A maintenance plan adjustment method and system based on constants and variables

Abstract

The present invention provides a maintenance plan adjustment method and system based on constants and variables, the method comprising: determining constants and decision variables; establishing a rail transit linear asset grid maintenance plan optimization adjustment model with a plan change minimum objective function according to the constants and decision variables; adjusting the maintenance plan according to the rail transit linear asset grid maintenance plan optimization adjustment model. The present invention enhances the guidance and practicality of the rail transit linear asset maintenance plan.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail transportation, and in particular relates to a maintenance plan adjustment method and system based on constants and variables. Background Art

[0002] Linear assets are generally considered to have a measured starting point and end point and can be maintained in sections. With the development of high-density and high-speed rail transit, the safe and uninterrupted operation of trains and the comfortable travel of passengers have put forward higher requirements for the reliability and stability of rail transit infrastructure. In order to ensure that managers can effectively maintain the quality status of rail transit linear assets and reasonably arrange maintenance and repair operations, according to relevant maintenance procedures and systems, various maintenance methods of rail transit linear assets should be planned and arranged periodically. At present, the maintenance of linear assets on-site in my country's rail transit is mainly based on fault repair and periodic repair. In the actual implementation process, due to the interference of various random factors, the maintenance plan of rail transit linear assets may be adjusted many times. How to minimize the changes in the maintenance plan to ensure the guidance of the maintenance plan of rail transit linear assets is another important problem faced by managers. Summary of the invention

[0003] In view of the above problems, the present invention provides a maintenance plan adjustment method based on constants and variables, the method comprising:

[0004] Identify constants and decision variables;

[0005] Based on constants and decision variables, a rail transit linear asset grid maintenance plan optimization adjustment model with a minimum plan change objective function is established;

[0006] Adjust the maintenance plan based on the optimization and adjustment model of the grid maintenance plan for rail transit linear assets.

[0007] Furthermore, the constants include basic maintenance constants, rail transit linear asset grid constants, and rail transit linear asset maintenance method constants.

[0008] Furthermore, the basic maintenance constants include:

[0009] SD, represents the starting mileage of the maintenance plan;

[0010] ED, represents the end mileage of the maintenance plan;

[0011] DR, represents the mileage length of maintenance activities.

[0012] Furthermore, the rail transit linear asset grid constants include:

[0013] LE, represents the length of the rail transit linear asset grid, where the rail transit linear asset grid is a grid segmented on the rail transit linear asset line in the spatial dimension;

[0014] N, represents the total number of grids divided by rail transit linear asset lines;

[0015] G i (i∈[1, 2, ..., N]), represents the i-th rail transit linear asset grid, where i represents the serial number of the rail transit linear asset grid.

[0016] Furthermore, the rail transit linear asset maintenance mode constants include:

[0017] M, represents the total number of categories of maintenance methods for rail transit linear assets;

[0018] C j (j∈[1, 2, ..., M]), represents the jth type of maintenance method, where j represents the serial number of the rail transit linear asset maintenance method;

[0019] C ij (i∈[1,2,...,N],j∈[1,2,...,M]), represents the rail transit linear asset grid G i The jth type of maintenance method;

[0020] E represents the total number of unit time in a planning cycle.

[0021] Furthermore, the decision variable represents whether a specified grid in the rail transit linear asset grid performs a maintenance activity of a specified maintenance method within a specified unit time, and its expression formula is as follows:

[0022]

[0023] Among them, the decision variables It indicates whether the i-th rail transit linear asset grid performs the maintenance activity of the j-th maintenance method in the e-th unit time, where j represents the serial number of the rail transit linear asset maintenance method; and e represents the serial number of the unit time in the planning cycle.

[0024] Furthermore, the formula of the plan change minimum objective function is as follows:

[0025] minA,

[0026] Among them, A represents the sum of the absolute values ​​of the decision variable differences, and its calculation formula is as follows:

[0027]

[0028] in, is the decision variable of the original plan, is the adjusted decision variable, and h means that the maintenance plan needs to be recompiled starting from the hth unit time.

[0029] On the other hand, the present invention also provides a maintenance plan adjustment system based on constants and variables, characterized in that the system comprises:

[0030] A constant and decision variable determination module, used to determine constants and decision variables;

[0031] A model building module is used to build a rail transit linear asset grid maintenance plan optimization adjustment model with constraints and a plan change minimum objective function based on constants and decision variables;

[0032] The maintenance plan adjustment module is used to adjust the maintenance plan according to the grid maintenance plan optimization adjustment model of rail transit linear assets.

[0033] Furthermore, the constants include basic maintenance constants, rail transit linear asset grid constants, and rail transit linear asset maintenance method constants.

[0034] Furthermore, the basic maintenance constants include:

[0035] SD, represents the starting mileage of the maintenance plan;

[0036] ED, represents the end mileage of the maintenance plan;

[0037] DR, represents the mileage length of maintenance activities.

[0038] Furthermore, the rail transit linear asset grid constants include:

[0039] LE, represents the length of the rail transit linear asset grid, where the rail transit linear asset grid is a grid segmented on the rail transit linear asset line in the spatial dimension;

[0040] N, represents the total number of grids divided by rail transit linear asset lines;

[0041] G i (i∈[1, 2, ..., N]), represents the i-th rail transit linear asset grid, where i represents the serial number of the rail transit linear asset grid.

[0042] Furthermore, the rail transit linear asset maintenance mode constants include:

[0043] M, represents the total number of categories of maintenance methods for rail transit linear assets;

[0044] C j(j∈[1, 2, ..., M]), represents the jth type of maintenance method, where j represents the serial number of the rail transit linear asset maintenance method;

[0045] C ij (i∈[1, 2, ..., N], j∈[1, 2, ..., M]), represents the j-th maintenance mode of the rail transit linear asset grid Gi;

[0046] E represents the total number of unit time in a planning cycle.

[0047] The beneficial effects of the present invention are as follows:

[0048] The present invention takes the spatiotemporal grid of rail transit linear assets as the basic unit, discretizes the rail transit linear asset maintenance activities in the spatial and temporal dimensions, and thus proposes a gridded maintenance plan optimization and adjustment model for rail transit linear assets, more carefully defines the activity sequence constraints and objective functions of different maintenance activities of rail transit linear assets in time and space, and the optimized and adjusted rail transit linear asset maintenance plan has the smallest change compared with the original plan, thereby enhancing the guidance and practicality of the rail transit linear asset maintenance plan.

[0049] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A principle block diagram of a method for optimizing and adjusting a maintenance plan for rail transit linear assets according to an embodiment of the present invention is shown.

[0052] Figure 2 A schematic diagram of a rail transit space-time grid according to an embodiment of the present invention is shown.

[0053] Figure 3 A schematic diagram of activity sequence constraints between rail transit linear asset maintenance activities according to an embodiment of the present invention is shown.

[0054] Figure 4 A schematic diagram of movement sequence constraints based on rail transit space-time grid according to an embodiment of the present invention is shown.

[0055] Figure 5 A principle block diagram of a system for optimizing and adjusting a maintenance plan for rail transit linear assets according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] At present, the maintenance plan management of my country's rail transit linear assets is mainly based on manual work (Excel spreadsheet form), which is backward and inefficient. The adjustment of the existing maintenance schedule is mainly based on the experience of the planner, and the maintenance schedule is saved and managed in Excel spreadsheets. The scientificity and visibility of the adjustment of the maintenance schedule need to be improved.

[0058] The present invention proposes to subdivide the maintenance activities of rail transit linear assets in time and space dimensions according to units of equal length, and to define the constraint system and objective function of different maintenance activities of rail transit linear assets in more detail.

[0059] The present invention proposes a method for optimizing and adjusting the maintenance plan of linear assets of rail transit with the goal of minimizing plan changes. When the actual progress deviates from the plan and the basic diagram of the maintenance plan of linear assets of rail transit needs to be recompiled, the influence of interference from various factors on the maintenance plan is reduced, thereby ensuring the guidance of actual maintenance activities on site.

[0060] Furthermore, the maintenance activities of rail transit linear assets have the following characteristics:

[0061] (1) Maintenance activities are continuous in the horizontal direction, such as rail grinding by large machines.

[0062] (2) Maintenance activities generally extend from one end of the rail transit line to the other, such as large-scale machine tamping of the line.

[0063] (3) Maintenance activities mainly consist of activities with repetitive characteristics. For example, large-scale machine cleaning activities on the line are generally carried out continuously and repeatedly in multiple sections.

[0064] (4) To ensure the safety of on-track personnel, maintenance activities are generally scheduled to be carried out during window hours, such as large-scale machine grinding of rails.

[0065] (5) There are logical constraints on the sequence of maintenance activities of different types in the time dimension.

[0066] (6) There are no multiple maintenance activities at the same time and space mileage position. For example, when implementing rail grinding maintenance activities, track tamping maintenance activities cannot be arranged at the same location at the same time.

[0067] (7) Maintenance activities are affected by a variety of temporal and spatial factors. For example, the activity rate is not a constant value over time and space, and is uncertain.

[0068] like Figure 1 As shown, the present invention provides a maintenance plan adjustment method based on constants and variables, the method comprising:

[0069] Identify constants and decision variables;

[0070] According to the constants and decision variables, an optimization and adjustment model of maintenance schedule for time-location grids (OAMMS-TG, OAMMS-TG) for linear assets of rail transit with the objective function of minimum plan change is established, where:

[0071] According to the model OAMMS-TG, adjust the maintenance plan.

[0072] The present invention also establishes a rail transit space-time grid, and OAMMS-TG is also established based on the rail transit space-time grid. The construction of the rail transit linear asset grid maintenance plan optimization adjustment model is described in detail below.

[0073] Segmentation of maintenance activities for rail transit linear assets based on space-time grid

[0074] In order to consider the influence of various factors, the present invention subdivides the rail transit linear asset maintenance activities in spatial and temporal dimensions, and proposes a new optimization and adjustment model for the grid maintenance plan of rail transit linear assets based on the characteristics of rail transit linear asset maintenance activities.

[0075] In the embodiment of the present invention, the rail transit lines with linear, continuous and strip layout are divided into several small sections according to certain rules. Preferably, the lines are divided into several adjacent small sections of equal length, so as to form a rail transit grid. The rail transit time-space grid refers to a number of small units formed by dividing the whole life cycle of rail transit line facilities according to certain rules based on the two dimensions of time and space. In the embodiment of the present invention, the life cycle process is a complete maintenance process. Figure 2As shown, the horizontal axis represents mileage, the vertical axis represents time, and each space-time grid is represented by G ij Indicates that i represents the i-th rail transit grid, and j represents the time period of the grid. The rail transit space-time grid is a basic unit based on time and space. For example, the rail transit space-time grid is established based on the space dimension of the rail transit line and the time dimension of the rail transit linear asset maintenance. Specifically, the rail transit space-time grid division method is as follows:

[0076] (1) Time grid division: According to the actual work requirements of rail transit infrastructure management, the entire life cycle of rail transit infrastructure can be divided into minutes, hours, days, weeks, months, and years in the time dimension. In different application scenarios, managers can choose the size of the time grid unit according to the actual scenario requirements.

[0077] (2) Spatial grid division: As the smallest unit for segmenting linear and continuous rail transit lines in the spatial dimension, the division of spatial grids should fully consider the business characteristics of maintenance activities and the management requirements of the site. In the embodiment of the present invention, the length of the rail transit grid is set to 200 meters, and the railway 100-meter mark is selected as the dividing point between adjacent grids.

[0078] Rail transit linear asset maintenance activities have clear time span and mileage range information, and consume a certain amount of time and resources during their execution. Based on the space-time grid, rail transit linear asset maintenance activities are divided into smaller time units and space units, which can more finely define the various time and space constraints of maintenance activities, and more accurately describe the impact of various time factors and space factors on maintenance activities, so that managers can manage rail transit infrastructure maintenance activities at a higher time and space resolution.

[0079] Constants and decision variables involved in grid-based maintenance activities of rail transit linear assets

[0080] Furthermore, in this embodiment, the constants are determined based on the rail transit space-time grid. Specifically, the constants include basic maintenance constants, rail transit linear asset grid constants, and rail transit linear asset maintenance method constants.

[0081] Among them, the basic maintenance constants include:

[0082] SD, represents the starting mileage of the maintenance plan;

[0083] ED, represents the end mileage of the maintenance plan;

[0084] DR, which indicates the mileage length of the maintenance activity, is the difference between the end mileage of the maintenance plan and the start mileage of the maintenance plan. The calculation formula is as follows:

[0085] DR = ED-SD;

[0086] Rail transit linear asset grid constants include:

[0087] LE, represents the length of the rail transit linear asset grid, where the rail transit linear asset grid is a grid divided on the rail transit linear asset line in the spatial dimension, generally 200 meters;

[0088] N represents the total number of grids divided by the rail transit linear asset line. The total number of grids divided by the rail transit linear asset line is the ratio of the mileage length of the maintenance activity to the length of the rail transit linear asset grid. The calculation formula is as follows:

[0089]

[0090] G i (i∈[1, 2, ..., N]), represents the i-th rail transit linear asset grid, where i represents the serial number of the rail transit linear asset grid;

[0091] Rail transit linear asset maintenance method constants include:

[0092] M, represents the total number of categories of maintenance methods for rail transit linear assets;

[0093] C j (j∈[1, 2, ..., M]), represents the jth type of maintenance method, where j represents the serial number of the rail transit linear asset maintenance method;

[0094] C ij (i∈[1,2,...,N],j∈[1,2,...,M]), represents the rail transit linear asset grid G i The jth type of maintenance method;

[0095] E represents the total number of unit time in a planning cycle, and e represents the e-th unit time, that is, e represents the sequence number of the unit time in the planning cycle;

[0096] B ab Represents the time constraint between maintenance activity b and its predecessor activity a.

[0097] In this embodiment, the decision variable is determined based on the rail transit spatiotemporal grid and for the specified rail transit linear asset grid. Specifically, the decision variable indicates whether the specified grid in the rail transit linear asset grid performs a maintenance activity of a specified maintenance method within a specified unit time. The expression formula is as follows:

[0098]

[0099] Among them, the decision variables Indicates whether the i-th rail transit linear asset grid performs the maintenance activity of the j-th maintenance method in the e-th unit time.

[0100] For maintenance method C j The corresponding optimization problem has N×E Boolean decision variables to be considered. There are M types of maintenance methods in the entire model, so the OAMMS-TG model has a total of M×N×E Boolean decision variables to be considered.

[0101] In this embodiment, OAMMS-TG also involves a decision expression, which is as follows:

[0102] z ij Indicates that in a maintenance plan preparation cycle, the grid G i Maintenance method C j The maintenance activity execution time. ij The elements in the grid G i In the z ij Unit time to perform maintenance method C i Maintenance activities. ij and The functional relationship of (e∈[1, 2, ..., E]) is as follows:

[0103]

[0104] in, Indicates the grid G i The maintenance method C is performed in the e-th unit time. j Maintenance activities, at this time, z ij =e, Inf means selecting elements that meet the conditions.

[0105] U i Indicates that in a maintenance plan preparation cycle, the grid G i The set consisting of the execution time of all maintenance activities for all maintenance methods. Set U i The number of elements in is equal to the grid G i The total maintenance pass threshold S for all maintenance methods i =M. Set U i The elements in Represents, m∈[1, 2, ..., M], Represents the grid G i In the Maintenance activities were performed per unit of time. and The functional relationship of j∈[1, 2, ..., M]) is as follows:

[0106]

[0107] in, Indicates the grid G i The maintenance method C is performed in the e-th unit time. j Maintenance activities, at this time,

[0108] Q ij Represents the grid G i The maintenance method is C j The number of maintenance activities is calculated as follows:

[0109]

[0110] Indicates that the maintenance method is C j The number of grids maintained by the maintenance activity in the e-th unit time is calculated as follows:

[0111]

[0112] Indicates that the maintenance method performed in the e-th unit time is C j The working group demand for maintenance activities is calculated as follows:

[0113]

[0114] OAMMS-TG assumes that the maintenance mode is C j There is only one working group for the maintenance activity. If the actual problem is for maintenance method C j If there are multiple working groups, they are divided into multiple sub-problems of a single working group according to the maintenance tasks.

[0115] Constraints between maintenance activities of rail transit linear assets

[0116] Rail transit linear asset maintenance activities refer to the sum of a series of actions performed by applying technical means to investigate the status of rail transit linear assets. It is the basic management unit in rail transit linear asset maintenance plan management, with clear time span and mileage range information, and a certain amount of time and resources consumed during its execution. A maintenance activity refers to a maintenance task that a work group is assigned to perform within a certain time span and mileage range.

[0117] Existing relevant research results lack the description and definition of the constraints between rail transit linear asset maintenance activities. Combined with the analysis of the characteristics of rail transit linear asset maintenance activities, the present invention includes the constraints between rail transit linear asset maintenance activities as activity sequence constraints, that is, OAMMS-TG has activity sequence constraints.

[0118] Activity order constraints

[0119] like Figure 3 As shown in the figure, according to the requirements of the maintenance process, rail transit linear asset maintenance activities have a sequence of execution, and there may be certain interval requirements. Activity b should be executed after its predecessor activity a, and the minimum time interval between them should not be less than B ab .

[0120] Violation of activity sequence constraints will lead to unqualified maintenance quality and cause serious consequences such as operational accidents.

[0121] Constraint system based on rail transit space-time grid

[0122] In this embodiment, the following maintenance activity constraint system will be defined in more detail based on the spatiotemporal grid of rail transit linear assets:

[0123] Activity order constraints

[0124] The activity sequence constraints satisfy the following conditions:

[0125] The time interval between the subsequent maintenance activity and the previous maintenance activity is greater than the time constraint between the subsequent maintenance activity and the previous maintenance activity; the activity sequence constraint is determined by the following formula:

[0126]

[0127] Among them, a and b represent different maintenance activities. Activity b is performed after activity a. ab represents the time constraint between maintenance activity b and activity a, z ia Indicates that activity a is in grid G i The execution time, z ib Indicates that activity b is in grid G i The execution time of ib- z ia ) is the time interval between the execution of two activities, so, if Figure 4 As shown, for each grid, the time to perform maintenance activity b is greater than the time to perform maintenance activity a.

[0128] Objective function based on rail transit space-time grid

[0129] The objective function is the minimum plan change objective function, where the minimum change in the maintenance plan of rail transit linear assets means that during the execution of rail transit linear asset maintenance activities, due to the disturbance of various random factors, it cannot be executed according to the original plan, and the adjusted maintenance plan has the smallest deviation from the original plan. OAMMS-TG uses the change in the number of space-time grids occupied by the maintenance plan before and after the adjustment as an indicator to measure the degree of change in the maintenance plan. The closer the adjusted maintenance plan is to the original plan and the smaller the deviation is, the smaller the impact on other work and the more orderly the work on site will be.

[0130] The objective function of minimizing plan changes is to minimize the sum of the absolute values ​​of the differences in the decision variables of the rail transit space-time grid from the start unit time of the maintenance plan adjustment to the end time of the maintenance plan.

[0131] The sum of the absolute values ​​of the decision variable differences is determined as follows: for each maintenance method of each rail transit space-time grid, the difference between the decision variable after the plan adjustment and the original plan value is determined; and the multiple differences obtained are summed.

[0132] During the actual implementation of the rail transit linear asset maintenance plan, when the actual progress deviates from the plan, in order to prevent the entire maintenance plan from being chaotic, the basic diagram of the rail transit linear asset maintenance plan is adjusted with the minimum plan change as the optimal goal to ensure the orderly implementation of the maintenance plan.

[0133] The objective function formula for minimizing planned changes is as follows:

[0134] minA,

[0135] Among them, A represents the sum of the absolute values ​​of the decision variable differences, and its calculation formula is as follows:

[0136]

[0137] in, is the decision variable of the original plan, is the adjusted decision variable, and h means that the maintenance plan needs to be recompiled starting from the hth unit time.

[0138] On the other hand, Figure 5 As shown, an embodiment of the present invention further provides a maintenance plan adjustment system based on constants and variables, the system comprising:

[0139] A constant and decision variable determination module, used to determine constants and decision variables according to the rail transit space-time grid;

[0140] A model building module is used to build a rail transit linear asset grid maintenance plan optimization adjustment model with constraints and a plan change minimum objective function based on constants and decision variables;

[0141] The maintenance plan adjustment module is used to adjust the maintenance plan according to the grid maintenance plan optimization adjustment model of rail transit linear assets.

[0142] The other functions and methods in a maintenance plan adjustment system based on constants and variables of the present invention correspond to the other functions and implementation methods in a maintenance plan adjustment method based on constants and variables of the present invention, and therefore, no further details are given here.

[0143] Since the maintenance tasks in the maintenance plan of rail transit linear assets are generally fixed, the maintenance plan of rail transit linear assets will inevitably be affected by various random disturbances (such as severe weather conditions) during its implementation, resulting in the actual maintenance progress being inconsistent with the plan. At this time, it is necessary to adjust the maintenance plan of the unimplemented part to minimize the changes compared with the original plan while completing the remaining maintenance tasks, so as to avoid delays in maintenance activities or disrupt the maintenance plan's arrangements for labor, materials, machinery and other resources in advance.

[0144] In rail transit production practice, rail transit linear asset maintenance plans are generally manually compiled and adjusted by managers based on experience, which makes it difficult to ensure the optimization of maintenance plans and minimize plan changes. Traditional network planning methods or Gantt chart methods are not applicable to linear asset maintenance activities. At present, domestic and foreign experts and scholars have conducted little direct research on the adjustment and optimization of adjacent maintenance activities in rail transit linear asset maintenance plans. Therefore, the present invention discloses a maintenance plan adjustment method and system based on constants and variables, which can ensure the optimization of maintenance plans and minimize plan changes.

[0145] This paper proposes a subdivision of rail transit linear asset maintenance activities based on spatiotemporal grids, and discusses in detail the definition and division method of spatiotemporal grids for rail transit linear assets. Spatiotemporal grid management of rail transit linear assets can more accurately describe the degree of influence of various influencing factors on maintenance activities, and more carefully define various constraints between maintenance activities, so that managers can finely manage rail transit infrastructure maintenance activities at a higher temporal and spatial resolution.

[0146] The present invention establishes a model for optimizing and adjusting the grid maintenance plan of rail transit linear assets. The model takes the spatiotemporal grid of rail transit linear assets as the basic unit, constructs the objective function and constraint system of the rail transit linear asset maintenance plan based on the spatiotemporal grid, takes the minimum change of the plan as the optimization goal, and ensures the guidance of the maintenance plan; the constraint system of the model for optimizing and adjusting the grid maintenance plan of rail transit linear assets includes activity sequence constraints, construction period constraints, space constraints, rate constraints, resource constraints and maintenance continuity constraints.

[0147] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A maintenance plan adjustment method based on constants and variables, characterized in that: The method comprises: Determine constants and decision variables based on the spatiotemporal grid of rail transit linear assets; Based on constants and decision variables, a rail transit linear asset grid maintenance plan optimization adjustment model with a minimum plan change objective function is established; Adjust the maintenance plan based on the optimization and adjustment model of the grid maintenance plan for rail transit linear assets; The constants include basic maintenance constants, rail transit linear asset grid constants, and rail transit linear asset maintenance mode constants; The basic maintenance constants include: SD, represents the starting mileage of the maintenance plan; ED, represents the end mileage of the maintenance plan; DR, represents the mileage length of maintenance activities; The rail transit linear asset grid constants include: LE, represents the length of the rail transit linear asset grid, where the rail transit linear asset grid is a grid segmented on the rail transit linear asset line in the spatial dimension; N, represents the total number of grids divided by rail transit linear asset lines; G i (i∈[1:2,...:N]), represents the i-th rail transit linear asset grid, where i represents the serial number of the rail transit linear asset grid; The rail transit linear asset maintenance method constants include: M, represents the total number of categories of maintenance methods for rail transit linear assets; C j (j∈[1:2,....:M]), represents the jth type of maintenance method, where j represents the serial number of the rail transit linear asset maintenance method; C ij (i∈[1:2,....:N]:j∈[1:2,....,M]), represents the rail transit linear asset grid G i The jth type of maintenance method; E represents the total number of unit time in a planning cycle; The decision variable indicates whether a specified grid in the rail transit linear asset grid performs a maintenance activity of a specified maintenance method in a specified unit time, and its expression formula is as follows: Among them, the decision variable l ij Indicates whether the i-th rail transit linear asset grid performs the maintenance activity of the j-th maintenance method in the e-th unit time, j represents the serial number of the rail transit linear asset maintenance method; e represents the serial number of the unit time in the planning cycle; The formula of the objective function of minimum plan change is as follows: minA. Among them, A represents the sum of the absolute values ​​of the decision variable differences, and its calculation formula is as follows: in, is the decision variable of the original plan, is the adjusted decision variable, h means that the maintenance plan needs to be re-compiled starting from the hth unit time; Set the activity sequence constraint based on the rail transit space-time grid: the time interval between the subsequent maintenance activity and the previous maintenance activity is greater than the time constraint between the subsequent maintenance activity and the previous maintenance activity; the expression of the activity sequence constraint is: Among them, a and b represent different maintenance activities. Activity b is performed after activity a. ab represents the time constraint between maintenance activity b and activity a, z ia Indicates that activity a is in grid G i The execution time, z ib Indicates that activity b is in grid G i The execution time of ib -z ia ) is the time interval between the execution of two activities.

2. A maintenance plan adjustment system based on constants and variables, characterized in that: The system comprises: A constant and decision variable determination module, used to determine constants and decision variables based on the space-time grid of rail transit linear assets; A model building module is used to build a rail transit linear asset grid maintenance plan optimization adjustment model with constraints and a plan change minimum objective function based on constants and decision variables; The maintenance plan adjustment module is used to adjust the maintenance plan according to the optimization and adjustment model of the grid maintenance plan of rail transit linear assets; The constants include basic maintenance constants, rail transit linear asset grid constants, and rail transit linear asset maintenance mode constants; The basic maintenance constants include: SD, represents the starting mileage of the maintenance plan; ED, represents the end mileage of the maintenance plan; DR, represents the mileage length of maintenance activities; The rail transit linear asset grid constants include: LE, represents the length of the rail transit linear asset grid, where the rail transit linear asset grid is a grid segmented on the rail transit linear asset line in the spatial dimension; N, represents the total number of grids divided by rail transit linear asset lines; G i (i∈[1:2,...:N]), represents the i-th rail transit linear asset grid, where i represents the serial number of the rail transit linear asset grid; The rail transit linear asset maintenance method constants include: M, represents the total number of categories of maintenance methods for rail transit linear assets; c j (j∈[1:2,...,M]), represents the jth type of maintenance method, where j represents the serial number of the rail transit linear asset maintenance method; C ij (i∈[1:2,...:N]:j∈[1,2,...:M]), represents the rail transit linear asset grid G i The jth type of maintenance method; E represents the total number of unit time in a planning cycle; The decision variable indicates whether a specified grid in the rail transit linear asset grid performs a maintenance activity of a specified maintenance method in a specified unit time, and its expression formula is as follows: Among them, the decision variable l ij Indicates whether the i-th rail transit linear asset grid performs the maintenance activity of the j-th maintenance method in the e-th unit time, j represents the serial number of the rail transit linear asset maintenance method; e represents the serial number of the unit time in the planning cycle; The formula of the objective function of minimum plan change is as follows: minA. Among them, A represents the sum of the absolute values ​​of the decision variable differences, and its calculation formula is as follows: in, is the decision variable of the original plan, is the adjusted decision variable, h means that the maintenance plan needs to be re-compiled starting from the hth unit time; Set the activity sequence constraint based on the rail transit space-time grid: the time interval between the subsequent maintenance activity and the previous maintenance activity is greater than the time constraint between the subsequent maintenance activity and the previous maintenance activity; the expression of the activity sequence constraint is: Among them, a and b represent different maintenance activities. Activity b is performed after activity a. ab represents the time constraint between maintenance activity b and activity a, z ia represents the execution time of activity a in grid Gi, z ib Indicates that activity b is in grid G i The execution time of ib -z ia ) is the time interval between the execution of two activities.

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