis, it can be seen that the pre-determined rectangle for abutting in the negative x direction obtained by offsetting the left side of the real-time rectangle of the contour of the part to be nested by px units can fully detect all the contours of the already nested parts that may overlap with the contour of the part to be nested in the negative x direction; similarly, the pre-determined rectangle for abutting in the negative y direction of the contour of the part to be nested can also fully detect all the contours of the already nested parts that may overlap with the contour of the part to be nested in the negative y direction.

[0060] As an improvement of the present invention, taking the completion of the negative direction docking of the contour x of the part to be arranged as an example, the specific process of step 2 is given:

[0061] 1) The left side of the real-time rectangle corresponding to the contour of the part to be arranged at the current position is offset by px units in the negative x direction to obtain the negative x direction abutment pre-judgment rectangle of the contour of the part to be arranged, where px is the discrete accuracy of the blank in the x direction;

[0062] 2) Determine one by one whether the real-time rectangle corresponding to the outline of the arranged part at the current position overlaps with the pre-determined rectangle of the negative x direction of the outline of the part to be arranged. If so, it means that the real-time rectangle corresponding to the outline of the arranged part is a relationship rectangle in the negative x direction of the outline of the part to be arranged, and the outline of the arranged part is a negative x direction abutting relationship contour of the outline of the part to be arranged, and the information of the outline of the arranged part is stored in a suitable container.

[0063] Further, the specific process of step 3 is as follows: the x-negative direction of the contour of the part to be arranged is adjacent to each other. After all the x-negative direction adjacent relationship contours of the contour of the part to be arranged are obtained in step 2, it is necessary to calculate the maximum non-overlapping adjacent distance between the contour of the part to be arranged and all the x-negative direction adjacent relationship contours, and the ray method is used to calculate the maximum non-overlapping adjacent distance between the contour of the part to be arranged and the x-negative direction adjacent relationship contours;

[0064] The negative y direction contact of the contour of the part to be arranged is obtained. After all the negative y direction contact relationship contours of the contour of the part to be arranged described in step 2 are obtained, it is necessary to calculate the maximum non-overlapping contact distance between the contour of the part to be arranged and all the negative y direction contact relationship contours. The ray method is used to calculate the maximum non-overlapping contact distance between the contour of the part to be arranged and the negative y direction contact relationship contours.

[0065] Furthermore, in the specific process of the ray method, taking polygon A located in the positive x direction of polygon B and calculating the maximum non-overlapping distance of polygon A translated in the negative x direction as an example, rays are drawn in the negative x direction with each vertex of polygon A as endpoints, and the intersection points of each ray with the vertex of A as endpoints and the edge of polygon B are obtained, and then the distances between each endpoint of the ray and its corresponding intersection points are obtained, and the minimum value of all the obtained distances is used as the alternative maximum non-overlapping distance 1 from polygon A to polygon B; similarly, rays are drawn in the positive x direction with each vertex of polygon B as endpoints, and the intersection points of each ray with the vertex of B as endpoints and the edge of polygon A are obtained, and then the distances between each endpoint of the ray and its corresponding intersection points are obtained, and the minimum value of all the obtained distances is used as the alternative maximum non-overlapping distance 2 from polygon A to polygon B; finally, the minimum value of the alternative maximum non-overlapping distance 1 from polygon A to polygon B and the alternative maximum non-overlapping distance 2 from polygon A to polygon B is used as the maximum non-overlapping distance from polygon A to polygon B;

[0066] The ray method used to calculate the maximum non-overlapping distance in the y direction is similar to the ray method used to calculate the maximum non-overlapping distance in the x direction, except that the ray in the x direction is replaced by a ray in the y direction.

[0067] Wherein, as an improvement of the present invention, the specific process in step 3 is:

[0068] Determine whether the container storing the negative x-direction contact relationship contours of the part contour to be arranged in step 2 is empty. If so, set the contact distance d of the part contour to be arranged in the negative x-direction equal to the discrete accuracy px of the blank in the x-direction. Otherwise, use the ray method to calculate the maximum non-overlapping contact distances between the part contour to be arranged and all the negative x-direction contact relationship contours; select the minimum value of all maximum non-overlapping contact distances as the contact distance d of the part contour to be arranged in this direction.

[0069] Embodiment 2:

[0070] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0071] For the convenience of explanation, the following symbols introduced in the example are first uniformly explained as shown in Table 1:

[0072] 1. Problem Assumptions

[0073] Considering the application scenarios and functions of this method, the following reasonable assumptions are made for the problem:

[0074] (1) The outer contours of all parts are represented by two-dimensional polygons;

[0075] (2) The outer contour of the blank is a rectangle with certain width and height;

[0076] (3) The possibility of internal holes in parts and blanks is not considered;

[0077] (4) The blank is large enough so that all parts can be arranged on one blank;

[0078] (5) The parts arrangement order is known.

[0079] 2. Symbol Definition

[0080] Table 1 Symbol Definition

[0081]

[0082]

[0083] 3. Implementation Process

[0084] Taking the docking process of the i-th (i=1,...,n) part as an example, the specific implementation process of this method in the example is given as follows:

[0085] (1) Input the information of the parts to be nested and all the parts that have been nested.

[0086] Enter the P of part i to be nested i, R i , and P of all nested parts t t , R t ,t=1,...,s. Calculate the R of the part i to be arranged y i , R y i The four vertices are (min_x, min_y-py), (max_x, min_y-py), (max_x, max_y), and (min_x, max_y) in order. The values ​​of min_x, min_y, max_x, and max_y are as described in the definition of the real-time rectangle in claim 2.

[0087] (2) Calculate all the negative y-direction relationship rectangles of the part i to be arranged. The calculation process is as follows: Figure 7 shown.

[0088] (3) Calculate the negative y-direction contact distance of the part i to be arranged. The calculation process is as follows: Figure 8 shown.

[0089] (4) Execute P i (0,-d y i ) and R i (0,-d y i ) operation to complete the negative y direction docking of the contour of the part to be arranged.

[0090] (5) Input the information of the parts to be arranged and all the arranged parts after the negative y direction docking is completed.

[0091] Enter the P of part i to be nested i , R i , and P of all nested parts t t , R t ,t=1,...,s. Calculate the R of the part i to be arranged x i , R x i The four vertices are (min_x-px,min_y), (max_x,min_y), (max_x,max_y), and (min_x-px,max_y) in order. The values ​​of min_x, min_y, max_x, and max_y are as described in the definition of the real-time rectangle in claim 2.

[0092] (6) Calculate all x-negative direction relationship rectangles of the part i to be arranged. The calculation process is as follows: Fig. 9 shown.

[0093] (7) Calculate the negative y-direction contact distance of the part i to be arranged. The calculation process is as follows: Fig.10 shown.

[0094] (8) Execute P i (-d x i ,0) and R i (-d x i ,0) operation to complete the negative x-direction docking of the contour of the part to be arranged.

[0095] (9) The docking process of part i to be arranged is completed, and part i to be arranged is marked as an arranged part, and s=s+1.

[0096] 4. Example comparison In order to verify the superiority of the method proposed in the present invention, Python language is used for programming, and the benchmark problem data provided by the European sample arrangement problem interest group ESCUP is used as a test example. The method proposed in the present invention is experimentally compared with the existing advance and retreat docking method. The two methods use the same parameter settings. The experimental parameter settings are shown in Tables 2 and 3, and the experimental results are shown in Tables 4, 5 and 6.

[0097] Table 2 Experimental parameter settings 1

[0098]

[0099] Table 3 Experimental parameter settings 2

[0100]

[0101] Table 4 Average operation time of 100 experiments

[0102]

[0103] Table 5 Average blank utilization rate of 100 experiments

[0104]

[0105]

[0106] Table 6 Fluctuation (variance) of blank utilization rate in 100 experiments

[0107]

[0108] It can be seen from Table 4 that the proposed docking method of the present invention has a significantly shorter operation time in the three groups of standard examples compared with the existing advance-retreat docking method, which is sufficient to verify the superiority of the algorithm proposed in the present invention in terms of operation efficiency; it can be seen from Table 5 that the proposed docking method of the present invention has a slightly higher average blank utilization rate after docking than the advance-retreat docking method under the premise of using the same part arrangement order. The reason is that the proposed docking method of the present invention belongs to precise docking, which can make the part contour closer to the ground; it can be seen from Table 6 that the proposed docking method of the present invention has a smaller fluctuation in blank utilization rate and a more stable docking process compared with the existing advance-retreat docking method in 100 experiments using the same part arrangement order. The above two docking methods are compared from the three perspectives of operation efficiency, blank utilization rate and docking stability. The comparison results show that the algorithm proposed in the present invention is superior to the existing advance-retreat docking method in the above three aspects.

Claims

1. A two-dimensional irregular parts arrangement and docking method based on relationship rectangles, characterized in that: The following steps are involved: Step 1: Input the contour information of the part to be nested and the contour information of all nested parts in the docking state, wherein the part contour information includes the vertex coordinates of the polygon corresponding to the part contour at the current position and the vertex coordinates of the real-time rectangle corresponding to the part contour; Step 2: Calculate all the relationship rectangles of the contour of the part to be arranged in a certain direction, and then obtain all the adjacent relationship contours of the contour of the part to be arranged in this direction; Step 3: Calculate the maximum non-overlapping distance between the contour of the part to be arranged and all the contours of the adjacent relationship, and select the minimum value of all the maximum non-overlapping distances as the adjacent distance of the contour of the part to be arranged in this direction. d ; Step 4: Move the contour of the part to be nested in this direction by the distance d Then the docking in this direction is completed; Step 5: Output the contour information of the parts to be nested after docking; The specific process of step 1 is as follows: The discretization method of the blank is to discretize the blank according to the discrete accuracy px and py Discretized into a series of arrangement points, these arrangement points are stored in the container according to the principle of the leftmost and the bottommost; in the arrangement process, the contour of the part to be arranged will shift the center of gravity to each arrangement point position in turn until the first selectable arrangement point position is found; the first selectable arrangement point refers to the arrangement point where the contour of the part to be arranged does not overlap with the contour of the arranged part and the contour of the blank after the center of gravity of the contour of the part to be arranged is shifted to the position corresponding to the point; The waiting docking state of the contour of the part to be arranged in step 1 refers to the state in which the contour of the part to be arranged is not docked to the boundary of the contour of the arranged part or the blank after the center of gravity of the contour of the part to be arranged is translated to the optional arrangement point position, and at this time, there is a gap between the contours; The real-time rectangle definition of the part outline described in step 1: Let the maximum x-coordinate value of all vertices of the polygon corresponding to the part outline be max_x , the minimum value is min_x The maximum y coordinate of all vertices is max_y , the minimum value is min_y , then the real-time rectangle of the part contour is defined as the four vertices in order: ( min_x, min_y )、( max_x, min_y )、( max_x, max_y )、( min_x, max_y ) After the nesting contour is translated, the corresponding real-time rectangle is translated in the same direction and distance, and there is no need to regenerate the real-time rectangle of the nesting contour; after the nesting contour is rotated, it is necessary to regenerate the real-time rectangle of the rotated nesting contour, and by comparing the mutual positions of the real-time rectangles of the nesting part contours, the mutual positions between the nesting part contours can be quickly pre-judged, thereby improving the efficiency of overlapping judgment between the nesting contours during the nesting process; The specific process of step 2 is: All the relationship rectangles in a certain direction of the contour of the part to be arranged in step 2 include x Negative direction relationship rectangle and y There are two types of negative direction relationship rectangles, which are used to realize the contour of the parts to be arranged. x Negative direction and y The docking is completed in the negative direction; The outline of the part to be nested x Negative direction relationship rectangle definition: Move the left side of the real-time rectangle of the contour A to be arranged to x Negative offset px After 1 unit, the resulting rectangle is called x The negative direction is close to the pre-judgment rectangle, and x The real-time rectangle of the outline of the part to be arranged that overlaps with the pre-judgment rectangle in the negative direction is called the real-time rectangle of the outline of the part to be arranged. x Negative direction relationship rectangle, for example: real-time rectangle of the arranged part contours B and D, the arranged part contours B and D are called the real-time rectangle of the part contour A to be arranged. x Negative direction abutment relationship contour; The outline of the part to be nested y Negative direction relationship rectangle definition: Move the bottom side of the real-time rectangle of the contour A to be arranged to y Negative offset py After 1 unit, the resulting rectangle is called y The negative direction is close to the pre-judgment rectangle, and y The real-time rectangle of the outline of the part to be arranged that overlaps with the pre-judgment rectangle in the negative direction is called the outline of the part to be arranged. y Negative direction relationship rectangle, for example: real-time rectangle of the arranged part contours B, E and F, the arranged part contours B, E and F are called the real-time rectangle of the part contour A to be arranged. y Negative direction abutment relationship profile.

2. A two-dimensional irregular parts arrangement and docking method based on relationship rectangles according to claim 1, characterized in that: The nesting process based on the blank discretization method is to x Negative direction and y The maximum contact distances in the negative direction are px and py Otherwise, the contour of the part to be arranged will overlap with the contour of the arranged part or the contour of the blank. Based on the above analysis, it can be seen that the left side of the real-time rectangle of the contour of the part to be arranged should be x Negative offset px The units obtained x The negative direction abutment pre-judgment rectangle can fully detect the contour of the parts to be arranged. x All the outlines of the arranged parts that may overlap with it during the negative direction docking process; similarly, the outlines of the parts to be arranged y The negative direction abutment pre-judgment rectangle can also fully detect the contour of the parts to be arranged. y All nested part contours that may overlap with it during the negative direction docking process.

3. The method for arranging and docking two-dimensional irregular parts based on relationship rectangles according to claim 1, characterized in that: The specific process of step 3 is as follows: The outline of the part to be nested x Negative direction docking, after obtaining all the contours of the parts to be arranged as described in step 2 x After the negative direction is close to the relationship contour, it is necessary to calculate the contour of the part to be arranged and all x The maximum non-overlapping distance of the negative direction contact relationship contour is calculated by using the ray method to calculate the contour of the part to be arranged and the x The maximum non-overlapping distance of the negative direction contact relationship contour; The outline of the part to be nested y Negative direction docking, after obtaining all the contours of the parts to be arranged as described in step 2 y After the negative direction is close to the relationship contour, it is necessary to calculate the contour of the part to be arranged and all y The maximum non-overlapping distance of the negative direction contact relationship contour is calculated by using the ray method to calculate the contour of the part to be arranged and the y The maximum non-overlapping distance for negative abutment profiles.

4. The method for arranging and docking two-dimensional irregular parts based on relationship rectangles according to claim 3, characterized in that: In the specific process of the ray method, polygon A is located at the center of polygon B. x Positive direction position, calculate the direction of polygon A x For example, take the vertices of polygon A as endpoints and move x Draw rays in the negative direction, find the intersection points of each ray with the vertex of A as the endpoint and the edge of polygon B, and then find the distance between each endpoint of the ray and its corresponding intersection point, and take the minimum value of all the distances obtained as the alternative maximum non-overlapping distance 1 from polygon A to polygon B; Similarly, take the vertices of polygon B as endpoints and x Draw rays in the positive direction, find the intersection points of each ray with the vertex of B as the endpoint and the edge of polygon A, and then find the distance between each endpoint of the ray and its corresponding intersection point, and take the minimum value of all the distances obtained as the alternative maximum non-overlapping distance 2 from polygon A to polygon B; finally, take the minimum value of the alternative maximum non-overlapping distance 1 from polygon A to polygon B and the alternative maximum non-overlapping distance 2 from polygon A to polygon B as the maximum non-overlapping distance from polygon A to polygon B; calculate y The maximum non-overlap distance in the direction is calculated using the ray method x The maximum non-overlap distance in the direction is similar to the ray method principle. x The direction of the ray is changed to y Direction of rays.

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