Aircraft service life echelon control method based on multi-life index

Abstract

The application discloses a kind of aircraft service life echelon control methods based on multiple life index, comprising: using the life relationship of multiple life index of aircraft to convert all life index into several equivalent flight hour life index;From several equivalent flight hour life index, optionally one index is sorted to initial fleet;According to the rest equivalent flight hour life index, the fleet of initial sorting is reordered respectively;According to the standard deviation of multiple life index of fleet under fleet service interval, the fleet of reordering is echelon sorted and tested;The fleet sorting corresponding to minimum standard deviation is optimal sorting;The service interval corresponding to multiple life index under optimal sorting is best service interval.The application equivalent flight hour life by taking off and landing times and calendar life, obtains the optimal solution of fleet life sorting and service interval by using variance test calculation, realizes multiple life index echelon control.

Description

Technical Field

[0001] This invention relates to the field of aircraft maintenance technology, and specifically to a method for tiered control of aircraft service life based on multiple life indicators. Background Technology

[0002] Currently, the primary method for controlling aircraft lifespan using the aircraft lifespan ladder diagram method is the one that utilizes a standard trapezoidal line representing 40% of the fleet's remaining lifespan to guide aircraft lifespan to maintain uniform intervals. This method is simple, intuitive, and widely used in aircraft lifespan control. However, it only addresses the control of aircraft flight hours and does not consider the matching of other lifespan control indicators such as takeoff and landing hours and calendar lifespan, which can easily lead to a waste of aircraft flight hours and calendar lifespan resources.

[0003] The mismatch between aircraft flight hours, number of takeoffs and landings, and calendar life consumption is becoming increasingly prominent, and life control methods using the life-life ladder diagram approach cannot solve this problem. Current research has proposed some improved aircraft ladder control methods that consider calendar life, but these methods do not account for the interrelationships between life indicators and are prone to getting trapped in local optima. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an aircraft service life tiered control method based on multiple life indicators, in order to solve the problem that the existing life control method using the remaining life ladder diagram method cannot solve the mismatch of life indicator consumption.

[0005] This invention provides a method for phased control of aircraft service life based on multiple life indicators, including: By utilizing the life determination relationship of multiple aircraft life indicators, all life indicators are converted into several equivalent flight hour life indicators. Select one of several equivalent flight hour life indicators to initially rank the aircraft fleet; The initially sorted aircraft groups were reordered based on the remaining equivalent flight hour life indicators. The reordered fleets are subjected to a tiered sorting test based on the standard deviation of multiple lifespan indicators of the fleet under the fleet usage interval. The cluster ranking corresponding to the minimum standard deviation is the optimal ranking; the usage interval corresponding to the multiple lifetime indicators under the optimal ranking is the best usage interval.

[0006] Optionally, life indicators include: flight hours, takeoff and landing times, and calendar life.

[0007] Optionally, the life determination relationship of multiple aircraft life indicators can be used to convert all life indicators into several equivalent flight hour life indicators, including: Based on flight hours, the number of takeoffs and landings and calendar life are converted into equivalent flight hours proportionally.

[0008] Optionally, the initially ranked fleet can be reordered based on the remaining equivalent flight hour life indices, including: The aircraft group was reordered based on the number of takeoffs and landings: If the number of takeoffs and landings of the (i+1)th aircraft is less than the number of takeoffs and landings of the ith aircraft, then swap the order of the (i+1)th aircraft and the ith aircraft. The fleet was reordered based on calendar lifespan: If the calendar life of the (j+1)th aircraft is less than that of the jth aircraft, then the order of the (j+1)th aircraft and the jth aircraft is swapped. Where i and j are both natural numbers greater than or equal to 1.

[0009] Optionally, it also includes: The maximum and minimum service intervals are determined based on the aircraft's remaining lifespan, the fleet's aircraft availability, and the overhaul facility's repair capacity.

[0010] Optionally, the maximum service interval is calculated based on the ratio of the fleet's maximum remaining service life to the number of aircraft during the overhaul period; Minimum operating intervals are determined by comparing the minimum operating intervals based on fleet aircraft availability limits with the minimum operating intervals based on overhaul facility repair capacity limits.

[0011] Optionally, the minimum usage interval is calculated based on the number of aircraft entering the facility, the maximum number of aircraft entering the facility simultaneously, the repair agreement time, the fleet entry rate, and the number of aircraft in the fleet.

[0012] Optionally, the reordered fleet is subjected to a tiered ranking test based on the standard deviation of multiple lifespan indicators of the fleet under the fleet usage interval, including: The variance test method is used to measure the variance between the actual lifespan of the computer cluster and the target value of the tiered control, in order to obtain the degree of deviation.

[0013] Beneficial effects of the embodiments of the present invention: This invention proposes a multi-lifetime index-based tiered control method for aircraft lifespan. It simultaneously considers lifetime indices, including flight hours, number of takeoffs and landings, and calendar life, into the tiered control of aircraft lifespan. By equating the number of takeoffs and landings and calendar life with flight hour life, the optimal solution for fleet lifespan ranking and usage interval is obtained using variance testing. This method achieves tiered control of multiple lifetime indices, including flight hours, flight takeoffs and landings, and calendar life, which is of great significance in solving the mismatch problem of lifespan consumption indices and reducing the waste of aircraft lifespan resources. Attached Figure Description

[0014] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings: Figure 1 A flowchart of an aircraft service life tiered control method based on multiple life indicators is shown in an embodiment of the present invention. Figure 2 Another flowchart of an aircraft service life tiered control method based on multiple life indicators is shown in an embodiment of the present invention. Figure 3 The graph shows the relationship between remaining flight hours, number of takeoffs and landings, and calendar life of a certain type of aircraft. Figure 4 The illustration shows the optimal control hierarchy diagram obtained by calculating and sorting a certain type of aircraft using an aircraft lifespan hierarchy control method based on multiple lifespan indices in an embodiment of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] This invention provides a method for tiered control of aircraft service life based on multiple life indicators, such as... Figure 1 As shown, it includes: Step S10: Use the life determination relationship of multiple life indicators of the aircraft to convert all life indicators into several equivalent flight hour life indicators.

[0017] In this embodiment, the lifespan indicators include flight hours, flight takeoffs and landings, and calendar lifespan. In a specific embodiment, flight hours are used as the baseline, and the number of flight takeoffs and landings and calendar lifespan are converted into equivalent flight hours proportionally.

[0018] Because lifespan indicators such as flight hours, takeoff and landing times, and calendar lifespan are interdependent and their units are not consistent, it is difficult to quantitatively evaluate the effectiveness of tiered control when controlling an aircraft fleet. Therefore, this embodiment proposes to use the lifespan relationship of multiple aircraft lifespan indicators to equate flight hours and calendar lifespan to flight hour lifespan. For example, if the first overhaul lifespan indicator for a certain type of aircraft is 1000 flights / 1600 takeoffs and landings / 10 years, then its takeoff and landing lifespan can be equivalent to 1.6:1 flight hours, and its calendar lifespan can be equivalent to 1:100 flight hours.

[0019] Step S20: Select one indicator from several equivalent flight hour life indicators to perform initial sorting of the aircraft fleet.

[0020] In this embodiment, flight hour life index is selected for initial sorting.

[0021] Step S30: Reorder the initially sorted aircraft group according to the remaining equivalent flight hour life indicators.

[0022] In this embodiment, the initial sorting based on the flight hour life index is followed by a re-sorting based on the number of flight takeoffs and landings and the calendar life index.

[0023] Step S40: Perform a tiered sorting test on the reordered fleet based on the standard deviation of multiple lifespan indicators of the fleet under the fleet usage interval.

[0024] In this embodiment, based on the standard deviation before and after the aircraft group sorting exchange in step S30, a new aircraft group sorting is obtained after re-sorting according to the number of flight takeoffs and landings. The new aircraft group sorting is then sorted by calendar lifetime. If the standard deviation after the calendar lifetime sorting exchange is greater than the standard deviation before the calendar lifetime sorting exchange, it indicates that the sorting effect after the exchange is worse. In this case, the sorting is exchanged again to restore the previous aircraft group sorting.

[0025] Step S50: Obtain the cluster ranking corresponding to the minimum standard deviation as the optimal ranking; the usage interval corresponding to the multiple lifetime indicators under the optimal ranking is the best usage interval.

[0026] In this embodiment, after completing the above sorting and inspection of all aircraft in the fleet, the obtained life control sorting is the optimal sorting, and the usage interval corresponding to multiple life indicators under the optimal sorting is the optimal usage interval.

[0027] This invention proposes a multi-lifetime index-based tiered control method for aircraft lifespan. It simultaneously considers lifetime indices, including flight hours, number of takeoffs and landings, and calendar life, into the tiered control of aircraft lifespan. By equating the number of takeoffs and landings and calendar life with flight hour life, the optimal solution for fleet lifespan ranking and usage interval is obtained using variance testing. This method achieves tiered control of multiple lifetime indices, including flight hours, flight takeoffs and landings, and calendar life, which is of great significance in solving the mismatch problem of lifespan consumption indices and reducing the waste of aircraft lifespan resources.

[0028] As an optional implementation, step S30 includes: The aircraft group was reordered based on the number of takeoffs and landings: If the number of takeoffs and landings of the (i+1)th aircraft is less than the number of takeoffs and landings of the ith aircraft, then swap the order of the (i+1)th aircraft and the ith aircraft. The fleet was reordered based on calendar lifespan: If the calendar life of the (j+1)th aircraft is less than that of the jth aircraft, then the order of the (j+1)th aircraft and the jth aircraft is swapped. Where i and j are both natural numbers greater than or equal to 1.

[0029] As an optional implementation, it also includes: The maximum and minimum service intervals are determined based on the aircraft's remaining lifespan, the fleet's aircraft availability, and the overhaul facility's repair capacity.

[0030] In this embodiment, the maximum operating interval is calculated based on the ratio of the fleet's maximum remaining lifespan to the number of aircraft within the overhaul period. The minimum operating interval is obtained by comparing the minimum operating interval limited by the fleet's aircraft availability rate with the minimum operating interval limited by the overhaul facility's repair capacity. The minimum operating interval is calculated based on the number of aircraft entering the facility, the maximum number of aircraft entering the facility simultaneously, the repair agreement time, the fleet's facility entry rate, and the number of aircraft in the fleet.

[0031] Aircraft lifespan tiered control is affected by both usage intervals and fleet sequencing. To reduce computational load, the maximum and minimum usage intervals for lifespan tiered control were first calculated. The usage interval for tiered control is mainly limited by remaining lifespan, fleet aircraft availability, and overhaul facility repair capacity.

[0032] In this embodiment, the maximum usage interval during the overhaul period is: (1) In the formula, T gmax For the maximum usage interval, T max N represents the maximum remaining lifespan of the fleet. in This refers to the number of aircraft during the overhaul period.

[0033] The minimum operational interval during the overhaul period is limited by the fleet's aircraft availability and the overhaul facility's repair capacity. The minimum operational interval limited by the fleet's aircraft availability is... (2) In the formula, n r T represents the number of items entering the factory simultaneously. r The equivalent repair agreement time is given, p is the fleet entry rate, and N is the number of aircraft in the fleet.

[0034] The minimum operating interval for overhaul workshop repair capacity is (3) In the formula, n is the maximum number of items that can enter the factory at the same time.

[0035] From equations (2) and (3), the minimum service interval during the renovation period is: (4) As an optional implementation, the reordered fleet is subjected to a tiered ranking test based on the standard deviation of multiple lifespan indicators of the fleet under the fleet usage interval, including: The variance test method is used to measure the variance between the actual lifespan of the computer cluster and the target value of the tiered control, in order to obtain the degree of deviation.

[0036] To quantitatively evaluate the results of tiered control, this embodiment uses the variance test method to evaluate the results, as shown in Equation (5). Equation (5) represents the deviation between the actual lifespan of the aircraft group and the target value of tiered control. The variance of the current aircraft is expressed by the equivalent lifespan T of the current aircraft. dx S is calculated by summing the squared differences between the current aircraft and all aircraft before it using the interval, and the variance of the previous aircraft. 2 The smaller the value, the smaller the adjustment range required for the fleet to reach the expected control target, and the faster the ideal tiered structure can be formed.

[0037] (5) like Figure 2 As shown, this embodiment of the invention also provides a calculation process for aircraft lifespan tiered control: (1) Input initial parameters such as the service life of the machine group The initial parameters input to the control method proposed in this embodiment include fleet lifespan, annual average lifespan, fleet maintenance visit rate, repair agreement period, and maximum simultaneous maintenance visit quantity. Fleet lifespan includes flight hours T. fx Flight takeoff and landing T ql and calendar lifespan T r1 Etc.: Average annual service life includes flight hours (T). mfx Flight takeoff and landing T mql and calendar lifespan T mrl Etc.: Flotation rate p, repair agreement period T xy The maximum number of simultaneous entries into the plant, n, is determined by factors such as equipment availability and overhaul plant repair capacity.

[0038] (2) Initial ranking of fleet lifespan For aircraft types such as fighter jets, their service life is constrained by lifespan indicators such as flight hours, takeoff and landing times, and calendar life. Due to the large number of lifespan control variables and the mutual constraints and influences of these indicators, lifespan control becomes complex. To simplify the tiered control of aircraft groups, a single indicator is selected to initially rank the aircraft group based on its consumption level. This embodiment first ranks the aircraft group based on its flight hour consumption.

[0039] (3) Equivalent other life indicators Based on the life-determining relationship of various aircraft life indicators, the life indicator equivalence method proposed in Section 1.2 is used to convert the number of takeoffs and landings and calendar life, as well as other life indicators, into flight hour life.

[0040] (4) Determine the maximum and minimum operating intervals of the fleet. The maximum and minimum operating intervals of the fleet life tiered control are calculated using equations (1) to (4).

[0041] (5) Flight takeoffs and landings and calendar life reordering Based on the aircraft's flight takeoffs and landings and calendar life consumption, the aircraft sequence is reordered. The number of takeoffs and landings of the i-th aircraft and the (i-1)-th aircraft is compared; if T... ql (i) <T ql If (i-1), then swap the order of the i-th aircraft and the (i-1)-th aircraft. Use the same method to sort other lifespan indicators such as calendar lifespan.

[0042] (6) Calculate the usage interval T g Minimum standard deviation S1 of the aircraft group Cluster usage interval T g It should be within the maximum and minimum usage interval determined in step (4). When T gmin ≤T g ≤T gmax Calculate using interval T g The standard deviation of multiple lifespan indicators of the fleet is determined, and the T corresponding to the minimum standard deviation S1 is determined. g .

[0043] (6) (7) Ranked test Using equation (5), compare the standard deviations before and after the aircraft sorting exchange in step (5). If S1(i) > S1(i-1), it indicates that the sorting effect after the exchange is worse. Then, exchange the order of the i-th aircraft and the (i-1)-th aircraft to restore the previous sorting. Continue to repeat steps (5) to (7) until all aircraft in the fleet have completed the sorting verification.

[0044] (8) Record the sorting and usage interval corresponding to the minimum standard deviation. After completing the above sorting and testing for all aircraft in the fleet, the standard deviation S1 corresponding to the life control sorting is obtained. min This sorting is the optimal sorting, and the usage interval T corresponding to multiple lifetime indicators. gfx T gql T grl This is the optimal usage interval.

[0045] In a specific embodiment, an airport has 24 aircraft of a certain type. Each aircraft has an average annual usage time of 100 hours / 160 takeoffs and landings. The first overhaul period for this aircraft type is 1000 hours / 1600 takeoffs and landings / 10 years. The remaining flight hours, number of takeoffs and landings, and calendar life of the fleet are as follows: Figure 3 As shown. The aircraft fleet's rate of being brought into the factory is controlled at 20%, and the overhaul facility can repair two aircraft of this type simultaneously, with a repair agreement period of 6 months.

[0046] Using the lifespan tiered control calculation method proposed in this embodiment of the invention, the optimal control tier was calculated for this aircraft group, as shown below. Figure 4 As shown.

[0047] To verify the effectiveness of the method proposed in this invention, the lifespan control of this aircraft model was calculated using the aircraft lifespan ladder diagram method, and compared with the method proposed in the embodiments of this invention. The standard deviation of the lifespan control ladder calculated by the embodiments of this invention is 151.55, while the standard deviation of the lifespan control ladder calculated by the aircraft lifespan ladder diagram method is 474.68. Compared with the aircraft lifespan ladder diagram method, the standard deviation of the lifespan ladder obtained by the method proposed in the embodiments of this invention is significantly reduced, indicating that the lifespan ladder control calculation method provided by the embodiments of this invention can effectively reduce the mismatch problem of aircraft lifespan consumption indicators and reduce the waste of aircraft lifespan resources.

[0048] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for phased control of aircraft service life based on multiple life indicators, characterized in that, include: By utilizing the life determination relationship of multiple aircraft life indicators, all life indicators are converted into several equivalent flight hour life indicators. Select one of the several equivalent flight hour life indicators to initially sort the aircraft fleet; The initially sorted aircraft group is reordered according to the remaining equivalent flight hour life indicators; Based on the standard deviation of multiple lifespan indicators of the cluster under the cluster usage interval, the reordered clusters are subjected to a tiered sorting test, including: using a variance test method to measure the variance of the actual lifespan value of the cluster and the tiered control target value to obtain the degree of deviation. The cluster ranking corresponding to the minimum standard deviation is the optimal ranking; the usage interval corresponding to the multiple lifetime indicators under the optimal ranking is the best usage interval. The maximum and minimum operating intervals are determined based on the aircraft's remaining lifespan, the fleet's aircraft availability rate, and the overhaul facility's repair capacity. The maximum operating interval is calculated as the ratio of the fleet's maximum remaining lifespan to the number of aircraft within the overhaul period. The minimum operating interval is determined by comparing the minimum operating interval limited by the fleet's aircraft availability rate with the minimum operating interval limited by the overhaul facility's repair capacity. The minimum operating interval is calculated based on the number of aircraft entering the facility, the maximum number of aircraft entering the facility simultaneously, the repair agreement time, the fleet's facility entry rate, and the number of aircraft in the fleet.

2. The aircraft service life tiered control method based on multiple life indicators according to claim 1, characterized in that, The lifespan metrics include: flight hours, takeoff and landing times, and calendar life.

3. The aircraft service life tiered control method based on multiple life indicators according to claim 2, characterized in that, By utilizing the life determination relationship of multiple aircraft life indicators, all life indicators are converted into several equivalent flight hour life indicators, including: Based on flight hours, the number of takeoffs and landings and the calendar lifespan are converted into equivalent flight hours proportionally.

4. The aircraft service life tiered control method based on multiple life indicators according to claim 2, characterized in that, The initially sorted fleet is reordered according to the remaining equivalent flight hour life indicators, including: The aircraft group was reordered based on the number of takeoffs and landings: If the number of takeoffs and landings of the (i+1)th aircraft is less than the number of takeoffs and landings of the ith aircraft, then swap the order of the (i+1)th aircraft and the ith aircraft. The fleet was reordered based on calendar lifespan: If the calendar life of the (j+1)th aircraft is less than that of the jth aircraft, then the order of the (j+1)th aircraft and the jth aircraft is swapped. Where i and j are both natural numbers greater than or equal to 1.

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