A method for discharging a shipyard steel plate stockyard

Abstract

The application discloses a discharging method for a shipyard steel plate stockyard, which comprises the following steps: S1: taking a steel plate stock amount as a source node, taking a discharging plan as a target node, checking whether there is a path directly reaching the target node in multiple information element constraints, directly generating the discharging plan if there is the path, and starting node selection and releasing a forward ant if there is not the path; S2: starting from the source node production plan, and the forward ant randomly selects a next node according to a multiple information element constraint table; S3: adding information and path information of the node into forward ant information; S4: the forward ant selects its next node according to a state conversion probability; S5: judging whether the node is the target node discharging plan, returning to S3 if the node is not the target node discharging plan, and directly generating the discharging plan if the node is the target node discharging plan; wherein the multiple information element constraint table comprises a production plan node, a processing line capacity node and a feeding node; and the application has the advantages of reducing steel plate residence time and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shipyard steel plate discharging method, and particularly relates to a discharging method for a shipyard steel plate yard. BACKGROUND

[0002] Steel plate is the main raw material of ship products, and a ship has several thousand tons to tens of thousands of tons of steel plate, and the purchasing cost usually accounts for 30-40% of the ship product purchasing cost. The types of the steel plate mainly include medium-thick steel plate, flat steel, bulb flat steel, equal-leg angle steel, unequal-leg angle steel, round steel and the like.

[0003] Due to the low overall level of logistics supply in China, the steel plate yard becomes an indispensable part of the shipyard production link, and it is the site for feeding, classifying and storing, and supplying the raw materials of the steel plate in the entire shipyard, and is the source of the logistics and information flow of the entire assembly production system. In order to ensure the use of the steel plate raw material, the shipyard purchases the steel plate in advance and stores it in the steel plate yard. However, most domestic shipyards do not have scientific planning for the steel plate yard, and the storage and management of the incoming steel plate need to be improved. Some steel plates are stored in the steel plate warehouse for too long, and the number of times of hoisting and taking the specified steel plate is large, so that time and labor are consumed, and the shipyard funds are stranded and the construction cost is increased.

[0004] Therefore, the present application provides a discharging method for a shipyard steel plate yard, which can solve the above problems. SUMMARY

[0005] The technical problem to be solved by the present application is that domestic shipyards do not have scientific planning for the steel plate yard, and some steel plates are stored in the steel plate warehouse for too long, and the number of times of hoisting and taking the specified steel plate is large, so that time and labor are consumed, and the shipyard funds are stranded and the construction cost is increased. Therefore, the present application provides a discharging method for a shipyard steel plate yard, which comprises:

[0006] S1: taking the steel plate storage amount as a source node, taking the discharging plan as a target node, checking whether there is a path directly reaching the target node in the multiple information element constraints, if yes, directly generating the discharging plan, and if no, starting node selection and releasing the forward ant;

[0007] S2: starting from the source node production plan, the forward ant randomly selects the next node according to the multiple information element constraint table;

[0008] S3: adding the information and path information of the node to the forward ant information;

[0009] S4: the forward ant selects its next node according to the state transition probability;

[0010] S5: judging whether the node is a target node of the discharge plan, if not, returning to S3, if yes, directly generating the discharge plan;

[0011] The multiple information element constraint table includes a production plan node, a processing line capacity node, and a feeding node.

[0012] Further, the S4 and the S5 further include:

[0013] judging whether the node is a feeding node, if yes, returning to S1, if not, entering S5.

[0014] Further, the state transition probability formula is:

[0015]

[0016] wherein, is a state transition probability of a forward ant k in the process from the node i to the node j, allowedx is a next selectable node of the forward ant k, and α and β are information heuristic factors and expected heuristic factors respectively, is a pheromone value on the path from the node i to the node j, is heuristic information of the path from the node i to the node j.

[0017] Further, the production plan node includes a first constraint condition and a second constraint condition, the first constraint condition is a weekly plan, and the second constraint condition is a weekly plan.

[0018] Further, the processing line capacity node includes a constraint condition of a steel plate discharge upper roller, a constraint condition of a steel plate discharge upper roller, a constraint condition of a steel plate dischargeable, and a capacity constraint condition.

[0019] Further, the constraint condition of the steel plate discharge upper roller is:

[0020] According to the priority principle, the steel plates are discharged together, and a plurality of virtual stalls are provided;

[0021] The materials of the two pretreatment lines are placed on different virtual stalls.

[0022] Further, the capacity constraint condition includes:

[0023] The specific time and the plate number of each cross trolley that has been fed and the plan that has not been implemented are collected;

[0024] The cutting capacity of each processing team;

[0025] The processing capacity of each pretreatment line and pretreatment.

[0026] Further, the constraint sequence in each constraint condition is sequentially constrained to the target value.

[0027] The present application has the following advantages:

[0028] 1. The method provided by the present application defines the constraints, reduces the risk of premature accumulation of resources and premature collection of algorithms, and can effectively balance the capacity of the steel plate yard, providing an effective method for daily discharge of the steel plate yard. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a flowchart of the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. EMBODIMENT

[0031] Please refer to the drawings in the description Figure 1 The technical problem to be solved in the present embodiment is that domestic shipyards do not plan the steel plate yard scientifically, and problems such as long residence time of part of the steel plates in the steel plate warehouse, multiple times of flipping the specified required steel plates to consume time and labor, etc. are easily caused in the process of discharging and stacking the steel plates. The discharge of the steel plate yard of the shipyard has the characteristics of complex constraints, dynamic randomness and multi-directionality.

[0032] Complex constraints: the discharge plan as an important link of the steel plate yard management plays a role in connecting the execution of the production master plan and the feeding of the pretreatment line. The discharge plan algorithm is a theoretical optimal solution of performance indicators under multiple constraints of equations and inequalities.

[0033] Dynamic randomness: the discharge process of the steel plate yard is dynamic and may encounter multiple unexpected events such as concentrated unloading, equipment maintenance, production master plan change, etc. Therefore, the discharge plan algorithm is a flexible algorithm with a clear goal.

[0034] Multi-directionality: after pretreatment, different types of steel plates are sent to different processing lines for secondary treatment, and each processing line has its own capacity range. Therefore, the discharge plan algorithm is a kind of genetic algorithm similar to multiple scheduling.

[0035] Considering the above research focuses, a discharge method for the steel plate yard of the shipyard is provided.

[0036] S1: taking the steel plate stock amount as a source node, taking the discharge plan as a target node, checking whether there is a path directly reaching the target node in multiple information element constraints, if yes, directly generating the discharge plan, if no, starting node selection, releasing the forward ant;

[0037] S2: starting from the source node production plan, the forward ant randomly selects the next node according to the multiple information element constraint table;

[0038] S3: adding the information and path information of the node to the forward ant information;

[0039] S4: the forward ant selects its next node according to the state transition probability;

[0040] S5: judging whether the node is the target node discharge plan, if no, returning to S3, if yes, directly generating the discharge plan;

[0041] The multiple information element constraint table includes the production plan node, the processing line capacity node and the feeding node.

[0042] Between S4 and S5, there are also:

[0043] Judging whether the node is the feeding node, if yes, returning to S1, if no, entering S5.

[0044] The state transition probability formula is:

[0045]

[0046] Among them, is the state transition probability of the forward ant k in the process from node i to node j, allowedx is the next selectable node of the forward ant k, and α and β are information heuristic factor and expected heuristic factor respectively, is the pheromone value on the path from node i to node j, its evolution formula is determined by the evaporation coefficient and the pheromone change value after the last cycle , that is , the evaporation coefficient is a constant, and the value of the path ij is determined by the system constant Q and the total distance of the ant in the last cycle, so the shorter the total distance, the greater the value, that is , is the heuristic information of the path from node i to node j.

[0047] The production plan node includes a first constraint condition and a second constraint condition, the first constraint condition is a ten-day plan, and the second constraint condition is a weekly plan, and the proportion weight of the first constraint condition is much larger than that of the second constraint condition.

[0048] The processing line capacity node includes a constraint condition of a steel plate discharging upper roller, a constraint condition of the steel plate discharging upper roller, a constraint condition of the steel plate discharging, and a capacity constraint condition.

[0049] The constraint condition of the steel plate discharging upper roller is:

[0050] The steel plates are discharged according to the priority principle, and a plurality of virtual stalls are arranged, and the priority principle mainly includes setting a weight for different production plans, and the steel plates are discharged preferentially according to the production plan with a high weight.

[0051] The materials of the two pretreatment lines are placed on different virtual stalls.

[0052] The capacity constraint condition includes:

[0053] The specific time and the plate number of each cross trolley that has been fed and the plan that has not been implemented are collected.

[0054] The cutting capacity of each processing team;

[0055] The processing capacity of each pretreatment line and pretreatment.

[0056] The constraint sequence in each constraint condition is sequentially constrained to the target value.

[0057] The multiple constraint conditions are used for multiple objective programming, and the multiple objective programming refers to a programming problem containing multiple objective functions. In mathematics, the multiple objective programming method can be written in the following form:

[0058]

[0059] Where k≥2, which refers to the number of objective functions, and the set X is a set of feasible decision vectors. The feasible set is usually defined by some constraint functions. In addition, the vector-valued objective function is usually defined as:

[0060] .

[0061] Elements are called feasible solutions or feasible decisions. The vector obtained by the feasible solution x* is the objective vector.

[0062] In multiple objective optimization, there is usually no feasible solution that minimizes all objective functions at the same time. Therefore, attention should be paid to the Pareto optimal solution, that is, a solution that cannot be improved in any objective without impairing at least one objective.

[0063] In the description of the application, it is to be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inner", "front", "central", "both ends" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0064] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "setting", "connecting", "fixing", "screwed" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrated; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited, the above-mentioned terms in the present application can be understood according to the specific meaning in the specific circumstances by those skilled in the art.

[0065] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for unloading steel plates from a shipyard's steel plate stockpile, characterized in that, include: S1: Take the steel plate stack quantity as the source node and the material output plan as the target node. Check whether there is a path that directly reaches the target node in the multiple information element constraints. If there is, generate the material output plan directly. If not, start node selection and release the forward ants. S2: Starting from the production plan of the source node, the forward ants randomly select the next node based on the multi-information element constraint table; S3: Add the node information and path information to the forward ant information; S4: The forward ant selects its next node based on the state transition probability; S5: Determine if the node is a feeding node. If yes, return to S1; otherwise, proceed to S6. S6: Determine if the node is the target node's output plan. If not, return to S3. If yes, directly generate the output plan. The multi-information element constraint table includes production planning nodes, processing line capacity nodes, and material feeding nodes; The state transition probability formula is: in, Let be the state transition probability of the forward ant k from node i to node j, let allowedx be the next selectable node for the forward ant k, and α and β be the information heuristic factor and the expectation heuristic factor, respectively. Let be the pheromone value along the path from node i to node j. Provide heuristic information for the path from node i to node j.

2. The unloading method for steel plate stockpiles in shipyards according to claim 1, characterized in that, The production planning nodes include a first constraint and a second constraint. The first constraint is the ten-day plan, and the second constraint is the weekly plan.

3. The unloading method for steel plate stockpiles in shipyards according to claim 1, characterized in that, The processing line capacity nodes include constraints on the steel plate discharge roller conveyor, constraints on the steel plate discharge capability, and capacity constraints.

4. The unloading method for steel plate stockpiles in shipyards according to claim 3, characterized in that, The constraint conditions for the steel plate discharge roller conveyor are as follows: Materials are discharged together according to priority, and multiple virtual stalls are set up; The materials from the two pretreatment lines were placed on different virtual booths.

5. The unloading method for a shipyard steel plate stockpile according to claim 3, characterized in that, The capacity constraints include: Collect the specific time and number of plates that have been fed into each cross-cart, as well as the plans that have not yet been implemented; The cutting capabilities of each processing team; Each pretreatment line and its processing capacity.

6. The unloading method for a shipyard steel plate stockpile according to claim 4 or 5, characterized in that, The constraints within each constraint condition are applied to the target value sequentially.

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