A method for encoding conversion of forced in-plant constraint generalized job-shop scheduling

Abstract

The application discloses a kind of forced same machine constraint generalized job shop scheduling encoding conversion method.The encoding conversion method steps of the present application include constructing the mathematical model of generalized job shop scheduling under forced same machine constraint;Using two-stage encoding mode, the process arrangement problem described in the mathematical model of generalized job shop scheduling under forced same machine constraint and machine selection problem are encoded;Construct process template, and the encoding of part of process is compressed;Encoding conversion is carried out, and the corresponding process encoding and machine encoding are obtained based on the scheduling scheme.The present application provides the encoding basis for the generalized job shop scheduling problem under forced same machine constraint.

Description

Technical Field

[0001] This invention belongs to the technical field of production management, specifically relating to a method for converting generalized job shop scheduling codes under mandatory co-operation constraints. Background Technology

[0002] In the field of shop floor scheduling, job shop scheduling (JSP) and flexible job shop scheduling (FJSP) are common research areas, widely found in typical discrete manufacturing industries such as automotive, electronics, and shipbuilding.

[0003] Generalized job shop scheduling problems with mandatory co-operation constraints are also widespread in various discrete manufacturing industries. Taking electronic product testing as an example, after designing the overall process route for prototypes of the same product, the workshop divides the prototypes into different groups. Each group of prototypes completes the testing of each process in sequence according to the sub-routes specified in the overall process route. Some testing prototype processes require cross-group combination testing, such as vibration testing, drop impact testing, and dust testing, forming mandatory co-operation coupling.

[0004] Job shop scheduling and flexible job shop scheduling restrict the exclusive use of designated equipment resources for specific workpiece processing operations. This means that designated equipment cannot simultaneously process different workpieces or two different operations on the same workpiece. However, generalized job shop scheduling under mandatory co-processing constraints breaks these constraints. Generalized job shop scheduling under mandatory co-processing constraints requires consideration of the actual situation where corresponding workpieces in some workshops require mandatory co-processing on the same machine. Examples include the combined processing of mold components and the separate assembly and inspection of the same product on different machine sets in an electronic product testing workshop. This results in mandatory co-processing for certain operations on different workpieces.

[0005] In the existing technology, there is a lack of intelligent scheduling optimization schemes for workshop production scheduling under the condition of mandatory same machine constraints, and the encoding conversion methods for job shop scheduling and flexible job shop scheduling problems cannot be directly transferred to the generalized job shop scheduling problem under the condition of mandatory same machine constraints. Summary of the Invention

[0006] In order to overcome one or more defects and deficiencies in the existing technology, the purpose of this invention is to provide a generalized job shop scheduling encoding conversion method under forced co-machine constraints, so as to provide a basis for optimizing the solution of the generalized job shop scheduling problem under forced co-machine constraints.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for converting generalized job shop scheduling codes under mandatory co-operation constraints includes the following steps:

[0009] S1. Construct a mathematical model for generalized job shop scheduling under mandatory co-operation constraints;

[0010] S2. A two-stage coding method is adopted to encode the process arrangement problem and machine selection problem described by the mathematical model of generalized job shop scheduling under forced same-machine constraints;

[0011] S3. Construct process templates and compress the codes for some processes;

[0012] S4. Perform encoding conversion based on the scheduling scheme to obtain the corresponding process code and machine code.

[0013] Preferably, in the mathematical model, the corresponding mathematical symbols include: N representing the number of workpieces, M representing the number of machines, Z representing the number of forced same-machine combination processes, I, P representing workpiece set numbers, J, K representing process set numbers, m representing machine number, O IJ Indicates the combination process O IJ ={O ij O pq ,…,O yz}, N i Indicates the number of operations for workpiece i, O ij Let j represent the operation of workpiece i, where j∈[1,N]. i ],(S ij ) represents O IJ (O ij The start time of C) IJ (C ij ) represents O IJ (O ij The end time of the operation, E IJm O IJ The job ends on machine m at time Z. i P represents the number of workpieces included in the forced same-machine combination process i. IJm O IJ During the working time of machine m, M IJ O IJ Optional machine set, C m Let Q represent the end time of the last operation on machine m, and let X represent a large positive real number. IJm O IJ Whether the operation is performed on machine m; 1 indicates the operation is performed on machine m, otherwise 0 indicates the operation is performed on machine m. IJPK O IJ and O PK The order of precedence, O IJ In O PK The previous assignment is 1, otherwise it is 0.

[0014] Furthermore, the mathematical model minimizes the maximum job completion time C. M To optimize the objective, the function for optimizing the objective is as follows:

[0015] C M =min(max(C m ),1≤m≤M.

[0016] Furthermore, the mathematical model's description of the mandatory co-operational constraints includes:

[0017] Once a process is started, it cannot be interrupted:

[0018] Each process is performed only once on the machine:

[0019] The start time of any operation process shall not exceed its end time.

[0020] The completion time of any operation shall not exceed the maximum completion time.

[0021] Each machine can only perform one process at a time:

[0022]

[0023] The start time of the current operation for any workpiece is not less than the end time of the operation immediately preceding the workpiece in that operation:

[0024]

[0025] The start time, operation time, and end time of any operation are all greater than 0:

[0026]

[0027] Furthermore, the two-segment encoding includes process code L1 and machine code L2, and the lengths of both process code L1 and machine code L2 are calculated as follows:

[0028]

[0029] The lengths of process code L1 and machine code L2 are random numbers ranging from -N to N.

[0030] Furthermore, the process of constructing a process template and compressing the code for some processes includes:

[0031] S31. Construct a process template to arrange all workpiece processes and combined processes with forced same-machine constraints;

[0032] S32. Once the process template is constructed, set the process template to Temp, Temp = [ON, OF];

[0033] S33. Based on the compression operation of the process template Temp encoding, construct an encoding table with five rows and a length column. The process template Temp is placed in the first row of the encoding table, and the process code L1 is placed in the second row of the encoding table. The two vectors of process template Temp and process code L1 correspond one-to-one.

[0034] Furthermore, the process of constructing the process template arranges all workpiece processes and combined processes with forced same-machine constraints, and the process includes:

[0035] S311. Set a one-dimensional array ON. For a job that is not subject to mandatory machine constraints, there is: Set the number of processes N corresponding to each job. i Therefore, there exists a number of processes N. i One job per workpiece;

[0036] Then, only after all the processes of the same type of workpiece have been sorted will the processes of the next type of workpiece job without mandatory same-machine constraints be sorted. This process continues until all the processes of the workpiece jobs without mandatory same-machine constraints have been sorted. Then, the sorting results of the processes of all the workpiece jobs without mandatory same-machine constraints are put into the array ON in sequence.

[0037] S312. Set a one-dimensional array OF. For a workpiece c_job under forced same-machine constraints, we have: The number of times job c_job appears in all mandatory same-machine combination operations is set to count. Based on the number of mandatory same-machine combination operations, the operation sorting results of job c_job with all types of mandatory same-machine constraints are put into array OF in sequence.

[0038] Furthermore, the compression operation of the process template Temp encoding includes:

[0039] S331. Compression types are classified as follows:

[0040] The preceding process of the combined process corresponding to the workpiece c_job with forced same-machine constraints is defined as the predecessor process, and the corresponding predecessor process compression type is defined.

[0041] The process following the combined process of the workpiece c_job with forced same-machine constraints is the subsequent process, and the corresponding subsequent process compression type is used.

[0042] When there is the same workpiece c_job among different combined processes under the forced same machine constraint, and one of the processes of the workpiece c_job is in these different combined processes, then the process of the workpiece c_job corresponds to the middle drive process compression type.

[0043] When there is a process with sequential processing constraints among different combined processes under the forced same-machine constraint, then the process is a forced same-machine combined process compression type.

[0044] S332. Obtain the combined operation O with mandatory same-machine constraints from the operation template Temp. IJ The corresponding process code L1 value code(b), b∈[1,Z]; the process code L1 value code(a), a∈[1,N], corresponding to the workpiece c_job with forced same-machine constraints, is obtained from the process template Temp. i -count], and then update the workpiece c_job and combined operation O with the forced same-machine constraint according to the corresponding compression type. IJ The corresponding process code L1 is set, and the updated result is placed in the third row of the coding table and set as the new process code C1;

[0045] Update the workpiece c_job and combined operation O that are subject to forced co-operation constraints. IJ The value of the corresponding process code L1 is determined according to the following formula:

[0046] Precursor process compression type:

[0047]

[0048] Post-process compression type:

[0049]

[0050] Compression type in intermediate drive process:

[0051]

[0052] Forced same-machine combined process compression type:

[0053]

[0054] S333. Perform a compression operation on the code of the process template Temp until the code table has been updated for all process codes C1.

[0055] Furthermore, the encoding conversion, based on the scheduling scheme, includes the following process:

[0056] S41. After obtaining the coding table of all process codes C1, sort the values ​​of each element of process code C1 in ascending order in the coding table, obtain the index of the sorted process code C1, and then put the index into the fourth row of the coding table accordingly.

[0057] S42. Based on the index of process code C1, adjust the first row of the coding table, generate a new process code D1 based on the scheduling scheme, and put process code D1 into the fifth row of the coding table;

[0058] A new process code D1 is generated based on the scheduling scheme. Then, the machine code L2 is operated on to obtain a new machine code D2, thereby determining the correspondence between process code D1 and machine code D2. The machine code L2 is operated on according to the following formula:

[0059]

[0060] Where x(i) represents the i-th element of the individual position vector of machine code L2, s(i) represents the number of machines that can be selected by the process code D1 of the scheduling scheme corresponding to element i, n(i)∈[1,s(i)] represents the sequence number of the selected machine in the set of available machines, and m is the number of workpieces; machine code D2 corresponds to the process of process template Temp and is used to represent the machine sequence number of the process or combination process corresponding to the selected machine in the specified set of available machines;

[0061] S43. List the results of process code D1 and machine code D2 to obtain the corresponding process code and machine code after conversion.

[0062] Furthermore, the new process code D1 generated based on the scheduling scheme is set as follows: Workpiece i, i∈[1,N] and its occurrence process j, j∈[1,N] i The corresponding process O is indicated by ] i,j For combined operations with forced co-operational constraints, a set of workpieces is used to describe the combined operations. The corresponding combined operations are the operations O corresponding to each workpiece in the set of workpieces. ij Describing by combination, for example, O 12 / O 41 Indicates process O 12 and O 41 The combined construction process.

[0063] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0064] This invention can encode the process and machine scheduling of generalized job shop scheduling under mandatory same-machine constraints, thus providing a foundation for subsequent optimization of generalized job shop scheduling under mandatory same-machine constraints in combination with relevant algorithms, filling the research gap in the existing technology for job shop scheduling problems under mandatory same-machine constraints. Attached Figure Description

[0065] Figure 1 This is a flowchart illustrating the mandatory same-machine constraint generalized job shop scheduling code conversion method of the present invention;

[0066] Figure 2 This is a schematic diagram showing the results of two-stage coding of the processes and machines involved, resulting in three process codes (L1) and machine codes (L2).

[0067] Figure 3 for Figure 2 The diagram shows the results of the three cases after sequentially going through process template construction, code compression, and code conversion;

[0068] Figure 4 for Figure 3 A schematic diagram of the final encoded result after conversion. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0070] It should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the disclosure of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the disclosure of this invention.

[0071] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Similarly, words such as "a," "one," or "the" do not indicate a quantity limitation but rather that at least one exists. Words such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "electrically connected" or "connected" are not limited to physical or mechanical electrical connections but can include electrical connections, whether direct or indirect.

[0072] Example

[0073] like Figure 1 As shown in the figure. This embodiment provides a method for converting generalized job shop scheduling codes under mandatory co-operation constraints, which includes the following steps:

[0074] S1. Constructing a mathematical model for generalized job shop scheduling under mandatory co-operation constraints; In this preferred embodiment, to construct the mathematical model, the corresponding mathematical symbols are first defined as shown in Table 1 below:

[0075] Table 1 Definitions of Mathematical Symbols

[0076]

[0077] The mathematical model minimizes the maximum job completion time C. M To optimize the objective, the function for optimizing the objective is as follows:

[0078] C M =min(max(C m ),1≤m≤M (1)

[0079] The mathematical model expresses the mandatory co-operational constraints as shown in the following formulas:

[0080]

[0081] Among them, Equation (2) indicates that the operation cannot be interrupted after the operation is started; Equation (3) indicates that any operation is only operated once on the machine; Equation (4) indicates that the start time of any operation is not greater than its end time; Equation (5) indicates that the end time of any operation is not greater than the maximum end time; Equation (6) indicates that each machine can only have one operation at the same time; Equation (7) indicates that the start time of the current operation of any workpiece is not less than the end time of the preceding operation (or set of operations) of the workpiece; Equation (8) indicates that the start time, operation time and end time of any operation are all greater than 0.

[0082] S2. A two-stage coding method is adopted to encode the process arrangement problem and machine selection problem described by the mathematical model of generalized job shop scheduling under forced same-machine constraints;

[0083] In this preferred embodiment, the lengths of process code L1 and machine code L2 are calculated as follows:

[0084]

[0085] The lengths of process code L1 and machine code L2 are random numbers ranging from -N to N.

[0086] S3. Construct process templates and compress the codes for some processes; the specific process includes:

[0087] S31. Construct a process template to arrange all workpiece processes and combined processes with forced same-machine constraints; specifically:

[0088] S311. Set a one-dimensional array ON. For a job that is not subject to mandatory machine constraints, there is: Set the number of processes N corresponding to each job. i Therefore, there exists a number of processes N. i One job per workpiece;

[0089] Then, only after all the processes of the same type of workpiece have been sorted will the processes of the next type of workpiece job without mandatory same-machine constraints be sorted. This process continues until all the processes of the workpiece jobs without mandatory same-machine constraints have been sorted. Then, the sorting results of the processes of all the workpiece jobs without mandatory same-machine constraints are put into the array ON in sequence.

[0090] S312. For workpiece c_job under forced same-machine constraint, we have: The number of times job c_job appears in all mandatory same-machine combination operations is set to count. Based on the number of mandatory same-machine combination operations, the sorting of job c_job is handled in the following three cases:

[0091] (1) The case where there is only one forced same-machine combination operation; in this case, a one-dimensional array OF is set to generate Z=1 combination operations O. IJ Then combine the Z=1 process O IJ Add to array OF; for each job c_job, there are N operations. i -count (count = 1) jobs c_job;

[0092] Then, sort all the combined operations of the same type of workpieces until the combined operations of the next type of workpiece c_job with mandatory same machine constraints are sorted. After all the combined operations of the workpiece c_job with mandatory same machine constraints are sorted, put the sorting results of the operations of the workpiece c_job with mandatory same machine constraints into the array OF in sequence.

[0093] (2) There are two or more mandatory combined operations on the same machine, and the workpieces included in each mandatory combined operation on the same machine are not duplicated; in this case, set a one-dimensional array OF to generate Z≥2 combined operations O IJ Then combine Z≥2 process O IJAdd to array OF; for each job c_job, there are N operations. i -count (count = 1) jobs c_job;

[0094] Then, sort all the combined operations of the same type of workpieces until the combined operations of the next type of workpiece c_job with mandatory same machine constraints are sorted. After all the combined operations of the workpiece c_job with mandatory same machine constraints are sorted, put the sorting results of the operations of the workpiece c_job with mandatory same machine constraints into the array OF in sequence.

[0095] (3) There are two or more forced same-machine combination processes, and the workpieces included in each forced same-machine combination process are repeated; in this case, set a one-dimensional array OF to generate Z≥2 combination processes O IJ Then combine Z≥2 process O IJ Add to array OF; for each job c_job, there are N operations. i -count(count∈[1,N i ]) number of job c_jobs;

[0096] Then, sort all the combined operations of the same type of workpieces until the combined operations of the next type of workpiece c_job with mandatory same machine constraints are sorted. After all the combined operations of the workpiece c_job with mandatory same machine constraints are sorted, put the sorting results of the operations of the workpiece c_job with mandatory same machine constraints into the array OF in sequence.

[0097] S32. Once the process template is constructed, set the process template to Temp, Temp = [ON, OF];

[0098] S33. Based on the compression operation of the process template Temp encoding, construct an encoding table with five rows and a length column. The process template Temp is placed in the first row of the encoding table, and the process code L1 is placed in the second row of the encoding table. The two rows of vectors, process template Temp and process code L1, correspond one-to-one.

[0099] The compression process for the Temp code of the process template includes:

[0100] S331. Compression types are classified as follows:

[0101] The preceding process of the combined process corresponding to the workpiece c_job with forced same-machine constraints is defined as the predecessor process, and the corresponding predecessor process compression type is defined.

[0102] The process following the combined process of the workpiece c_job with forced same-machine constraints is the subsequent process, and the corresponding subsequent process compression type is used.

[0103] When there is the same workpiece c_job among different combined processes under the forced same machine constraint, and one of the processes of the workpiece c_job is in these different combined processes, then this process of the workpiece c_job corresponds to the middle drive process compression type.

[0104] When there is a process with sequential processing constraints among different combined processes under the forced same-machine constraint, then the process is a forced same-machine combined process compression type.

[0105] S332. Obtain the combined operation O with mandatory same-machine constraints from the operation template Temp. IJ The corresponding process code L1 value code(b), b∈[1,Z]; the process code L1 value code(a), a∈[1,N], corresponding to the workpiece c_job with forced same-machine constraints, is obtained from the process template Temp. i -count], and then update the workpiece c_job and combined operation O with the forced same-machine constraint according to the corresponding compression type. IJ The corresponding process code L1 is set as the value, and the updated result is placed in the third row of the coding table and set as the new process code C1.

[0106] Update the workpiece c_job and combined operation O that are subject to forced co-operation constraints. IJ The value of the corresponding process code L1 is determined according to the following formula:

[0107] Precursor process compression type:

[0108]

[0109] Post-process compression type:

[0110]

[0111] Compression type in intermediate drive process:

[0112]

[0113] Forced same-machine combined process compression type:

[0114]

[0115] S333, Perform a compression operation on the code of the process template Temp until the code table has completed the update of all process codes C1;

[0116] S4. Perform encoding conversion based on the scheduling scheme to obtain the corresponding process code and machine code; the specific process includes:

[0117] S41. After obtaining the coding table of all process codes C1, sort the values ​​of each element of process code C1 in ascending order in the coding table, obtain the index of the sorted process code C1, and then put the index into the fourth row of the coding table accordingly.

[0118] S42. Based on the index of process code C1, adjust the first row of the coding table (that is, the process template Temp), generate a new process code D1 based on the scheduling scheme, and put the process code D1 into the fifth row of the coding table;

[0119] The new process code D1 generated based on the scheduling scheme is set as follows: It is based on the workpiece i, i∈[1,N] and its frequency j, j∈[1,N]. i The corresponding process O is indicated by ] ij For combined operations with forced co-operational constraints, a set of workpieces is used to describe the combined operations. The corresponding combined operations are the operations O corresponding to each workpiece in the set of workpieces. ij Describing by combination, for example, O 12 / O 41 Indicates process O 12 and O 41 The combined process of construction;

[0120] A new process code D1 is generated based on the scheduling scheme. Then, the machine code L2 is operated on to obtain a new machine code D2, thereby determining the correspondence between process code D1 and machine code D2. The machine code L2 is operated on according to the following formula:

[0121]

[0122] Where x(i) represents the i-th element of the individual position vector of machine code L2, s(i) represents the number of machines that can be selected by the process code D1 of the scheduling scheme corresponding to element i, n(i)∈[1,s(i)] represents the sequence number of the selected machine in the set of available machines, and m is the number of workpieces; machine code D2 corresponds to the process of process template Temp and is used to represent the machine sequence number of the process or combination process corresponding to the selected machine in the specified set of available machines;

[0123] S43. List the results of process code D1 and machine code D2 from the calculation results of step S42 to obtain the corresponding process code and machine code after conversion.

[0124] To further illustrate the applicability of the steps in this embodiment, this embodiment is preferably described in conjunction with the following examples:

[0125] For operation scenarios that conform to the generalized job shop scheduling under the mandatory same machine constraint, a corresponding mathematical model can be constructed according to step S1, and then two-stage coding can be performed based on the mathematical model according to step S2 to obtain the process code L1 and machine code L2.

[0126] Next, a process template is constructed according to step S3. For forced same-machine combination processes, including the three scenarios in step S312, the template is combined with, for example... Figure 2 The coded cases shown in Case 1, Case 2, and Case 3 are explained below. The selectable machines, corresponding workpieces, and processes for each of the three cases are shown in the following three tables:

[0127] Table 2 Case 1

[0128]

[0129]

[0130] Table 3 Case 2

[0131]

[0132]

[0133] Table 4 Case 3

[0134]

[0135] In Tables 2 to 4 above, J1 represents workpiece 1, O 12 This indicates the second process of J1, and so on for the others; O 22 / O 33 O 23 O 33 To force the combination of processes in the same machine, the number in the column of selectable machines indicates the processing time of the process on the corresponding machine M. "—" indicates that the corresponding process of the workpiece cannot be processed by machine M.

[0136] By sequentially executing steps S32 (constructing the process template), S33 (encoding compression), and S41 and S42 (encoding conversion) for Case 1, Case 2, and Case 3, the following results can be obtained: Figure 3 The process code L1, process code C1, index, and process code D1 are as follows: Figure 4 As shown, process code D1 is the final process code generated based on the scheduling scheme, and the corresponding machine code D2 is the final machine code.

[0137] Compared with the prior art, the advantages of this embodiment are as follows:

[0138] This embodiment can encode the process and machine scheduling of generalized job shop scheduling under mandatory same-machine constraints, thus providing a foundation for subsequent optimization of generalized job shop scheduling under mandatory same-machine constraints in combination with relevant algorithms, filling the research gap in the existing technology for job shop scheduling problems under mandatory same-machine constraints.

[0139] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for encoding conversion of a generalized job shop scheduling problem with forced identical machine constraints, characterized by, The steps comprise: S1, constructing a mathematical model of generalized job shop scheduling under forced same-machine constraint; S2, using two-stage coding to code the process arrangement problem and the machine selection problem described by the mathematical model of generalized job shop scheduling under forced same-machine constraint; S3, constructing a process template and compressing the coding of part of the process; S4, coding conversion, coding based on the scheduling scheme, thereby obtaining the corresponding process coding and machine coding; In the mathematical model, the corresponding mathematical symbols are set to include: N represents the number of workpieces, M represents the number of machines, Z represents the number of forced same-machine combined processes, I and P represent workpiece set numbers, J and K represent process set numbers, m represents a machine number, O IJ represents a combined process, N i represents the number of processes of a workpiece i, O ij represents a process j of a workpiece i and j∈[1,N i ], S IJ represents the start operation time of a combined process O IJ , S ij represents the start operation time of a process O ij , C IJ represents the end operation time of a combined process O IJ , C ij represents the end operation time of a process O ij , E IJm represents the O IJ end operation time on a machine m, Z i represents the number of workpieces contained in a forced same-machine combined process i, P IJm represents the O IJ operation time on a machine m, M IJ represents the O IJ optional machine set, C m represents the end operation time of the last process on a machine m, Q represents a large positive real number, X IJm represents whether the O IJ is operated on a machine m, 1 if operated on a machine m, otherwise 0, Y IJPK represents the O IJ and O PK precedence order, O IJ is 1 if O PK is operated before, otherwise 0; The mathematical model minimizes the maximum end job time C M For the optimization objective, the function of the optimization objective is shown in the following formula: C M = min(max(C m )), 1≤m≤M; The description of the forced same-machine constraint in the mathematical model comprises: The process cannot be interrupted midway through the operation: Any of the processes is performed only once on the machine: The start operation time of any process is not greater than its end operation time: The end operation time of any process is not greater than the maximum end operation time: Each machine can only have one process at the same time: The start time of any process of any workpiece is not less than the end time of the immediately preceding process of the workpiece: The start time, operation time and end time of any process are all greater than 0: The two-stage coding comprises process coding L1 and machine coding L2, and the length length of the process coding L1 and the machine coding L2 is calculated as follows: Wherein, the length of the process coding L1 and the machine coding L2 is a random number in the range of (-N, N).

2. The method of claim 1, wherein the method is a method of encoding conversion of the GSPD with the forced identical-machine constraint. The process of constructing the process template and compressing the coding of part of the process comprises: S31, constructing a process template, arranging all workpiece processes and forced same-machine constraint combination processes, comprising: S311, setting a one-dimensional array ON, for the workpiece job in the non-forced same-machine constraint, has Set the number of processes N corresponding to each workpiece job i Therefore, there are workpieces job with process number N i ​ Then sort all the processes of the same kind of workpiece until the processes of the next kind of workpiece job are sorted, and then put the sorted results of the processes of all kinds of workpiece jobs into the array ON in turn; S312, setting a one-dimensional array OF, for the workpiece c_job under the forced same-machine constraint, has The number of times the workpiece c_job appears in all the forced same-machine combination processes is set as count, and the process ordering results of all the workpieces c_job under the forced same-machine constraint are sequentially placed in the array OF according to the number of the forced same-machine combination processes. S32, after the process template is constructed, set the process template as Temp, Temp=[ON, OF]; S33, based on the compression operation of the process template Temp coding, construct a coding table with five rows and length columns, wherein the process template Temp is put into the first row of the coding table, the process coding L1 is put into the second row of the coding table, and the process template Temp and the process coding L1 are one-to-one corresponding.

3. The method of claim 2, wherein the method further comprises: The compression operation of the process template Temp coding comprises: S331, divide the compression types as follows: Set the process before the combination process corresponding to the forced same-machine constraint workpiece c_job as the predecessor process, and the corresponding predecessor process compression type; The process after the combination process corresponding to the forced same-machine constraint workpiece c_job is the successor process, and the corresponding successor process compression type; When there are same workpiece c_job between different combination processes under forced same-machine constraint, and one process of the workpiece c_job is in the different combination processes, then the process of the workpiece c_job corresponds to the middle drive process compression type; When there are processes with front and rear processing sequence constraints between different combination processes under forced same-machine constraint, then the process is a forced same-machine combination process compression type; S332, from the process template Temp, acquire the combination process O of the mandatory co-located constraint IJ the value code(b) of the process code L1 corresponding to the combination process O; from the process template Temp, acquire the value code(a) of the process code L1 corresponding to the mandatory co-located constraint workpiece c_job, a∈[1, N i -count], and then update the mandatory co-located constraint workpiece c_job and the combination process O according to the corresponding compression type IJ the value code(b) of the process code L1 corresponding to the combination process O; from the process template Temp, acquire the value code(a) of the process code L1 corresponding to the mandatory co-located constraint workpiece c_job, a∈[1, N Workpiece c_job updating the mandatory co-location constraint, combined operation O IJ The value of the corresponding operation code L1 is given by the following equation: Predecessor process compression type: Successor process compression type: Middle drive process compression type: Forced same-machine combination process compression type: S333, perform a compression operation on the encoding of the process template Temp until the encoding table completes the update of all process encodings C1.

4. The method of claim 3, wherein the encoding conversion is performed by using a constraint programming method. The process of performing encoding conversion and encoding based on the scheduling scheme includes: S41, after obtaining the encoding table of all process encodings C1, arrange the values of each position element of the process encoding C1 in the encoding table in ascending order, obtain the index index of the sorted process encoding C1, and then put the index index into the fourth row of the encoding table correspondingly; S42, according to the index index of the process encoding C1, adjust the first row of the encoding table, generate a new process encoding D1 based on the scheduling scheme, and put the process encoding D1 into the fifth row of the encoding table; Based on the scheduling scheme, a new process encoding D1 is generated, and then the machine encoding L2 is operated to obtain a new machine encoding D2, so as to determine the corresponding relationship between the process encoding D1 and the machine encoding D2; the machine encoding L2 is operated according to the following formula: Wherein, x(i) represents the i-th element of the machine encoding L2 individual position vector, s(i) represents the number of machines that the element i of the process encoding D1 can select according to the scheduling scheme, n(i) ∈ [1, s(i)] represents the serial number of the selected machine in the set of selectable machines, and m is the number of workpieces; the machine encoding D2 and the process of the process template Temp correspond to each other, and is used to represent the machine serial number of the selected machine corresponding to the specified selectable machine set or the combined process; S43, list the results of the process encoding D1 and the machine encoding D2 to obtain the corresponding process encoding and machine encoding after conversion.

5. The method of claim 4, wherein the encoding conversion is performed by using a constraint programming method. The setting of generating a new process code D1 based on the scheduling scheme is: taking the workpiece i, i ∈ [1, N] and the process j, j ∈ [1, N] where the workpiece i appears as an example i The corresponding process O represented by the set of workpieces is described ij The combination process of the work coupling under the forced same-machine constraint is described by the set of workpieces, and the corresponding combination process takes the corresponding process O of each workpiece in the set of workpieces ij The combination is described.

Images