An Optimization Method for Material Aggregation and Distribution in Offshore Engineering Construction

Abstract

The present invention discloses an optimization method for the material collection and distribution in ocean engineering construction, so as to carry out the material collection and distribution plan and allocation for ocean engineering construction that are widely applicable, efficient and flexible, and improve the space utilization rate and arrangement efficiency of the collection and distribution process. The method includes: establishing a database of ocean engineering collection and distribution stations; establishing a database of construction materials to be collected and distributed in ocean engineering; preliminary diversion of the collection and distribution stations; sorting the priority of warehouse location allocation; optimization of warehouse location allocation: constructing an optimization function for warehouse location allocation, and establishing a warehouse location allocation decision aiming at maximizing the space utilization rate for the construction materials within the same collection and distribution station; optimizing the collection and distribution plan by genetic algorithm: performing iterative optimization based on the genetic algorithm to select the optimal collection and distribution plan that meets the collection and distribution constraint conditions. This method greatly improves the space utilization rate of the collection and distribution process and the management efficiency of construction materials, and effectively reduces the secondary handling and the situation of construction material retention.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and more specifically, to a method for optimizing the allocation of marine engineering construction materials. Background Art

[0002] With the increasing attention paid to the development and utilization of marine resources around the world, the marine engineering equipment industry has ushered in a new opportunity for development. my country's marine engineering equipment manufacturing enterprises have made great improvements in product levels, industrial division of labor, business scale, etc., and their competitive position in the global marine engineering equipment market has been significantly improved. However, with the continuous expansion of the number and scale of marine engineering projects, the storage and turnover of construction materials have also increased significantly, which has put forward higher requirements for the classification, storage and use of construction materials.

[0003] The offshore engineering manufacturing industry is a typical discrete manufacturing industry, and its final products are composed of various parts, self-made parts and equipment through a complex assembly process. Each offshore engineering project involves a large number of construction materials with complex classifications. The number of parts for a single offshore engineering equipment can reach 7 million. Enterprises usually carry out multiple offshore engineering projects at the same time, and each project may have different goals and priorities in the same period, which makes the construction material management task more complicated.

[0004] Traditionally, construction material planning and management often rely on manual experience. Decision makers may make decisions that are inconsistent with the actual situation due to differences in considerations, untimely information communication, or lack of overall consideration. Or they may spend a lot of time in the decision-making stage, which may lead to secondary handling of construction materials, duplication or omission of construction materials, or even cause the construction materials to be stranded in the distribution link and project delays.

[0005] At present, in order to solve the problems of difficult management, low efficiency and low accuracy in the process of material distribution for marine engineering construction, some enterprises have introduced digital and intelligent technologies, and some scholars have proposed negotiation models and decision algorithms for the problem of warehouse allocation. However, based on the characteristics of multiple distribution stations in marine engineering, no effective technical solutions have been found. Summary of the invention

[0006] In order to solve the problems of great difficulty, low efficiency and poor accuracy in the distribution of construction materials at multiple distribution stations for marine engineering, the present invention proposes a method for optimizing the distribution of construction materials for marine engineering, which can carry out distribution planning and allocation of marine engineering construction materials with wide applicability, high efficiency and flexibility, improve the space utilization and arrangement efficiency of the distribution process, and promote the standardized management of marine engineering construction materials.

[0007] The technical solution adopted to achieve the purpose of the present invention is:

[0008] An optimization method for the material distribution of offshore engineering construction, comprising the following steps:

[0009] Step 1, establish a database of the offshore engineering distribution station;

[0010] Step 2, establish a database of the construction materials to be distributed for offshore engineering;

[0011] Step 3, preliminary distribution station diversion: conduct preliminary distribution station diversion according to the database of the offshore engineering distribution station established in Step 1 and the database of the construction materials to be distributed established in Step 2;

[0012] Step 4, priority ranking of storage location allocation: establish an evaluation index for the priority of storage location allocation, rank the priorities of the construction materials in the same distribution station, and determine the optimal storage location allocation order;

[0013] Step 5, optimization of storage location allocation: construct an optimization function for storage location allocation, and establish a storage location allocation decision for the construction materials in the same distribution station with the goal of maximizing space utilization;

[0014] The specific formula for constructing the optimization function for storage location allocation is as follows:

[0015]

[0016] In the formula, Vol SUP is the volume of the storage location occupied by the construction material SUP; Vol SL represents the maximum volume of the storage location SL where the construction material SUP is placed, and Vol SUP ≤Vol SL ; SUP represents the types of construction materials to be distributed at this distribution station, and its value is n, where n is a positive integer;

[0017] The constraint conditions include: safety distance constraint, weight and center of gravity constraint, stacking area constraint, physical and chemical property constraint, and correlation constraint of adjacent construction materials;

[0018] (1) The safety distance constraint is as follows:

[0019] minD(a, b)≥d var ;

[0020] Among them, D(a, b) represents the positional relationship between object a and object b in the distribution station, and d var is the standard safety distance value;

[0021] (2) The weight and center of gravity constraint is as follows:

[0022]

[0023] M maxis the maximum load weight of the shelf or storage location; S is the construction material for the storage location layout, and its value is c, where c is a positive integer and c ≤ n; m Sk is the weight of the k-th item in the construction material S; G per is the maximum allowable center of gravity height coordinate of the storage location; M represents the total weight of the shelf or storage location at this time; Z Sk is the center of gravity height coordinate of the k-th item in the construction material S; represents the weighted average center of gravity after placing c types of construction materials in this storage location; N S represents the number of items in the construction material S, which is a set of positive integers; only when both the weight and the center of gravity meet the constraints can f(M, Z) = TRUE be obtained; otherwise, if any one of the conditions is not met, f(M, Z) = FALSE;

[0024] (3) Stacking area constraint:

[0025] The stacking area constraint for each stack is as follows:

[0026] W STK ≤ W var ;

[0027] where, W STK represents the area of the stacking storage location, with the unit of m 2 ; W var represents the safe value of the stacking area;

[0028] (4) Physical and chemical property constraints are as follows:

[0029] Penalty(i, j) = λ · conflict(i, j);

[0030] where, the calculation of Penalty(i, j) is based on the conflict function conflict(i, j). conflict(i, j) represents whether there is a conflict in the physical properties or chemical properties between construction material i and construction material j. When there is a physical or chemical property conflict, the value is 1, and when there is no conflict in both physical and chemical properties, the value is 0; λ is a sufficiently large positive integer;

[0031] (5) Adjacent construction material correlation constraints are as follows:

[0032] cor(e, g) ≥ cor var ;

[0033] where, cor(e, g) represents the correlation between adjacent construction materials e and g, and its value range is [0, 1]. A value of 1 indicates that the adjacent construction materials are of the same type, and a value of 0 indicates that the adjacent construction materials are not related; cor var takes 0.6, and only when the correlation of adjacent construction materials is greater than or equal to 0.6 can the constraint conditions be passed;

[0034] Step 6, Optimize the assembly and distribution plan using genetic algorithm: Iteratively search for the optimal solution based on the genetic algorithm to select the optimal assembly and distribution plan that meets the assembly and distribution constraints.

[0035] Step 7, Execute and update the database: According to the optimal assembly and distribution plan, transport the construction materials to the assembly and distribution station and update the database information of the assembly and distribution station.

[0036] Step 1 includes: Analyze the assembly and distribution station drawings and comprehensively form the offshore engineering assembly and distribution station database based on the spatial location, assembly and distribution type, assembly and distribution conditions, and resource status information of the assembly and distribution station.

[0037] Step 2 includes: Integrate the procurement documents, production plan documents, and waste recycling documents, count the list of construction materials to be assembled and distributed, obtain the attributes of the construction materials, assembly and distribution specifications, and additional requirements, and form the database of construction materials to be assembled and distributed.

[0038] The assembly and distribution station is divided into an offshore engineering comprehensive spare parts warehouse, an offshore engineering materials assembly and distribution yard, a coating oil storage warehouse, an offshore engineering hazardous waste treatment warehouse, and an offshore engineering solid waste temporary storage yard; Step 3, the preliminary assembly and distribution station is divided as follows:

[0039]

[0040] Step 4, the priority ranking of the storage location allocation is obtained through the storage location allocation priority evaluation index P SA as follows:

[0041] The storage location allocation priority evaluation index P SA The calculation formula is as follows:

[0042]

[0043] And w1 + w2 + w3 + w4 = 1;

[0044] In the formula: P SA is the storage location allocation priority evaluation index of the construction material SA; SA is the construction material diverted into a certain assembly and distribution station; T SA is the earliest time to use the construction material SA in the project; T max is the latest time to use all the construction materials to be assembled and distributed in this assembly and distribution station; R SA is the remaining quantity of the construction material SA in this assembly and distribution station; E SA is the quantity of the construction material SA required by the project; F SA is the number of times the construction material SA entered and exited in the previous quarter; F max is the number of times all the construction materials entered and exited this assembly and distribution station in the previous quarter; V SA is the value of the construction material SA, V maxis the total value of all the construction materials to be assembled and distributed at the assembly and distribution station; w1 is the weight of the usage time of the assembly and distribution station; w2 is the weight of the inventory ratio of the assembly and distribution station; w3 is the weight of the flow frequency of the assembly and distribution station; w4 is the weight of the value of the construction materials at the assembly and distribution station.

[0045] Object a is any one of stack, pallet, construction material, and item, and object b is any one of stack, pallet, lamp, wall, floor slab, flat roof, column, and the edge of the loadable area. The standard safety distance variable d var takes the following values, in meters:

[0046]

[0047] Step 6 includes the following steps:

[0048] Step 6.1, generate an initial population according to the initial parameters of the genetic algorithm;

[0049] Step 6.2, enter the iterative optimization of the genetic algorithm;

[0050] Step 6.3, output the current generation population and calculate the individual fitness;

[0051] Step 6.4, perform the layout of the construction materials;

[0052] Step 6.4.1, input the information of the construction materials and the diversion situation of the assembly and distribution station;

[0053] Step 6.4.2, select the layout direction of the construction materials and start the longitudinal or transverse layout;

[0054] Step 6.4.3, after the preliminary layout, evaluate whether the assembly and distribution plan meets all the constraints; if it meets, enter Step 6.4.4; if it does not meet, move the construction materials to re-layout, and the re-layout is allowed to change the storage location, distance, and layout direction; when the layout of the construction materials meets all the constraints, enter Step 6.4.4;

[0055] Step 6.4.4, write the coordinates and information of the construction materials into the database;

[0056] Step 6.4.5, judge whether the construction materials can be stacked; if they can, enter Step 6.4.6; if they cannot, directly enter Step 6.4.9;

[0057] Step 6.4.6, perform the stacking layout of the construction materials according to the stacking requirements of the construction materials and the storage location and stack height limits;

[0058] Step 6.4.7, judge again whether it meets the constraints; if it meets, enter Step 6.4.8; if it does not meet the constraints, exit the stacking layout and enter Step 6.4.9;

[0059] Step 6.4.8, complete the stacking layout and update the construction material information;

[0060] Step 6.4.9, start the insertion layout;

[0061] Step 6.4.10, increase the spacing along the layout direction to obtain the new coordinates of the construction materials;

[0062] Step 6.4.11 and determine whether all constraints are met; if so, proceed to Step 6.4.12; if not, exit the insertion layout and then proceed to Step 6.4.13;

[0063] Step 6.4.12, complete the insertion layout and update the construction material information;

[0064] Step 6.4.13, determine whether there are unarranged construction materials of the same type. If there are, return to Step 6.4.2 to arrange the construction materials. If not, proceed to Step 6.4.14;

[0065] Step 6.4.14, complete the arrangement of the construction materials of this type and update the construction material information;

[0066] Step 6.4.15, determine whether there are unarranged construction materials. If there are, select the construction materials with the next priority for arrangement and return to Step 6.4.2; if not, proceed to Step 6.4.16;

[0067] Step 6.4.16, complete the arrangement of the construction materials at the distribution station;

[0068] Step 6.5, obtain the layout plan of this generation;

[0069] Step 6.6, determine whether the iteration termination condition is reached; if not, proceed to Step 6.6.1; if so, proceed to Step 6.7;

[0070] Step 6.6.1, compare the space utilization rate, the correlation of adjacent construction materials, and the distribution efficiency of individuals to determine the best and worst individuals of this generation, and add the worst layout plan to the taboo list;

[0071] Step 6.6.2, generate the next generation of population;

[0072] Step 6.6.3, compare the taboo list. If the generated new generation of population has a record in the taboo list, regenerate the population; compare the regenerated population with the bad solutions in the taboo list. If they are the same, regenerate. If they are different, proceed to Step 6.3;

[0073] Step 6.7, end the genetic algorithm and output the optimal distribution plan.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] 1. The optimization method of the present invention constructs a database of marine engineering distribution stations and a database of construction materials to be distributed, combines distribution station diversion, location allocation priority sorting and optimization of location allocation, greatly improves the space utilization rate and construction material management efficiency of the distribution process, and effectively reduces secondary handling and construction material retention.

[0076] 2. The method of the present invention ensures that the optimal distribution scheme is selected under the constraints of safety distance, weight and center of gravity, stacking area, physical and chemical properties and correlation of adjacent construction materials, further improving the intelligent level of distribution management. In addition, the application of genetic algorithms for continuous iteration and optimization of distribution schemes helps to achieve adaptive adjustment and long-term optimization of the distribution system.

[0077] 3. The method of the present invention takes into account the numerous, huge quantities and complex classification of construction materials faced by marine engineering distribution, as well as the problems of discrepancies between construction material distribution accounts and actual conditions and backlog of construction materials caused by frequent distribution. Through intelligent distribution planning and allocation, information interaction of the distribution station database is realized, and distribution plans are provided in a timely and efficient manner, thereby improving the space utilization and scheduling efficiency of the distribution process and promoting standardized management of marine engineering construction materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a flow chart of a method for optimizing the distribution of materials for marine engineering construction according to the present invention;

[0079] Figure 2 This is a flow chart of materials distribution for marine engineering construction in an embodiment of the present invention;

[0080] Figure 3 This is a flow chart of performing iterative optimization based on a genetic algorithm to select the optimal set matching solution in an embodiment of the present invention;

[0081] Figure 4 It is a schematic diagram of the utilization rate of the allocation space according to an embodiment of the present invention. DETAILED DESCRIPTION

[0082] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0083] The present invention proposes a method for optimizing the allocation of marine engineering construction materials, the process is as follows: Figures 1 - 3 As shown, the specific steps are as follows:

[0084] Step 1: Construct the database of the offshore engineering assembly and distribution station: Analyze the assembly and distribution station drawings, obtain the informatization data such as the spatial location of the assembly and distribution station, warehouse layout, resource status, and storage location requirements, etc., summarize the information of the same assembly and distribution station, and comprehensively form the database of the offshore engineering assembly and distribution station.

[0085] In the offshore engineering field, assembly and distribution stations usually include the following categories:

[0086] (1) Offshore engineering comprehensive spare parts warehouse: Store offshore engineering mechanical and electrical equipment, standard parts, spare parts, outsourcing parts, cables, etc., mainly metals, glass, and non-combustible items;

[0087] (2) Offshore engineering material assembly yard: Mostly used for stacking construction materials such as raw materials, steel, or sections;

[0088] (3) Coating oil storage warehouse: Mainly store paints required for coating, etc.;

[0089] (4) Offshore engineering hazardous waste treatment warehouse: Used to store hazardous solid waste generated during the production process;

[0090] (5) Offshore engineering solid waste temporary storage yard: Used to store general solid waste generated during the production process;

[0091] Among them, general industrial solid waste is sold externally, the empty paint barrels in hazardous waste are handed over to the supplier for reuse, and the rest of the hazardous waste is handed over to qualified units for treatment.

[0092] In order to make better use of the assembly and distribution space, the storage locations of each assembly and distribution station are divided according to the characteristics of the construction materials. Shelf storage locations, stack storage locations, and pallets are provided in the offshore engineering comprehensive spare parts warehouse, coating oil storage warehouse, and offshore engineering hazardous waste treatment warehouse; stack storage locations are provided in the offshore engineering material assembly yard and offshore engineering solid waste temporary storage yard.

[0093] Step 2: Establish the database of offshore engineering construction materials to be assembled and distributed: Integrate procurement documents, production plan documents, and waste recycling documents, count the list of construction materials to be assembled and distributed, obtain the attributes of construction materials, assembly and distribution specifications, and additional requirements, and form the database of construction materials to be assembled and distributed.

[0094] Since offshore engineering companies often carry out multiple offshore engineering projects simultaneously, involving a large number of construction material types, considering the material attributes comprehensively, they can be divided into the following five categories: raw materials, components, intermediate products, outsourced parts, and solid waste. The first four types of materials are used to support the hull installation, outfitting, painting, and general assembly work of offshore engineering construction, and the assembly and treatment of solid waste generated during the production process helps to ensure the green development of offshore engineering.

[0095] To ensure the integrity and effectiveness of construction material management, it is necessary to read and analyze the procurement documents, production plan documents, and waste recycling documents of multiple projects to form a unified list of construction materials to be assembled and distributed. By uniformly obtaining the attributes, assembly and distribution specifications, and additional requirements of construction materials, omission or duplicate recording can be avoided, ensuring the effective management and full utilization of construction material information for all projects.

[0096] Step 3: Conduct preliminary distribution station diversion according to the offshore engineering assembly and distribution station database and the database of construction materials to be assembled and distributed.

[0097] Differences in the usage frequency, storage conditions, and processing requirements of different construction materials determine that they need to be allocated to the most suitable distribution station for management. Therefore, in this embodiment, based on the following distribution station diversion requirements, preliminary diversion of construction materials is carried out:

[0098]

[0099] Step 4: Sort the priority of storage location allocation: Establish an evaluation index for the priority of storage location allocation, sort the priorities of construction materials within the same assembly and distribution station, and determine the optimal storage location allocation order.

[0100] For the construction materials within the same assembly and distribution station, establish a scientific evaluation index system for the priority of storage location allocation to optimize the assembly and distribution order of construction materials. Considering the four influencing factors of the usage time, inventory ratio, flow frequency, and value of construction materials, establish an evaluation mechanism for storage location allocation according to the weight coefficients, sort the priorities of construction materials in the same assembly and distribution station, and give priority to the assembly and distribution of construction materials with high priorities.

[0101] The priority sorting of storage location allocation is obtained through the storage location allocation priority evaluation index P SA as follows:

[0102] The storage location allocation priority evaluation index P SA The calculation formula is as follows:

[0103]

[0104] And w1 + w2 + w3 + w4 = 1;

[0105] In formula (1): P SA is the storage location allocation priority evaluation index of construction material SA; SA is the construction material diverted into a certain assembly and distribution station; T SA is the earliest time for the project to use construction material SA; T max is the latest time for all construction materials to be assembled and distributed in this distribution station to be used; R SA is the remaining quantity of construction material SA in this distribution station; E SA is the quantity of construction material SA required by the project; FSA is the number of times of incoming and outgoing of construction material SA in the previous quarter; F max is the number of times of incoming and outgoing of all construction materials at this consolidation station in the previous quarter; V SA is the value of construction material SA, V max is the total value of all construction materials to be consolidated at this consolidation station; w1 is the weight of the usage time of the consolidation station; w2 is the weight of the inventory ratio of the consolidation station; w3 is the weight of the flow frequency of the consolidation station; w4 is the weight of the value of the consolidation station.

[0106] In this embodiment, when the consolidation station is an offshore waste treatment warehouse, w1 = 0.1; w2 = 0.1; w3 = 0.7; w4 = 0.1;

[0107] When the consolidation station is an offshore solid waste temporary storage yard, w1 = 0.1; w2 = 0.1; w3 = 0.6; w4 = 0.2;

[0108] When the consolidation station is a painting oil storage warehouse, w1 = 0.3; w2 = 0.3; w3 = 0.2; w4 = 0.2;

[0109] When the consolidation station is an offshore material consolidation yard, w1 = 0.2; w2 = 0.5; w3 = 0.1; w4 = 0.2;

[0110] When the consolidation station is an offshore comprehensive spare parts warehouse, w1 = 0.4; w2 = 0.2; w3 = 0.1; w4 = 0.3.

[0111] Step 5, Optimization of storage location allocation: Construct an optimization function for storage location allocation, aiming to maximize the space utilization rate, and establish a storage location allocation decision.

[0112] Specifically, the space utilization rate target aims to maximize the use of the consolidation space while meeting safety requirements, ensure the consolidation compactness, so as to make full use of the limited space and reduce the construction material consolidation cost. The specific formula is as follows:

[0113]

[0114] In the formula, Vol SUP is the volume of the construction material SUP occupying the storage location; Vol SL represents the maximum volume of the storage location SL where the construction material SUP is placed, and Vol SUP ≤Vol SL . SUP represents the types of construction materials to be consolidated at this consolidation station, and its value is n, where n is a positive integer.

[0115] The constraint conditions in step 5 include: safety distance constraint, weight and center of gravity constraint, stacking area constraint, physical and chemical property constraint, and correlation constraint of adjacent construction materials.

[0116] (1) Safety distance constraint:

[0117] A series of distance requirements are proposed for the distribution station layout and inventory management. The safety distance constraint aims to ensure that the construction material distribution plan meets the distance requirements.

[0118] Specifically, the safety distance constraint ensures that there is sufficient safety distance between construction materials and buildings, between different stacks and storage locations, and between different construction materials, ensuring that the distribution plan complies with relevant regulations, minimizing potential safety risks, and ensuring the safe operation of the distribution station. The safety distance constraint is summarized as follows:

[0119] minD(a, b) ≥ d var (3);

[0120] Among them, D(a, b) represents the positional relationship between object a and object b in the distribution station. a and b can represent stacks, pallets, construction materials, etc. In this embodiment, object a can be any one of stacks, pallets, construction materials, items, etc., and object b can be any one of stacks, pallets, lights, walls, floors, flat roofs, columns, and the edge of the loadable area. And the standard safety distance d var is determined according to the specific distribution station and objects, selected according to experience, and the unit is meters:

[0121]

[0122] (2) Weight and center of gravity constraint:

[0123] The weight and center of gravity constraint is to ensure the safety and stability of construction materials during the distribution process, and effectively prevent distribution facility accidents caused by overloading or unreasonable center of gravity positions.

[0124] When construction materials are placed in the storage location, their weight shall not exceed the maximum load that the storage location can bear. Exceeding the maximum load may cause the shelf to bear excessive pressure, thus affecting the stability of the shelf and increasing the risk of the shelf tipping or collapsing. In addition, the placement of goods will change the center of gravity position of the shelf. The construction material distribution plan needs to ensure that the overall center of gravity of the shelf after the construction materials are placed is at a suitable position, avoiding tipping or instability caused by eccentricity.

[0125] The weight and center of gravity constraint is shown in Equation (4):

[0126]

[0127] M max is the maximum loading weight of the shelf or storage location; S is the construction materials arranged in the storage location, and its value is c, c is a positive integer, and c ≤ n; m Sk is the weight of the kth item in the construction material S; G peris the maximum allowable center of gravity height coordinate of the storage location; M represents the total weight of the shelf or storage location at this time; Z Sk is the center of gravity height coordinate of the k-th item in the construction material S; represents the weighted average center of gravity after placing c types of construction materials in this storage location; N S represents the number of items in the construction material S, which is a set of positive integers; only when both the weight and the center of gravity meet the constraints can f(M, Z) = TRUE be obtained; otherwise, if any one of the conditions is not met, f(M, Z) = FALSE.

[0128] (3) Stacking area constraint:

[0129] Define the safety values of the area of each stack of construction materials in the warehouse and outdoor storage to prevent safety accidents such as tipping or collapse during the stacking process. The stacking area constraint is:

[0130] W STK ≤W var (5);

[0131] Among them, W STK represents the stacking area, with the unit of m 2 ; W var represents the safety value of the stacking area. In this embodiment: during indoor distribution, W var = 150; during outdoor distribution, W var = 1000.

[0132] (4) Physical and chemical property constraint:

[0133] During the process of specifying the distribution plan, the physical properties and chemical properties of adjacent construction materials cannot conflict. Therefore, a penalty function, Penalty(i, j), is introduced, and this function directly affects the optimization of the objective function:

[0134] Penalty(i, j) = λ·conflict(i, j) (6);

[0135] Specifically, the calculation of Penalty(i, j) is based on the conflict function conflict(i, j). conflict(i, j) represents whether there is a conflict in the physical properties or chemical properties between construction material i and construction material j. When there is a physical or chemical property conflict, the value is 1, and when there is no conflict in both physical properties and chemical properties, the value is 0; λ is a sufficiently large positive integer used to affect the objective function.

[0136] (5) Correlation constraint of adjacent construction materials:

[0137] The relevance of adjacent construction materials focuses on placing goods with high relevance in adjacent positions, facilitating the quick and easy finding of relevant construction materials during a specific stage of hull installation, outfitting, painting, and general assembly in the production process, improving the smoothness of the production process, and reducing the problem of secondary handling of construction materials.

[0138] The constraints on the relevance of adjacent construction materials are as follows:

[0139] cor(e, g) ≥ cor var (7);

[0140] Among them, cor(e, g) represents the relevance between adjacent construction materials e and g, with a value range of [0, 1]. A value of 1 indicates that the adjacent construction materials are of the same type, and a value of 0 indicates that the adjacent construction materials are not relevant; cor var takes 0.6, and only when the relevance of adjacent construction materials is greater than or equal to 0.6 can the constraint condition be passed.

[0141] Step 6: Perform iterative optimization based on the genetic algorithm to select the optimal assembly plan that meets the assembly constraints;

[0142] Step 6.1: Generate an initial population according to the initial parameters of the genetic algorithm;

[0143] Step 6.2: Enter the iterative optimization of the genetic algorithm;

[0144] Step 6.3: Output the current generation population and calculate the individual fitness;

[0145] Step 6.4: Carry out the layout of construction materials:

[0146] The layout of the construction materials is based on the preliminary distribution of the assembly station and the priority ranking of the warehouse location allocation, mainly including assembly operations such as moving, stacking, and interposing to complete the assembly of construction materials category by category.

[0147] Step 6.4.1, input the construction material information and the distribution situation of the distribution station; Step 6.4.2, select the layout direction of the construction materials and start the longitudinal or transverse layout; Step 6.4.3, evaluate whether the distribution plan meets all constraints after the preliminary layout. If it meets the requirements, enter Step 6.4.4; if it does not meet the requirements, move the construction materials to re-layout, and the re-layout allows changing the storage location, distance, and layout direction. When the layout of the construction materials meets all the constraint conditions, enter Step 6.4.4, write the coordinates and information of the construction materials into the database. Then enter Step 6.4.5 to judge whether the construction materials can be stacked. If it can, enter Step 6.4.6, and carry out the stacking layout of the construction materials according to the stacking requirements of the construction materials and the storage location and stacking height limits; if it cannot, directly enter Step 6.4.9. Subsequently, enter Step 6.4.7 to judge again whether the constraints are met. If it meets the requirements, enter Step 6.4.8 to complete the stacking layout and update the construction material information; if the constraints are not met, exit the stacking layout and enter Step 6.4.9. After starting the insertion layout, enter Step 6.4.10, increase the spacing along the layout direction to obtain the new coordinates of the construction materials. Enter Step 6.4.11 and judge whether it meets the constraints. If it meets the requirements, enter Step 6.4.12 to complete the insertion layout and update the construction material information; if it does not meet the requirements, exit the insertion layout. Then enter Step 6.4.13 to judge whether there are unlaid construction materials of the same type. If there are, return to Step 6.4.2 to carry out the layout of the construction materials. If not, enter Step 6.4.14 to complete the layout of this type of construction materials and update the construction material information. Subsequently, enter Step 6.4.15 to judge whether there are unlaid construction materials. If there are, select the construction materials of the next priority for layout and return to Step 6.4.2; if not, enter Step 6.4.16 to complete the layout of the construction materials at the distribution station.

[0148] Step 6.5, obtain the layout plan of this generation;

[0149] Step 6.6, judge whether the iteration termination condition is reached; if the iteration termination condition is not reached, enter Step 6.6.1;

[0150] Step 6.6.1, compare the space utilization rates of individuals, determine the best individual and the worst individual of this generation, and add the worst layout plan to the taboo list.

[0151] Step 6.6.2, generate the next generation of population. The excellent individuals have a high probability of generating offspring, and the worst individuals are prohibited from generating offspring.

[0152] Step 6.6.3, compare the taboo list. If the generated new generation of population is recorded in the taboo list, re-generate the population. Compare the re-generated population with the bad solutions in the taboo list. If they are the same, re-generate. If they are different, enter Step 6.3.

[0153] If the iteration termination condition is reached, go to step 6.7.

[0154] Step 6.7, end the genetic algorithm and output the optimal assembly plan.

[0155] Step 7, execute and update the database: Transport the construction materials to the designated layout positions according to the final optimization plan, and update the offshore engineering assembly station database and the database of construction materials to be assembled to reflect the latest assembly status.

[0156] Based on the output optimal assembly plan, the staff can effectively schedule resources such as personnel and AGV vehicles to achieve the rapid storage of construction materials. At the same time, the database can be updated in a timely manner to strengthen the recording of construction materials, so that subsequent assembly activities can proceed smoothly.

[0157] Embodiment

[0158] After the initial diversion at the assembly station, there are 9 construction materials to be arranged in the offshore engineering comprehensive spare parts warehouse. Each construction material has 9 characteristics, namely the construction material number, construction material name, construction material quantity, length, width, height, total quantity, whether it can be stacked, the maximum number of stacking layers, etc. The specific data is shown in Table 1.

[0159] Table 1:

[0160]

[0161]

[0162] In the "whether it can be stacked" characteristic, 0 means that the construction material cannot be stacked, and the default maximum number of stacking layers for non-stackable construction materials is 1; 1 means that the construction material can be stacked, and the maximum number of stacking layers is greater than or equal to 2.

[0163] Use the storage location allocation priority evaluation index P SA Rank the construction materials in the offshore engineering comprehensive spare parts warehouse by priority. The formula is as follows:

[0164]

[0165] The ranking results are shown in Table 2.

[0166] Table 2:

[0167]

[0168] Input the above list of construction materials to be assembled and the available storage location information of the offshore engineering comprehensive spare parts warehouse, read the cargo parameter information, available storage location coordinate information, etc., and generate the global variables required for cargo layout and genetic algorithm iteration.

[0169] Set the initial parameters of the genetic algorithm: Take the population size as 50, the number of iterations as 150 times, generate the initial population, and enter the iteration of the genetic algorithm. At the same time, take the objective function as the fitness function, and at this time n = 9.

[0170]

[0171] Processing process of the genetic algorithm:

[0172] Selection operation: After calculating the fitness of each individual in the population, determine which individuals will be used for reproduction and generate the next generation through the selection operation. Individuals with higher fitness values have a greater probability of being selected, and their genetic material is passed on to the next generation.

[0173] Crossover operation: Select the parental chromosomes from the population and generate new individuals through the crossover combination of the chromosomes.

[0174] Mutation operation: Randomly select an individual from the population and mutate a certain segment of the encoding in its chromosome to generate a better individual.

[0175] After completing the arrangement of all individuals in this generation, compare the utilization effects of the assembly and distribution utilization rates of the individuals, determine the best and worst individuals in this generation and add them to the corresponding comprehensive variable list. Subsequently, generate the next generation population. The probability of the best individuals generating offspring is high, and the worst individuals are prohibited from generating offspring. And compare each generated population with the worst individual of the previous generation recorded in the list one by one. If they are the same, regenerate.

[0176] After meeting the termination conditions, output the final arrangement plan as shown in Table 3.

[0177] Table 3:

[0178] Assembly sequence Construction material number Goods layout warehouse location number Goods stacking condition Goods intercalation condition 1 4415 B04 2 0 2 0015 A02 1 0 3 3001 B10 2 0 4 1452 C14 3 0 5 0340 A03 2 0 6 4521 C12 1 1 7 2102 C11 1 1 8 1046 A05 1 0 9 7654 A08 1 0

[0179] In the "goods insertion situation" characteristic, 0 indicates that the construction material cannot be inserted; 1 indicates that the construction material can be inserted.

[0180] For this example, the utilization rate of the assembly space is as Figure 4 shown. After adopting this optimization method, the utilization rate of the assembly space reaches 86.9%. The assembly planning time changes from one hour of manual arrangement to 28 minutes, and the construction material assembly planning time is shortened by 46%.

[0181] The optimization method for the material distribution of ocean engineering construction in the present invention significantly improves the space utilization rate during the distribution process and the efficiency of construction material management, effectively reducing the secondary handling and the situation of construction material retention by constructing a database for the ocean engineering distribution station and a database for the construction materials to be distributed, and combining the distribution of the distribution station, the priority sorting of storage location allocation, and the optimized storage location allocation. Through the intelligent distribution plan and allocation, the information interaction of the distribution station database is realized, and the distribution plan is provided in a timely and efficient manner, thereby improving the space utilization rate and arrangement efficiency during the distribution process, and facilitating the promotion of the standardized management of ocean engineering construction materials.

[0182] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and refinements can be made without departing from the principle of the present invention, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for optimizing the distribution of marine engineering construction materials, characterized in that: The steps include: Step 1: Establish a marine engineering distribution station database; Step 2: Establish a database of construction materials to be assembled for marine engineering projects; Step 3: Preliminary distribution station diversion: Perform preliminary distribution station diversion based on the offshore engineering distribution station database established in step 1 and the database of construction materials to be distributed established in step 2; Step 4: Priority sorting of warehouse allocation: Establish evaluation indicators for warehouse allocation priority, prioritize construction materials in the same distribution station, and determine the optimal warehouse allocation sequence; Step 5: Optimize warehouse allocation: Construct a warehouse allocation optimization function, and establish warehouse allocation decisions for construction materials in the same distribution station with the goal of maximizing space utilization; The specific formula for constructing the storage location allocation optimization function is as follows: ； In the formula, For construction materials The volume of the storage space; Indicates construction materials Placed in storage location The maximum volume of ; Indicates the type of construction materials to be collected and distributed at the distribution station. Its value is , is a positive integer; Constraints include: safety distance constraints, weight and center of gravity constraints, stacking area constraints, physical and chemical property constraints, and adjacent construction material correlation constraints; (1) Safety distance constraints are as follows: ； in, Indicates the positional relationship between object a at the distribution station and object b at the distribution station, is the standard safety distance value; (2) Weight and center of gravity constraints are as follows: ； The maximum loading weight of the shelf or storage location; The construction material arranged in the storage location is , is a positive integer, and ; For construction materials Middle The weight of the item; The maximum allowable center of gravity height coordinate of the storage location; Indicates the total weight of the shelf or storage location at this time; For construction materials Middle The height coordinates of the center of gravity of each item; Indicates that the storage location is placed The weighted average center of gravity of the construction materials; Indicates construction materials The number of items is a set of positive integers; only when the weight and center of gravity meet the constraints can we get Otherwise, no matter which of the conditions is not met, ; (3) Stacking area constraints: The area constraints for each stack are as follows: ； in, Indicates the area of ​​the stacking location, in m 2 ; Indicates the safe value of stacking area; (4) The physical and chemical property constraints are as follows: ； in, The calculation is based on the conflict function , Indicates construction materials and construction materials Whether the physical or chemical properties conflict with each other. When the physical or chemical properties conflict, the value is 1; when neither the physical or chemical properties conflict, the value is 0; is a positive integer; (5) The constraints on the correlation of adjacent construction materials are as follows: ； in, Indicates adjacent construction materials , The correlation between them is in the range of [0,1]. A value of 1 indicates that the adjacent construction materials are the same type of construction materials, and a correlation of 0 indicates that the adjacent construction materials are unrelated. Take 0.6, and only when the correlation of adjacent construction materials is greater than or equal to 0.6 can the constraint condition be passed; Step 6: Genetic algorithm optimization of the set matching scheme: perform iterative optimization based on the genetic algorithm to select the optimal set matching scheme that meets the set matching constraint conditions; Step 7: Execution and database update: According to the optimal distribution plan, the construction materials are transported to the distribution station and the distribution station database information is updated.

2. The method for optimizing the distribution of marine engineering construction materials according to claim 1, characterized in that: Step 1 includes: parsing the distribution station drawings, and forming a marine engineering distribution station database based on the distribution station's spatial location, distribution type, distribution conditions, and resource status information.

3. The method for optimizing the distribution of marine engineering construction materials according to claim 2, characterized in that: Step 2 includes: integrating procurement documents, production plan documents and waste recycling documents, compiling a list of construction materials to be assembled, obtaining construction material attributes, assembly specifications and additional requirements, and forming a database of construction materials to be assembled.

4. The method for optimizing the distribution of marine engineering construction materials according to claim 3 is characterized in that: The distribution station is divided into an integrated offshore spare parts warehouse, an offshore material distribution yard, a coating oil storage warehouse, an offshore hazardous waste treatment warehouse and an offshore solid waste temporary storage yard; Step 3 The preliminary distribution station is divided into: 。 5. The method for optimizing the distribution of marine engineering construction materials according to claim 4, characterized in that: Step 4: Prioritize the location allocation by evaluating the location allocation priority index have to: Evaluation index of storage location allocation priority The calculation formula is as follows: ； and ; Where: It is a construction material The evaluation index of the priority of storage location allocation; To divert construction materials to a certain distribution station; The project uses construction materials The earliest time; It is the latest time when all the construction materials to be collected and distributed at the distribution station can be used; The remaining construction materials in the distribution station the number of It is the construction material needed for the project the number of It is the construction material from the previous quarter. Number of entries and exits; The number of times all construction materials entered and exited the distribution station in the previous quarter; It is a construction material The value of It is the total value of all the construction materials to be collected and distributed at the distribution station; The weight of the use time of the distribution station; is the weight of the inventory ratio of the distribution station; is the weight of the flow frequency of the distribution station; It is the weight of the construction material value of the distribution station.

6. The method for optimizing the distribution of marine engineering construction materials according to claim 5, characterized in that: Object a is any one of a stack, a pallet, a construction material, or an article; object b is any one of a stack, a pallet, a lamp, a wall, a floor, a flat roof, a column, or an edge of a loadable area; standard safety distance variables The values ​​of are as follows, in meters: 。 7. The method for optimizing the distribution of marine engineering construction materials according to claim 5, characterized in that: Step 6 includes the following steps: Step 6.1, generating an initial population according to the initial parameters of the genetic algorithm; Step 6.2, enter the genetic algorithm iterative optimization; Step 6.3, pass out the population of this generation and calculate the individual fitness; Step 6.4, arrange construction materials; Step 6.4.1, input construction material information and distribution station diversion situation; Step 6.4.2, select the direction of construction material layout, and start vertical or horizontal layout; Step 6.4.3, after the preliminary arrangement, evaluate whether the distribution plan meets all constraints; if so, proceed to step 6.4.4; if not, move the construction materials and rearrange them. The rearrangement allows the change of storage location, distance and arrangement direction; when the arranged construction materials meet all constraints, proceed to step 6.4.4; Step 6.4.4, write the coordinates and information of the construction materials into the database; Step 6.4.5, determine whether the construction materials can be stacked; if yes, proceed to step 6.4.6; if no, proceed directly to step 6.4.9; Step 6.4.6, arrange the stacking of construction materials according to the requirements of the stacking of construction materials and the restrictions on the storage location and stacking height; Step 6.4.7, determine again whether the constraints are met; if so, proceed to step 6.4.8; if not, exit the stacking arrangement and proceed to step 6.4.9; Step 6.4.8, complete the stacking arrangement and update the construction material information; Step 6.4.9, start the plug-in arrangement; Step 6.4.10, increase the spacing along the layout direction to obtain the new coordinates of the construction materials; Step 6.4.11, determine whether all constraints are met; if so, proceed to step 6.4.12; if not, exit the plug-in arrangement and then proceed to step 6.4.13; Step 6.4.12, complete the plug-in arrangement and update the construction material information; Step 6.4.13, determine whether there are similar unarranged construction materials. If so, return to step 6.4.2 to arrange the construction materials. If not, proceed to step 6.4.14; Step 6.4.14, complete the layout of this type of construction materials and update the construction material information; Step 6.4.15, determine whether there are any unarranged construction materials. If so, select the next priority construction material for arrangement and return to step 6.4.2; if not, proceed to step 6.4.16; Step 6.4.16, complete the material layout of the distribution station; Step 6.5, obtaining the current generation layout plan; Step 6.6, determine whether the iteration termination condition is met; if the iteration termination condition is not met, proceed to step 6.6.1; If the iteration termination condition is reached, go to step 6.7; Step 6.6.1, compare the space utilization rate, adjacent construction material correlation, and collection efficiency of the individuals, determine the best and worst individuals of this generation, and add the worst layout plan to the taboo table; Step 6.6.2, generate the next generation population; Step 6.6.3, compare the taboo table. If the new generation population has a record in the taboo table, regenerate the population; compare the regenerated population with the bad solution in the taboo table. If they are the same, regenerate; if they are different, go to step 6.3; Step 6.7, end the genetic algorithm and output the optimal set matching solution.

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