A method for determining maintenance cycle of urban rail equipment with incomplete maintenance

Abstract

The present invention relates to the field of urban rail transit maintenance technology, and in particular to a method for determining the maintenance period of incompletely maintained urban rail transit equipment, comprising the steps of: obtaining urban rail transit equipment fault data; introducing an age regression factor and a reliability decreasing factor to obtain a reliability function of the reliability of the urban rail transit equipment during a preventive maintenance period as a function of operating time; calculating the reliability of the equipment during each preventive maintenance period, and when the reliability is equal to a preset reliability threshold, outputting a preventive maintenance period for the urban rail transit equipment to perform preventive maintenance. By introducing an age regression factor and a reliability decreasing factor based on the urban rail transit equipment fault data to describe the reliability change trend of the equipment after previous incomplete maintenance, the preventive maintenance period of the equipment is determined on the premise of ensuring the reliability of the equipment, thereby improving the operational reliability of the urban rail transit equipment, and reducing its maintenance and management costs, providing efficient and powerful support for the formulation of an urban rail transit equipment maintenance and overhaul plan.

Description

Technical Field

[0001] The invention relates to the technical field of urban rail transit maintenance, and in particular to a method for determining a maintenance period of incompletely maintained urban rail equipment. Background Art

[0002] my country's urban rail transit has developed rapidly in recent years. As of December 31, 2020, my country has opened a total of 7,978 kilometers of urban rail transit lines. With the continuous increase in the number and mileage of urban rail transit lines, the number of urban rail transit operating equipment has also continued to increase, which has put forward higher requirements for rail transit operation and management units in the daily maintenance, repair, and overhaul of urban rail equipment.

[0003] At present, the rail transit operation and management model has gradually changed from the initial single-line operation and management to multi-line and networked operation and management, and urban rail transit has begun to enter the comprehensive operation and maintenance period from the initial high-speed construction period. The repair, inspection and maintenance of urban rail equipment have gradually become the focus of rail transit operation and management units. At present, the main equipment maintenance methods adopted in my country's urban rail transit are mostly fault repair or regular maintenance. The formulated equipment maintenance cycle lacks rationality and scientificity, is inefficient and has high maintenance costs, and it is difficult to meet the reliability and economic requirements for the operation and maintenance of urban rail equipment. The maintenance methods of fault repair and regular maintenance are prone to cause "under-repair" or "over-repair" of equipment, which may even affect normal operation and endanger driving safety in serious cases.

[0004] The existing methods for determining the preventive maintenance cycle of urban rail equipment mainly assume that the equipment is completely restored to its original state after maintenance under ideal conditions, but this does not happen in actual equipment maintenance. In addition, the current methods ignore the impact of maintenance activities on equipment reliability changes and the actual service life of the equipment to a certain extent. That is, although the reliability of the equipment can be improved after preventive maintenance, the speed of reliability degradation and the change pattern of the equipment will be quite different from those before maintenance.

[0005] Therefore, the existing equipment maintenance cycle determination method cannot accurately describe the reliability of the equipment after maintenance, which is not conducive to the maintenance of urban rail equipment. Summary of the invention

[0006] The present invention provides a method for determining the maintenance period of urban rail equipment with incomplete maintenance, so as to solve the defect that the reliability of the equipment after maintenance cannot be accurately described in the above-mentioned prior art, and proposes a method that can accurately describe the reliability of the equipment after maintenance and scientifically and reasonably determine the preventive maintenance period of the urban rail equipment according to the equipment reliability, so as to improve the operational reliability of the urban rail equipment, reduce its maintenance and management costs, and provide necessary theoretical support for formulating the maintenance and overhaul plan of the urban rail equipment.

[0007] The present invention provides a method for determining the maintenance period of urban rail equipment with incomplete maintenance, comprising:

[0008] S1 obtains urban rail equipment fault data, and pre-processes the urban rail equipment fault data to obtain a data set of equipment fault-free operation time;

[0009] S2 calculates the initial reliability function of the urban rail equipment in the first preventive maintenance cycle as the reliability changes with the operating time based on the data set of the equipment's trouble-free operating time;

[0010] S3 introduces the service age regression factor and reliability reduction factor, and calculates the reliability function of each preventive maintenance cycle after the first preventive maintenance cycle;

[0011] S4 obtains all reliability functions and obtains the overall reliability function of urban rail equipment;

[0012] S5: obtaining a reliability threshold, and calculating the reliability of the equipment in each preventive maintenance cycle based on the urban rail equipment reliability function;

[0013] For any preventive maintenance cycle, when the reliability is equal to the reliability threshold, the preventive maintenance cycle for the urban rail equipment is output.

[0014] Wherein, obtaining the urban rail equipment fault data includes:

[0015] Name of faulty equipment, fault time, fault phenomenon, fault cause, fault repair time and equipment type.

[0016] Specifically, in step S1, preprocessing the urban rail equipment fault data to obtain a data set of equipment fault-free operation time includes:

[0017] Sort the failure time of the same type of equipment in ascending order, obtain the equipment failure-free operation time, and obtain the equipment failure-free operation time data set of such equipment, and apply the formula:

[0018] t i =Fault_t i -Fault_t i-1 ;

[0019] Among them, t i is the fault-free operation time of the i-th device, Fault_t i is the i-th failure time of the equipment, 1≤i≤N, and N is the total number of equipment failures.

[0020] Further, in step S2, the initial reliability function R1(t) of the urban rail equipment reliability varying with the operating time in the first preventive maintenance cycle is calculated, including the steps of:

[0021] S21 uses the two-parameter Weibull distribution to establish the equipment reliability function R1(t), and the application formula is:

[0022] R1(t)=exp(-(t / η) β );

[0023] Where t is the trouble-free operation time of the equipment, η is the scale parameter of the Weibull distribution, and β is the shape parameter of the Weibull distribution;

[0024] S22 calculates the observed reliability value of the equipment according to the median rank formula based on the data set of the equipment's trouble-free operation time Get sample data Application formula:

[0025]

[0026] S23 establishes a linear regression equation based on the sample data;

[0027] S24 will ln t i and Substituting into the linear regression equation, ln t i is the independent variable x of the linear regression equation i ,by is the dependent variable y of the linear regression equation i ;

[0028] The scale parameter and the shape parameter are estimated based on the least squares method, applying the formula:

[0029]

[0030] in, For all x i The average value of For all y i The average value of .

[0031] S25 takes T1 as the first preventive maintenance cycle of the equipment, and the time range of the reliability function R1(t) of the equipment in the first preventive maintenance cycle is 0≤t<T1.

[0032] Furthermore, in step S3, the service age regression factor a is introduced k and reliability reduction factor b k , calculate the reliability function R of the kth preventive maintenance cycle after the first preventive maintenance cycle k (t), obtain the reliability function R of the equipment in the k+1th preventive maintenance cycle k+1 (t):

[0033] Rk+1 (t) = b k *R k (t+a k T k );

[0034] Among them, a k , b k are the equipment age regression factor and reliability reduction factor after the kth preventive maintenance, T k It is the kth preventive maintenance cycle of the equipment, and k = 1, 2, 3, ...

[0035] Furthermore, the actual service life of the equipment before and after the kth preventive maintenance in step S3 is:

[0036]

[0037] Among them, L k - is the actual service life of the equipment before the kth preventive maintenance, L k + is the actual service life of the equipment after the kth preventive maintenance, L0 + It is the actual service life of the equipment when it was first put into use.

[0038] Further, in step S4, all reliability functions are obtained, and the reliability function R(t) of the equipment in each preventive maintenance cycle is summarized as follows:

[0039]

[0040] Further, in step S5, the preset reliability threshold is R best ,

[0041] When the reliability of the equipment is equal to the reliability threshold, the corresponding equipment is subject to preventive maintenance. The preventive maintenance cycle T of the equipment when it undergoes the kth preventive maintenance is k satisfy:

[0042] R k (T k )=R best ;

[0043] Get the preventive maintenance cycle T of the equipment when it performs the kth preventive maintenance k , apply the formula:

[0044]

[0045] According to each preventive maintenance cycle T k The numerical value of is used to obtain the value of each preventive maintenance and determine the time point of each preventive maintenance of the equipment.

[0046] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any of the above-mentioned preventive maintenance cycle determination methods are implemented.

[0047] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of any of the above-mentioned preventive maintenance cycle determination methods are implemented.

[0048] The present invention provides a method for determining the maintenance period of incompletely maintained urban rail equipment. The method introduces an age regression factor and a reliability reduction factor on the basis of urban rail equipment fault data to describe the reliability change trend of the equipment after previous incomplete maintenance, and determines the preventive maintenance period of the equipment on the premise of ensuring the reliability of the equipment. The method is more scientific and reasonable, improves the maintenance and overhaul level of the urban rail equipment, and is conducive to ensuring the safe operation of the equipment. The preventive maintenance period of the urban rail equipment is scientifically and reasonably determined based on the equipment reliability, improves the operational reliability of the urban rail equipment, reduces its maintenance and management costs, and provides efficient and powerful support for formulating the maintenance and overhaul plan of the urban rail equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the present invention or 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.

[0050] Figure 1 It is a flow chart of a method for determining a maintenance period of urban rail equipment provided by the present invention;

[0051] Figure 2 It is a schematic diagram of equipment service age of the method for determining the maintenance period of urban rail equipment provided by the present invention;

[0052] Figure 3 It is a schematic diagram of the preventive maintenance cycle of the method for determining the maintenance cycle of urban rail equipment provided by the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0054] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0055] In one embodiment, Figure 1 As shown, the present invention provides a method for determining the maintenance period of urban rail equipment with incomplete maintenance, comprising the following steps:

[0056] S1 obtains urban rail equipment fault data, and pre-processes the urban rail equipment fault data to obtain a data set of equipment fault-free operation time;

[0057] S2 calculates the initial reliability function of the urban rail equipment in the first preventive maintenance cycle as the reliability changes with the operating time based on the data set of the equipment's trouble-free operating time;

[0058] S3 introduces the service age regression factor and reliability reduction factor, and calculates the reliability function of each preventive maintenance cycle after the first preventive maintenance cycle;

[0059] S4 obtains all reliability functions and obtains the overall reliability function of urban rail equipment;

[0060] S5: obtaining a reliability threshold, and calculating the reliability of the equipment in each preventive maintenance cycle based on the urban rail equipment reliability function;

[0061] For any preventive maintenance cycle, when the reliability is equal to the reliability threshold, the preventive maintenance cycle for the urban rail equipment is output.

[0062] Specifically, in step S1, obtaining the urban rail equipment fault data includes:

[0063] Name of faulty equipment, fault time, fault phenomenon, fault cause, fault repair time and equipment type.

[0064] Specifically, in step S1, preprocessing the urban rail equipment fault data to obtain a data set of equipment fault-free operation time includes:

[0065] Sort the failure time of the same type of equipment in ascending order, obtain the equipment failure-free operation time, and obtain the equipment failure-free operation time data set of such equipment, and apply the formula:

[0066] t i =Fault_t i -Fault_t i-1 ;

[0067] Among them, t i is the fault-free operation time of the i-th device, Fault_t i is the i-th failure time of the equipment, 1≤i≤N, N is the total number of equipment failures;

[0068] Among them, the equipment's trouble-free operation time is the interval between two equipment failure times;

[0069] Optionally, the fault-free operation time of the device is usually in hours or days, and the first fault-free operation time of the device t1 = Fault_t1 - Fault_t0, wherein Fault_t0 is the initial commissioning time of the device.

[0070] Further, in step S2, the initial reliability function R1(t) of the urban rail equipment reliability varying with the operating time in the first preventive maintenance cycle is calculated, including the steps of:

[0071] S21 uses the two-parameter Weibull distribution to establish the equipment reliability function R1(t), and the application formula is:

[0072] R1(t)=exp(-(t / η) β );

[0073] Where t is the trouble-free operation time of the equipment, η is the scale parameter of the Weibull distribution, and β is the shape parameter of the Weibull distribution;

[0074] S22 calculates the observed reliability value of the equipment according to the median rank formula based on the data set of the equipment's trouble-free operation time Get sample data The median rank formula is as follows:

[0075]

[0076] S23 establishes a linear regression equation based on the sample data:

[0077] y = Ax + B;

[0078] Among them, x, y, A, and B are the independent variable, dependent variable, slope, and intercept of the linear regression equation respectively;

[0079] S24 will ln t i and Substituting into the linear regression equation, ln t i is the independent variable x of the linear regression equation i ,by is the dependent variable y of the linear regression equation i ;

[0080] The scale parameter η and the shape parameter β are estimated based on the least squares method, using the formula:

[0081]

[0082] in, For all x i The average value of For all y i The average value of .

[0083] S25 takes T1 as the first preventive maintenance cycle of the equipment, and the time range of the reliability function R1(t) of the equipment in the first preventive maintenance cycle is 0≤t<T1.

[0084] It should be noted that equipment maintenance can be divided into incomplete maintenance and complete maintenance according to the effect after maintenance. Among them, incomplete maintenance refers to the equipment status after maintenance is "repaired but not new", that is, the equipment cannot be as good as new after maintenance; complete maintenance refers to the equipment status after maintenance is "repaired as new", that is, the equipment is completely like new after maintenance, and complete maintenance can usually be achieved by replacing the equipment. In the actual maintenance of equipment, although preventive maintenance activities can improve and enhance equipment performance, it is difficult to completely repair all damages and cannot make the equipment completely restored to its good condition, that is, after the equipment undergoes incomplete maintenance, its equipment status is improved to between the perfect state and the state to be repaired; the time span between previous preventive maintenance is the corresponding preventive maintenance cycle;

[0085] Furthermore, in step S3, the service age regression factor a is introduced k and reliability reduction factor b k , calculate the reliability function R of the kth preventive maintenance cycle after the first preventive maintenance cycle k (t), the actual service life of the equipment based on the service life regression factor is shown in the figure below: Figure 2 As shown, the reliability function R of the equipment's k+1th preventive maintenance cycle is obtained. k+1 (t):

[0086] R k+1 (t) = b k *R k (t+a k T k );

[0087] Among them, a k , b kare the equipment age regression factor and reliability reduction factor after the kth preventive maintenance, T k is the kth preventive maintenance cycle of the equipment, and k=1,2,3,......;

[0088] It should be noted that the service age regression factor a k and reliability reduction factor b k Generally, it is set according to maintenance experience and actual maintenance conditions of the equipment, and the present invention does not limit this; usually a1=a2=......=a k =a,b1=b2=......=b k =b, and 0<a<1, b<1; specifically, the smaller the a value is, the more the actual service life of the equipment is reduced, and the better the preventive maintenance effect is; the smaller the b value is, the faster the equipment reliability decreases and the faster the equipment performance deteriorates;

[0089] Furthermore, the actual service life of the equipment before and after the kth preventive maintenance in step S3 is:

[0090]

[0091] Among them, L k - is the actual service life of the equipment before the kth preventive maintenance, L k + is the actual service life of the equipment after the kth preventive maintenance, L0 + The actual service life of the equipment when it was first put into use;

[0092] Generally, the actual service life of the equipment when it is first put into use is L0. + is 0;

[0093] Further, in step S4, all reliability functions are obtained, and the reliability function R(t) of the equipment in each preventive maintenance cycle is summarized as follows:

[0094]

[0095] Further, in step S5, the preset reliability threshold is R best , with reliability as a constraint, the preventive maintenance period of the equipment is calculated according to the equipment reliability function: within the preventive maintenance period, the reliability R(t) of the equipment should always be greater than or equal to the reliability threshold R best , that is, R(t)≥R best ;

[0096] Optionally, the reliability threshold here is not randomly set, but is selected according to the reliability requirements of different devices. 0.9 or 0.95 can be selected as the reliability threshold; the larger the value of the reliability threshold, the higher the reliability requirement for the device operation;

[0097] When the reliability of the equipment drops to the reliability threshold, the corresponding equipment should be started to be maintained. The preventive maintenance cycle T of the equipment during the kth preventive maintenance is k satisfy:

[0098] R k (T k )=R best ;

[0099] Get the preventive maintenance cycle T of the equipment when it performs the kth preventive maintenance k , apply the formula:

[0100]

[0101] According to each preventive maintenance cycle T k The numerical value of is used to obtain the value of each preventive maintenance and determine the time point of each preventive maintenance of the equipment;

[0102] As an example, the equipment preventive maintenance cycle T in the above step S5 is k The specific solution is as follows:

[0103] R1(T1)=exp(-(T1 / η) β )=R best ;

[0104] R2(T2)=b1*exp(-((T2+a1T1) / η) β )=R best ;

[0105] R3(T3)=b1*b2*exp(-((T3+a1T1+a2T2) / η) β )=R best ;

[0106] …

[0107]

[0108] …

[0109] For the kth preventive maintenance cycle T k R k (T k ) is solved and the logarithm can be calculated:

[0110]

[0111]

[0112] ......;

[0113] T k That is, the size of the kth preventive maintenance cycle of the equipment. The calculation result is usually dynamic, such as Figure 3 As shown, based on this result, a preventive maintenance plan for the equipment is developed in the future, and the time point of each preventive maintenance is obtained:

[0114] For example, if the value of k is set to 5, that is, the time points for the next five maintenance of the equipment are set, if T1 = 50, T2 = 45, T3 = 35, T4 = 20, T5 = 8, then the time points for the next five maintenance of the equipment are the 50th day, 50th + 45 = 90th day, and so on, and the time points for the five maintenance are calculated in sequence; the T k The preventive maintenance time point of the equipment can be determined according to its value; this is only used as an example of the present invention and should not be regarded as a further limitation of the present invention.

[0115] The present invention also provides an electronic device, which may include: a processor, a communications interface, a memory, and a communications bus, wherein the processor, the communications interface, and the memory communicate with each other via the communications bus. The processor may call logic instructions in the memory to execute the method for determining the maintenance period of incompletely repaired urban rail equipment, including:

[0116] S1 obtains urban rail equipment fault data, and pre-processes the urban rail equipment fault data to obtain a data set of equipment fault-free operation time;

[0117] S2 calculates the initial reliability function of the urban rail equipment in the first preventive maintenance cycle as the reliability changes with the operating time based on the data set of the equipment's trouble-free operating time;

[0118] S3 introduces the service age regression factor and reliability reduction factor, and calculates the reliability function of each preventive maintenance cycle after the first preventive maintenance cycle;

[0119] S4 obtains all reliability functions and obtains the overall reliability function of urban rail equipment;

[0120] S5: obtaining a reliability threshold, and calculating the reliability of the equipment in each preventive maintenance cycle based on the urban rail equipment reliability function;

[0121] For any preventive maintenance cycle, when the reliability is equal to the reliability threshold, the preventive maintenance cycle for the urban rail equipment is output.

[0122] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0123] On the other hand, the present invention further provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, and when the program instructions are executed by a computer, the computer can execute the method for determining the maintenance period of incompletely repaired urban rail equipment provided by the above methods, comprising the steps of:

[0124] S1 obtains urban rail equipment fault data, and pre-processes the urban rail equipment fault data to obtain a data set of equipment fault-free operation time;

[0125] S2 calculates the initial reliability function of the urban rail equipment in the first preventive maintenance cycle as the reliability changes with the operating time based on the data set of the equipment's trouble-free operating time;

[0126] S3 introduces the service age regression factor and reliability reduction factor, and calculates the reliability function of each preventive maintenance cycle after the first preventive maintenance cycle;

[0127] S4 obtains all reliability functions and obtains the overall reliability function of urban rail equipment;

[0128] S5: obtaining a reliability threshold, and calculating the reliability of the equipment in each preventive maintenance cycle based on the urban rail equipment reliability function;

[0129] For any preventive maintenance cycle, when the reliability is equal to the reliability threshold, the preventive maintenance cycle for the urban rail equipment is output.

[0130] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the method for determining the maintenance period of the urban rail equipment with incomplete maintenance provided by the above methods, comprising the steps of:

[0131] S1 obtains urban rail equipment fault data, and pre-processes the urban rail equipment fault data to obtain a data set of equipment fault-free operation time;

[0132] S2 calculates the initial reliability function of the urban rail equipment in the first preventive maintenance cycle as the reliability changes with the operating time based on the data set of the equipment's trouble-free operating time;

[0133] S3 introduces the service age regression factor and reliability reduction factor, and calculates the reliability function of each preventive maintenance cycle after the first preventive maintenance cycle;

[0134] S4 obtains all reliability functions and obtains the overall reliability function of urban rail equipment;

[0135] S5: obtaining a reliability threshold, and calculating the reliability of the equipment in each preventive maintenance cycle based on the urban rail equipment reliability function;

[0136] For any preventive maintenance cycle, when the reliability is equal to the reliability threshold, the preventive maintenance cycle for the urban rail equipment is output.

[0137] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0138] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. 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 replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the maintenance period of urban rail equipment with incomplete maintenance, characterized in that: include: S1 obtains urban rail equipment fault data, and pre-processes the urban rail equipment fault data to obtain a data set of equipment fault-free operation time; S2 calculates the initial reliability function of the urban rail equipment in the first preventive maintenance cycle as the reliability changes with the operating time based on the data set of the equipment's trouble-free operating time; S3 introduces the service age regression factor and reliability reduction factor, and calculates the reliability function of each preventive maintenance cycle after the first preventive maintenance cycle; S4 obtains all reliability functions and obtains the overall reliability function of urban rail equipment; S5: obtaining a reliability threshold, and calculating the reliability of the equipment in each preventive maintenance cycle based on the urban rail equipment reliability function; For any preventive maintenance cycle, when the reliability is equal to the reliability threshold, output the preventive maintenance cycle for the urban rail equipment; In step S2, the initial reliability function R1(t) of the urban rail equipment reliability varying with the operating time in the first preventive maintenance cycle is calculated, including the following steps: S21 uses the two-parameter Weibull distribution to establish the equipment reliability function R1(t), and the application formula is: R1(t)=exp(-(t / η) β ); Where t is the trouble-free operation time of the equipment, η is the scale parameter of the Weibull distribution, and β is the shape parameter of the Weibull distribution; S22 calculates the observed reliability value of the equipment according to the median rank formula based on the data set of the equipment's trouble-free operation time Get sample data Application formula: S23 establishes a linear regression equation based on the sample data; S24 will ln t i and Substituting into the linear regression equation, ln t i is the independent variable x of the linear regression equation i ,by is the dependent variable y of the linear regression equation i ; The scale parameter and the shape parameter are estimated based on the least squares method, applying the formula: in, For all x i The average value of For all y i The average value of S25 takes T1 as the first preventive maintenance cycle of the equipment, then the time range of the reliability function R1(t) of the equipment in the first preventive maintenance cycle is 0≤t <T1; In step S3, the service age regression factor a is introduced k and reliability reduction factor b k , calculate the reliability function R of the kth preventive maintenance cycle after the first preventive maintenance cycle k (t), obtain the reliability function R of the equipment in the k+1th preventive maintenance cycle k+1 (t): R k+1 (t)=b k *R k (t+a k T k ); Among them, a k , b k are the equipment age regression factor and reliability reduction factor after the kth preventive maintenance, T k It is the kth preventive maintenance cycle of the equipment, and k = 1, 2, 3, ...

2. A method for determining the maintenance period of urban rail equipment with incomplete maintenance according to claim 1, characterized in that: Acquiring the urban rail equipment fault data includes: Name of faulty equipment, fault time, fault phenomenon, fault cause, fault repair time and equipment type.

3. The method for determining the maintenance period of urban rail equipment with incomplete maintenance according to claim 2, characterized in that: In step S1, the urban rail equipment fault data is preprocessed to obtain a data set of equipment fault-free operation time, including: Sort the failure time of the same type of equipment in ascending order, obtain the equipment failure-free operation time, and obtain the equipment failure-free operation time data set of such equipment, and apply the formula: t i =Fault_t i -Fault_t i-1 ; Among them, t i is the fault-free operation time of the i-th device, Fault_t i is the i-th failure time of the equipment, 1≤i≤N, and N is the total number of equipment failures.

4. The method for determining the maintenance period of urban rail equipment with incomplete maintenance according to claim 1, characterized in that: The actual service life of the equipment before and after the kth preventive maintenance in step S3 is: Among them, L k - is the actual service life of the equipment before the kth preventive maintenance, L k + is the actual service life of the equipment after the kth preventive maintenance, L0 + It is the actual service life of the equipment when it was first put into use.

5. A method for determining the maintenance period of urban rail equipment with incomplete maintenance according to claim 4, characterized in that: In step S4, all reliability functions are obtained, and the reliability function R(t) of the equipment in each preventive maintenance cycle is summarized as follows:

6. A method for determining the maintenance period of urban rail equipment with incomplete maintenance according to claim 5, characterized in that: In step S5, the preset reliability threshold is R best , When the reliability of the equipment is equal to the reliability threshold, the corresponding equipment is subject to preventive maintenance. The preventive maintenance cycle T of the equipment when it undergoes the kth preventive maintenance is k satisfy: R k (T k )=R best ; Get the preventive maintenance cycle T of the equipment when it performs the kth preventive maintenance k , apply the formula: According to each preventive maintenance cycle T k The numerical value of is used to obtain the value of each preventive maintenance and determine the time point of each preventive maintenance of the equipment.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the maintenance period determination method according to any one of claims 1 to 6 are implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the maintenance period determination method according to any one of claims 1 to 6 are implemented.

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