Ship steel plate storage yard warehousing operation planning method considering preprocessing time

Abstract

The invention provides a ship steel plate storage yard warehousing operation planning method considering preprocessing time. The ship steel plate storage yard warehousing operation planning method comprises the steps that the warehousing sequence of steel plates and the preprocessing time of the warehousing steel plates are collected, grouping is conducted according to the manufacturing date of segments where the steel plates are located, parameters of a storage yard are determined, and the moving time of a traveling crane between different stacking positions is determined; through a heuristic algorithm, an initial warehousing sequence and a plate turning result of the steel plates are determined; setting a pheromone matrix value of the ant colony and the weight of a pheromone value and a heuristic value, and carrying out iteration by adopting an ant colony algorithm to obtain a steel plate warehousing operation scheme of each stage; determining a plate turning result of the warehousing operation scheme obtained during each iteration, and updating the optimal warehousing operation scheme, the pheromone matrix and the weight of the pheromone value and the heuristic value; and judging whether a stopping condition of the method is reached. According to the method, pretreatment time information of the steel plates is fully considered, and the number of plate turning times during warehouse-out is reduced by reasonably planning the warehouse-in storage stacking positions of the steel plates.

Description

Technical Field

[0001] The present invention relates to the technical field of steel plate storage, and in particular to a method for planning ship steel plate storage yard storage operations taking preprocessing time into consideration. Background Art

[0002] For the shipbuilding industry, steel plates are the most important raw material for shipbuilding. There are a large number of steel plates in the shipyard, so the extraction and transportation of steel plates has become a major constraint on the shipyard's shipbuilding capacity. Warehousing is the first link in shipbuilding, and the warehousing operation process directly determines the position of the steel plates in the yard. The position of the steel plates in the yard determines the number of times these steel plates are turned over when they are out of the warehouse, affecting the supply of steel plates and thus the subsequent production of ships. Therefore, steel plate logistics is the first and most important link in ship logistics. Steel plates come from multiple external suppliers of the shipyard, so multiple batches of steel plates need to be warehoused at the same time when entering the warehouse. Steel plates need to be pre-processed and cut before they can be processed into sections, and then form the total section of the ship. However, the warehousing time and out-of-warehouse time of steel plates are affected by factors such as external supply chain, internal production fluctuations of shipyards, and rework. There is great uncertainty in the out-of-warehouse and warehousing time of steel plates.

[0003] In the early stages of the industry, the steel plate warehousing, material sorting, plate turning and extraction processes in shipyards were mostly completed by manual experience due to the lack of information and intelligent means. However, faced with such a huge workload and information, it is difficult for workers' historical experience to obtain the most reasonable operation plan, resulting in low efficiency in the steel plate outbound process. When manually and using simple rules to handle warehousing operations, it is impossible to consider the impact of steel plate warehousing on subsequent outbound operations, resulting in an increase in the number of plate turning during outbound operations and low outbound efficiency. Therefore, in order to overcome the long-term reliance of workers' historical experience on warehousing operations in existing shipyards for steel plate yards, resulting in high costs, low efficiency, poor results and many other problems during outbound operations, it is necessary to provide a method for generating intelligent warehousing plans using computers. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a method for planning the warehousing operations of ship steel plates in a yard taking into account the pretreatment time. The method of the present invention fully considers the information such as the outbound time and pretreatment time of the steel plates, and reduces the number of plate flipping times when leaving the warehouse by reasonably planning the storage locations of the steel plates entering the warehouse.

[0005] To solve the above problems, the technical solution of the present invention is:

[0006] A method for planning ship steel plate storage yard warehousing operations taking into account preprocessing time comprises the following steps:

[0007] Collect the order of steel plates entering the warehouse and the pre-processing time of the steel plates entering the warehouse, group them according to the manufacturing date of the section where the steel plates are located, determine the parameters of the yard, and determine the moving time of the driving vehicle between different stacking positions;

[0008] The initial storage order and plate turning result of steel plates are determined by heuristic algorithm;

[0009] The pheromone matrix value of the ant colony and the weights of the pheromone value and the heuristic value are set, and the ant colony algorithm is used to iteratively obtain the steel plate storage operation plan for each stage;

[0010] Determine the flipping result of the warehousing operation plan obtained in each iteration, and update the optimal warehousing operation plan, pheromone matrix, and weights of pheromone values ​​and heuristic values;

[0011] Determine whether the method's stop condition has been reached.

[0012] Preferably, the steps of collecting the storage order of steel plates and the preprocessing time of the steel plates entering the warehouse, grouping them according to the manufacturing date of the segment where the steel plates are located, determining the parameters of the yard, and determining the moving time of the crane between different stacking positions specifically include: for the sorting of steel plates, first obtaining the serial number of each incoming steel plate and the segment information corresponding to each steel plate from the arrival list, and finding the manufacturing date of the segment where the steel plate is located from the schedule plan, so as to determine the approximate outgoing time of each incoming steel plate, and according to the approximate outgoing time of the steel plates, grouping the steel plates out of the warehouse on the same day into the same group, and sorting the groups according to the outgoing time, defining the group with the earliest outgoing as the first group, the group with the second earliest outgoing as the second group, and so on; determining the parameters of the yard, including the number of stacking positions in the yard, and the capacity of steel plates that can be stored in each stacking position; determining the moving parameters of the crane, including the time between storing the incoming steel plates in different stacking positions and the turning time between different stacking positions.

[0013] Preferably, the step of determining the initial storage order and the turning result of the steel plates by a heuristic algorithm specifically includes: using a heuristic algorithm to determine the storage stack of the stored steel plates, starting from the first stack, if it is blank, store it in the stack; if the steel plates on the stack are full, store them in the next stack, and so on.

[0014] Preferably, the pheromone matrix value of the ant colony and the weights of the pheromone value and the heuristic value are set, and an ant colony algorithm is used to iteratively obtain the steel plate warehousing operation plan for each stage, specifically including: establishing a feasible set of flipping operations, calculating the heuristic value of each flipping movement through heuristic rules, combining the heuristic value and the pheromone matrix value and determining the storage stack position in the form of roulette.

[0015] Preferably, in the step of determining the flipping result of the warehousing operation plan obtained in each iteration and updating the optimal warehousing operation plan, the pheromone matrix, and the weights of the pheromone value and the heuristic value, for the update of the pheromone matrix value, for each ant i, the pheromone reward value of each flipping action is calculated according to the following formula:

[0016]

[0017] where f i represents the estimated number of flips of ant i, λ is the correction value to ensure that the reward value is not too large or too small, is the set of flipping actions that a single ant walks through; get the pheromone reward value of a single ant After that, the pheromone matrix is ​​updated according to the following formula:

[0018]

[0019] Where A is the number of ant colonies, ρ is the weight decay value; the update method of pheromone value weight α and heuristic value weight β is:

[0020]

[0021] α=1-β

[0022] Where t is the number of iterations and MAX_ITER is the maximum iteration value.

[0023] Preferably, in the step of determining whether the stopping condition of the method is reached, a maximum number of iterations is set as the stopping condition of the method.

[0024] Preferably, in the step of determining whether the stop condition of the method is met, if the stop condition of the method is met, the determined steel plate warehousing sequence and storage plan are expressed in a standardized semantic model as system output.

[0025] Compared with the prior art, the present invention proposes an ant colony algorithm-based optimization scheme for steel plate warehousing operations. The method of the present invention fully considers the steel plate's outbound time, preprocessing time and other information, and reduces the number of steel plate flipping times when leaving the warehouse by reasonably planning the steel plate's inbound storage locations and the flipping of in-warehouse steel plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 This is a flowchart of a method for planning ship steel plate storage yard warehousing operations taking pre-processing time into consideration according to the present invention;

[0028] Figure 2 A flowchart of a method for generating initial warehousing operations for steel plates based on a heuristic algorithm;

[0029] Figure 3 Schematic diagram of the method for determining the blocking plate;

[0030] Figure 4 Generate a method flow chart for a single iteration of the warehousing operation plan. DETAILED DESCRIPTION

[0031] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0032] Specifically, the present invention provides a method for planning the storage operation of ship steel plates in a yard taking into account the pre-processing time, such as Figure 1 As shown, the method comprises the following steps:

[0033] S1: Collect the order of steel plates entering the warehouse and the pre-processing time of the steel plates entering the warehouse, group the steel plates according to the manufacturing date of the segment they are in, determine the parameters of the yard, and determine the moving time of the driving vehicle between different stacking positions;

[0034] Specifically, for the sorting of steel plates, first obtain the number of each incoming steel plate and the corresponding segment information of each steel plate from the arrival list, and find the manufacturing date of the segment where the steel plate is located from the schedule plan, so as to determine the approximate outbound time of each incoming steel plate. According to the approximate outbound time of the steel plates, the steel plates outbound on the same day are grouped in the same group, and the groups are sorted according to the outbound time. The group with the earliest outbound is defined as the first group, the group with the second earliest outbound is defined as the second group, and so on.

[0035] Determine the parameters of the yard, including the number of stacks in the yard and the capacity of steel plates that can be stored in each stack. Determine the movement parameters of the crane, including the time between storing the incoming steel plates in different stacks and the time between turning over the plates in different stacks.

[0036] S2: Determine the initial storage order and plate turnover result of the steel plates through a heuristic algorithm;

[0037] Specifically, Figure 2 As shown in the figure, the heuristic algorithm is first used to determine the storage location of the incoming steel plates, starting from the first location, if there is a vacancy, it is stored in this location. If the steel plates on this location are full, they are stored in the next location, and so on.

[0038] Furthermore, the number of blocking plates is used as an estimate of the number of outbound flip plates. Figure 3 As shown in the figure, if there is a steel plate with an earlier delivery time under a stack position, the plate is a blocking plate.

[0039] S3: Set the pheromone matrix value of the ant colony and the weights of the pheromone value and the heuristic value, and use the ant colony algorithm to iteratively obtain the steel plate storage operation plan for each stage;

[0040] Specifically, pheromone τ is an S×S matrix, and each value in the matrix is ​​initialized to 1. The weight of the pheromone value is set to α, and the weight of the heuristic value is set to β. At the initial moment, α=0.1 and β=0.9.

[0041] A single iteration process is as follows Figure 4 As shown, assume that a = (s1, s2) represents the flipping action of moving the top steel plate of stack s1 to stack s2. First, the probability p of flipping action a is determined by the following formula: a .

[0042]

[0043] Where τ(a) represents the pheromone value of flip action a, is the inspiration value of flip action a. The calculation method of is as follows:

[0044] If the steel plate being moved was a blocking plate before being moved and is still a blocking plate after being moved to the new stacking position, then The value is calculated as follows:

[0045]

[0046] Where G is the number of groups, is the minimum grouping of the steel plates stored in the stack s, g n is the grouping of steel plate n, is the number of steel plates grouped as g.

[0047] If the steel plate being moved is a blocking plate before being moved and becomes a non-blocking plate after being moved to the new stacking position, then The value is calculated as follows:

[0048]

[0049] Where ε is a constant. If the steel plate being moved is a non-blocking plate before and after the movement, then The value is calculated as follows:

[0050]

[0051] If the steel plate being moved is a non-blocking plate before it is moved and becomes a blocking plate after it is moved, then The value is calculated as follows:

[0052]

[0053] Determine the probability p of completing the flip action a a After that, the next step is to select the flipping action in the roulette way to determine whether the action is feasible.

[0054] The selected flipping action (s1, s2) needs to meet the following two conditions at the same time:

[0055] (1)

[0056] (2)

[0057] If the selected flipping action does not meet the above conditions, you need to select a flipping action again in the roulette way.

[0058] After the plate flipping action is determined, the next step is to move the top steel plate of stack s1 to stack s2 in the yard. After completion, it is necessary to determine whether there are steel plates that can be put into storage. If yes, it is necessary to select the storage stack for the steel plates to be put into storage. Assume that the steel plates to be put into storage are n, g n For each candidate stack s, first determine whether it has an empty layer. If so, determine the probability of storing the steel plate μ(s) according to the following formula:

[0059]

[0060] The stacking position with the largest μ(s) is selected first for storage. After completion, the above plate turning and storage operations are continued until all steel plates are stored.

[0061] S4: Determine the flipping result of the warehousing operation plan obtained in each iteration, and update the optimal warehousing operation plan, the pheromone matrix, and the weights of the pheromone value and the heuristic value;

[0062] Specifically, for each ant's storage operation plan, the number of blocking plates is calculated as the estimated value of the number of flipping plates according to the method proposed in step S2. If the number of blocking plates obtained by an ant's operation plan is less than the optimal result, the optimal result is updated.

[0063] For the update of the pheromone matrix value, for each ant i, the pheromone reward value of each flipping action is calculated according to the following formula:

[0064]

[0065] where fi represents the estimated number of flips of ant i, λ is the correction value to ensure that the reward value is not too large or too small, is the set of flipping actions that a single ant walks through. Get the pheromone reward value of a single ant After that, the next step is to update the pheromone matrix according to the following formula:

[0066]

[0067] Where A is the number of ant colonies, and ρ is the weight decay value. The update method of pheromone value weight α and heuristic value weight β is as follows:

[0068]

[0069] α=1-β

[0070] Where t is the number of iterations and MAX_ITER is the maximum iteration value.

[0071] S5: Determine whether the stop condition of the method is reached;

[0072] Specifically, if the number of iterations t = MAX_ITER, the algorithm stops; otherwise, the iterative calculation continues to obtain the steel plate storage operation plan for each stage, and the maximum number of iterations is set as the stopping condition of the algorithm.

[0073] If the stop condition of the method is reached, the yard warehousing operation plan determined by the method is output according to specific rules, that is, the determined steel plate warehousing order and storage plan are expressed in a standardized semantic model as the system output. For example, the steel plate number and the stack number are used as the basic semantic units to establish a semantic model for the steel plate warehousing plan. The steel plate warehousing statement = <operation sequence number, steel plate number, removal stack number, storage stack number>, thereby forming a steel plate outbound operation plan including steel plate extraction and flipping operations. Among them, if the steel plate is put into storage, the removal stack number is -1.

[0074] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for planning ship steel plate storage yard warehousing operations considering pre-processing time, characterized in that: The method comprises the following steps: Collect the order of steel plates entering the warehouse and the pre-processing time of the steel plates entering the warehouse, group them according to the manufacturing date of the section where the steel plates are located, determine the parameters of the yard, and determine the moving time of the driving vehicle between different stacking positions; The initial storage order and plate turning result of steel plates are determined by heuristic algorithm; The pheromone matrix value of the ant colony and the weights of the pheromone value and the heuristic value are set, and the ant colony algorithm is used to iteratively obtain the steel plate storage operation plan for each stage; Determine the flipping result of the warehousing operation plan obtained in each iteration, and update the optimal warehousing operation plan, pheromone matrix, and weights of pheromone values ​​and heuristic values; Determine whether the method's stop condition has been reached.

2. The method for planning ship steel plate storage yard warehousing operation considering pre-processing time according to claim 1 is characterized in that: The steps of collecting the storage order of steel plates and the preprocessing time of the steel plates entering the warehouse, grouping the steel plates according to the manufacturing date of the segment where the steel plates are located, determining the parameters of the yard, and determining the moving time of the crane between different stacking positions specifically include: for the sorting of steel plates, first obtaining the number of each incoming steel plate and the segment information corresponding to each steel plate from the arrival list, and finding the manufacturing date of the segment where the steel plate is located from the schedule plan, so as to determine the approximate outgoing time of each incoming steel plate, and according to the approximate outgoing time of the steel plates, grouping the steel plates outgoing on the same day into the same group, and sorting the groups according to the outgoing time, defining the group with the earliest outgoing as the first group, the group with the second earliest outgoing as the second group, and so on; determining the parameters of the yard, including the number of stacking positions in the yard, and the capacity of steel plates that can be stored in each stacking position; determining the moving parameters of the crane, including the time between storing the incoming steel plates in different stacking positions and the turning time between different stacking positions.

3. The method for planning ship steel plate storage yard warehousing operation considering pre-processing time according to claim 1 is characterized in that: The steps of determining the initial storage order and the turning result of the steel plates by the heuristic algorithm specifically include: using the heuristic algorithm to determine the storage stack of the stored steel plates, starting from the first stack, if there is a blank, store it in the stack; if the steel plates on the stack are full, store them in the next stack, and so on.

4. The method for planning ship steel plate storage yard warehousing operation considering pre-processing time according to claim 1 is characterized in that: The pheromone matrix value of the ant colony and the weights of the pheromone value and the heuristic value are set, and the ant colony algorithm is used to iteratively obtain the steel plate warehousing operation plan for each stage, which specifically includes: establishing a feasible set of flipping operations, calculating the heuristic value of each flipping movement through heuristic rules, combining the heuristic value and the pheromone matrix value and determining the storage stack position in the form of roulette.

5. The method for planning ship steel plate storage yard warehousing operation considering pre-processing time according to claim 1 is characterized in that: In the step of determining the flipping result of the warehousing operation plan obtained in each iteration, and updating the optimal warehousing operation plan, the pheromone matrix, and the weights of the pheromone value and the heuristic value, for the update of the pheromone matrix value, for each ant i, the pheromone reward value of each flipping action is calculated according to the following formula: Where f represents the estimated number of flips of ant i, and λ is the correction value to ensure that the reward value is not too large or too small. is the set of flipping actions that a single ant walks through; get the pheromone reward value of a single ant After that, the pheromone matrix is ​​updated according to the following formula: Where A is the number of ant colonies, ρ is the weight decay value; the update method of pheromone value weight α and heuristic value weight β is: Where t is the number of iterations and MAX_ITER is the maximum iteration value.

6. The method for planning ship steel plate storage yard warehousing operation considering pre-processing time according to claim 1 is characterized in that: In the step of determining whether the stop condition of the method is reached, a maximum number of iterations is set as the stop condition of the method.

7. The method for planning ship steel plate storage yard warehousing operation considering pre-processing time according to claim 1 is characterized in that: In the step of determining whether the stop condition of the method is met, if the stop condition of the method is met, the determined steel plate warehousing sequence and storage plan are expressed in a standardized semantic model as system output.

Images