CN105911982A - Piler scheduling path model establishment method based on distributed warehouse in/out layout mode - Google Patents

Abstract

The invention discloses a piler scheduling path model establishment method based on a distributed warehouse-in/out layout mode. The piler scheduling path model established through the piler scheduling path model establishment method uses the time needed by the piler to finish the task sequence as an evaluation standard, enables the improvement of universality of the piler scheduling model through completing the current piler SC/DC operation mode, and solves the problem that the current piler scheduling model cannot satisfy the working condition of multiple warehouse in/out platforms. The piler scheduling path model establishment method can satisfy the practical working condition requirement of 'multiple warehouse out/in platforms'. Meanwhile, the single warehouse out/in platform is a special case of the multiple-warehouse-out/in-platform layout. During the process of performing optimization and solving on the piler scheduling path, the piler scheduling path model establishment method adopts a genetic algorithm and solves the problem that the current optimization method cannot completely show the relevant information between the goods locations and the warehouse out/in platforms through combined encoding of the good locations and the warehouse out/in platforms.

Description

Stacking machine scheduling path model establishing method based on distributed warehouse-out/warehouse-in layout mode

Technical Field

The invention belongs to the field of stacker scheduling path model establishment in the field of automatic stereoscopic warehouse scheduling, and particularly relates to a method for establishing a stacker scheduling path model based on a distributed warehouse-out/warehouse-in layout mode.

Background

The scheduling of the pilers, also called the sorting operation scheduling of the pilers, is a core part of the scheduling problem of the stereoscopic warehouse. The existing stacker scheduling model is generally established based on an automatic stereoscopic warehouse layout mode in a centralized warehouse-out/warehousing form, and the stereoscopic warehouse layout structure is characterized in that the number of warehouse-out/warehousing platforms of the same shelf is unique. When the existing stacker scheduling model is adopted to solve the problem of automatic stereoscopic warehouse stacker scheduling in a distributed warehouse-out/warehousing mode, the problem of automatic stereoscopic warehouse stacker scheduling in the distributed warehouse-out/warehousing mode cannot be solved because the 'stacker SC/DC operation mode' in the existing model cannot meet the actual working conditions of multiple warehouse-out/warehousing platforms.

Disclosure of Invention

Aiming at the defects or shortcomings in the prior art, the invention aims to provide a method for establishing a stacker dispatching path model based on a distributed warehouse-out/warehouse-in layout mode, wherein the stacker dispatching path model established by the method takes the time required by a stacker to complete a task sequence as an evaluation standard, and the stacker dispatching model is more universal by improving the SC/DC operation mode of the existing stacker, so that the problem that the existing stacker dispatching model cannot meet the working conditions of a warehouse-out/warehouse-in platform is solved.

In order to realize the task, the invention adopts the following technical scheme:

1. a method for establishing a stacker dispatching path model based on a distributed warehouse-out/warehouse-in layout mode is characterized by comprising the following steps:

when the stacker operates, the movement in the horizontal and vertical directions starts at the same time, and the operation time of finishing one warehouse-in/out instruction by the stacker depends on the maximum value of the operation time in the horizontal and vertical directions;

in the goods shelf, the length of the goods position is set to be l, the height of the goods position is set to be h, and the horizontal running speed of the stacker is set to be V_xVertical running speed V of stacker_yThen the stacker goes from a certain position [ i, j ]]Move to a specified position [ u, w ]]The required time is as follows:

t＝max(|i-u|t_x,|j-w|t_y) (1)

wherein, t_xWhen the stacker passes through a goods space, the time length required by the movement in the horizontal direction is as follows: t is t_x＝l/V_x；

t_yWhen the stacker passes through a goods space, the movement in the vertical direction needs a long time: t is t_y＝h/V_y；

The automatic stereoscopic warehouse in/out operation in the distributed in/out mode has the following characteristics:

(1) there are m warehousing tasks, which are represented in the task sequence as:

(2) there are n ex-warehouse tasks, which are represented in the task sequence as:

wherein:

indicating the goods position address of goods required to be stored by the stacker in the ith task and the address of a warehousing platform of the goods in the warehousing task sequence;

showing the goods position address of the goods which are required to be taken out by the stacker in the jth task and the address of the delivery platform of the goods in the delivery task sequence;

based on the above-mentioned out/in-storage operation characteristics, the SC/DC operation mode of the automatic stereoscopic warehouse stacker in the distributed out/in-storage layout mode is as follows:

(1) SC operation mode:

the SC operation mode is a single command operation mode, namely the stacker only completes one warehouse-out or warehouse-in task after one warehouse-in and warehouse-out operation; in the distributed layout mode, the SC operation mode of the stacker means: the stacker starts from an initial warehouse-in/out platform or a warehouse-in/out platform for unloading goods appointed by a last task, moves to an appointed goods position for loading goods, and then moves to the warehouse-in/out platform appointed by the goods for unloading the goods; or after a certain warehouse-in/out platform is loaded with goods, the stacker conveys the goods to a specified goods location to unload the goods, and then moves to the warehouse-in/out platform needing to load the goods in the next instruction;

therefore, when there are n task instructions in the SC operation mode, the total movement time of the stacker is:

$T_s=\underset{i=1}{\overset{n}{\Σ}}(T_{P_i}+T_{P_i{\mathrm{IO}}_{i+1}})+2{\mathrm{n\τ}}_{IO}---\left(2\right)$

wherein:

n is the number of tasks to be put in/out of the warehouse in the SC operation mode;

i is a sequence number of a certain exit/entry task instruction in the task sequence;

in the ith out-of-warehouse task instruction, the walking time of the stacker is the time length between the goods position of the goods to be stored/taken and the initial or appointed out-of-warehouse table;

starting the delivery/storage platform for the cargo position of the object to be stored/taken and the designated unloading or the next delivery taskThe walking time of the stacker is long;

τ_IOthe time length required by fork operation when the stacker carries out loading/unloading operation for one time;

(2) DC operation mode

The DC operation mode is a compound command operation mode, namely the stacker finishes one warehouse-in operation and one warehouse-out operation by one warehouse-in and warehouse-out operation; in the distributed layout mode, the DC operation mode of the stacker is as follows: the stacker moves to a specified warehouse-in/out platform to load goods to be warehoused, directly moves to the specified goods location of the warehouse-out task to load the goods to be warehoused after the goods are conveyed to the specified goods location, and then conveys the goods to the specified warehouse-in/out platform;

therefore, when there are n task instructions in the DC operation mode, the total movement time of the stacker is:

wherein n is the total number of DC operation mode instructions;

the movement time of the stacker between the goods position of the goods to be stored/taken and the corresponding warehouse-in/out platform is the time length;

the movement time of the stacker between the goods position of the goods put in storage and the goods position of the goods out of storage in the same DC command is the same;

in one DC command, the goods are put in or out of the warehouse corresponding to the warehouse-in platform and the goods are put in or out of the warehouse corresponding to the next DC commandThe movement duration of the stacker;

τ_IOthe time length required by fork operation when the stacker carries out loading/unloading operation for one time;

based on the SC/DC operation mode of the automatic stereoscopic warehouse stacker in the distributed warehouse-out/warehouse-in layout mode, the stacker scheduling path model is as follows:

$T=\underset{i=0}{\overset{Q_1-Q_2}{\Σ}}(T_{P_i}+T_{P_i{\mathrm{IO}}_{i+1}})+\underset{i=1}{\overset{2Q_2}{\Σ}}{T}_{P_i}+\underset{i=1}{\overset{Q_2}{\Σ}}{T}_{P_{2i-1}{P}_{2i}}+\underset{i=1}{\overset{Q_2-1}{\Σ}}{T}_{{\mathrm{IO}}_{2i}{\mathrm{IO}}_{2i+1}}+2(Q_1+Q_2){\mathrm{\τ}}_{IO}---\left(4\right)$

wherein:

n₁the number of warehousing operations;

n₂the number of ex-warehouse operations.

In actual working conditions, the number of tasks received by the stacker is large, so that in the formula (3), the movement time lengths of the stacker are greatly different due to different task sequences, and if the tasks are listed one by adopting an enumeration method, long time is consumed for operation; therefore, an intelligent optimization algorithm must be provided for solving the optimal solution of the model:

the optimal solution is calculated for the formula (3) by applying the global optimization characteristic of the genetic algorithm and adopting a goods space-warehouse-in/out table combined information coding mode, so that the optimal scheduling path of the stacker can be obtained more quickly and accurately;

the goods space-warehouse-out/warehouse-in table combined information code is expressed as follows:

$A=\left|\begin{array}{cccc}{a}_{1x}& a_{1y}& a_{1IOx}& a_1\\ a_{2x}& a_{2y}& a_{2IOx}& a_2\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ a_{ix}& a_{iy}& a_{iIOx}& a\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ a_{kx}& a_{ky}& a_{kIOx}& a\end{array}\right|---\left(5\right)$

wherein:

k is the number of warehouse-in/warehouse-out tasks;

a_ixand a_iyThe coordinates of the goods position corresponding to the goods in the ith task are obtained;

andcoordinates of an out/in warehouse table corresponding to goods in the ith task;

based on the above coding representation, the DC and SC job mode task sequences can be represented as:

D＝A_DI|A_D(6)

wherein:

d is a composite command job sequence generated according to the given task sequence A;

s is a single command operation sequence generated according to the given task sequence A;

A_DIand A_DORespectively as the warehousing and ex-warehousing sequences of the composite command sequence;

A_SIand A_SOA warehousing or warehousing sequence that can form a single command sequence;

and (4) calculating the optimal solution of the formula (4) by combining the coding modes of the formulas (5), (6) and (7) by using a genetic algorithm.

The method for establishing the stacker dispatching path model based on the distributed warehouse-out/warehouse-in layout mode overcomes the defects of the existing stacker dispatching path model, the established stacker dispatching path model suitable for the automatic stereoscopic warehouse in the distributed layout mode is applied to the engineering field (stacker dispatching) for the first time, and the actual working condition requirement of 'multiple warehouse-out/warehouse-in platforms' can be met by perfecting the SC/DC operation mode in the existing stacker dispatching model. Meanwhile, a single out/in bay layout is a special case of a multiple out/in bay layout.

When the stacker dispatching path is optimized and solved, a genetic algorithm is adopted, and the problem that the prior optimization method cannot completely express the associated information of the goods position and the warehouse-in/warehouse-out table is solved by using a mode of joint coding of the goods position and the warehouse-in/warehouse-out table.

Drawings

FIG. 1 is an exemplary diagram of a stacker working path in the SC working mode;

FIG. 2 is an exemplary illustration of a stacker work path in DC mode of operation;

fig. 3 is a stacker scheduling route diagram.

The present invention will be described in further detail with reference to the following drawings and examples.

Detailed Description

According to the technical scheme of the invention, the embodiment provides a method for establishing a stacker dispatching path model based on a distributed warehouse-in/warehouse-out layout mode, which specifically comprises the following steps:

when the stacker operates, the movement in the horizontal and vertical directions starts at the same time, and the operation time of finishing one warehouse-in/out instruction by the stacker depends on the maximum value of the operation time in the horizontal and vertical directions; in the goods shelf, the length of the goods position is set to be l, the height of the goods position is set to be h, and the horizontal running speed of the stacker is set to be V_xVertical running speed V of stacker_y. The stacker then moves from a certain position [ i, j ]]Move to a specified position [ u, w ]]The required time is as follows:

t＝max(|i-u|t_x,|j-w|t_y) (1)

wherein, t_xWhen the stacker passes through a goods space, the time length required by the movement in the horizontal direction is as follows: t is t_x＝l/V_x；

t_yWhen the stacker passes through a goods space, the movement in the vertical direction needs a long time: t is t_y＝h/V_y。

The automatic stereoscopic warehouse in/out operation in the distributed in/out mode has the following characteristics:

(1) there are m warehousing tasks, which are represented in the task sequence as:

(2) there are n ex-warehouse tasks, which are represented in the task sequence as:

wherein,indicating the goods position address of goods required to be stored by the stacker in the ith task and the address of a warehousing platform of the goods in the warehousing task sequence;

showing the goods position address of the goods which are required to be taken out by the stacker in the jth task and the address of the delivery platform of the goods in the delivery task sequence;

based on the above-mentioned out/in-storage operation characteristics, the SC/DC operation mode of the automatic stereoscopic warehouse stacker in the distributed out/in-storage layout mode is as follows:

(1) SC operation mode:

the SC operation mode is a single command operation mode, namely the stacker only finishes one warehouse-out or warehouse-in task after one warehouse-in and warehouse-out operation. In the distributed layout mode, the SC operation mode of the stacker means: the stacker starts from an initial warehouse-in/out platform or a warehouse-in/out platform for unloading goods appointed by a last task, moves to an appointed goods position for loading goods, and then moves to the warehouse-in/out platform appointed by the goods for unloading the goods; or after a certain warehouse-in/out platform loads the goods, the stacker conveys the goods to a specified goods location to unload the goods, and then moves to the warehouse-in/out platform needing to load the goods in the next instruction. Fig. 1 shows an example of a stacker working path in the SC working mode in the multi-entry/exit base mode.

Therefore, when there are n task instructions in the SC operation mode, the total movement time of the stacker is:

$T_s=\underset{i=1}{\overset{n}{\Σ}}(T_{P_i}+T_{P_i{\mathrm{IO}}_{i+1}})+2{\mathrm{n\τ}}_{IO}---\left(2\right)$

wherein: n is the number of tasks to be put in/out of the warehouse in the SC operation mode;

i is the sequence number of a certain out/in-storage task instruction in the task sequence;

in the ith out-of-warehouse task instruction, the walking time of the stacker is the time length between the goods position of the goods to be stored/taken and the initial or appointed out-of-warehouse table;

starting the time length of the stacker walking between the goods position of the goods to be stored/fetched and the appointed goods to be unloaded or the next delivery task and the delivery/storage platform;

τ_IOthe time required by fork operation is long when the stacker carries out loading/unloading operation once.

(2) DC operation mode

The DC operation mode is a compound command operation mode, namely the stacker finishes one warehouse-in operation and one warehouse-out operation by one warehouse-in and warehouse-out operation. In the distributed layout mode, the DC operation mode of the stacker is as follows: the stacker moves to a specified warehouse-in/out platform to load goods to be warehoused, directly moves to a specified goods position of a warehouse-out task to load the goods to be warehoused after the goods are conveyed to the specified goods position, and then conveys the goods to the specified warehouse-in/out platform. Fig. 2 shows an example of a stacker working path in the DC working method in the multi-entrance/exit station mode.

Therefore, when there are n task instructions in the DC operation mode, the total movement time of the stacker is:

$T_D=\underset{i=1}{\overset{2n}{\Σ}}{T}_{P_i}+\underset{i=1}{\overset{n}{\Σ}}{T}_{P_{2i-1}{P}_{2i}}+\underset{i=1}{\overset{n-1}{\Σ}}{T}_{{\mathrm{IO}}_{2i}{\mathrm{IO}}_{2i+1}}+4{\mathrm{n\τ}}_{IO}---\left(3\right)$

wherein: n is the total number of DC operation mode instructions;

the movement time of the stacker between the goods position of the goods to be stored/taken and the corresponding warehouse-in/out platform is the time length;

the movement time of the stacker between the goods position of the goods put in storage and the goods position of the goods out of storage in the same DC command is the same;

in one DC instruction, the movement time of the stacker between the warehouse-out platform and the warehouse-in platform corresponding to the warehouse-out/warehouse-in platform of the warehouse-out goods and the warehouse-in platform corresponding to the next DC instruction is long;

τ_IOthe time required by fork operation is long when the stacker carries out loading/unloading operation once.

Based on the SC/DC operation mode of the automatic stereoscopic warehouse stacker in the distributed warehouse-out/warehouse-in layout mode, the stacker scheduling path model is as follows:

$T=\underset{i=0}{\overset{Q_1-Q_2}{\Σ}}(T_{P_i}+T_{P_i{\mathrm{IO}}_{i+1}})+\underset{i=1}{\overset{2Q_2}{\Σ}}{T}_{P_i}+\underset{i=1}{\overset{Q_2}{\Σ}}{T}_{P_{2i-1}{P}_{2i}}+\underset{i=1}{\overset{Q_2-1}{\Σ}}{T}_{{\mathrm{IO}}_{2i}{\mathrm{IO}}_{2i+1}}+2(Q_1+Q_2){\mathrm{\τ}}_{IO}---\left(4\right)$

wherein:

n₁the number of warehousing operations;

n₂the number of ex-warehouse operations.

In actual conditions, the number of tasks received by the stacker is large. Therefore, in the formula (3), the movement time of the stacker has a large difference due to different task sequences. If the enumeration method is adopted for listing, the operation takes longer time. Therefore, an intelligent optimization algorithm is required to be provided for solving the optimal solution of the model.

And (3) calculating the optimal solution by using the global optimization characteristic of the genetic algorithm and adopting a goods space-warehouse-in/warehouse-out table combined information coding mode, so that the optimal scheduling path of the stacker can be obtained more quickly and accurately.

The goods space-warehouse-out/warehouse-in table combined information code is expressed as follows:

$A=\left|\begin{array}{cccc}{a}_{1x}& a_{1y}& a_{1IOx}& a_1\\ a_{2x}& a_{2y}& a_{2IOx}& a_2\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ a_{ix}& a_{iy}& a_{iIOx}& a\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ a_{kx}& a_{ky}& a_{kIOx}& a\end{array}\right|---\left(5\right)$

wherein: k is the number of warehouse-in/warehouse-out tasks;

a_ixand a_iyThe coordinates of the goods position corresponding to the goods in the ith task are obtained;

andand coordinates of the warehouse-in/warehouse-out table corresponding to the goods in the ith task.

Based on the above coding representation, the DC and SC job mode task sequences can be represented as:

D＝A_DI|A_DO(6)

wherein: d is a composite command job sequence generated according to the given task sequence A;

s is a single command operation sequence generated according to the given task sequence A;

A_DIand A_DORespectively as the warehousing and ex-warehousing sequences of the composite command sequence;

A_SIand A_SOA warehousing or warehousing sequence that can form a single command sequence;

and (3) calculating the optimal solution of the formula (4) by using a genetic algorithm and combining the coding modes of the formulas (5), (6) and (7).

The specific implementation steps are given below:

the order related parameters are set as: goods correspond to the goods space abscissa a_ixGoods corresponding to the goods position ordinate a_iyAnd the horizontal coordinate a of the corresponding warehouse-in/warehouse-out table of the goods_iIOxLongitudinal coordinate of warehouse-in/warehouse-out table corresponding to goodsNumber of orders put in storage n₁Number of orders to leave warehouse n₂。

The relevant parameters of the goods shelf and the stacker are set as follows: horizontal running speed V of stacker_xVertical running speed V of stacker_yThe time length tau required by the movement of the fork when the stacker finishes storing and taking goods_IO. The goods shelf has a goods shelf length of l and a goods shelf height of h.

And (5) completely expressing the goods position information in the required warehouse-in/out order and the corresponding warehouse-in/out platform information. And (3) converting the warehousing order information matrix and the ex-warehouse order information matrix into an SC/DC operation mode task sequence matrix of the stacker by applying the formulas (6) and (7), so as to obtain an SC and DC operation mode task sequence: s, D are provided.

And (3) optimizing and calculating the scheduling path of the stacker by using a genetic algorithm and taking the formula (4) as an objective function in combination with the calculation formula of the operation time of the stacker, which is provided by the formula (1).

The formula (4) provided by the embodiment is used for solving the scheduling path of the stacker in the automatic stereoscopic warehouse in the distributed warehouse-in/warehouse-out layout mode, and overcomes the problem that the conventional stacker scheduling model cannot adapt to a plurality of warehouse-in/warehouse-out stations, so that the stacker scheduling path model has higher universality.

The following are specific examples given by the inventors:

the automatic stereoscopic warehouse adopts a fixed shelf picking mode, each row of shelves has 12 layers of × 80 columns which are 960 cargo spaces, each row of shelves has 4 warehouse-in/out platforms, and the coordinates of the warehouse-in/out platforms at two ends are [1,0 ]]And [1,81 ]]The coordinates of the in-shelf warehouse-in/out table are [1,22 ]]And [1,50 ]]. The goods position length L is 1m, the goods position width W is 1m, and the goods position height H is 1 m. The horizontal running and the vertical running of the stacker do not interfere with each other and start at the same time, and the horizontal running speed V of the stacker_xVertical running speed V of 3m/s_y1m/s, fork travel speed τ_IO＝0.2m/s。

In the warehouse-in/warehouse-out task, the order instructions received by one stacker are shown in table 1.

TABLE 1 Exit/warehouse Command sequences

The parameters of the genetic algorithm are set as follows: sequence set size m 1000, iteration number Max _ ga 400, crossover operator p_c0.95 mutation operator p_m0.05. And (4) calculating the dispatching path of the stacker for the task order by using the stacker dispatching model provided by the formula (4).

Through genetic algorithm calculation, the population tends to be stable when evolving to 187 generations. The execution time of the stacker required for completing the task order is as follows: 1429 s. The diagram of the stacker dispatching path is shown in fig. 3, wherein the dotted line part and the solid line part in the diagram respectively represent the stacker dispatching path under the DC and SC command sequences.

Therefore, the stacker scheduling path model based on the distributed warehouse-in/warehouse-out layout mode established according to the method of the embodiment can be calculated for the stacker scheduling path under the working condition of multiple warehouse-in/warehouse-out platforms. The problem that the existing stacker scheduling model cannot adapt to the working conditions of multiple warehouse-in/warehouse-out platforms is effectively solved, and the stacker scheduling path model has higher universality.

Claims (1)

1. A method for establishing a stacker dispatching path model based on a distributed warehouse-out/warehouse-in layout mode is characterized by comprising the following steps:

when the stacker operates, the movement in the horizontal and vertical directions starts at the same time, and the operation time of finishing one warehouse-in/out instruction by the stacker depends on the maximum value of the operation time in the horizontal and vertical directions;

in the goods shelf, the length of the goods position is set to be l, the height of the goods position is set to be h, and the horizontal running speed of the stacker is set to be V_xVertical running speed V of stacker_yThen the stacker goes from a certain position [ i, j ]]Move to a specified position [ u, w ]]The required time is as follows:

t＝max(|i-u|t_x,|j-w|t_y) (1)

wherein, t_xWhen the stacker passes through a goods space, the time length required by the movement in the horizontal direction is as follows: t is t_x＝l/V_x；

t_yWhen the stacker passes through a goods space, the movement in the vertical direction needs a long time: t is t_y＝h/V_y；

The automatic stereoscopic warehouse in/out operation in the distributed in/out mode has the following characteristics:

(1) there are m warehousing tasks, which are represented in the task sequence as:

(2) there are n ex-warehouse tasks, which are represented in the task sequence as:

wherein:

indicating the goods position address of goods required to be stored by the stacker in the ith task and the address of a warehousing platform of the goods in the warehousing task sequence;

showing the goods position address of the goods which are required to be taken out by the stacker in the jth task and the address of the delivery platform of the goods in the delivery task sequence;

based on the above-mentioned out/in-storage operation characteristics, the SC/DC operation mode of the automatic stereoscopic warehouse stacker in the distributed out/in-storage layout mode is as follows:

(1) SC operation mode:

the SC operation mode is a single command operation mode, namely the stacker only completes one warehouse-out or warehouse-in task after one warehouse-in and warehouse-out operation;

in the distributed layout mode, the SC operation mode of the stacker means: the stacker starts from an initial warehouse-in/out platform or a warehouse-in/out platform for unloading goods appointed by a last task, moves to an appointed goods position for loading goods, and then moves to the warehouse-in/out platform appointed by the goods for unloading the goods; or after a certain warehouse-in/out platform is loaded with goods, the stacker conveys the goods to a specified goods location to unload the goods, and then moves to the warehouse-in/out platform needing to load the goods in the next instruction;

therefore, when there are n task instructions in the SC operation mode, the total movement time of the stacker is:

$T_s=\underset{i=1}{\overset{n}{\Σ}}(T_{P_i}+T_{P_i{\mathrm{IO}}_{i+1}})+2{\mathrm{n\τ}}_{IO}---\left(2\right)$

wherein:

n is the number of tasks to be put in/out of the warehouse in the SC operation mode;

i is a sequence number of a certain exit/entry task instruction in the task sequence;

in the ith out-of-warehouse task instruction, the walking time of the stacker is the time length between the goods position of the goods to be stored/taken and the initial or appointed out-of-warehouse table;

starting the time length of the stacker walking between the goods position of the goods to be stored/fetched and the appointed goods to be unloaded or the next delivery task and the delivery/storage platform;

τ_IOthe time length required by fork operation when the stacker carries out loading/unloading operation for one time;

(2) DC operation mode

The DC operation mode is a compound command operation mode, namely the stacker finishes one warehouse-in operation and one warehouse-out operation by one warehouse-in and warehouse-out operation;

in the distributed layout mode, the DC operation mode of the stacker is as follows: the stacker moves to a specified warehouse-in/out platform to load goods to be warehoused, directly moves to the specified goods location of the warehouse-out task to load the goods to be warehoused after the goods are conveyed to the specified goods location, and then conveys the goods to the specified warehouse-in/out platform;

therefore, when there are n task instructions in the DC operation mode, the total movement time of the stacker is:

wherein n is the total number of DC operation mode instructions;

the movement time of the stacker between the goods position of the goods to be stored/taken and the corresponding warehouse-in/out platform is the time length;

the goods in warehouse are in the same DC command and go to the goods out of warehouseThe movement duration of the stacker between the cargo spaces;

in one DC instruction, the movement time of the stacker between the warehouse-out platform and the warehouse-in platform corresponding to the warehouse-out/warehouse-in platform of the warehouse-out goods and the warehouse-in platform corresponding to the next DC instruction is long;

τ_IOthe time length required by fork operation when the stacker carries out loading/unloading operation for one time;

based on the SC/DC operation mode of the automatic stereoscopic warehouse stacker in the distributed warehouse-out/warehouse-in layout mode, the stacker scheduling path model is as follows:

$T=\underset{i=0}{\overset{Q_1-Q_2}{\mathrm{\Σ}}}\left(T_{P_i}+T_{P_i{\mathrm{IO}}_{i+1}}\right)+\underset{i=1}{\overset{2Q_2}{\mathrm{\Σ}}}{T}_{P_i}+\underset{i=1}{\overset{Q_2}{\mathrm{\Σ}}}{T}_{P_{2i-1}{P}_{2i}}+\underset{i=1}{\overset{Q_2-1}{\mathrm{\Σ}}}{T}_{{\mathrm{IO}}_{2i}{\mathrm{IO}}_{2i+1}}+2\left(Q_1+Q_2\right){\mathrm{\τ}}_{IO}---\left(4\right)$

wherein:

n₁the number of warehousing operations;

n₂the number of ex-warehouse operations.

In actual working conditions, the number of tasks received by the stacker is large, so that in the formula (3), the movement time lengths of the stacker are greatly different due to different task sequences, and if the tasks are listed one by adopting an enumeration method, long time is consumed for operation; therefore, an intelligent optimization algorithm must be provided for solving the optimal solution of the model:

the optimal solution is calculated for the formula (3) by applying the global optimization characteristic of the genetic algorithm and adopting a goods space-warehouse-in/out table combined information coding mode, so that the optimal scheduling path of the stacker can be obtained more quickly and accurately;

the goods space-warehouse-out/warehouse-in table combined information code is expressed as follows:

$A=\left|\begin{array}{cccc}{a}_{1x}& a_{1y}& a_{1IOx}& a_1\\ a_{2x}& a_{2y}& a_{2IOx}& a_2\\ \begin{array}{c}.\\ .\\ .\end{array}& \begin{array}{c}.\\ .\\ .\end{array}& \begin{array}{c}.\\ .\\ .\end{array}& \begin{array}{c}.\\ .\\ .\end{array}\\ a_{ix}& a_{iy}& a_{iIOx}& a\\ \begin{array}{c}.\\ .\\ .\end{array}& \begin{array}{c}.\\ .\\ .\end{array}& \begin{array}{c}.\\ .\\ .\end{array}& \begin{array}{c}.\\ .\\ .\end{array}\\ a_{kx}& a_{ky}& a_{kIOx}& a\end{array}\right|---\left(5\right)$

wherein:

k is the number of warehouse-in/warehouse-out tasks;

a_ixand a_iyThe coordinates of the goods position corresponding to the goods in the ith task are obtained;

andcoordinates of an out/in warehouse table corresponding to goods in the ith task;

based on the above coding representation, the DC and SC job mode task sequences are represented as:

wherein:

d is a composite command job sequence generated according to the given task sequence A;

s is a single command operation sequence generated according to the given task sequence A;

A_DIand A_DORespectively as the warehousing and ex-warehousing sequences of the composite command sequence;

A_SIand A_SOA warehousing or warehousing sequence that can form a single command sequence;

and (4) calculating the optimal solution of the formula (4) by combining the coding modes of the formulas (5), (6) and (7) by using a genetic algorithm.