A kind of inspection method and system based on balance and adjustability

Abstract

The present invention provides an inspection method based on balance and adjustability: based on the spatial dimension of the rail transit line and the time dimension of the rail transit linear asset inspection, a rail transit spatiotemporal grid is established; based on the rail transit spatiotemporal grid, a rail transit linear asset grid inspection plan optimization compilation model is determined, including: based on the rail transit spatiotemporal grid, a decision variable is determined, and the decision variable is used to represent the execution of a specified inspection activity in the spatiotemporal grid; based on the rail transit spatiotemporal grid and the decision variable, a balance objective function is determined; based on the rail transit spatiotemporal grid and the decision variable, an adjustability objective function is determined; a balance objective function and an adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model; and an optimal inspection plan is determined according to the rail transit linear asset grid inspection plan optimization compilation model. A scientific and efficient inspection plan determination is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail transportation, and in particular relates to an inspection method and system based on balance and adjustability. Background Art

[0002] Linear assets refer to assets that have a starting point and an end point for measurement and can be maintained in sections. IBM defines linear assets as assets that require section-by-section maintenance, and measurements can be taken along the linear assets to specify work, monitoring, metering, marking locations, etc. For linear assets, their length plays a key role in maintenance. For example, the tracks, roadbeds, contact lines, tunnels, bridges and other equipment in rail transit infrastructure are all linear assets, which have the characteristics of linear, continuous, and strip-shaped layouts in spatial distribution. Their inspection activities are organized in relatively small, strip-shaped spaces and are easily affected by a variety of time and space factors.

[0003] 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 timely perceive the quality status of rail transit linear assets, effectively arrange maintenance and repair operations, and maintain railway facilities in accordance with relevant regulations, various inspection methods of rail transit linear assets should be arranged in a planned and periodic manner.

[0004] At present, there are few direct studies by experts and scholars at home and abroad on the optimization of the balance and adjustability of the time intervals between adjacent inspection activities in the linear asset inspection plan of rail transit. At present, the relevant research of experts and scholars at home and abroad on the optimization of the inspection plan for transportation infrastructure mainly focuses on the following two aspects.

[0005] ① Optimal selection of transportation infrastructure inspection methods based on safety, cost and other objectives. This type of research assumes that transportation infrastructure adopts a regular inspection strategy, and only one inspection method can be selected from multiple different inspection methods each time, and multiple inspection methods cannot be selected at the same time.

[0006] ② Taking safety and cost as optimization goals, the number of inspections of the same inspection method and the time interval between two adjacent inspections of transportation infrastructure within a certain planning period are optimized. This type of research ignores the impact of other inspection methods of the transportation infrastructure on the time interval between two adjacent inspections of the inspection method under study.

[0007] Domestic and foreign experts and scholars have conducted little direct research on the optimization of inspection plan preparation for multiple inspection methods for transportation infrastructure with fixed inspection tasks and inspection frequencies.

[0008] Due to the high reliability and high stability requirements of rail transit infrastructure, in order to ensure that managers can perceive the quality status of rail transit linear assets in a timely manner, according to relevant repair rules, various inspection methods of equipment should be planned and arranged periodically. Therefore, the relevant research results of Category ① cannot be directly used to solve the problem of optimizing the preparation of inspection plans for multiple inspection methods of rail transit linear assets with fixed inspection tasks and inspection frequencies.

[0009] The inspection frequency of various inspection methods for rail transit linear assets is high, and there is overlap in the inspection items of different inspection methods. For example, the inspection by track inspection vehicle, track inspection instrument, and portable instrument are all used to investigate the smoothness of track geometry, and the inspection by rail flaw detection vehicle, rail flaw detection instrument, and manual inspection are all used to investigate the damage of rails. This causes the intervals between two adjacent inspections of different inspection methods to affect each other. Therefore, the relevant research results of the second category cannot be directly used to optimize the preparation of inspection plans for multiple inspection methods of rail transit linear assets.

[0010] In rail transit production practice, rail transit linear asset inspection plans are generally manually compiled by managers based on experience, which makes it difficult to ensure the balance and adjustability of the inspection plan. Traditional network planning methods or Gantt chart methods are not applicable to linear asset inspection activities.

[0011] How to scientifically and efficiently compile inspection plans for multiple inspection methods for rail transit linear assets and rationally allocate inspection resources is an urgent problem to be solved in the field of rail transit technology. Summary of the invention

[0012] In view of the above problems, the present invention provides a checking method based on balance and adjustability, comprising:

[0013] Establish a rail transit space-time grid based on the spatial dimension of rail transit lines and the temporal dimension of rail transit linear asset inspection;

[0014] Based on the space-time grid of rail transit, the optimization compilation model of the grid inspection plan for rail transit linear assets is determined, including:

[0015] Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid;

[0016] Determine the equilibrium objective function based on the rail transit space-time grid and decision variables;

[0017] Determine the adjustability objective function based on the rail transit space-time grid and decision variables;

[0018] The balance objective function and the adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model;

[0019] The optimal inspection plan is determined based on the optimization compilation model of the grid inspection plan for rail transit linear assets.

[0020] Furthermore, the establishment of the rail transit time-space grid includes:

[0021] In the spatial dimension, the rail transit lines are divided into several rail transit linear asset grids;

[0022] In terms of time dimension, the entire inspection planning cycle process is divided into several units of time;

[0023] The rail transit space-time grid is constructed based on the rail transit linear asset grid and unit time.

[0024] Furthermore, the decision variables are determined to include:

[0025] Based on the rail transit space-time grid, determine whether to perform inspection activities of the specified inspection method within the specified unit time for the specified rail transit linear asset grid.

[0026] Furthermore, the rail transit time-space grid and inspection activities are represented by the following methods:

[0027] N represents the total number of grids divided into rail transit linear asset lines;

[0028] G i (i∈[1, 2, ..., N]) represents the i-th rail transit linear asset grid;

[0029] M represents the total number of categories of rail transit linear asset inspection methods;

[0030] C j (j∈[1,2,...,M]) represents the jth type of inspection method;

[0031] C ij (i∈[1,2,...,N],j∈[1,2,...,M]) represents the rail transit linear asset grid G i The jth type of inspection method;

[0032] E represents the total number of unit time in a planning cycle, and e represents the e-th unit time.

[0033] Furthermore, the decision variable formula is:

[0034]

[0035] Among them, i represents the serial number of the rail transit linear asset grid; j represents the serial number of the rail transit linear asset inspection method; e represents the serial number of the unit time in the planning cycle; the decision variable Indicates whether the i-th rail transit linear asset grid performs the j-th inspection method inspection activity at the e-th unit time.

[0036] Furthermore, the equilibrium objective function is determined based on the rail transit space-time grid and decision variables, including:

[0037] Determine the time entropy of each rail transit linear asset grid based on the decision variables, where the time entropy of the rail transit linear asset grid is the information entropy of the unit time distribution of the inspection activities on the rail transit linear asset grid;

[0038] Determine the time entropy of the rail transit space-time grid according to the time entropy of each rail transit linear asset grid;

[0039] The equilibrium objective function is determined according to the time entropy of the rail transit space-time grid.

[0040] Furthermore, the balance objective function is:

[0041] The ratio of the time entropy of the rail transit space-time grid to the ideal maximum time entropy of the rail transit linear asset grid is the largest;

[0042] The ideal maximum time entropy is the time entropy of the rail transit space-time grid when all inspection activities on all rail transit linear asset grids are equally spaced.

[0043] Furthermore, the time entropy of each rail transit linear asset grid is determined based on the decision variables, and the equilibrium objective function is determined based on the time entropy of the rail transit linear asset grid. The time entropy of the rail transit linear asset grid is calculated as follows:

[0044]

[0045]

[0046]

[0047] TH i G is the linear asset grid of rail transit i The time entropy of Represents the linear asset grid G ​​of rail transit i The time interval between the n+1th inspection activity and the nth inspection activity, and Represents the linear asset grid G ​​of rail transit respectively i In the and The inspection activity was performed in units of time, at which time,

[0048]

[0049] S i G is the linear asset grid of rail transit i The total number of inspection passes for all inspection methods is the threshold. For the set U i The elements in S, n∈[1, 2, ..., S i -1].

[0050] Furthermore, the equilibrium objective function is:

[0051] max THR (22), where

[0052]

[0053]

[0054]

[0055] Furthermore, the adjustability objective function is determined based on the rail transit space-time grid and decision variables, including:

[0056] Determine the minimum time interval between two adjacent inspection activities of each rail transit linear asset grid based on the decision variables;

[0057] The adjustability objective function is determined based on the minimum time interval.

[0058] Further, determining the adjustability objective function according to the minimum time interval includes:

[0059] The ratio of the minimum time interval to the total number of unit times is used as an adjustability index, and the adjustability objective function is a maximum adjustability index function.

[0060] Furthermore, the adjustability objective function is determined based on the decision variables and is calculated as follows:

[0061] max R (24)

[0062]

[0063] in, Represents the linear asset grid G ​​of rail transit i The time interval between the n+1th inspection activity and the nth inspection activity,

[0064]

[0065] in, and Represents the linear asset grid G ​​of rail transit respectively i In the and The inspection activity was performed in units of time, at which time,

[0066]

[0067] S i G is the linear asset grid of rail transit i The total number of inspection passes for all inspection methods is the threshold. For the set U i The elements in S, n∈[1, 2, ..., S i -1].

[0068] The present invention provides an inspection system based on balance and adjustability, comprising:

[0069] A space-time grid determination module, used to establish a rail transit space-time grid based on the space dimension of the rail transit line and the time dimension of the rail transit linear asset inspection;

[0070] The model determination module is used to determine the optimization compilation model of the grid inspection plan for rail transit linear assets based on the rail transit time-space grid, including:

[0071] Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid;

[0072] Determine the equilibrium objective function based on the rail transit space-time grid and decision variables;

[0073] Determine the adjustability objective function based on the rail transit space-time grid and decision variables;

[0074] The balance objective function and the adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model;

[0075] The inspection plan determination module is used to determine the optimal inspection plan based on the rail transit linear asset grid inspection plan optimization compilation model.

[0076] The present invention provides an inspection system based on balance and adjustability, the system comprising at least one processor and at least one memory;

[0077] The memory stores a computer program for executing the above method, and the processor calls the computer program in the memory to execute the above method.

[0078] The inspection method and system based on balance and adjustability of the present invention are of great significance for timely grasping the health status of rail transit linear assets and rationally arranging the maintenance and repair operations of rail transit linear assets. The present invention proposes an optimization compilation model for rail transit linear asset inspection plans, which subdivides rail transit linear asset inspection activities in time and space dimensions according to units of specified lengths, and defines more carefully the various constraints and objective functions of different inspection activities of rail transit linear assets in time and space. The objective function takes into account the balance and adjustability of the rail transit linear asset inspection plan. Based on the maximum entropy criterion, entropy is used to measure the balance of the distribution of inspection plans in the time dimension.

[0079] The present invention can be used to scientifically compile inspection plans for multiple inspection methods of rail transit linear assets, reasonably allocate inspection resources, avoid rail transit linear assets not being inspected for a long time span, and avoid the problem of being inspected multiple times in a short time span.

[0080] 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

[0081] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces 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 creative work.

[0082] Figure 1 A schematic diagram showing adjacent inspection time intervals of inspection activities in different inspection modes according to an embodiment of the present invention is shown;

[0083] Figure 2 A flow chart of another inspection method based on balance and adjustability according to an embodiment of the present invention is shown;

[0084] Figure 3 A schematic diagram of time constraints for rail transit linear asset inspection activities according to an embodiment of the present invention is shown;

[0085] Figure 4 A schematic diagram of duration constraints for rail transit linear asset inspection activities according to an embodiment of the present invention is shown;

[0086] Figure 5 A schematic diagram of space constraints for rail transit linear asset inspection activities according to an embodiment of the present invention is shown;

[0087] Figure 6 A schematic diagram of rate constraints for linear asset inspection activities in rail transit according to an embodiment of the present invention is shown;

[0088] Figure 7 A schematic diagram of resource constraints for a rail transit linear asset inspection activity according to an embodiment of the present invention is shown;

[0089] Figure 8 A schematic diagram of inspection continuity constraint for rail transit linear asset inspection activities according to an embodiment of the present invention is shown;

[0090] Fig. 9 A schematic diagram of a railway space-time grid according to an embodiment of the present invention is shown;

[0091] FIG. 10( a ) shows a schematic diagram of a rail transit linear asset inspection activity based on a spatiotemporal grid according to an embodiment of the present invention;

[0092] FIG10( b ) shows a schematic diagram of space-time constraints of two adjacent activities of a rail transit linear asset based on a space-time grid according to an embodiment of the present invention;

[0093] Fig.11 The decision variables in the model OISM-TG according to an embodiment of the present invention are shown. Schematic diagram;

[0094] Fig.12 A schematic diagram of time constraints based on a rail transit space-time grid according to an embodiment of the present invention is shown;

[0095] Fig.13 A schematic diagram of construction period constraints based on rail transit time-space grid according to an embodiment of the present invention is shown;

[0096] Fig.14 A schematic diagram of spatial constraints based on a rail transit space-time grid according to an embodiment of the present invention is shown;

[0097] Fig.15 A schematic diagram of rate constraints based on a rail transit space-time grid according to an embodiment of the present invention is shown;

[0098] Fig.16 A schematic diagram of resource constraints based on a rail transit space-time grid according to an embodiment of the present invention is shown;

[0099] Fig.17 A schematic diagram of continuity constraint based on rail transit space-time grid according to an embodiment of the present invention is shown;

[0100] Fig.18 The actual track inspection plan diagram of the Lanzhou-Xinjiang Line down line of the Jiayuguan Line Workshop of the Lanzhou Railway Bureau in December 2016 is shown according to an embodiment of the present invention;

[0101] Fig.19 The figure shows the down track inspection plan diagram of the Lanzhou-Xinjiang Line compiled by the Jiayuguan Line Workshop of the Lanzhou Railway Bureau in December 2016 according to the model OISM-TG of an embodiment of the present invention;

[0102] Fig. 20 A structural schematic diagram of an inspection system based on balance and adjustability according to an embodiment of the present invention is shown;

[0103] Fig.21 A schematic structural diagram of another inspection system based on balance and adjustability according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0104] 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.

[0105] The inspection tasks and inspection frequencies in the rail transit linear asset inspection plan are generally fixed. The main challenge in its preparation is to achieve the balance of the time intervals between adjacent inspection activities in the inspection plan and optimize the overall adjustability. The balance of the time intervals between adjacent inspection activities in the inspection plan means that the time intervals between different inspection activities should be as balanced as possible, such as Figure 1 As shown, T j , T j+1 , T j+2 , T j+3 With T j+4 They should be as equal as possible to avoid rail transit linear assets not being inspected in a longer time span but being inspected multiple times in a shorter time span. Figure 1 The horizontal axis represents mileage, the vertical axis represents time, and lines of different shapes represent different inspection activities. The adjustability of the inspection plan refers to the ability of the inspection plan to reduce the impact of various random disturbances (such as bad weather conditions) during execution, while meeting the inspection requirements min (T j ,T j+1 ,T j+2 ,T j+3 ,T j+4 ) should be as large as possible to ensure that the inspection plan has greater time flexibility and to avoid delays in inspection activities or disrupting the inspection plan's arrangements for labor, materials, machines and other resources in advance.

[0106] Although there are many types of rail transit linear asset inspection methods and the inspection principles of different inspection methods are different, in general, rail transit linear asset inspection activities have the following characteristics.

[0107] (1) Rail transit linear asset inspection activities are continuous in the horizontal direction; rail transit linear asset inspection activities generally extend from one end of the line section to the other end; rail transit linear asset inspection activities are mainly composed of activities with repetitive characteristics. For example, dynamic vehicle inspection activities are generally carried out continuously and repeatedly in multiple line sections, consuming time while continuously moving forward in mileage position.

[0108] (2) There are overlaps in the inspection items of different inspection methods. For example, the inspection items of rail inspection vehicles and rail inspection instruments include height, track direction, track gauge, level, and triangular pits. Rail flaw detection vehicles, rail flaw detectors, and manual inspections all check the damage condition of the rails.

[0109] (3) In order to ensure the safety of on-track personnel, some inspection activities need to be arranged during the window time, such as track inspection and rail flaw detector inspection. At the same time, some inspection activities do not need to be arranged during the window time, such as track vehicle inspection, dynamic inspection vehicle inspection, and rail flaw detector vehicle inspection.

[0110] (4) There is no logical constraint on the order of inspection activities of different inspection methods in the time dimension, that is, the order of inspection activities of different inspection methods in time does not affect the perception of the track status.

[0111] (5) There are no multiple inspection activities at the same time and space mileage position. For example, when implementing rail flaw detector inspection activities, track inspection instrument inspection activities cannot be arranged at the same location at the same time.

[0112] (6) Inspection activities are affected by a variety of temporal and spatial factors. For example, in line sections where there are high-risk hidden dangers in equipment quality, the frequency of inspection activities should be increased. The inspection rate is affected by a variety of temporal and spatial factors and is uncertain.

[0113] In the embodiment of the present invention, rail transit linear asset inspection refers to the sum of a series of actions performed by applying technical means to investigate the status of rail transit linear assets. Rail transit linear asset inspection has clear time span and mileage range information, and consumes a certain amount of time and resources during its execution. An inspection activity refers to an inspection task that a working group is assigned to perform within a certain time span and mileage range.

[0114] like Figure 2 As shown, the inspection methods based on balance and adjustability include:

[0115] Establish a rail transit space-time grid based on the spatial dimension of rail transit lines and the temporal dimension of rail transit linear asset inspection;

[0116] Based on the space-time grid of rail transit, the optimization compilation model of the grid inspection plan for rail transit linear assets is determined, including:

[0117] Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid;

[0118] Determine the equilibrium objective function based on the rail transit space-time grid and decision variables;

[0119] Determine the adjustability objective function based on the rail transit space-time grid and decision variables;

[0120] The balance objective function and the adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model;

[0121] The optimal inspection plan is determined based on the optimization compilation model of the grid inspection plan for rail transit linear assets.

[0122] Combined with the analysis of the characteristics of rail transit linear asset inspection activities, the embodiments of the present invention also consider dividing the constraints between rail transit linear asset inspection activities into time constraints, construction period constraints, space constraints, rate constraints, resource constraints, inspection continuity constraints, etc.

[0123] (1) Time constraints

[0124] like Figure 3 As shown in the figure, the time interval T between two adjacent inspections of the same rail transit linear asset using the same inspection method is j Should meet the minimum time constraint and maximum time constraint, T j ≥minT j , T j ≤maxT j , maxT j Indicates the maximum time constraint threshold, minT j It represents the minimum time constraint threshold, and the threshold value is determined by the inspection frequency of different inspection methods specified in the repair rules. In the figure, the horizontal axis represents the line mileage, the vertical axis represents the time, and the lines of different shapes represent the inspection activities of different inspection methods.

[0125] Violation of the maximum time constraint will result in managers being unable to promptly discover quality problems of rail transit linear assets, and violation of the minimum time constraint will result in a waste of inspection resources.

[0126] (2) Construction period constraints

[0127] According to relevant repair rules, rail transit linear asset inspection activities need to be completed within the specified time period. When managers prepare inspection plans, due to interference from various random factors, some rail transit linear assets may not be organized for corresponding inspection activities within the specified time period, that is, missed inspections. Figure 4 As shown, mileage d i >0, mileage d i+1 >0, the construction period constraint is violated. The length of the construction period is determined by the inspection frequency of different inspection methods. For example, the inspection frequency of the track inspection instrument on conventional railways is once a month, and the corresponding construction period is 1 month. The horizontal axis in the figure represents the line mileage, the vertical axis represents the time, and the dotted line represents the deadline of the inspection plan.

[0128] Violation of construction period constraints may cause originally risk-free rail transit linear assets to evolve into risk hazards, and the original low risk may evolve into high risk.

[0129] (3) Spatial constraints

[0130] There are minimum distance constraints and minimum time constraints between different inspection activities. The time of the inspection activities satisfies T j ≥minT j , T j+1 ≥minT j+1 ; Check that the distance of the activity meets d i ≥mind i , d i+1 ≥mind i+1 ,like Figure 5 shown. mind i 、mind i+1 Indicates the minimum distance constraint threshold, minT j 、minT j+1 Indicates the minimum time constraint threshold. The threshold setting is used to ensure that different inspection activities do not interfere or conflict with each other during execution. In the figure, the horizontal axis represents the line mileage, the vertical axis represents time, and different shapes represent inspection activities of different inspection methods.

[0131] If the above constraints are violated, there will be temporal and spatial conflicts between inspection activities, which will affect the efficiency and safety of the inspection activities.

[0132] (4) Rate Constraint

[0133] Rail transit linear asset inspection activities are subject to various time and space factors, and their rate is uncertain, but they should meet the minimum rate constraint and the maximum rate constraint. j ≤v j ≤maxv j , minv j+1 ≤v j+1≤maxv j+1 ,like Figure 6 As shown. min v j 、min v j+1 Indicates the activity minimum rate constraint threshold, max v j 、max v j+1 Indicates the maximum rate constraint threshold min v j and max v j Used to indicate the rate variation range when the start time is determined, min v j+1 and maxv j+1 It is used to indicate the speed variation range when the end time is determined. The threshold value is generally determined by the technical parameters of the detection instrument or device. For example, the track inspection instrument usually travels at a speed of 3 to 4 km / h, and the fastest should not exceed 8 km / h. The horizontal axis in the figure represents the line mileage, the vertical axis represents the time, and the dotted line represents the deadline of the inspection plan.

[0134] Meeting the maximum rate constraint is used to ensure inspection quality and prevent false detection and missed detection; meeting the minimum rate constraint is used to ensure the efficiency of inspection activities.

[0135] (5) Resource constraints

[0136] The amount of resources that can be used during the rail transit linear asset inspection process is often limited. To ensure the smooth progress of the inspection activities, the number of inspection activities organized at the same time should be less than or equal to the number of working groups (i.e., resource usage). Figure 7 As shown in the figure. The work group is the basic unit for inspection activities, which is composed of machinery, personnel and related auxiliary production materials. It represents a certain resource allocation and corresponds to a certain inspection efficiency. The horizontal axis in the figure represents time, the vertical axis represents the number of work groups, and the dotted line represents the threshold of resource usage. The size of the threshold is represented by RC.

[0137] Meeting resource constraints is the basic guarantee for the feasibility of the inspection plan. If the amount of resources used by the inspection activity exceeds the available resources, it will directly lead to the inability to organize and arrange the inspection activity.

[0138] (6) Check continuity constraints

[0139] Rail transit linear asset inspection activities are characterized by linearity, continuity, and repetition. They are organized and arranged as a complete whole within a unit of time WT, and their execution should be continuous and uninterrupted. j =0,d i =0, such as Figure 8 In the figure, the horizontal axis represents the route mileage, the vertical axis represents the time, and the two horizontal dotted lines represent the start time and end time of the unit time respectively.

[0140] If the above constraints are violated, inspection activities will be discontinuous or intermittent, which will cause waste of resources, loss of inspection efficiency and increase management costs.

[0141] The embodiment of the present invention takes the spatiotemporal grid of rail transit linear asset inspection as the basic unit, discretizes the rail transit linear asset inspection activities in the spatial and temporal dimensions, and proposes an Optimal Inspection Scheduling Model for Time-location Grids (OISM-TG) for rail transit linear asset inspection, which more carefully defines various constraints and objective functions of different inspection activities of rail transit linear assets in time and space, optimizes the balance and adjustability of the compiled rail transit linear asset inspection plan, and enhances the practicability of the rail transit linear asset inspection plan.

[0142] The construction of the optimization model for grid-based inspection plan of rail transit linear assets is described in detail below.

[0143] In the embodiment of the present invention, the rail transit lines with linear, continuous and strip layouts are divided into several small sections according to certain rules to form a rail transit grid. Without loss of generality, the line is divided into several adjacent small sections of equal length. The rail transit time-space grid refers to a number of small units formed by dividing the entire life cycle of the 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 declaration cycle process is a complete maintenance process. Fig. 9 As shown, the horizontal axis represents mileage, the vertical axis represents time, and each space-time grid is represented by G ij Indicates, i represents the i-th rail transit grid, and j represents the time period of the grid. The rail transit time-space grid is a basic unit based on time-space. Exemplarily, the rail transit time-space grid division method is as follows.

[0144] (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.

[0145] (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 the inspection 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.

[0146] Rail transit linear asset inspection 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 inspection activities are divided into smaller time units and space units, which can more finely define the various time and space constraints of inspection activities, and more accurately describe the impact of various time factors and space factors on inspection activities, so that managers can manage rail transit infrastructure inspection activities at a higher time and space resolution, such as Figure 10(a) , 10(b) As shown. In the figure, the horizontal axis represents the line mileage, the vertical axis represents the time of activity execution, and the broken line represents the inspection activity of rail transit infrastructure. In Figure 10(b), the angle between the broken line and the horizontal axis represents the speed of activity execution. The smaller the angle, the faster the execution rate of the corresponding activity. The shaded part in Figure 10(b) represents the spatiotemporal constraints between any time and any mileage point in the entire process of execution of two adjacent activities.

[0147] Rail transit linear asset inspection activities may be delayed or temporarily cancelled due to various time and space factors (such as bad weather), and the rail transit linear asset inspection plan may be adjusted multiple times during actual implementation. Therefore, the embodiment of the present invention summarizes the concept of "rail transit linear asset inspection plan basic diagram", which is a graphical representation of the time and space relationship of the inspection activities using the coordinate principle, and is used to describe the start time, end time, starting mileage, and end mileage of each inspection activity of the rail transit linear asset, the order of the intervals occupied by different inspection activities, and the length of time each inspection activity occupies the interval.

[0148] During the actual implementation of the rail transit linear asset inspection plan, when the actual progress deviates from the plan, in order to prevent the entire inspection plan from being chaotic, the basic diagram of the rail transit linear asset inspection plan is adjusted with the minimum plan change as the optimal goal to ensure the orderly implementation of the inspection plan.

[0149] In order to consider the influence of various factors, the embodiment of the present invention subdivides the rail transit linear asset inspection activities in space and time dimensions, and proposes OISM-TG in combination with the characteristics of rail transit linear asset inspection activities, which more carefully defines the various time and space constraints and objective functions of different inspection activities of rail transit linear assets, optimizes the balance and / or adjustability of the compiled rail transit linear asset inspection plan, and enhances the practicality of the rail transit linear asset inspection plan. OISM-TG contains at least an objective function and may also contain constraints. Among them, the objective function is to minimize the change in the plan; the constraint system includes time constraints, construction period constraints, space constraints, rate constraints, resource constraints, inspection continuity constraints, etc.

[0150] The construction of the OISM-TG model is described below by way of example. The specific implementation process of the embodiments of the inspection method based on balance and adjustability can be learned based on the construction process of the OISM-TG model.

[0151] The constants involved in the OISM-TG model are as follows:

[0152] SD represents the starting mileage of the inspection plan;

[0153] ED represents the end mileage of the inspection plan;

[0154] DR represents the mileage length of the inspection activity, and its calculation is shown in formula (1);

[0155] DR=ED-SD (1)

[0156] LE represents the length of the linear asset grid of rail transit, which is generally 200 meters;

[0157] The rail transit time-space grid and inspection activities are represented by the following method (the embodiment of the present invention does not limit the symbols represented, and other variables or symbols can be replaced):

[0158] N represents the total number of grids divided by the rail transit linear asset line, and its calculation is shown in formula (2);

[0159]

[0160] G i (i∈[1, 2, ..., N]) represents the i-th rail transit linear asset grid; i represents the sequence number of the rail transit linear asset grid;

[0161] M represents the total number of categories of rail transit linear asset inspection methods;

[0162] C j (j∈[1, 2, ..., M]) represents the jth type of inspection method; j represents the sequence number of the rail transit linear asset inspection method;

[0163] C ij (i∈[1,2,...,N],j∈[1,2,...,M]) represents the rail transit linear asset grid G i The jth type of inspection method;

[0164] 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;

[0165] S ij Indicates that within a planning cycle, the linear asset grid G ​​of rail transit i Inspection method Cj The inspection frequency threshold of different rail transit linear asset grids may be different due to the influence of various time and space factors.

[0166] S i Indicates that within a planning cycle, the linear asset grid G ​​of rail transit i The total number of inspection passes for all inspection methods is calculated as follows:

[0167]

[0168] min T ij Indicates that within a planning cycle, the linear asset grid G ​​of rail transit i Inspection method C j The minimum check interval threshold;

[0169] max T ij Indicates that within a planning cycle, the linear asset grid G ​​of rail transit i Inspection method C j The maximum check interval threshold;

[0170] Indicates the inspection mode C per unit time j The maximum check grid number threshold;

[0171] min L j Indicates the inspection mode C per unit time j The minimum check grid number threshold;

[0172] RC j Indicates that the execution check mode is C j Number of working groups for inspection activities;

[0173] RC represents the total number of working groups performing inspection activities.

[0174] The model OISM-TG involves decision variables. In the embodiment of the present invention, the decision variables are variables that determine whether to perform inspection activities of a specified inspection method in a specified unit time for a specified rail transit linear asset grid based on the rail transit space-time grid.

[0175] The decision variables of the OISM-TG model are This variable represents the rail transit linear asset grid G i Whether to execute the check method C at the e-th unit time j inspection activities, See formula (4). Represents the linear asset grid G ​​of rail transit i The check method executed at the e-th unit time is C jinspection activities, Represents the linear asset grid G ​​of rail transit i The check method C is not executed at the e-th unit time j inspection activities.

[0176]

[0177] For inspection method C j , the corresponding optimization problem has N×E Boolean decision variables to consider, such as Fig.11 As shown. There are M types of inspection methods for the entire model, so the model OISM-TG has a total of M×N×E Boolean decision variables that need to be considered. The embodiment of the present invention uses Boolean values ​​as decision variable values, which has fast calculation speed and is not prone to errors. However, the embodiment of the present invention does not limit the value-taking method of the decision variable. In other embodiments, integers and other types can also be used, so that the value is not limited to 0 and 1, as long as it can be used to calculate the changes in the inspection plan.

[0178] The decision expression is determined according to the decision variables. The decision expressions involved in the model OISM-TG are as follows. The decision expression can be used to construct constraint conditions.

[0179] Z ij Indicates that in one inspection plan preparation cycle, grid G i Inspection method C j The set of execution times of all inspection activities. Set Z ij The number of elements in is equal to the grid G i Inspection method C j The inspection pass threshold S ij . Set Z ij The elements in Z ij Represents, n∈[1, 2, ..., S ij ], Represents the grid G i In the Unit time to perform the check method C j inspection activities. and The functional relationship is shown in formula (5). Indicates the grid G i The check method C is executed at the e-th unit time j Inspection activities, at this time,

[0180] Inf means selecting elements that meet the conditions.

[0181] U iIndicates that in one inspection plan preparation cycle, grid G i The set consisting of the execution time of all inspection activities of all inspection methods. Set U i The number of elements in is equal to the grid G i The total number of inspection passes for all inspection methods is S i . Set U i The elements in Represents, n∈[1, 2, ..., Si], Represents the grid G i In the Inspection activities were performed per unit of time. and The functional relationship is shown in formula (6). Indicates the grid G i The check method C is executed at the e-th unit time j Inspection activities, at this time,

[0182]

[0183] Q ij Represents the grid G i Execution check mode is C j The number of inspection activities is calculated as shown in formula (7).

[0184]

[0185] Indicates that the inspection method is C j The number of grids inspected in the e-th unit time of the inspection activity is calculated as shown in formula (8).

[0186]

[0187] Indicates that the execution check method for the e-th unit time is C j The demand for work groups for inspection activities is calculated as shown in formula (9). The model OISM-TG assumes that the inspection method is C j There is only one working group for the inspection activity. If the actual problem is for the inspection method C j If there are multiple working groups, they will be divided into multiple sub-problems of a single working group according to the inspection tasks for processing.

[0188]

[0189] Determine an objective function based on the space-time grid. The objective function of the OISM-TG model in the embodiment of the present invention includes a balance objective function and / or an adjustability objective function.

[0190] Balanced objective function

[0191] In the embodiment of the present invention, the model OISM-TG uses entropy theory to construct an index to measure the balance of the rail transit linear asset inspection plan in the time dimension, which is called time entropy. The larger the time entropy, the more balanced the inspection plan is in the time dimension.

[0192] Information entropy, also known as Shannon entropy, was first proposed by Claude Elwood Shannon in 1948 to measure the uncertainty of information. When the state or result of an event is completely known, the information entropy H is equal to 0; when the possible states or results of an event are more, the greater the uncertainty, the greater the H. The mathematical abstraction of information entropy H is that an event has n possible results X. i (i∈[1, 2, ..., n]), the probability of each result occurring is p i The calculation of information entropy H, which measures the uncertainty of the event, is shown in formula (10).

[0193]

[0194]

[0195] p i ≥0,i∈[1,2,...,n] (12)

[0196] Based on the maximum entropy criterion, when p i When (i=1, 2, 3, ..., n) satisfies the following formula (13), H in formula (10) has a maximum value. When the entropy is smaller, the deviation of the group of data from the mean is greater; when the entropy is larger, it indicates that the group of data is more concentrated near the mean and the data distribution is more balanced; when a group of data is completely equal, the entropy value reaches the maximum.

[0197]

[0198] In an embodiment of the present invention, the balance objective function of the model OISM-TG is determined based on the rail transit space-time grid and decision variables, including: determining the time entropy of each rail transit linear asset grid based on the decision variables, the time entropy of the rail transit linear asset grid is the information entropy of the unit time distribution of the inspection activities on the rail transit linear asset grid; determining the time entropy of the rail transit space-time grid according to the time entropy of each rail transit linear asset grid; determining the balance objective function according to the time entropy of the rail transit space-time grid. The objective function is the maximum ratio of the time entropy of the rail transit space-time grid and the ideal maximum time entropy of the rail transit linear asset grid. Among them, the ideal maximum time entropy is the time entropy of the rail transit space-time grid when all inspection activities on all rail transit linear asset grids are equally spaced.

[0199] Specifically, the OISM-TG model uses the time interval between two adjacent inspection activities The probability of the event outcome is defined as the ratio of the sum of the interval unit times within the planning period Substituting the variable p in formula (10) i , redefine entropy. In the embodiment of the present invention, the sum of the interval unit time is set to E-1. This entropy is called grid G i Time entropy TH i , as a measure of the grid G i The balance index of the time interval between two adjacent inspection activities in a planning cycle is shown in formula (14). Time entropy TH i The larger the value, the more balanced the time interval between two adjacent inspection activities in the inspection plan. Represents the grid G i The time interval between the n+1th inspection activity and the nth inspection activity is shown in formula (15), where n and n+1 represent the grid G i The sequence numbers of two adjacent inspection activities. express The ratio of the total number of unit time E-1 in the planning cycle is shown in formula (16). Where i∈[1, 2, ..., N], n∈[1, 2, ..., S i -1]. Adopting the E-1 definition The reason is that the grid G i During the planning cycle, all S i -1 time interval The sum is less than or equal to E-1.

[0200]

[0201]

[0202]

[0203]

[0204] According to the maximum entropy criterion, the grid G i Time entropy TH i When it reaches the maximum value, The two are equal. That is, within a planning cycle, the time entropy TH i The larger the value of i The closer the time interval between two adjacent inspection activities is, the smaller the grid G i The more balanced the inspection plan is.

[0205] The time entropy of the spatiotemporal grid of rail transit linear assets is represented by TH, which is used to measure the spatiotemporal grid of rail transit linear assets, that is, all grids check the balance of plans within a planning cycle. Its calculation is shown in formula (18).

[0206]

[0207] When the time entropy TH of the entire rail transit linear asset reaches a maximum value, the grid G i (i∈[1,2,...,N] time entropy TH i When the maximum value is reached, the inspection plan of each grid within the entire rail transit linear asset is most balanced.

[0208] According to the maximum entropy criterion, without considering the task constraints, the grid G i Time entropy TH i The ideal maximum value TH i，max , as shown in formula (19). When the time intervals between all activities are equal, the ideal maximum value is reached.

[0209]

[0210] Correspondingly, the ideal maximum value of the time entropy TH of all grids of rail transit linear assets is TH max , as shown in formula (20).

[0211]

[0212] The time entropy TH of all grids of rail transit linear assets and its ideal maximum value TH max The ratio is expressed as THR, as shown in formula (21).

[0213]

[0214] The equilibrium objective function of the OISM-TG model is shown in formula (22).

[0215] max THR (22)

[0216] In the embodiment of the present invention, the balance objective function is defined by a ratio, and the ideal maximum value should be 1, so that the gap between the ratio and the most balanced state can be clearly seen from the calculation result, which is used as an indicator for measuring the plan.

[0217] Adjustability objective function

[0218] The adjustability of the rail transit linear asset inspection plan refers to the ability of the rail transit linear asset inspection plan to withstand various random anti-disturbance factors during its execution. Due to the influence of spatial factors and time factors (such as bad weather and holidays), rail transit linear asset inspection activities may be delayed or temporarily cancelled, which may easily lead to confusion in the entire inspection plan. Therefore, the compiled inspection plan should reduce the impact of various random disturbances.

[0219] In an embodiment of the present invention, the adjustability objective function of the model OISM-TG is determined based on the rail transit spatiotemporal grid and the decision variables, including: determining the minimum time interval between two adjacent inspection activities of each rail transit linear asset grid based on the decision variables; and determining the adjustability objective function according to the minimum time interval. Among them, determining the adjustability objective function according to the minimum time interval includes: taking the ratio of the minimum time interval to the total number of unit time as the adjustability index, and the adjustability objective function is the maximum function of the adjustability index.

[0220] Specifically, the OISM-TG model defines the adjustability index R as the ratio of the minimum time interval between two adjacent inspection activities in a grid within an inspection plan preparation cycle to the total number of unit times E within the plan preparation cycle. It is used as an important indicator to measure the flexibility of inspection plan changes. Its calculation is shown in formula (23).

[0221]

[0222] Represents the grid G i The time interval between the n+1th inspection activity and the nth inspection activity is shown in formula (15).

[0223] The adjustability objective function of the model OISM-TG is shown in formula (24), that is, the minimum time interval between two activities reaches the maximum.

[0224] max R (24)

[0225] Weight-based multi-objective function

[0226] In an embodiment of the present invention, the above-mentioned balance objective function or adjustability objective function can be used alone as the optimization objective for preparing the inspection plan. The two objective functions can also be considered comprehensively to prepare the inspection plan. Exemplarily, the model OISM-TG realizes the multi-objective optimization of the balance and adjustability of the time intervals of adjacent inspection activities in the inspection plan. The multi-objective optimization problem is converted into a single-objective optimization problem by weighted summation. The optimal objective function after the conversion of the model OISM-TG is shown in formula (25). In the formula, α and β are the weights of the two objective functions. The values ​​of α and β are set by the manager according to the importance of the balance and adjustability objectives in actual conditions.

[0227] max αTHR+βR (1)

[0228] in,

[0229] α+β=1 (2)

[0230] 0≤α,β≤1 (3)

[0231] The embodiment of the present invention proposes to subdivide the rail transit linear asset inspection activities in time and space dimensions according to units of specified lengths, so that the objective functions of different inspection activities of rail transit linear assets can be defined more carefully. And a rail transit linear asset inspection plan optimization compilation model with balance and adjustability as optimization objectives is proposed, which enhances the practicality of the compiled inspection plan. Through the balance optimization objective, the inspection plan can try to avoid the rail transit linear assets not being inspected in a long time span, but being inspected multiple times in a short time span, reducing the difficulty of implementing maintenance activities and facilitating scientific construction. Based on the maximum entropy criterion, the embodiment of the present invention innovatively proposes to use entropy to define an indicator to measure the balance of time intervals between adjacent inspection activities in the inspection plan. Adjustability target optimization can reduce the impact of interference on the inspection plan by various factors and ensure the guidance of actual on-site inspection activities. In the embodiment of the present invention, the model OISM-TG only includes a balance objective function or an adjustability objective function, or it can include these two objective functions, or it can be a weight-based multi-objective function composed of these two objective functions.

[0232] Furthermore, the embodiment of the present invention also checks the feasibility of the compiled inspection plan through a constraint system based on the spatiotemporal grid. In the embodiment of the present invention, the following six types of inspection activity constraints are defined more finely based on the spatiotemporal grid of rail transit linear assets: time constraints, duration constraints, space constraints, rate constraints, resource constraints and inspection continuity constraints. The model OISM-TG can include one or more of these inspection activity constraints.

[0233] Time Constraints

[0234] like Fig.12As shown in the figure, the time constraints of rail transit linear asset inspection activities are as follows: ① In a planning cycle, grid G i Inspection method C j The time interval between two consecutive inspections should be greater than or equal to the minimum inspection interval threshold minT ij , see formula (28); ② In a planning cycle, the grid G i Inspection method C j The time interval between two consecutive inspections should be less than or equal to the maximum inspection interval threshold max T ij , see formula (29). In an inspection plan preparation cycle, if the number of inspections specified by a certain inspection method is 1, the time constraint of the inspection activity corresponding to the inspection method is not considered. Fig.12 The horizontal axis represents the line mileage, the vertical axis represents time, and the polylines of different shapes represent inspection activities of different inspection methods. The horizontal axis is divided by grid length, and the vertical axis is divided by the time granularity required for management, forming a time-space grid for rail transit linear assets.

[0235]

[0236]

[0237] Represents the grid G i In the Unit time to perform the check method C j Inspection activities, Represents the grid G i In the Unit time to perform the check method C j Inspection activities, m and m+1 are two adjacent inspections, and Represents the grid G i Inspection method C j The time between two adjacent inspections.

[0238] Violation of the maximum time constraint will result in managers being unable to promptly discover quality problems of rail transit linear assets, and violation of the minimum time constraint will result in a waste of inspection resources.

[0239] Duration Constraints

[0240] The construction period constraints of rail transit linear asset inspection activities include two aspects: ① Within a planning cycle, each type of inspection method needs to complete the specified number of inspections; ② Each type of inspection method needs to inspect all rail transit linear asset grids during each inspection to avoid missed inspections. Therefore, within a planning cycle, the grid G i Execution check mode is C jNumber of inspection activities Q ij Should be equal to the threshold S of the number of inspection passes ij , see formula (30) and Fig.13 . Fig.13 The horizontal axis represents the line mileage, and the vertical axis represents the time. The horizontal axis is divided by the grid length, and the vertical axis is divided by the time granularity required for management, forming a rail transit linear asset space-time grid. The dotted line represents the deadline of the inspection plan. i >0, resulting in the dotted box area Q ij <S ij , the construction period constraint is not met.

[0241]

[0242] Violation of construction period constraints may cause originally risk-free rail transit linear assets to evolve into risk hazards, and the original low risk may evolve into high risk.

[0243] Space constraints

[0244] The spatial constraint of rail transit linear asset inspection activities means that at most one inspection activity can occur in any rail transit linear asset space-time grid. i At most one inspection activity can occur in a unit of time, see formula (31) and Fig.14 . Fig.14 The horizontal axis represents the line mileage, the vertical axis represents time, and lines of different shapes represent inspection activities of different inspection methods. The horizontal axis is divided into scales according to the grid length, and the vertical axis is divided according to the time granularity required for management, forming a time-space grid for rail transit linear assets.

[0245]

[0246] If the above constraints are violated, there will be temporal and spatial conflicts between inspection activities, which will affect the efficiency and safety of the inspection activities.

[0247] Rate Constraint

[0248] The OAMIS-TG model defines the inspection rate by the number of rail transit linear asset grids inspected per unit time for each type of inspection activity. Fig.15 As shown in the figure, the rate constraints of rail transit linear asset inspection activities are as follows: ① The inspection method is C j The number of grids inspected per unit time Should be less than or equal to the maximum rate threshold maxL j , see formula (32); ② The inspection method is C j The number of grids inspected per unit time Should be greater than or equal to the minimum rate threshold minLj , see formula (33). Fig.15 The horizontal axis represents the line mileage, and the vertical axis represents time. The horizontal axis is divided according to the grid length, and the vertical axis is divided according to the time granularity required for management, forming a space-time grid for rail transit linear assets.

[0249]

[0250]

[0251] Meeting the maximum rate constraint is used to ensure inspection quality and prevent false detection and missed detection; meeting the minimum rate constraint is used to ensure the efficiency of inspection activities.

[0252] Resource Constraints

[0253] The resource constraint of rail transit linear asset inspection activity refers to the number of inspection methods C per unit time. j Number of inspection activities Less than or equal to the corresponding working group number RC j , see formula (34) and Fig.16 . Fig.16 The horizontal axis represents time, and the vertical axis represents the number of work groups. The dotted line represents the resource usage threshold RC j .

[0254]

[0255] Meeting resource constraints is the basic guarantee for the feasibility of the inspection plan. If the amount of resources used by the inspection activity exceeds the available resources, it will directly lead to the inability to organize and arrange the inspection activity.

[0256] Check continuity constraints

[0257] The continuity constraint of rail transit linear asset inspection means that each working group performs the inspection in the following way: j The inspection activities should be continuous and uninterrupted within a unit of time, see formula (35) and Fig.17 . Fig.16 The horizontal axis represents the line mileage, and the vertical axis represents time. The horizontal axis is divided by the grid length, and the vertical axis is divided by the time granularity required for management, forming a rail transit linear asset space-time grid. The dotted line represents the start and end time of the e-th unit time. i >0, the check continuity constraint is not satisfied.

[0258]

[0259] Where p represents the mileage position starting from the e-th unit time, then Indicates the mileage position where the execution of the e-th unit time ends. If the above constraints are violated, the inspection activities will be discontinuous or intermittent, which will cause waste of resources and loss of inspection efficiency, and increase management costs. For example, for the same type of inspection activities, if it is necessary to inspect a two-kilometer line when executing it on a certain day, then according to the inspection continuity constraint, these two kilometers must be continuous and one kilometer cannot be skipped in the middle. Otherwise, the skipped mileage needs to be inspected again separately, which increases the cost of manpower and mechanical transportation and wastes resources.

[0260] This model can be used to generate optimization solutions as well as to screen or evaluate existing inspection plans. When used to generate optimization solutions, the objective function and constraints of this model can be applied to the solution software, and the optimization solution can be automatically calculated by the solution software. Exemplarily, the solution software has a global optimal algorithm, and the embodiment of the present invention does not limit the choice of the solution software. There is no restriction on how to obtain one or more inspection plans, for example, a new inspection plan can be obtained through manual planning or an inspection plan can be obtained by automatic calculation by a computer, or a combination of the two. Through the OISM-TG model of the embodiment of the present invention, optimal screening and feasibility screening can be performed on multiple inspection plans to obtain the final optimized inspection plan. Based on the subdivided spatiotemporal grid and the variables of the inspection activity execution, the embodiment of the present invention manages the inspection activities in the entire inspection cycle in a detailed and comprehensive manner, provides a scientific optimization basis, can calculate the objective function based on the decision variables of the embodiment of the present invention, and can conveniently use computer programs to realize automatic, efficient and accurate inspection plan evaluation and optimization. Furthermore, the generation of the inspection plan can use a computer to randomly combine and generate a variety of alternative plans, and use the model of this application for automatic screening, thus avoiding the problems of low efficiency and strong subjectivity of manual compilation and failure to achieve the optimal or better result.

[0261] The inspection method based on balance and adjustability of the embodiment of the present invention has achieved good technical effects in practical applications. The following takes the track inspection plan of the Lanzhou-Xinjiang Line from K721+000 to K765+000 in December 2016 as an example to verify the effectiveness of the model OI SM-TG proposed in the embodiment of the present invention.

[0262] Railway tracks are a typical linear asset of rail transit. The line section length DR of the Lanxin Line from K721+000 to K765+000 is 44km, and the daily inspection and maintenance of the engineering equipment is undertaken by the Jiayuguan Line Workshop of China Railway Lanzhou Bureau Group Co., Ltd. (hereinafter referred to as "Lanzhou Bureau"). The track grid length LE is 200 meters, so the number of track grids N involved in the Lanxin Line Downward in this example is 220.

[0263] The total number of days in the planning cycle of this example is E=31, involving 4 types of inspection methods, namely, track inspection instrument inspection, rail flaw detection inspection, manual inspection, and track inspection vehicle inspection. Table 1 shows the inspection task volume of the Lanxin Line Downward Track of the Jiayuguan Line Workshop of Lanzhou Bureau in December 2016. Among them, the track quality status of the Lanxin Line Downward Track from K731+000 to K736+000 is poor, so the manual inspection frequency of the track grid within this mileage range is one more than that of other track grids. The track inspection vehicle inspection has been pre-arranged on the 8th and 21st, respectively, to conduct the first and second inspections of the Lanxin Line Downward Track.

[0264] Table 1 Inspection workload of the Lanzhou-Xinjiang Line Downward Track by the Jiayuguan Line Workshop of Lanzhou Bureau in December 2016

[0265]

[0266] This example involves four working groups, namely the Jiayuguan inspection and monitoring area, the Jiayuguan line maintenance area, the Jiayuguan rail flaw detection area, and the track inspection vehicle working group. In order to observe the overall distribution of the data set and identify possible outliers in the data set, 581 historical inspection rate data of these working groups in the three years from January 2015 to December 2017 were analyzed, and the first and third quartiles of the historical inspection rate data were selected as the upper and lower thresholds of the inspection rate, where the inspection rate was defined by the line length inspected within a unit window time.

[0267] Table 2 Inspection rate constraints of different inspection methods on Lanxin Line

[0268]

[0269] Model results analysis

[0270] By analyzing the comparison contents in Table 3, we can see that

[0271] (1) Constraints: The actual inspection plan in the case does not meet the construction period constraints, space constraints, and rate constraints. This is because the preparation of the railway on-site inspection plan is mainly based on the management experience of on-site engineers, and it is difficult to comprehensively and systematically consider the inspection activity constraint system established in the embodiment of the present invention.

[0272] (2) Objective function: Compared with the actual inspection plan at the railway site, the inspection plan compiled by the OISM-TG model has an improvement of 22.5% in terms of balance target and 0.161 in terms of adjustability. The corresponding weighted objective function value has been improved by 42.5%.

[0273] Based on the above analysis, Fig.18 , Fig.19The visualization results show that the railway track inspection plan prepared by the model OISM-TG is better than the actual inspection plan prepared by the on-site engineers in the case, and has better balance and adjustability.

[0274] Table 3 Comparison between the inspection plan prepared by the model OISM-TG and the actual inspection plan on site

[0275]

[0276] Establish a rail transit space-time grid based on the spatial dimension of rail transit lines and the temporal dimension of rail transit linear asset inspection;

[0277] The grid inspection plan evaluation model for rail transit linear assets is determined based on the rail transit space-time grid, including:

[0278] Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid;

[0279] Determine constraints based on rail transit space-time grid and decision variables;

[0280] The inspection plan is determined based on the grid inspection plan evaluation model for rail transit linear assets.

[0281] The inspection plan evaluation method for rail transit linear assets of the embodiment of the present invention can screen and evaluate the rationality of the inspection plan through an evaluation model with constraints when formulating or optimizing the inspection plan, thereby improving the scientificity and efficiency of the plan evaluation.

[0282] Furthermore, the constraint condition includes at least one of the following constraint conditions: time constraint, duration constraint, space constraint, rate constraint, resource constraint, and inspection continuity constraint. Some or all of the constraints can be selected as needed to construct the evaluation model.

[0283] The specific expression of the model construction process and constraints based on space-time grids and decision variables can be obtained from the above-mentioned embodiments related to the optimization and adjustment model of the rail transit linear asset grid inspection plan, and will not be repeated here.

[0284] Based on the same inventive concept, the embodiment of the present invention also provides an inspection system based on balance and adjustability, such as Fig. 20 As shown, including:

[0285] A space-time grid determination module, used to establish a rail transit space-time grid based on the space dimension of the rail transit line and the time dimension of the rail transit linear asset inspection;

[0286] The model determination module is used to determine the optimization compilation model of the grid inspection plan for rail transit linear assets based on the rail transit time-space grid, including:

[0287] Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid;

[0288] Determine the equilibrium objective function based on the rail transit space-time grid and decision variables;

[0289] Determine the adjustability objective function based on the rail transit space-time grid and decision variables;

[0290] The balance objective function and the adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model;

[0291] The inspection plan determination module is used to determine the optimal inspection plan based on the rail transit linear asset grid inspection plan optimization compilation model.

[0292] The specific implementation of the inspection system based on balance and adjustability in the embodiment of the present invention can be obtained according to any embodiment method of the present invention, and will not be described in detail.

[0293] The method of the present invention can be implemented by a system controlled by a computer or an embedded program. Therefore, correspondingly, another inspection system based on balance and adjustability is also provided in the embodiment of the present invention, such as Fig.21 As shown, the system includes at least one processor and at least one memory; the memory stores a computer program for executing any of the above methods of the embodiments of the present invention, and the processor calls the computer program in the memory to execute any of the methods of the embodiments of the present invention.

[0294] Furthermore, the memory may be communicatively connected to one or more processors, and the memory may store instructions that may be executed by one or more processors. The instructions are executed by one or more processors so that the one or more processors can implement the method of the present invention.

[0295] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for checking balance and adjustability, characterized in that: include: Establish a rail transit space-time grid based on the spatial dimension of rail transit lines and the temporal dimension of rail transit linear asset inspection; Based on the space-time grid of rail transit, the optimization compilation model of the grid inspection plan for rail transit linear assets is determined, including: Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid; Determine the equilibrium objective function based on the rail transit space-time grid and decision variables; Determine the adjustability objective function based on the rail transit space-time grid and decision variables; The balance objective function and the adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model; Determine the optimal inspection plan based on the rail transit linear asset grid inspection plan optimization compilation model; Among them, the equilibrium objective function determined based on the rail transit space-time grid and decision variables includes: Determine the time entropy of each rail transit linear asset grid based on the decision variables, where the time entropy of the rail transit linear asset grid is the information entropy of the unit time distribution of the inspection activities on the rail transit linear asset grid; Determine the time entropy of the rail transit space-time grid according to the time entropy of each rail transit linear asset grid; Determine the equilibrium objective function according to the time entropy of the rail transit space-time grid; The balance objective function is: The ratio of the time entropy of the rail transit space-time grid to the ideal maximum time entropy of the rail transit linear asset grid is the largest; The ideal maximum time entropy is the time entropy of the rail transit space-time grid when all inspection activities on all rail transit linear asset grids are equally spaced; Among them, the adjustability objective function determined based on the rail transit space-time grid and decision variables includes: Determine the minimum time interval between two adjacent inspection activities of each rail transit linear asset grid based on the decision variables; Determining an adjustability objective function based on a minimum time interval; Determining the adjustability objective function according to the minimum time interval includes: The ratio of the minimum time interval to the total number of unit times is used as an adjustability index, and the adjustability objective function is a maximum adjustability index function.

2. The inspection method based on balance and adjustability according to claim 1, characterized in that: The establishment of the rail transit time-space grid includes: In the spatial dimension, the rail transit lines are divided into several rail transit linear asset grids; In terms of time dimension, the entire inspection planning cycle process is divided into several units of time; The rail transit space-time grid is constructed based on the rail transit linear asset grid and unit time.

3. The inspection method based on balance and adjustability according to claim 2, characterized in that: The decision variables include: Based on the rail transit space-time grid, determine whether to perform inspection activities of the specified inspection method within the specified unit time for the specified rail transit linear asset grid.

4. The inspection method based on balance and adjustability according to claim 2, characterized in that: The rail transit time-space grid and inspection activities are represented by the following method: N represents the total number of grids divided into rail transit linear asset lines; represents the i-th rail transit linear asset grid; M represents the total number of categories of rail transit linear asset inspection methods; Indicates the jth type of inspection method; Represents a linear grid of rail transit assets The jth type of inspection method; E represents the total number of unit time in a planning cycle, and e represents the e-th unit time.

5. The inspection method based on balance and adjustability according to claim 4, characterized in that: The decision variable formula is: （4）， Among them, i represents the serial number of the rail transit linear asset grid; j represents the serial number of the rail transit linear asset inspection method; e represents the serial number of the unit time in the planning cycle; the decision variable Indicates whether the i-th rail transit linear asset grid performs the j-th inspection method inspection activity at the e-th unit time.

6. The inspection method based on balance and adjustability according to claim 5, characterized in that: The time entropy of each rail transit linear asset grid is determined based on the decision variables, and the equilibrium objective function is determined based on the time entropy of the rail transit linear asset grid. The time entropy of the rail transit linear asset grid is calculated as follows: （14） （15） （16） Linear asset grid for rail transit The time entropy of Represents a linear grid of rail transit assets The time interval between the n+1th inspection activity and the nth inspection activity, and Represents the linear asset grid of rail transit In the and The inspection activity was performed in units of time, at which time, =e, （6）， Linear asset grid for rail transit The total number of inspection passes for all inspection methods is the threshold. For collection The elements in .

7. The inspection method based on balance and adjustability according to claim 6, characterized in that: The equilibrium objective function is: (22), where （21）， （20）， （18）。 8. The inspection method based on balance and adjustability according to claim 5, characterized in that: The adjustability objective function is determined based on the decision variables and is calculated as follows: （24） （23）， in, Represents a linear grid of rail transit assets The time interval between the n+1th inspection activity and the nth inspection activity, （15）， in, and Represents the linear asset grid of rail transit In the and The inspection activity was performed in units of time, at which time, =e, （6）， Linear asset grid for rail transit The total number of inspection passes for all inspection methods is the threshold. For collection The elements in .

9. An inspection system based on balance and adjustability, characterized in that: include: A space-time grid determination module, used to establish a rail transit space-time grid based on the space dimension of the rail transit line and the time dimension of the rail transit linear asset inspection; The model determination module is used to determine the optimization compilation model of the grid inspection plan for rail transit linear assets based on the rail transit time-space grid, including: Determining a decision variable based on the rail transit space-time grid, wherein the decision variable is used to represent the execution status of the specified inspection activity in the space-time grid; Determine the equilibrium objective function based on the rail transit space-time grid and decision variables; Determine the adjustability objective function based on the rail transit space-time grid and decision variables; The balance objective function and the adjustability objective function are weighted and summed to determine the optimal objective function of the rail transit linear asset grid inspection plan optimization compilation model; The inspection plan determination module is used to determine the optimal inspection plan based on the optimization compilation model of the grid-based inspection plan for rail transit linear assets; Among them, the equilibrium objective function determined based on the rail transit space-time grid and decision variables includes: Determine the time entropy of each rail transit linear asset grid based on the decision variables, where the time entropy of the rail transit linear asset grid is the information entropy of the unit time distribution of the inspection activities on the rail transit linear asset grid; Determine the time entropy of the rail transit space-time grid according to the time entropy of each rail transit linear asset grid; Determine the equilibrium objective function according to the time entropy of the rail transit space-time grid; The balance objective function is: The ratio of the time entropy of the rail transit space-time grid to the ideal maximum time entropy of the rail transit linear asset grid is the largest; The ideal maximum time entropy is the time entropy of the rail transit space-time grid when all inspection activities on all rail transit linear asset grids are equally spaced; Among them, the adjustability objective function determined based on the rail transit space-time grid and decision variables includes: Determine the minimum time interval between two adjacent inspection activities of each rail transit linear asset grid based on the decision variables; Determining an adjustability objective function based on a minimum time interval; Determining the adjustability objective function according to the minimum time interval includes: The ratio of the minimum time interval to the total number of unit times is used as an adjustability index, and the adjustability objective function is a maximum adjustability index function.

10. An inspection system based on balance and adjustability, characterized in that: The system includes at least one processor and at least one memory; The memory stores a computer program for executing any one of the methods of claims 1 to 8, and the processor calls the computer program in the memory to execute any one of the methods of claims 1 to 8.

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