A method for designing availability targets for large complex repairable systems

Abstract

The application relates to a design method of a large complex repairable device availability target, and belongs to the technical field of large complex repairable devices. Through carding of a device running stage and preset boundary conditions, based on a Monte Carlo method, a fault mean interval time and a fault maintenance time are sampled, the annual running times of the device are calculated, the mathematical connection between the intrinsic indexes of the device and the user indexes is established, the device availability index decomposition, index optimization and index evaluation are supported, the device availability index design is supported, and the optimal device cost is realized through optimization parameters.

Description

Technical Field

[0001] This invention belongs to the technical field of large, complex, and repairable devices, and specifically relates to a design method for the availability target of large, complex, and repairable devices. Background Technology

[0002] Large-scale equipment refers to equipment with a large number of constituent units and subsystems. The complexity of the equipment refers to the complexity of the relationships between them due to the large number of constituent units and subsystems. In actual engineering, most large and complex equipment is repairable. Large, complex, and repairable equipment needs to achieve its usability target design.

[0003] Availability targets typically include user metrics such as number of runs and uptime. These user metrics impose requirements on the intrinsic characteristics of the device, such as MTBF (Mean Time Between Failure), MTTR (Mean Time To Repair), and other intrinsic characteristics. However, the complex dependencies between user metrics and the intrinsic characteristics of the device cannot be expressed by a single analytical expression. In addition, cost needs to be considered during the design process, making the design of availability targets for large, complex, and repairable devices challenging. Summary of the Invention

[0004] To address the shortcomings of existing technologies and solve the aforementioned problems, a design method for the availability target of large, complex, and repairable devices is proposed. Based on the Monte Carlo method, the correlation between intrinsic device indicators and user indicators is established, and the optimal device cost is achieved by optimizing variable parameters.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A design method for usability targets of large, complex, and repairable devices includes:

[0007] The operating logic is formed based on the various operating stages of the device and the preset boundary conditions. The boundary conditions include the fault maintenance boundary time and the daily operating boundary time. The fault maintenance boundary time is the limit time for which the device can continuously maintain the same spatial accuracy.

[0008] A function for the number of times the device operates throughout the year is constructed based on the operational logic;

[0009] The average fault interval and fault repair time are used as variable characteristic inputs to the annual number of device operations function. The function iterates through all values ​​of the variable characteristic and outputs the annual number of device operations corresponding to the value.

[0010] The operating cost of the device is calculated based on the number of times the device is operated throughout the year, and the variable characteristic value corresponding to the minimum operating cost is taken as the optimal solution for the availability target design.

[0011] The technical solution is further configured such that the device operation phase includes, in sequence, a power-on inspection phase, a preparation phase, a formal operation phase, and a post-processing and recovery phase. The preparation phase, the formal operation phase, and the post-processing and recovery phase constitute a single-shot operation. After the power-on inspection phase, the device repeatedly performs single-shot operations. After the current single-shot operation is completed, it automatically enters the next single-shot operation.

[0012] This technical solution is further configured such that the operating logic is formed based on the various operating stages of the device and preset boundary conditions, specifically as follows:

[0013] The device is currently in the operating phase. After the operating time corresponding to the current operating phase is completed, it will enter the next operating phase.

[0014] When the total operating time of the device in each operating stage and the total fault repair time exceed the daily operating boundary time, the device stops operating. The daily operating boundary time is greater than the operating time corresponding to each operating stage, and the daily operating boundary time is greater than the fault repair boundary time.

[0015] The technical solution is further configured such that if a fault occurs in the device during the preparation phase, the device continues the preparation phase if the fault repair time is no greater than the fault repair boundary time; otherwise, the device restarts the preparation phase.

[0016] The technical solution is further configured such that when the device experiences multiple failures during the preparation phase, the device continues the preparation phase if the sum of the failure repair time and the average failure interval time is not greater than the failure repair boundary time; otherwise, the device restarts the preparation phase.

[0017] This technical solution is further configured such that if a fault occurs in the device during the post-processing and recovery phase, and the fault repair time is no greater than the corresponding operating time of the post-processing and recovery phase, the device continues to perform the post-processing and recovery phase; otherwise, the device directly proceeds to the next operating phase.

[0018] This technical solution is further configured such that when the device experiences multiple failures during the post-processing and recovery phase, if the sum of the failure repair time and the average failure interval time is not greater than the corresponding running time of the post-processing and recovery phase, the device continues to perform the post-processing and recovery phase; otherwise, the device directly proceeds to the preparation phase for the next single-shipment operation.

[0019] This technical solution is further configured such that the function for constructing the annual number of device operations based on operational logic is specifically:

[0020] Based on the daily operating boundary time, fault repair boundary time, operating time corresponding to the operating phase, annual operating days of the device, and operating logic, a function for the number of times the device operates throughout the year is constructed.

[0021] The technical solution is further configured such that the variable characteristic quantity conforms to a specific distribution characteristic, which includes a normal distribution characteristic, an exponential distribution characteristic, a skewed distribution characteristic, and a uniform distribution characteristic.

[0022] This technical solution is further configured such that, before calculating the device operating cost based on the number of times the device operates throughout the year, it also includes:

[0023] Based on the preset annual target number of operations, devices with an annual operation count exceeding the annual target number of operations are screened out.

[0024] The beneficial effects of this invention are:

[0025] By analyzing the operational phases of the device and the preset boundary conditions, and based on the Monte Carlo method, the mean time between failures and the time to repair failures are sampled to calculate the number of times the device operates throughout the year. This establishes a mathematical relationship between the intrinsic indicators of the device and the user indicators, which supports the decomposition, optimization, and evaluation of device availability indicators, and supports the design of device availability indicators. At the same time, by optimizing parameters, the device cost is optimized. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the present invention;

[0027] Figure 2 This is a schematic diagram of the device's operating logic;

[0028] Figure 3 This is a schematic diagram of a malfunction that occurred during the equipment's preparation for operation.

[0029] Figure 4 This is a schematic diagram of a device malfunctioning during the post-processing and recovery phase. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0031] Example 1:

[0032] like Figure 1 As shown, a design method for the availability target of a large, complex, repairable device includes:

[0033] S100. Based on the various operating stages of the device and preset boundary conditions, an operating logic is formed. The boundary conditions include fault maintenance boundary time and daily operating boundary time. The fault maintenance boundary time is the limit time during which the device can continuously maintain the same spatial accuracy.

[0034] Specifically, the device operation phases include the power-on inspection phase, preparation phase, formal operation phase, and post-processing and recovery phase in sequence. The preparation phase, the formal operation phase, and the post-processing and recovery phase constitute a single-shot operation. After the power-on inspection phase, the device repeatedly performs single-shot operations. After the current single-shot operation is completed, it automatically enters the next single-shot operation.

[0035] Specifically, the operational logic formed based on the various operational stages of the device and preset boundary conditions includes:

[0036] 1. The device is in the current operating phase. After the operating time corresponding to the current operating phase is completed, it will enter the next operating phase.

[0037] like Figure 2 As shown, the operation of the device must go through the following stages: startup inspection takes H0 hours, preparation stage takes H1 hours, formal operation stage takes M minutes (the formal operation stage is short and can be ignored, so let M≈0), post-processing and recovery stage takes H2 hours, and each operation requires (H1+H2) hours. Due to the time requirement of a single operation, based on a working time of no more than 18 hours per day, under ideal conditions without random failures, the maximum number of operations per day is N. d Therefore, the upper limit of the number of annual operations, N0, can be calculated, where N0 = N d ×D6≥N, where D6 represents the number of operating days per year and N represents the number of operations per year.

[0038] 2. When the total operating time of the device in each operating stage and the total fault repair time exceed the daily operating boundary time, the device shall be shut down. The daily operating boundary time shall be greater than the operating time corresponding to each operating stage and greater than the fault repair boundary time.

[0039] It is worth noting that if a fault occurs during the preparation phase, the preparation phase will continue if the fault repair time is no greater than the fault repair boundary time; otherwise, the preparation phase will restart.

[0040] When the device experiences multiple failures during the preparation phase, if the sum of the failure repair time and the average failure interval time does not exceed the failure repair boundary time, the device continues the preparation phase; otherwise, the device restarts the preparation phase.

[0041] Specifically, such as Figure 3 As shown, assume the kth firing T k0 If preparation begins and no problems occur, the system will proceed directly to full operation. The full operation time will then be: T. ks =T k0 +H1; If m+1 faults occur during the preparation phase, where the fault intervals are T... f0 T f1 , ..., T fm The next fault interval is T. fm+1 The repair time for each fault is T. r0 T r1 , ..., T rm-1 Therefore, the official running time for this launch is:

[0042] if but (and at this time it is satisfied) ),if but:

[0043] (and at this time it is satisfied) ).

[0044] It is worth noting that if a fault occurs in the post-processing and recovery phase, the device will continue to perform the post-processing and recovery phase if the fault repair time is no greater than the corresponding operating time of the post-processing and recovery phase; otherwise, the device will directly proceed to the next operating phase.

[0045] When the device experiences multiple failures during the post-processing and recovery phase, if the sum of the failure repair time and the average failure interval time is not greater than the corresponding operating time of the post-processing and recovery phase, the device will continue to perform the post-processing and recovery phase; otherwise, the device will directly proceed to the preparation phase for the next single-shipment operation.

[0046] Specifically, such as Figure 4 As shown, assume the kth occurrence is less than T. ks If preparation begins and no faults occur, the process directly proceeds to the formal operation phase of the next single-launch operation. The preparation time T for the next single-launch operation is then... (k+1)0 For: T (k+1)0 =T ks +H2.

[0047] If m+1 faults occur during the post-processing and recovery phases, where the fault intervals are T... f0 Tf1 , ..., T fm The next fault interval is T. fm+1 The repair time for each fault is T. r0 T r1 , ..., T rm-1 Then the actual start preparation time T for the next single shot is... (k+1)s for:

[0048] if Then T (k+1)0 =T ks +H2.

[0049] if but

[0050] S200, Construct a function for the number of times the device runs throughout the year based on the operating logic.

[0051] Specifically, based on the daily operating boundary time, fault repair boundary time, operating time corresponding to the operating phase, annual operating days of the device, and operating logic, a function for the number of times the device operates throughout the year is constructed.

[0052] It is worth noting that the overall indicator for large, complex, and repairable equipment is the annual number of operations (N). This annual number of operations (N) is a user-oriented overall indicator and does not directly impose any constraint on any specific intrinsic indicator of the equipment. It is influenced by a series of intrinsic indicators of the equipment, including: boundary conditions, the equipment's operating phases and the operating time of each phase, operating logic, mean time between failures (MTBF), and repair time. Among these, the boundary conditions, the operating phases and the operating time of each phase, and the operating logic are deterministic. The MTBF and repair time are statistical values; the actual interval between failures and the repair time have a degree of randomness, and therefore cannot be described by a single mathematical expression.

[0053] Specifically, if the device does not malfunction throughout the day, then 1 to N will be completed. d The launch (official operation) times are H0+H1, H0+H1+H2+H1, ..., H0+(H1+H2)×(N0-1)+H1. The device can successfully complete all operational missions for the day and shut down at H0+(H1+H2)×(N0-1)+H1+H3. The device's overtime time is Totp. If the device starts preparing for the (x+1)th single launch of the day at Tx0, the preparation time will be until T... f0 Faults occur frequently and repairs are performed. If time reaches T... ow =H0+(H1+H2)×(N) dIf -1)+H1+Totp still does not complete the preparation phase, the preparation phase should be stopped, the launch should be abandoned, and the machine should be shut down directly. If the time reaches T on that day... ow =H0+(H1+H2)×(N) d If the repair is still not completed after -1)+H1+Totp, the repair should be stopped, the machine should be shut down, and the repair should be resumed the next day. The time occupied by the repair on the next day is the total repair time minus the repair time already completed on the previous day.

[0054] S300: Input the annual operating count function of the device with the average fault interval time and fault repair time as variable characteristic quantities, iterate through all values ​​of the variable characteristic quantities, and output the annual operating count of the device corresponding to the value.

[0055] Specifically, the variable characteristic quantity conforms to a specific distribution characteristic, which includes normal distribution, exponential distribution, skewed distribution, and uniform distribution. The relevant software generates random numbers conforming to the specific distribution characteristic as the average fault interval T of the device. f and fault repair time T r .

[0056] S400. Calculate the operating cost of the device based on the number of times the device operates throughout the year, and take the variable characteristic value corresponding to the minimum operating cost of the device as the optimal solution for the availability target design.

[0057] Specifically, before calculating the device operating cost based on the number of times the device operates throughout the year, the following steps are also included:

[0058] Based on the preset annual target number of operations, devices with an annual operation count exceeding the annual target number of operations are screened out.

[0059] For the parameter combination that meets the annual target number of operations, the cost is calculated using a cost function, and the optimal parameter set with the lowest cost is selected as the final design result.

[0060] The cost function involved is as follows:

[0061]

[0062] A and B represent constants, f represents the likelihood of realization, and the higher the likelihood, the lower the cost. T fmin T represents f The theoretical minimum value, T fmax T represents f The theoretical maximum value is given by α, which represents a constant related to the ease of maintenance.

[0063] C=γ / (T r -T rmin), where γ represents a constant, and T rmin T represents r The theoretical minimum value.

[0064] C=β*T otp β represents a constant.

[0065] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of this application should still fall within the scope of the present invention.

Claims

1. A method for designing usability targets for large, complex, repairable devices, characterized in that, include: The operating logic is formed based on the various operating stages of the device and the preset boundary conditions. The boundary conditions include the fault maintenance boundary time and the daily operating boundary time. The fault maintenance boundary time is the limit time for which the device can continuously maintain the same spatial accuracy. Specifically, after the device is in its current operating phase and has completed the corresponding operating time for that phase, it will enter the next operating phase. The device operating phases include the start-up inspection phase, preparation phase, formal operation phase, and post-processing and recovery phase. When the total operating time of the device in each operating phase and the total fault repair time exceed the daily operating boundary time, the device will stop operating. The daily operating boundary time is greater than the operating time corresponding to each operating phase and is also greater than the fault repair boundary time. If a fault occurs during the preparation phase, the device will continue the preparation phase if the fault repair time is no greater than the fault repair boundary time; otherwise, the device will restart the preparation phase. If a fault occurs during the post-processing and recovery phase, the device will continue the post-processing and recovery phase if the fault repair time is no greater than the corresponding operating time of the post-processing and recovery phase; otherwise, the device will directly proceed to the next operating phase. A function for the number of times the device operates throughout the year is constructed based on the operational logic; The average fault interval and fault repair time are used as variable characteristic inputs to the annual number of device operations function. The function iterates through all values ​​of the variable characteristic and outputs the annual number of device operations corresponding to the value. The operating cost of the device is calculated based on the number of times the device is operated throughout the year, and the variable characteristic value corresponding to the minimum operating cost is taken as the optimal solution for the availability target design.

2. The design method for the availability target of a large, complex, repairable device according to claim 1, characterized in that, The preparation phase, the formal operation phase, and the post-processing and recovery phase constitute a single-shot operation. After the power-on inspection phase, the device repeatedly performs single-shot operations. After the current single-shot operation is completed, it automatically enters the next single-shot operation.

3. The design method for the availability target of a large, complex, repairable device according to claim 1, characterized in that, If the device experiences multiple failures during the preparation phase, and the sum of the failure repair time and the average failure interval time is not greater than the failure repair boundary time, the device continues the preparation phase; otherwise, the device restarts the preparation phase.

4. The design method for the availability target of a large, complex, repairable device according to claim 1, characterized in that, If the device experiences multiple failures during the post-processing and recovery phase, and the sum of the failure repair time and the average failure interval is not greater than the corresponding operating time of the post-processing and recovery phase, the device will continue to perform the post-processing and recovery phase. Otherwise, the device will directly proceed to the preparation phase for the next single-shipment operation.

5. A method for designing availability targets for a large, complex, repairable device according to any one of claims 1-4, characterized in that, The function for constructing the annual number of device operations based on operational logic is specifically as follows: Based on the daily operating boundary time, fault repair boundary time, operating time corresponding to the operating phase, annual operating days of the device, and operating logic, a function for the number of times the device operates throughout the year is constructed.

6. The design method for the availability target of a large, complex, repairable device according to claim 5, characterized in that, The variable characteristic quantity conforms to a specific distribution characteristic, which includes normal distribution characteristics, exponential distribution characteristics, skewed distribution characteristics, and uniform distribution characteristics.

7. The design method for the availability target of a large, complex, repairable device according to claim 6, characterized in that, Before calculating the device operating cost based on the number of times the device operates throughout the year, the following steps are also included: Based on the preset annual target number of operations, devices with an annual operation count exceeding the annual target number of operations are screened out.

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