A method for stacking timber beams based on a wooden window frame strategy

Abstract

This invention discloses a method for stacking timber beams according to a frame-assembly strategy for wooden windows. The method includes the following steps: Step S01, extracting processing order information; Step S02, formulating a frame-assembly strategy; Step S03, updating the dataset; Step S04, establishing the three-dimensional space of the pallet; Step S05, determining constraints; Step S06, formulating a fitness function; Step S07, stacking. This invention ensures the stability and safety of stacking by setting strict constraints, such as the center of gravity position, timber size limits, and the ratio of support area to underside area, avoiding collapse or damage caused by unstable stacking. By extracting processing order information, automatically matching and encoding timber beams reduces the time and error of manual timber selection in subsequent frame-assembly stages, improving overall production efficiency. This method is applicable to the boxing problem of stacking wooden windows according to a frame-assembly strategy, and helps improve production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of wood window processing and goods packing technology, and relates to a method for stacking timber beams, specifically a method for stacking timber beams based on a timber window grouping strategy using an ant colony algorithm. Background Technology

[0002] The 3D packing problem is a typical combinatorial optimization problem that plays an important role in industrial production. Online 3D packing, as an important variant, is also a sequential decision problem, which is particularly significant for palletizing and packing problems on production lines. It helps to improve packing efficiency, reduce costs, and increase the level of factory automation.

[0003] Currently, in the wooden window processing industry, based on the actual processing needs of factories, logs of standard length are sawn and then manually stacked and moved to the next workstation for further processing into complete windows. In the existing factory processes, manual selection of timber from the stacks for the same type of window is required, which is not only time-consuming and labor-intensive but also susceptible to human error. In a single order, the lengths of the cut timber vary widely, ranging from 400mm to 3000mm, exhibiting significant dynamic changes. However, since the pallet dimensions are fixed and standardized, a dimensional limit needs to be imposed on the spliced ​​timber to ensure the subsequent stability of the stacks.

[0004] Therefore, there is an urgent need for a method for stacking timber beams according to the strategy of assembling wooden windows, in order to solve the above problems. Summary of the Invention

[0005] To address a variation of the three-dimensional packing problem arising from wooden window frame assembly in the wooden window manufacturing industry, this invention provides a method for stacking timber beams according to a wooden window frame assembly strategy. This method is applicable to the packing problem of wooden windows stacked according to a frame assembly strategy, and helps improve production efficiency.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A method for stacking timber beams according to a wooden window frame strategy includes the following steps:

[0008] Step S01: Extract processing order information: Each wooden window is made up of four wooden blocks. Extract the processing order information according to the actual processing in the factory.

[0009] Step S02: Formulate a grouping strategy: Each wooden block corresponds to a unique attribute string. The two pairs of opposite sides of the wooden window are equal. Through search and matching, the two adjacent sides of each wooden window are spliced ​​together to form a wooden block. A wooden window consists of two spliced ​​wooden blocks participating in stacking.

[0010] Step S03, Dataset Update: The spliced ​​timber is coded and marked using a combination coding method. The coding includes the original timber output sequence, the total size after splicing, and the information of the wooden window to which it belongs.

[0011] Step S04: Establish the three-dimensional space of the pallet: Based on the updated dataset, establish the three-dimensional space of the pallet, set the X, Y, and Z axis dimensions in the three-dimensional space, and perform two-dimensional spatial planar meshing on the X and Y axes. Record the height information of the internal space of the pallet in a matrix manner. The value of each position in the matrix represents the height of the highest layer of wood at the corresponding position in the current internal space of the pallet.

[0012] Step S05: Determine the constraints: Determine the constraints according to the stacking requirements. The constraints include: the center of gravity of the stack is located inside the pallet; the maximum size of the spliced ​​timber is not greater than the length of the pallet space; the total width of the timber is not greater than the width of the pallet space; and the ratio of the supporting area of ​​the timber to the underside area of ​​the timber meets the threshold of the stacking requirements.

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

[0014] Step S07, Palletizing: After all the timber in the order has been searched and traversed, the grouping strategy checks whether there is a suitable place to place the current grouped timber in the pallet space after matching and verification, and ensures that the timber of the same window is placed in the same column and adjacent to each other, until all the spliced ​​timber is placed.

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

[0016] 1. The method of the present invention addresses the problem of selecting and assembling timber in the actual production and processing of wooden windows. It is a variant of the three-dimensional packing problem. The method uses an ant colony algorithm to extract the actual processing orders from the factory, encode and mark the timber in the orders, and enable the timber of the same window to be stacked in a hierarchical manner during the subsequent stacking process.

[0017] 2. This invention ensures the stability and safety of stacking by setting strict constraints, such as the center of gravity position, timber size limits, and the ratio of support area to underside area, thus avoiding collapse or damage caused by unstable stacking.

[0018] 3. This invention extracts processing order information, automatically matches timber and marks it with codes, reducing the time and error of manual selection of timber in the subsequent frame assembly process, and improving overall production efficiency. Attached Figure Description

[0019] Figure 1 A flowchart of a method for stacking timber beams according to a timber window frame strategy;

[0020] Figure 2 This is a diagram illustrating the splicing of timber.

[0021] Figure 3 To create a schematic diagram of the three-dimensional space and grid position of the pallet;

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

[0023] Figure 5 This is a schematic diagram of a timber beam stacking scheme using a frame assembly strategy. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0025] This invention provides a method for stacking timber beams according to a wooden window frame strategy, such as... Figure 1 As shown, the method includes the following steps:

[0026] Step S01: Extract processing order information: Each wooden window is made up of four wooden blocks. Extract the processing order information according to the actual processing of the factory.

[0027] In this step, the order information includes the cross-sectional information of the timber beams, their length dimensions, the output sequence, and the information of the wooden windows. During the order input phase, the cross-sectional dimensions of this batch of timber are defined as s = {w, h}, where w is the width of the timber and h is its height. The output sequence of the timber beams is output using the length dimensions of the timber beams as data, L = [l1, l2, ... l...]. 4p ], l is the length of the timber, 4p indicates the output sequence of the timber, p represents the quantity of timber, for example l1 is the length of the first timber beam, and the length and width of each wooden window are stored in a two-dimensional array, M=[M1:M 1l M 1w M2:M 2l M 2w ...M n :M nl M nw M represents wooden windows, and n represents the number of wooden windows. nl M represents the length of the nth window. nw Let be the width dimension of the nth window.

[0028] Step S02: Formulate a frame grouping strategy: Each wooden block corresponds to a unique attribute string. The two pairs of opposite sides of a wooden window are equal. Through search and matching, the two adjacent sides of each wooden window are spliced ​​together to form a wooden block. In subsequent steps, a wooden window is represented by two spliced ​​wooden blocks for stacking.

[0029] In this step, each timber beam is uniquely encoded using attribute strings. The format of the attribute string is selected based on the size range of the timber beams, and is set to Lxxxx-ODxxx-Mxx, where Lxxxx represents the length of the timber beam, ODxxx represents the output sequence of the timber beams, and Mxx represents the window number. Specifically, a window requires two pairs of timber beams of the same length. First, the specific size requirement of window M1 is identified from the two-dimensional array M of the window's length and width dimensions. Then, a sequential search is performed in the timber beam output sequence L, and the timber beam that meets the size requirement of M1 is assigned to M1. Based on this, a unique attribute string is generated for each timber beam. This process continues for windows after M1, performing size matching, extraction, and encoding of timber beams until the timber beam requirements of all windows are met. Two counters F are set. A and F B This is used to store the two pairs of wooden beams that make up the wooden window. Assume that the wooden beams that make up M1 are A1, A2, B1, and B2, where A1 = A2 and B1 = B2. Initialize the counter F. A and F B If the value is 0, iterate through each element in the timber beam coding table. If the current element matches size A, store it in the counter F. A If the current element matches a size of B, store it in counter F. B Ensure that A and B exist in pairs, and check F. A and F B If the quantity is 2N, the traversal ends. Group all found A and B pairs into boxes, for example, A1+B1=C1, A2+B2=C2, C1=C2, M1=C1+C2. This completes the search and grouping of all timber beams. A diagram of timber splicing is shown below. Figure 2 As shown.

[0030] Step S03, Dataset Update: The spliced ​​timber is coded and marked using a combination coding method. The coding includes the original timber output sequence, the total size after splicing, and the information of the wooden window to which it belongs.

[0031] In this step, the timber strips completed in step S02 are re-encoded and marked, including the total length after splicing, the original timber strip output order that makes up the spliced ​​timber strip C, and the information of the wooden window to which it belongs. The encoding format is Lxxxx-ODxxx-ODxxx-Mxxx, where Lxxxx represents the total length after splicing, ODxxx represents the original timber output order, and Mxxx represents the wooden window information. For example, A1 is the first timber strip with a size of 800mm, B1 is the tenth timber strip with a size of 1200mm and belongs to the fourth wooden window, then the spliced ​​timber strip C1 is L2000-OD001-OD010-M004. The spliced ​​timber strips are encoded to generate a new dataset.

[0032] Step S04: Establish the three-dimensional space of the pallet: Based on the updated dataset, establish the three-dimensional space of the pallet, set the X, Y, and Z axis dimensions in the three-dimensional space, and perform two-dimensional spatial planar meshing on the X and Y axes. Record the height information of the internal space of the pallet in a matrix manner. The value of each position in the matrix represents the height of the highest layer of wood at the corresponding position in the current internal space of the pallet.

[0033] In this step, based on the updated dataset, the parameters of the pallet's 3D spatial model are set, including its X-axis, Y-axis, and Z-axis dimensions. The pallet's XY plane is meshed, dividing the bottom plane of the pallet into a regular mesh system with a mesh size of 25cm × 10cm. Each mesh cell represents a small area on the bottom of the pallet, and each mesh cell is assigned a unique coordinate (i,j), where i represents the position along the X-axis and j represents the position along the Y-axis. A matrix of size m1 × n1 is initialized, where m1 and n1 correspond to the number of meshes along the X and Y axes, respectively. Each element h(i,j) in the matrix represents the height of the highest layer of timber above the mesh cell (i,j). All elements of the matrix are initialized to 0, indicating that there are no timbers on the pallet initially. A timber window information matrix is ​​set to store the timber window numbers to which the spliced ​​timbers belong. A schematic diagram of the pallet's 3D space and mesh positions is shown below. Figure 3 As shown, P(i,j) is equivalent to h(i,j), representing the height of the timber at grid coordinate (i,j). A schematic diagram of the stacking height matrix and timber window information matrix, taking s = {7, 7} as an example, is shown below. Figure 4 As shown.

[0034] Step S05: Determine the constraints: Determine the constraints according to the stacking requirements. The constraints include: the center of gravity of the stack is located inside the pallet; the maximum size of the spliced ​​timber is not greater than the length of the pallet space; the total width of the timber is not greater than the width of the pallet space; and the ratio of the supporting area of ​​the timber to the area of ​​the underside of the timber meets the threshold of the stacking requirements.

[0035] In this step, constraints are set. First, the center of gravity position constraint is set, let C... x and C y These are the coordinates of the pallet centroid on the X and Y axes, respectively; L and W are the length and width of the pallet; and the safety distance is α mm. The maximum dimension of the spliced ​​timber shall not exceed the length of the pallet space, Lxxxx max ≤L, the total width of the timber shall not exceed the width of the pallet space. p is the quantity of timber; the supporting area A a This refers to the area of ​​the timber that contacts the timber or pallet below it when stacking; the lower area A. b This refers to the total area of ​​the bottom of the timber, which is the length multiplied by the width of the bottom of the timber. A threshold is set. Ensure that the supporting area of ​​the timber is in a certain ratio to the area beneath it to meet the stability and safety requirements of stacking. Support area A a With the lower side area A b satisfy

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

[0037] In this step, a suitable fitness function is developed to evaluate the performance of each individual (i.e., each possible palletizing layout). This fitness function will be based on multiple factors, including utilization, fit, and diversity. First, relevant parameters and variables are defined. ik Let L be the length of the k-th timber in the i-th individual, and L and W be the length and width of the pallet, respectively. Let p be the number of timbers in the individual. jk Let be the length of the k-th timber in the output sequence, m be the number of timbers in the output sequence, and δ be an indicator function, when l ik With l jk The value is 1 for a match and 0 otherwise. l is the set of timber lengths for all individuals. i Ii is the length of the timber in the i-th individual, and Ii is an indicator function, when l i The value is 1 when the population is equal to 1, otherwise it is 0. P is the total number of individuals in the population, and the utilization rate U is: Match degree M s : Diversity D: Therefore, the fitness function can be defined as: F = ω1·U + ω2·M s +ω3·D, where ω1, ω2, and ω3 are weighting coefficients.

[0038] Step S07, Palletizing: After all the timber in the order has been searched and traversed, the grouping strategy checks whether there is a suitable place to place the current grouped timber in the pallet space after matching and verification, and ensures that the timber of the same window is placed in the same column and adjacent to each other, until all the spliced ​​timber is placed.

[0039] In this step, after steps S01-S06 are completed, the stacking process begins. Based on the fitness function evaluation results, the optimal stacking scheme is selected. When placing the frame timber, it is checked and ensured that the timber for the same window is placed in the same column and adjacent to each other. If this is not met, the placement of the timber is adjusted until it is. After each timber is placed, the height value at the corresponding position in the height matrix is ​​updated, and the window information matrix is ​​also updated. After all timber has been placed, a final check is performed to ensure that all timber has been correctly placed and meets all requirements. The stacking results are then recorded. A schematic diagram of the frame strategy timber beam stacking scheme is shown below. Figure 5 As shown.

Claims

1. A method for stacking timber beams according to a timber window framing strategy, characterized in that The method comprises the following steps: Step S01, extracting processing order information: each wooden window is completed by combining four wooden bars, and the processing order information is extracted according to the actual processing of the factory; Step S02, formulating a frame grouping strategy: each wooden bar corresponds to a unique attribute string, and two pairs of opposite edges of the wooden window are equal, so that each two adjacent edges of the wooden window are spliced into a wooden bar, and a wooden window is formed by two spliced wooden bars participating in stacking; Step S03, updating a data set: the spliced wooden bar is encoded and marked by using a combination coding method, and the coding contains the discharge sequence of the original wooden bar, the total size after splicing and the wooden window information to which the wooden bar belongs; Step S04, establishing a three-dimensional space where a pallet is located: a three-dimensional space where a pallet is located is established according to the updated data set, X, Y and Z axis sizes are set in the three-dimensional space, the X and Y axes are two-dimensional space planar gridding, the height information of the internal space of the pallet is recorded in the form of a matrix, and the numerical value of each position in the matrix represents the height of the highest layer of the wooden bar at the corresponding position in the internal space of the pallet; Step S05, determining a constraint condition: the constraint condition is determined according to the requirements of stacking, and the constraint condition includes that the center of gravity of the stack type is located in the internal space of the pallet, the maximum size of the spliced wooden bar is not greater than the length of the pallet space, the total width of the wooden bar is not greater than the width of the pallet space, and the ratio of the support area of the wooden bar to the lower side area of the wooden bar meets the threshold value required by stacking; Step S06, formulating fitness function: define a fitness function to evaluate the fitness of each individual, and the fitness function is formulated as: F=ω1·U+ω2·M+ω3·D, wherein ω1, ω2, ω3 are weight coefficients, U is utilization rate, M is matching degree, and D is diversity. s s +ω3·D, wherein ω1, ω2, ω3 are weight coefficients, U is utilization rate, M​ Step S07, stacking: after all the wooden bars in the order are searched, whether there is a suitable position to place the current frame grouping wooden bar in the pallet space is checked after the frame grouping strategy is verified, and it is ensured that the wooden bars of the same wooden window are placed in the same column and next to each other, until all the spliced wooden bars are placed.

2. The method according to claim 1, wherein The order information includes cross-sectional information of the timber beam, length size of the timber beam, and discharge sequence, and wood window information in the step S01. In the order input stage, the cross-sectional size s={w, h} of the timber is defined, w is the width of the timber, h is the height of the timber, the discharge sequence of the timber beam is taken as the data output of the length size of the timber beam, L=[l1, l2,...l 4p ], l is the length size of the timber, p represents the number of timbers, and the length and width size of each wood window is stored in the form of a two-dimensional array, M=[M1:M 1l , M 1w 2:M 2l , M 2w 2...M n : M nl , M nw ], M represents the wood window, n represents the number of wood windows, M nl represents the length size of the nth window, and M nw represents the width size of the nth window.

3. The method of claim 1, wherein the method further comprises the steps of: determining the number of the wood beams to be stacked; and determining the number of the wood frames to be stacked. The step S02, take attribute string to each wood beam unique coding, according to the size range of wood beam selection attribute string format, attribute string format set to Lxxxx-ODxxx-Mxx, wherein Lxxxx represents the length of wood beam, ODxxx represents the wood beam order, Mxx represents the wood window number, a wood window needs two pairs of length size of wood beam composition, first from the wood window length and width size two-dimensional array M to identify the specific size requirements of wood window M1, in the wood beam order L sequence retrieval, the first to meet the size requirements of M1 wood beam allocation to M1, according to each wood beam to generate unique attribute string, in this way, continue for M1 after the wood window size matching, extraction and coding of wood beam, until all the wood window wood beam demand is satisfied, set two counters F A And F B To store the two pairs of wood beam found to constitute the wood window respectively, assuming that the wood beam to constitute M1 are A1, A2, B1, B2, A1=A2, B1=B2, initialization counter F A And F B 0, traversal of each element in the wood beam coding table, if the current element matches the size of A, stored to counter F A If the current element matches the size of B, stored to counter F B , to ensure that A and B are paired, check F A And F B Number is 2N, traversal end, all the A and B found to frame.

4. The method of claim 1, wherein the method further comprises the steps of: determining the number of the wood window frames to be grouped; and grouping the wood window frames according to the determined number. In the step S03, the wooden bar after the frame grouping in the step S02 is re-encoded and marked, and the total length after splicing is contained, the discharge sequence of the original wooden bar and the wooden window information to which the spliced wooden bar C belongs are recorded, and the coding format is Lxxxx-ODxxx-ODxxx-Mxxx, wherein Lxxxx represents the total length after splicing, ODxxx represents the discharge sequence of the original wooden bar, and Mxxx represents the wooden window information. A new data set is generated by encoding the spliced wooden bar.

5. The method of claim 1, wherein the method further comprises the step of: 5-1) arranging the wood window frames in a group of frames in a wood window frame group frame arrangement strategy. In the step S04, parameters of the three-dimensional space model of the pallet are set according to the updated data set, the X axis size, the Y axis size and the Z axis size of the pallet are set, the X-Y plane of the pallet is gridded, that is, the bottom plane of the pallet is divided into a regular grid system, each grid unit represents a small area on the bottom of the pallet, each grid unit is allocated a unique coordinate (i, j), wherein i represents the position along the X axis and j represents the position along the Y axis, an m1*n1 matrix is initialized, wherein m1 and n1 correspond to the number of grids along the X axis and the Y axis respectively, each element h(i, j) in the matrix represents the height of the highest layer of the wooden bar above the grid unit (i, j), all elements of the matrix are initialized to 0, indicating that there is no wooden bar on the pallet at the initial time, and a wooden window information matrix is set to store the wooden window number to which the spliced wooden bar belongs.

6. The method of claim 1, wherein the method further comprises the steps of: determining the number of the wood beams to be stacked; and determining the number of the wood frames to be stacked. The step S05 first sets the barycenter position constraint, set C x and C y are the coordinates of the palletizing barycenter on the X axis and the Y axis respectively, L and W are the length and width of the pallet, the safety distance is ɑmm, The maximum size of the spliced wood is not greater than the length of the pallet space, Lxxxx max ≤L, the total width of the wood is not greater than the width of the pallet space, p is the number of the wood; a threshold value is set To ensure that the support area of the wood reaches a certain proportion with the lower side area to meet the stability and safety requirements of the palletizing A a and the lower side area A b satisfy 7. The method of claim 1, wherein the method further comprises the step of: 7-1) arranging the wood window frames in a group of frames in a wood window frame group frame arrangement strategy. In step S06 l ik Let L be the length of the k-th timber in the i-th individual, and L and W be the length and width of the pallet, respectively. Let p be the number of timbers in the individual. jk Let δ be the length of the k-th timber in the output sequence, and let δ be an indicator function. ik With l jk The value is 1 for a match and 0 otherwise. l is the set of timber lengths for all individuals. i Ii is the length of the timber in the i-th individual, and Ii is an indicator function, when l i =1 when =1, otherwise 0, P is the total number of individuals in the population.

8. The method of claim 1, wherein the method further comprises the step of: 8-1) arranging the wood window frames in a group of frames in a wood window frame group frame arrangement strategy. In the step S07, after the steps S01-S06 are executed, the stacking work is started. According to the evaluation result of the fitness function, the best stacking scheme is selected. When placing the group frame wood, it is checked and ensured that the wood of the same wooden window is placed in the same column and next to each other. If it does not meet the requirement, the wood placement position is adjusted until it meets the requirement. After placing each wood, the height value of the corresponding position in the height matrix is updated, and the wood window information matrix is updated. After all the wood is placed, a final check is performed to ensure that all the wood has been correctly placed and meets all the requirements. The stacking result is recorded.

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