CN-116415924-B - Method and device for airplane low-utilization maintenance interval conversion

CN116415924BCN 116415924 BCN116415924 BCN 116415924BCN-116415924-B

Abstract

The invention provides a method and a device for converting maintenance intervals when an aircraft is low in utilization rate, comprising the following steps of S1 obtaining an aircraft maintenance outline, S2 determining the number of months to be counted and counting the aircraft utilization rate, S3 predicting the low utilization rate of the aircraft, S4 converting maintenance intervals, judging the importance of the maintenance intervals, and S5 summarizing new maintenance tasks. The device comprises a database, an airplane utilization rate statistics module, a low utilization rate prediction module, a maintenance task conversion module and a maintenance task output module, wherein the maintenance task conversion module comprises a screening module, a weight module and a conversion module. The invention directly adopts the maintenance interval conversion method for unimportant maintenance tasks, reduces the number and complexity of maintenance analysis tasks with reliability as the center, and can obtain the maintenance tasks and the maintenance intervals thereof under low utilization rate more quickly.

Inventors

JIANG QINGXI
REN WENMING
JIN YONG
Nan Yanfei
ZHANG ZESEN
Tao Ruichao

Assignees

中国航空综合技术研究所

Dates

Publication Date: 20260512
Application Date: 20221209

Claims (5)

1. A method for maintaining interval conversion when an aircraft is low in utilization rate is characterized by comprising the following steps: S1, acquiring an aircraft maintenance outline; The aircraft maintenance outline database is a data storage mode of an aircraft maintenance outline, and at least comprises an aircraft normal utilization rate interval, all aircraft maintenance tasks, maintenance object failure influences, maintenance object types, maintenance task types of maintenance objects, maintenance interval values of maintenance tasks and maintenance interval units of maintenance tasks; s2, determining the month number to be counted and counting the utilization rate of the airplane: According to the number I C-check of aircraft C inspection or base maintenance intervals, the number of the least continuous calendar months to be counted is obtained as follows: n=[I C-check -1] (1) Wherein I C-check is the number of maintenance intervals of the C inspection or the base level of the aircraft, and n is the number of minimum continuous calendar months to be counted; Obtaining the month utilization rate of the first k months in the units of flight hours according to the calendar days of the month n day,k and the accumulated flight hours of the month n fhm,k of the first k months The method comprises the following steps: Wherein n fhm,k is the month-long cumulative flight hours of the first k months, k=1, 2. S3, low utilization rate prediction of the airplane: according to the month utilization statistics data of the previous n months, a GM (1, 1) model of a gray model is adopted for prediction to obtain a month utilization prediction value of the (n+1) th month If it is The following conditions are satisfied Performing maintenance task conversion, and continuing to execute the step S4, wherein u fh-low is the lower limit of annual utilization rate; S4, maintenance task interval conversion: S41, screening maintenance tasks R h with maintenance intervals of engine replacement hours, APU hours, flight hours and flight cycles from a maintenance outline database in a condition screening mode, wherein h=1, 2, and N are the number of maintenance tasks obtained through screening; S42, judging the importance of the maintenance task R h , wherein the specific steps are as follows: The importance factor s of the maintenance task is calculated, s=s 1 +s 2 +s 3 (14) Wherein s 1 is a failure influence factor, s 2 is a type factor, s 3 is a task type factor, and s is an importance factor; judging importance factors S, if S is more than or equal to 8, carrying out maintenance analysis centering on reliability on a maintenance task R h , and if S is less than 8, executing a step S43 to carry out maintenance interval value and time unit conversion on the maintenance task R h ; s43, maintenance task interval conversion calculation: First, the numerical conversion method of the maintenance task interval is as follows: Obtaining a month utilization rate average value according to the month utilization rate statistical data sequence U (0) of the previous n months and the month utilization rate of the n+1th month predicted in the step S3 Obtaining maintenance interval value I 0 of maintenance task R h from aircraft maintenance outline, and obtaining maintenance interval value I 1 with low utilization rate according to formula (16) as Directly changing the maintenance interval unit of the maintenance task R h into a unit of month to obtain a maintenance interval value and a maintenance interval unit of the maintenance task R h which are I 1 and month respectively; Judging whether all maintenance tasks needing to be converted are converted, if yes, executing a step S5, and if not, returning to a step S42 to continue to convert the next maintenance task; S5, summarizing new maintenance tasks And step S42, summarizing the maintenance task interval conversion results to form new maintenance requirements, and marking the maintenance requirements suitable for low utilization rate.
2. The method for aircraft low-utilization maintenance interval transition according to claim 1, wherein in the aircraft maintenance outline in S1, The failure influencing factors of the maintenance object are classified into five types, namely obvious safety, obvious mission performance, obvious economy performance, hidden safety and hidden non-safety; the maintenance object type factors are divided into three types, namely mechanical, electric and electronic; the maintenance task type factors of the maintenance object are divided into seven types, namely SV/LU and VC/OP, GVI, DET, SDI, FNC, RS/DI; maintenance intervals used for maintenance tasks include engine change hours, APU hours, flight cycles, calendar days.
3. The method for converting maintenance intervals when the aircraft is low in utilization rate according to claim 1, wherein in the step S3, according to the month utilization rate statistical data of the previous n months, a GM (1, 1) model of a gray model is adopted to predict the month utilization rate of the (n+1) th month, specifically: The n month utilization statistics sequence is U (0) , which is expressed as follows: Wherein U (0) is a month utilization rate statistical data sequence of the previous n months, and the elements in the month utilization rate statistical data sequence are month utilization rates obtained according to a formula (2) After 1 time of accumulation, U is obtained (1) Wherein, the Is the accumulated value; Establishing whitening differential equations Wherein a is the development coefficient, b is the gray action quantity, and corresponds to the gray differential equation Wherein the method comprises the steps of The least square method is adopted to calculate the parameter vector (a,b) T ＝(B T B) -1 BY (9) Wherein the method comprises the steps of Predictive value of the n+1th accumulated value Reduction of predicted value for n+1th month Obtaining a month utilization rate predicted value of the n+1th month
4. The method for converting maintenance intervals when the aircraft is low in utilization according to claim 1, wherein the specific values of the failure influencing factors S 1 , the type factors S 2 4 and the task type factors S 3 in the step S42 are as follows: Determining a value of a failure influence factor s 1 according to the failure influence of a maintenance object, wherein the value is s 1 =3 when the failure influence is obvious safety, s 1 =2 when the failure influence is obvious mission or hidden non-safety, s 1 =1 when the failure influence is obvious economy, and s 1 =4 when the failure influence is hidden safety; Determining the value of a type factor s 2 according to the type of the maintenance object, specifically s 2 =3 when the type is "mechanical", s 2 =2 when the type is "electrical", s 2 =1 when the type is "electronic"; The value of the task type factor s 3 is determined according to the maintenance task type of the maintenance object, specifically s 3 =1 when the maintenance task type is "SV/LU", s 3 =2 when the maintenance task type is "VC/OP", s 3 =3 when the maintenance task type is "GVI", s 3 =4 when the maintenance task type is "DET", s 3 =5 when the maintenance task type is "SDI", s 3 =6 when the maintenance task type is "FNC", and s 3 =7 when the maintenance task type is "RS/DI".
5. The utility model provides an aircraft low utilization ratio maintenance interval conversion equipment, includes the database, aircraft utilization ratio statistics module, low utilization ratio prediction module, maintenance task conversion module, maintenance task output module, specifically does: The database comprises an aircraft maintenance outline database and a flight database, wherein the aircraft maintenance outline database is used for the data storage of the aircraft maintenance outline; The aircraft utilization rate statistics module is used for generating a month utilization rate statistics data sequence, obtaining the number n of minimum continuous calendar months to be counted according to the aircraft C detection or base level maintenance interval number I C-check by using a formula (1), obtaining the accumulated flight hours n fhm,k of the current month according to the previous k months from a flight database, and obtaining the month utilization rate of the previous k months according to a formula (2) The month utilization rate of the previous n months And (3) sequentially arranging to obtain a month utilization rate statistical data sequence U (0) in the previous n months, wherein the formula (1) is as follows: n=[I C-check -1] (1) Wherein I C-check is the number of maintenance intervals of the C inspection or the base level of the aircraft, and n is the number of minimum continuous calendar months to be counted; The formula (2) is: Wherein n fhm,k is the month-long cumulative flight hours of the first k months, k=1, 2. The low-utilization-rate prediction module is used for judging whether the maintenance task conversion module needs to be started, receiving U (0) from the aircraft utilization rate statistics module, and obtaining a month utilization rate prediction value of the (n+1) th month by using the GM (1, 1) model function module of the gray model U fh-low is obtained from the aircraft maintenance outline database, judgment is carried out by using a formula (13), if not, the operation is finished, if yes, a starting signal is sent to a maintenance task conversion module, and the maintenance task conversion module is started, wherein the formula (13) is as follows: the maintenance task conversion module is used for converting maintenance tasks of which the maintenance interval unit is engine replacement hour, APU hour, flight hour or flight cycle into calendar day maintenance tasks under low utilization rate, and comprises a screening module, a weight module and a conversion module, and specifically comprises the following steps: After the maintenance task conversion module receives the starting signal sent by the low-utilization-rate prediction module, a screening module is used for screening maintenance tasks R h of which maintenance intervals are engine replacement hours, APU hours, flight hours and flight cycles from an aircraft maintenance outline database; The weight module calculates importance factors s of maintenance tasks R h according to a formula (14), if s is more than or equal to 8, the maintenance tasks R h are not operated, if s is less than 8, the maintenance tasks R h are sent to the conversion module, all maintenance tasks R h of s is sent to the conversion module through the weight module, wherein the formula (14) is as follows: s=s 1 +s 2 +s 3 (14) Wherein s 1 is a failure influence factor, s 2 is a type factor, s 3 is a task type factor, and s is an importance factor; The conversion module converts the maintenance task interval under the normal utilization rate into the maintenance task interval under the low utilization rate, firstly receives U (0) from the aircraft utilization rate statistics module, and receives the month utilization rate of the n+1th month from the low utilization rate prediction module Obtaining a month utilization average value using the formula (15) Obtaining maintenance interval value I 0 of maintenance task R h from an aircraft maintenance outline database, obtaining maintenance interval value I 1 under low utilization rate according to formula (16), changing maintenance interval unit of maintenance task R h into unit of month directly, judging whether all maintenance tasks with importance factors s <8 are converted, if not, continuing conversion, and if so, transmitting conversion results of all maintenance tasks to a maintenance task output module, wherein formula (15) is as follows: Equation (16) is: The maintenance task output module is used for receiving and outputting the conversion result of the maintenance task from the maintenance task conversion module, and the maintenance interval value and maintenance interval unit of the maintenance task R h after maintenance conversion are I 1 and I 1 months respectively.

Description

Method and device for airplane low-utilization maintenance interval conversion Technical Field The invention relates to the field of aircraft maintenance engineering, in particular to a method and a device for switching low-utilization-rate maintenance intervals of an aircraft. Background Typically, an aircraft determines its preventative maintenance tasks and its maintenance intervals based on its intended utilization for reliability-centric maintenance analysis (RCMA). In formulating preventive maintenance tasks for aircraft, applicable aircraft utilization ranges are well-defined, whether in Policy and Program Handbooks (PPH) or maintenance schematics. For example, the applicable aircraft utilization for the Boeing company B747-400 repair outline is in the range of 440 to 1320FC/1500 to 5500FH per year and the applicable aircraft utilization for the air passenger company A330-200 repair outline is in the range of 367 to 1100FC/1677 to 5667FH per year. Within a given utilization range, preventive maintenance tasks can maintain the inherent level of safety, reliability and economy of the aircraft. When the actual utilization rate of the airplane operated by the airplane user (such as an airline company) is lower than the specified utilization rate minimum value, the situation of low utilization rate is the case. If the aircraft is continuously operated under the condition, accumulation of water vapor (such as soundproof flame-retardant cotton, a structural residual water discharge system and the like) can occur, the lubrication efficiency of lubricating oil or lubricating grease is reduced, the lubricating oil or lubricating grease can be chemically decomposed, sealing of the system or the components can age, the fuel oil, lubricating oil and the like leak, the inside of the structure, the power device and the components are corroded, the control steel cable and the mechanism can be influenced by corrosion, the structural residual water discharge system of the aircraft can generate accumulation of water vapor and cannot work normally, accumulated water is generated in the fuel oil system, microorganisms and precipitates are bred, and the aircraft is influenced by the conditions of non-working or power-off state, the reliability reduction of electronic or electric components and the like for a long time. Thus, in low utilization conditions, the aircraft user should use maintenance tasks in low utilization conditions. However, due to the limited understanding of the aircraft's technical conditions by the aircraft user, manufacturers are required to provide technical services and support, low-utilization maintenance tasks and maintenance intervals therefor. In the prior art, maintenance analysis with reliability as a center is usually carried out on maintenance tasks to provide low-utilization maintenance tasks and maintenance intervals thereof, but the maintenance tasks in the aviation field are quite various, and the importance levels are different, and if the maintenance analysis with reliability as a center is adopted in all, the maintenance analysis with reliability as a center is quite complex, and if the maintenance intervals of the maintenance tasks with the utilization rate can be rapidly determined without passing the maintenance analysis with reliability as a center, the complexity of the maintenance analysis with reliability as a center can be reduced, and the maintenance tasks with the low utilization rate and the maintenance intervals thereof can be provided as soon as possible. In addition, the occurrence of the low-utilization-rate running condition has uncertainty and the deviation degree from the normal utilization rate also has uncertainty, and in the case, if a prediction method can be adopted aiming at the actual running condition, firstly the impending time of the low utilization rate can be judged, secondly the deviation degree from the normal utilization rate can be obtained, the maintenance task interval can be calculated better, and the cost and the running risk can be reduced. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a maintenance task and a maintenance interval thereof under low utilization rate as soon as possible, and provides a method for switching the maintenance interval when the utilization rate of an aircraft is low, which is characterized by comprising the following steps: S1, acquiring an aircraft maintenance outline; The aircraft maintenance outline database is a data storage mode of an aircraft maintenance outline, and at least comprises an aircraft normal utilization rate interval, all aircraft maintenance tasks, maintenance object failure influences, maintenance object types, maintenance task types of maintenance objects, maintenance interval values of maintenance tasks and maintenance interval units of maintenance tasks; s2, determining the month number to be counted and counting the utilization rate of t