Method for stacking batten beams according to wooden window framing strategy

Abstract

The invention discloses a method for stacking batten beams according to a wooden window framing strategy. The method comprises the following steps that S01, processing order information is extracted; step S02, formulating a framing strategy; step S03, updating the data set; s04, establishing a three-dimensional space where the tray is located; s05, determining a constraint condition; step S06, formulating a fitness function; and S07, stacking is conducted. Strict constraint conditions such as the gravity center position, the batten size limitation and the proportion of the supporting area to the lower side area are set, the stacking stability and safety are guaranteed, and collapse or damage caused by unstable stacking is avoided; the processing order information is extracted, the battens are automatically matched and coded and marked, the time and errors of manually selecting the battens in the subsequent framing link are reduced, and the overall production efficiency is improved. The method is suitable for the boxing problem of stacking the wooden windows according to a frame assembling strategy, and production efficiency can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical fields of wooden window processing and article packing, and relates to a method for palletizing wooden beams, in particular to a method for palletizing wooden beams according to the wooden window framing strategy based on the ant colony algorithm. Background Art

[0002] The three-dimensional packing problem is a typical combinatorial optimization problem and plays an important role in industrial production. As an important variant, online three-dimensional packing is also a sequential decision-making problem, especially of great significance for the palletizing and packing problems on the production line, which helps to improve the packing efficiency, reduce costs, and increase the degree of factory automation.

[0003] Currently, in the field of wooden window processing, according to the actual processing requirements of the factory, the logs with standard lengths are sawn and then palletized manually and moved to the next station for further processing according to the whole window. In the existing factory processes, it is necessary for workers to select the wooden beams of the same window from the pallet pattern for further processing, which is not only time-consuming and laborious, but also there is a possibility of human error. In a batch of orders, the lengths of the sawn wooden beams are different, and the length range has a large span, which can be up to 400 mm to 3000 mm at most, with large dynamic changes. However, due to the fixed size of the pallet and the standard specifications, it is necessary to limit the size of the spliced wooden beams to ensure the subsequent stability of the pallet pattern.

[0004] Therefore, there is an urgent need for a method for palletizing wooden beams according to the wooden window framing strategy to solve the above problems. Summary of the Invention

[0005] Aiming at the variant of the three-dimensional packing problem generated by the wooden window framing in the field of wooden window processing, the present invention provides a method for palletizing wooden beams according to the wooden window framing strategy. This method is applicable to the packing problem of palletizing wooden windows according to the framing strategy, which helps to improve the production efficiency.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] A method for palletizing wooden beams according to the wooden window framing strategy includes the following steps:

[0008] Step S01, extracting processing order information: Each wooden window is completed by combining four wooden beams. According to the actual processing of the factory, extract the processing order information;

[0009] Step S02, formulating a framing strategy: Each wooden beam corresponds to a unique attribute string. The two pairs of opposite sides of the wooden window are equal. By searching and matching, the two adjacent sides of each wooden window are spliced end to end to form a wooden beam. One wooden window is two spliced wooden beams participating in the palletizing;

[0010] Step S03, dataset update: The spliced wooden square timbers are encoded and marked using the combined coding method. The encoding includes the discharging order of the original wooden square timbers, the total size after splicing, and the information of the wooden window to which they belong.

[0011] Step S04, establishing the three-dimensional space where the pallet is located: Based on the updated dataset, establish the three-dimensional space where the pallet is located. Set the X, Y, and Z-axis dimensions in this three-dimensional space. Mesh the X and Y axes into a two-dimensional space plane, and record the height information of the internal space of the pallet in a matrix manner. The value at each position in the matrix represents the height of the highest layer of wooden square timbers at the corresponding position in the current internal space of the pallet.

[0012] Step S05, determining the constraint conditions: Determine the constraint conditions according to the requirements of palletizing. The constraint conditions include: the center of gravity of the stack type is located inside the pallet; the maximum size of the spliced wooden square timbers is not greater than the length of the pallet space; the total width of the wooden square timbers is not greater than the width of the pallet space; the ratio of the supporting area of the wooden square timbers to the lower side area meets the threshold value required for palletizing.

[0013] Step S06, formulating the fitness function: Define a fitness function to evaluate the fitness of each individual. The fitness function is formulated as: F = ω1·U + ω2·M s + ω3·D, where ω1, ω2, and ω3 are weight coefficients, U is the utilization rate, M s is the matching degree, and D is the diversity.

[0014] Step S07, palletizing: After all the wooden square timbers in the order have been traversed and searched, after the group frame strategy passes the matching verification, check whether there is a suitable position in the pallet space to place the current group of framed wooden square timbers, and ensure that the wooden square timbers of the same wooden window are placed in the same column and adjacent to each other until all the spliced wooden square timbers are placed.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The method of the present invention aims at the problem of selecting wooden square timbers for group framing in the actual production and processing of wooden windows, which belongs to a variant of the three-dimensional bin packing problem. Using the method based on the ant colony algorithm, by extracting the actual processing orders of the factory, encoding and marking the wooden square timbers in the order, in the subsequent palletizing process, the wooden square timbers of the same wooden window can be stacked in a hierarchical arrangement.

[0017] 2. The present invention ensures the stability and safety of palletizing by setting strict constraint conditions, such as the position of the center of gravity, the size limit of the wooden square timbers, the ratio of the supporting area to the lower side area, etc., and avoids collapse or damage caused by unstable palletizing.

[0018] 3. The present invention extracts the processing order information, automatically matches the wooden square timbers and encodes and marks them, reducing the time and error of manual selection of wooden square timbers in the subsequent group framing process and improving the overall production efficiency. Description of the Drawings

[0019] Figure 1 It is a flowchart of the method for stacking wooden beams according to the window frame assembly strategy of wooden windows;

[0020] Figure 2 It is a schematic diagram of the splicing of wooden beams;

[0021] Figure 3 It is a schematic diagram of establishing the three-dimensional space and grid position of the pallet;

[0022] Figure 4 It is a schematic diagram of the stacking height matrix and the window information matrix with s = {7, 7} as an example;

[0023] Figure 5 It is a schematic diagram of the stacking scheme of the wooden beam according to the window frame assembly strategy. Detailed Implementation Manner

[0024] The technical solutions of the present invention will be further described below in conjunction with the drawings, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0025] The present invention provides a method for stacking wooden beams according to the window frame assembly strategy of wooden windows, as Figure 1 shown, the method includes the following steps:

[0026] Step S01, extracting processing order information: Each wooden window is completed by combining four wooden beams. According to the actual processing in the factory, the processing order information is extracted.

[0027] In this step, the order information includes the cross-sectional information of the wooden beam, the length dimension and the discharging order of the wooden beam, and the window information. In the order input stage, the cross-sectional dimension of this batch of wooden beams is defined as s = {w, h}, where w is the width of the wooden beam and h is the height of the wooden beam. The discharging order of the wooden beam takes the length dimension of the wooden beam as the data output, L = [l1, l2,... l 4p , l is the length dimension of the wooden beam, 4p represents the discharging order of the wooden beam, p represents the number of wooden beams. For example, l1 is the length dimension of the first wooden beam, and the length and width dimensions of each wooden window are stored in the form of a two-dimensional array, M = [M1:M 1l , M 1w ; M2:M 2l , M 2w ... M n :M nl , M nw , M represents the wooden window, n represents the number of wooden windows, M nl represents the length dimension of the nth window, and M nw is the width dimension of the nth window.

[0028] Step S02, formulating the frame strategy: Each wooden square corresponds to a unique attribute string. The two pairs of opposite sides of the wooden window are equal. By searching and matching, every two adjacent sides of the wooden window are spliced end to end to form a wooden square. In the subsequent steps, one wooden window is composed of two spliced wooden squares participating in palletizing.

[0029] In this step, the attribute string is used to uniquely encode each wooden square. According to the dimension range of the wooden square beam, the format of the attribute string is selected, and the attribute string format is set as Lxxxx-ODxxx-Mxx, where Lxxxx represents the length of the wooden square beam, ODxxx represents the discharging sequence of the wooden square beam, and Mxx represents the wooden window number. Specifically, one wooden window needs to be composed of two pairs of wooden square beams with the same length dimension. First, identify the specific dimension requirements of the wooden window M1 from the two-dimensional array M of the length and width dimensions of the wooden window, perform sequential retrieval in the discharging sequence L of the wooden square beam, and allocate the wooden square beam that meets the dimension requirements of M1 and is the first to be discharged to M1. Based on this, a unique attribute string is generated for each wooden square beam. And so on, continue to perform dimension matching, extraction, and encoding of the wooden square beam for the wooden windows after M1 until the wooden square beam requirements of all wooden windows are met. Set two counters F A and F B to respectively store the two pairs of wooden square beams that form the wooden window. Assume that the wooden square beams forming M1 are A1, A2, B1, B2 respectively, A1 = A2, B1 = B2. Initialize the counters F A and F B to 0. Traverse each element in the wooden square beam coding table. If the current element matches the dimension A, store it in the counter F A , if the current element matches the dimension B, store it in the counter F B , ensure that both A and B exist in pairs, and check the quantities of F A and F B to see if they are 2N. After the traversal ends, frame all the found A and B. For example, A1 + B1 = C1, A2 + B2 = C2, C1 = C2, M1 = C1 + C2, and complete the search and framing of all wooden square beams. The schematic diagram of wooden square splicing is as Figure 2 shown.

[0030] Step S03, dataset update: Use the combined coding method to encode and mark the spliced wooden squares. The encoding includes the original discharging sequence of the wooden square, the total dimension after splicing, and the information of the wooden window to which it belongs.

[0031] In this step, the wooden square after the completion of the grouping in step S02 is re-coded and marked, including the total length after splicing, recording the discharging order of the original wooden squares that make up the spliced wooden square C and the information of the wooden window to which it belongs. The coding format is Lxxxx-ODxxx-ODxxx-Mxxx, where Lxxxx represents the total length after splicing, ODxxx represents the discharging order of the original wooden material, and Mxxx represents the wooden window information. For example, A1 is the first wooden square with a size of 800 mm, B1 is the tenth wooden square with a size of 1200 mm, and it belongs to the fourth wooden window. Then the spliced wooden square C1 is L2000-OD001-OD010-M004, and a new data set is generated by coding the spliced wooden square.

[0032] Step S04. Establish the three-dimensional space where the pallet is located: According to the updated data set, establish the three-dimensional space where the pallet is located. Set the X, Y, and Z axis dimensions in this three-dimensional space, perform two-dimensional space plane meshing on its X and Y axes, and record the height information of the internal space of the pallet in the form of a matrix. The value at each position in the matrix represents the height of the highest layer of wooden square at the corresponding position in the current internal space of the pallet.

[0033] In this step, according to the updated data set, set the parameters of the three-dimensional space model of the pallet, set its X-axis dimension, Y-axis dimension, and Z-axis dimension, and mesh the X-Y plane of the pallet, that is, divide the bottom plane of the pallet into a regular grid system. The grid specification is set to 25 cm × 10 cm. Each grid unit represents a small area at the bottom of the pallet. Assign a unique coordinate (i, j) to each grid unit, where i represents the position along the X axis and j represents the position along the Y axis. Initialize a matrix with a size of m1×n1, where m1 and n1 respectively correspond to the number of grids along the X axis and Y axis. Each element h(i, j) in the matrix represents the height of the highest layer of wooden square above the grid unit (i, j). Initialize all elements of the matrix to 0, indicating that there are no wooden squares on the pallet initially, and set up a wooden window information matrix to store the numbers of the wooden windows to which the spliced wooden squares belong. A schematic diagram of the three-dimensional space of the pallet and the grid positions is as Figure 3 shown. P(i, j), that is, h(i, j), represents the height of the wooden square at the grid coordinate (i, j). A schematic diagram of the height matrix and the wooden window information matrix of the palletizing with s = {7, 7} as an example is as Figure 4 shown.

[0034] Step S05. Determine the constraint conditions: Determine the constraint conditions according to the requirements of palletizing. The constraint conditions include: the center of gravity of the stack type is located inside the pallet; the maximum size of the spliced wooden square is not greater than the length of the pallet space; the total width of the wooden squares is not greater than the width of the pallet space; the ratio of the supporting area of the wooden square to the lower side area of the wooden square meets the threshold value required by the palletizing.

[0035] In this step, set the constraint conditions. First, set the centroid position constraint. Let C x and C y be the coordinates of the pallet centroid on the X-axis and Y-axis respectively, L and W be the length and width of the pallet, and the safety distance be ɑ mm. The maximum size of the spliced wooden square does not exceed the length of the pallet space, Lxxxx max ≤L, and the total width of the wooden squares does not exceed the width of the pallet space. p is the number of wooden squares; the supporting area A a refers to the area where the wooden square contacts the lower-layer wooden square or the pallet during palletizing. The lower-side area A b refers to the total area of the bottom of the wooden square, that is, the length multiplied by the width of the bottom of the wooden square. Set a threshold to ensure a certain ratio between the supporting area of the wooden square and its lower-side area to meet the requirements of palletizing stability and safety. The supporting area A a and the lower-side area A b meet

[0036] Step S06, formulate the fitness function: Define a fitness function to evaluate the fitness of each individual. The fitness function is weighted based on multiple factors such as utilization rate, matching degree, and diversity.

[0037] In this step, formulate a suitable fitness function to evaluate the pros and cons of each individual (i.e., each possible palletizing layout). This fitness function will be based on multiple factors, including utilization rate, matching degree, and diversity. First, define the relevant parameters and variables. Let l ik be the length of the k-th wooden square in the i-th individual, L and W be the length and width of the pallet respectively, p be the number of wooden squares in the individual, l jk be the length of the k-th wooden square in the discharging order, m be the number of wooden squares in the discharging order, δ be an indicator function, which takes the value of 1 when l ik matches l jk , and 0 otherwise. Let l be the set of wooden square lengths in all individuals, l i be the wooden square length in the i-th individual, and II be an indicator function, which takes the value of 1 when l i =l, and 0 otherwise. Let P be the total number of individuals in the population. The utilization rate U: The matching degree M s : The diversity D: Therefore, the fitness function can be formulated as: F = ω1·U + ω2·M s + ω3·D, where ω1, ω2, and ω3 are weight coefficients.

[0038] Step S07, Palletizing: After all the wooden beams in the order have been traversed and searched, and the framing strategy has passed the matching verification, check if there is a suitable position in the pallet space to place the current framed wooden beam, and ensure that the wooden beams of the same wooden window are placed in the same column and adjacent to each other until all the spliced wooden beams are placed.

[0039] In this step, after steps S01 - S06 are completed, the palletizing work begins. According to the evaluation results of the fitness function, select the best palletizing scheme. When placing the framed wooden beams, check and ensure that the wooden beams of the same wooden window are placed in the same column and adjacent to each other. If not satisfied, adjust the placement position of the wooden beam until satisfied. After placing each wooden beam, update the height value at the corresponding position in the height matrix, and update the wooden window information matrix. After all the wooden beams are placed, conduct a final inspection to ensure that all the wooden beams have been correctly placed and meet all requirements, and record the palletizing results. The schematic diagram of the framed wooden beam palletizing scheme is as Figure 5 shown.

Claims

1. A method for stacking wooden beams according to the framing strategy of wooden windows, characterized in that The method includes the following steps: Step S01, extracting processing order information: Each wooden window is completed by combining four wooden beams. According to the actual processing in the factory, extract the processing order information. Step S02, formulating a framing strategy: Each wooden beam corresponds to a unique attribute string. The two pairs of opposite sides of the wooden window are equal. By searching and matching, the two adjacent sides of each wooden window are spliced end to end to form a wooden beam. One wooden window is composed of two spliced wooden beams participating in palletizing. Step S03, dataset update: The spliced wooden beams are encoded and marked by the combined coding method. The encoding includes the original wooden beam discharging order, the total size after splicing, and the wooden window information to which it belongs. Step S04, establishing the three-dimensional space where the pallet is located: According to the updated dataset, establish the three-dimensional space where the pallet is located. Set the X, Y, and Z axis dimensions in this three-dimensional space. The X and Y axes are meshed in a two-dimensional space plane. Record the height information of the internal space of the pallet in the form of a matrix. The value at each position in the matrix represents the height of the highest layer of wooden beam at the corresponding position in the current internal space of the pallet. Step S05, determining the constraint conditions: Determine the constraint conditions according to the requirements of palletizing. The constraint conditions include: the center of gravity of the stack type is located inside the pallet; the maximum size of the spliced wooden beam is not greater than the length of the pallet space; the total width of the wooden beams is not greater than the width of the pallet space; the ratio of the supporting area of the wooden beam to the lower side area of the wooden beam meets the threshold value required for palletizing. Step S06, formulating a fitness function: Define a fitness function to evaluate the fitness of each individual. The fitness function is formulated as: F = ω1·U + ω2·M s + ω3·D, where ω1, ω2, and ω3 are weight coefficients, U is the utilization rate, M s is the matching degree, and D is the diversity; Step S07, palletizing: After all the wooden beams in the order are traversed and searched, and the framing strategy passes the matching verification, check whether there is a suitable position in the pallet space to place the current framed wooden beam, and ensure that the wooden beams of the same wooden window are placed in the same column and adjacent to each other until all the spliced wooden beams are placed.

2. The method for stacking wooden beams according to the wooden window framing strategy as claimed in claim 1, wherein In the step S01, the order information includes the cross-sectional information of the wooden beam, the length dimension of the wooden beam, the discharging sequence, and the wooden window information. In the order input stage, the cross-sectional dimension s = {w, h} of this batch of wooden beams is defined, where w is the width of the wooden beam and h is the height of the wooden beam. The discharging sequence of the wooden beams outputs the length dimension of the wooden beams, L = [l1, l2,... l 4p , l is the length dimension of the wooden beam, p represents the quantity of the wooden beams, and the length and width dimensions of each wooden window are stored in the form of a two-dimensional array, M = [M1:M 1l ,M 1w ; M2:M 2l ,M 2w ... M n :M nl ,M nw , M represents the wooden window, n represents the number of wooden windows, M nl represents the length dimension of the nth window, and M nw is the width dimension of the nth window.

3. The method for palletizing wooden beams according to the wooden window framing strategy as claimed in claim 1, characterized in that In step S02, each wooden square is uniquely encoded with an attribute string. The format of the attribute string is selected according to the size range of the wooden square beam, and the attribute string format is set to Lxxxx-ODxxx-Mxx, where Lxxxx represents the length of the wooden square beam, ODxxx represents the discharging order of the wooden square beam, and Mxx represents the wooden window number. A wooden window is composed of two pairs of wooden square beams with the same length dimension. First, identify the specific size requirements of the wooden window M1 from the two-dimensional array M of the length and width dimensions of the wooden window, perform sequential retrieval in the discharging order L of the wooden square beams, and allocate the wooden square beam that meets the size requirements of M1 and is the first to be discharged to M1. Accordingly, a unique attribute string is generated for each wooden square beam, and so on. Continue to perform size matching, extraction, and encoding of the wooden square beams for the wooden windows after M1 until the requirements for the wooden square beams of all wooden windows are met. Set two counters F A and F B to store the two pairs of wooden square beams that make up the wooden window respectively. Assume that the wooden square beams that make up M1 are A1, A2, B1, B2, A1 = A2, B1 = B2. Initialize the counters F A and F B to 0. Traverse each element in the wooden square beam encoding table. If the current element matches the size of A, store it in the counter F A , if the current element matches the size of B, store it in the counter F B , ensure that both A and B exist in pairs, and check the quantities of F A and F B to see if they are 2N. After the traversal ends, frame all the found A and B.

4. The method for palletizing wooden beams according to the wooden window framing strategy as claimed in claim 1, wherein In step S03, the wooden beams after framing in step S02 are re-encoded and marked, which includes the total length after splicing, records the original wooden beam discharging order and the wooden window information to which the spliced wooden beam C belongs. Its encoding format is Lxxxx-ODxxx-ODxxx-Mxxx, where Lxxxx represents the total length after splicing, ODxxx represents the discharging order of the original wood, and Mxxx represents the wooden window information. Generate a new dataset with the encoded spliced wooden beams.

5. The method for stacking wooden beams according to the wooden window framing strategy as claimed in claim 1, characterized in that In step S04, according to the updated dataset, set the parameters of the three-dimensional space model of the pallet, set its X-axis dimension, Y-axis dimension, and Z-axis dimension. Mesh the X-Y plane of the pallet, that is, divide the bottom plane of the pallet into a regular grid system. Each grid cell represents a small area at the bottom of the pallet. Assign a unique coordinate (i, j) to each grid cell, where i represents the position along the X-axis and j represents the position along the Y-axis. Initialize a matrix with a size of m1×n1, where m1 and n1 respectively correspond to the number of grids along the X-axis and Y-axis. Each element h(i, j) in the matrix represents the height of the highest layer of wooden beam above the grid cell (i, j). Initialize all elements of the matrix to 0, indicating that there are no wooden beams on the pallet initially, and set up a wooden window information matrix to store the wooden window numbers to which the spliced wooden beams belong.

6. The method for stacking wooden beams according to the wooden window frame assembly strategy as claimed in claim 1, wherein In the step S05, first, set the centroid position constraint. Let C x and C y be the coordinates of the palletizing centroid on the X-axis and Y-axis respectively, L and W be the length and width of the pallet, and the safety distance be ɑ mm. The maximum size of the spliced wooden square is not greater than the length of the pallet space, Lxxxx max ≤L, and the total width of the wooden squares is not greater than the width of the pallet space. p is the number of wooden squares; set a threshold to ensure a certain ratio between the supporting area of the wooden square and its lower side area to meet the stability and safety requirements of palletizing. The supporting area A a and the lower side area A b satisfy 7. The method for stacking wooden beams according to the wooden window frame assembling strategy as claimed in claim 1, wherein In the step S06, l ik is the length of the k-th wooden square in the i-th individual, L and W are the length and width of the pallet respectively, p is the number of wooden squares in the individual, l jk is the length of the k-th wooden square in the discharging order, δ is an indicator function, when l ik matches l jk the value is 1, otherwise it is 0, l is the set of the lengths of the wooden squares in all individuals, l i is the length of the wooden square in the i-th individual, II is an indicator function, when l i = l, the value is 1, otherwise it is 0, P is the total number of individuals in the population.

8. The method for palletizing wooden beams according to the wooden window framing strategy as claimed in claim 1, wherein In step S07, when steps S01 - S06 are completed, the palletizing work begins. According to the evaluation results of the fitness function, the best palletizing scheme is selected. When placing the framing timbers of the window group, check and ensure that the timbers of the same wooden window are placed in the same column and adjacent to each other. If not satisfied, adjust the placement position of the timbers until satisfied. After placing each timber, update the height value at the corresponding position in the height matrix and update the window information matrix. After all timbers are placed, conduct a final inspection to ensure that all timbers are correctly placed and meet all requirements, and record the palletizing results.

Images