阅读说明：本技术 一种飞机发动机高级振动监测装置 (Advanced vibration monitoring device for aircraft engine ) 是由 焦龙 刘宇辉 黄莹 欧阳祖铁 于 2021-07-26 设计创作，主要内容包括：本发明公开了一种飞机发动机高级振动监测装置,其被配置为执行如下流程：通过ACMS实时监控发动机振动超限事件,在事件发生时,自动采集相关参数信息并通过下行ACARS报文及时向地面系统反馈,从而使地面端能及时获知发动机振动超限事件的发生并及时准确地获取对监控与分析发动机振动情况有用的相关数据。(The invention discloses an advanced vibration monitoring device of an aircraft engine, which is configured to execute the following procedures: the ACMS monitors the engine vibration overrun event in real time, and when the event occurs, the relevant parameter information is automatically acquired and fed back to the ground system in time through the downlink ACARS message, so that the ground end can timely know the occurrence of the engine vibration overrun event and timely and accurately acquire relevant data which are useful for monitoring and analyzing the engine vibration condition.)

1. An aircraft engine advanced vibration monitoring apparatus, characterized in that it is configured to perform the following procedure: the ACMS monitors the engine vibration overrun event in real time, and when the event occurs, the relevant parameter information is automatically acquired and fed back to the ground system in time through a downlink ACARS message.

2. The apparatus of claim 1, comprising the program modules embedded in the ACMS as follows:

the ACMS engine vibration parameter acquisition module is used for acquiring the vibration value of the engine in real time;

the ACMS vibration monitoring logic module is used for filtering and monitoring the vibration value and triggering data acquisition and transmission of an ACARS vibration warning message according to the monitoring logic;

the ACMS vibration monitoring logic module comprises a plurality of vibration monitoring submodules, and each vibration monitoring submodule carries out independent monitoring and instruction triggering on each engine;

the vibration monitoring submodule includes:

the engine vibration overrun capturing module monitors the vibration value when the program is in a searching state, judges whether the vibration value exceeds a corresponding threshold value, and drives the program to enter a capturing state from the searching state after monitoring that the vibration value exceeds the threshold value;

the acquisition vibration overrun processing module records the start time of a vibration event after a program enters an acquisition state, sets the message serial number of the vibration event to be 1, distributes a vibration event overrun code, then sends a message data acquisition instruction, and starts a message time counter;

when the timing of the message time counter reaches a set time length T1, a message sending instruction is sent, the message time counter is restarted, and whether the current vibration value continuously exceeds the limit is judged:

if so, sending a message data acquisition instruction again after the vibration event message serial number is + 1;

if not, the driving program returns to the searching state to continuously monitor the vibration value;

the T1 value is set according to the capacity limit of a single message;

the ACMS vibration warning message data acquisition module is used for acquiring data according to a preset rule after receiving a message data acquisition instruction sent by the ACMS vibration monitoring logic module; the method comprises the following specific steps:

after receiving the data acquisition instruction, the ACMS vibration warning message data acquisition module respectively performs instantaneous acquisition and time window acquisition;

the method comprises the steps of instantly collecting data for explaining the general condition characteristics of the engine vibration overrun events, wherein the data comprises the vibration event starting time, the vibration event message sequence number and the vibration event overrun codes recorded by the ACMS vibration monitoring logic module;

the time window is used for collecting data describing the development process of the engine vibration event in a set time length T2, wherein T1 is T2;

and the ACMS vibration warning message transmission module is used for receiving a message sending instruction sent by the ACMS vibration monitoring logic module, arranging the data acquired by the ACMS vibration warning message data acquisition module into a message in a set format and transmitting the message to a ground system through an ACARS link.

3. The apparatus of claim 2, wherein the engine vibration values monitored by the engine vibration overrun capture module include a fan vibration value and a core engine vibration value, and wherein the core engine vibration value is preferentially monitored, and wherein the fan vibration value is determined only after the core engine vibration value is not overrun.

4. The apparatus of claim 3, wherein the threshold ranges of the fan vibration value and the core engine vibration value monitored by the engine vibration overrun capture module are 1.0CU ≦ threshold ≦ 5.0 CU.

5. The apparatus of claim 2, wherein the engine vibration overrun capture module comprises:

the input module is used for continuously acquiring a vibration value of a monitored parameter;

the signal verification module is used for verifying the monitored parameter vibration value input by the input module by calling a signal verification statement of the ACMS;

the delay module is used for acquiring historical data of the monitored parameter vibration value currently input by the input module;

the threshold comparison module is used for comparing the current vibration value of the monitored parameter input by the input module with the historical vibration value of the current monitored parameter input by the delay module with the threshold thereof;

the logic AND gate is used for performing AND operation on the outputs of the signal validation module and the threshold comparison module;

and the overrun judgment result output module is used for judging whether the vibration value of the monitored parameter is overrun or not according to the operation result of the logic AND gate, and outputting overrun only when the acquired data is valid and all the data are greater than corresponding threshold values.

6. The apparatus of claim 5, wherein the historical data selects sample data between T3 seconds ago and the current time, 2 ≦ T3 ≦ 5.

7. The apparatus according to claim 6, wherein the ACMS vibration warning message data collection module, after receiving the message data collection instruction, sets a time window as follows: the total duration from the time before the message data acquisition instruction is received to the time after the message data acquisition instruction is T2, the advance time is more than T3 seconds and is 1 to2 seconds more.

8. The apparatus of claim 2, wherein the parameters acquired by the time window acquisition mode comprise:

N1A1P；N2A1P；FFP1；FFRP1；VB1P1；VB2P1；OITP1；OIPP1；OIQP1；EGT1P；FFAN1P；FVN11P；FVN21P；N1COM1P；RFAN1P；RVN11P；RVN21P；ODP1P；UTCSS。

9. the apparatus of claim 2, wherein the parameters acquired in the instantaneous acquisition mode comprise: FLTNUM; TATP; ALTP; CASP; MNP; GWP; CGP; CPU2 VER; ENGTPYPE; ENGVEPR; ACID1 REP; ACID2 REP; ACID3 REP; ACID4 REP; ACID5 REP; ACID6 REP; FROM 1; FROM 2; FROM 3; FROM 4; TO 1; TO 2; TO 3; TO 4; QSW 42161; DATEYY; DATEMM; DATEDD; UTCHH; a UTCMM; UTCSS; PHNUMPRT; PFLP; PFRP; ADW1B 111; QSW 30181; QSW 31181; ICESW 272; ICESW 282; BMCW 4152; BMCW 4172; BMCW 5151; BMCW 5172; 0 VERHW; RPTCNT 47; RPTCD 947; CZMDV1T 1; CZMDV2T 1; CZMDUTC 1; czmsrc 1; ESNL 1; ESNL 2; ESNL 3; ESNL 4; ESNL 5; ESNL 6; EHRS1P 1; ECYC1P 1; BAFP 1; HPCTC 1P; LPCTC 1P; NF 1P; PB 1P; SVAP 1; TLA 1P; VSVA 1P; ODM5F 1; ODM6F 1; ODM7F 1; B251P.

10. The apparatus as claimed in claim 2, further comprising an MCDU vibration parameter adjustment display program module integrated in the MCDU and implemented by developing a vibration monitoring related page and associating threshold parameters for obtaining and displaying a current vibration threshold of each of the vibration monitoring submodules on the MCDU display screen, wherein the thresholds have different parameter names, and each threshold parameter is adjusted by the MCDU vibration monitoring related page.

Technical Field

The invention relates to the air traffic transportation industry, in particular to the vibration monitoring aspect of large commercial transport aircraft engines, and particularly relates to a device for monitoring and analyzing the vibration condition of an engine in real time.

Background

Engine vibration phenomena in large commercial transport aircraft

Most modern civil airliners use turbofan engines as their main power and supply sources. The engine has the characteristics of large takeoff thrust, low exhaust speed, low noise and the like, and generally comprises an air inlet channel, a low-pressure air compressor, a high-pressure air compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a spray pipe, a fan and an outer duct. The gases passing through the combustion chamber form a high density and high pressure gas stream that subsequently propels the turbine in rotation. The rotating turbine drives more turbines and fans to rotate by the output torque of the rotor, and more gas is obtained to generate thrust.

During commercial operation, engine components rotating at high speed may deviate from a designed equilibrium state due to design defects, foreign object impacts, or maintenance loss, etc., thereby causing a vibration phenomenon of the engine. For example, the low-pressure turbine 3-stage blade of the PW1100 type engine is made of a light titanium-aluminum alloy material in the initial design, the weight is light, but the strength is poor, so that the blade is easy to break in the operation process of the engine, and at present, many sudden high-vibration events of the engine caused by the reason occur worldwide. For a commercial operating airplane, the occurrence of such high vibration events will most probably cause the pilot to close the affected engine and carry out the standby landing operation in the air, and great threat is generated to the civil aviation operation safety.

Existing engine vibration monitoring means and defects thereof

As the high vibration phenomenon of the engine greatly influences the safety of civil aviation transportation, each operator establishes a corresponding fault reporting and monitoring mechanism and tries to find problems and take measures in the shortest time. When a high vibration condition occurs, the electronic central monitoring system (ECAM/EICAS) of the aircraft will generate a high vibration warning and alert the pilot. Normally, the pilot immediately checks for faults according to the flight manual and takes corresponding measures, and the ground engineer is informed by satellite phone or aviation telegram that this may happen after minutes of the event. The event reporting mode has the defects of larger delay, less information transmission, transmission error and the like.

After the event, the ground engine engineer can only analyze the fault reason by means of a very small amount of voice information in the satellite telephone and prepare a troubleshooting measure in advance by means of incomplete or even inaccurate information. The means relying on QAR (fast access recorder) data analysis must wait tens of minutes after the flight has landed.

In addition, vibration events that do not trigger an ECAM/EICAS (or similar crew warning display assembly) warning may be left out of the way, and vibration events that do not trigger a pilot operation and reporting mechanism due to transient vibration may only transmit information in the form of a post-flight log book, which greatly hinders preventive maintenance work for the engine due to untimely information transmission and insufficient information granularity, or even buries a potential hazard for more serious faults.

Disclosure of Invention

The invention aims to provide a device for enabling non-crew members to monitor and analyze the vibration condition of an aircraft engine in real time.

The invention aims to be realized by the following technical scheme: an aircraft engine advanced vibration monitoring apparatus configured to perform the following process: the method comprises the steps of monitoring an engine vibration overrun event in real time through an ACMS (aircraft state monitoring system), automatically acquiring relevant parameter information and feeding back the information to a ground system in time through a downlink ACARS message when the event occurs, so that a ground end can timely acquire the occurrence of the engine vibration overrun event and timely and accurately acquire relevant data useful for monitoring and analyzing the vibration condition of the engine.

The device specifically comprises the following program modules embedded in the ACMS:

the ACMS engine vibration parameter acquisition module is used for acquiring the vibration value of the engine in real time;

the ACMS vibration monitoring logic module is used for filtering and monitoring the vibration value and triggering data acquisition and transmission of an ACARS vibration warning message according to the monitoring logic;

the ACMS vibration warning message data acquisition module is used for acquiring data according to a preset rule after receiving a message data acquisition instruction sent by the ACMS vibration monitoring logic module;

and the ACMS vibration warning message transmission module is used for receiving a message sending instruction sent by the ACMS vibration monitoring logic module, arranging the data acquired by the ACMS vibration warning message data acquisition module into a message in a set format and transmitting the message to a ground system through an ACARS link.

The ACMS vibration monitoring logic module comprises a plurality of vibration monitoring submodules, and each vibration monitoring submodule carries out independent monitoring and instruction triggering on each engine.

An aircraft is typically equipped with more than two engines, so that several refer to more than two here. Each vibration monitoring submodule carries out independent monitoring on each engine, and after the vibration overrun event of the corresponding engine is monitored, the vibration monitoring submodule sends a data acquisition instruction and a data sending instruction aiming at the engine, and the vibration monitoring submodules are not interfered with each other.

The vibration monitoring submodule includes:

the engine vibration overrun capturing module monitors the vibration value when the program is in a searching state, judges whether the vibration value exceeds a corresponding threshold value, and drives the program to enter a capturing state from the searching state after monitoring that the vibration value exceeds the threshold value;

the acquisition vibration overrun processing module records the start time of a vibration event after a program enters an acquisition state, sets the message serial number of the vibration event to be 1, distributes a vibration event overrun code, then sends a message data acquisition instruction, and starts a message time counter;

when the timing of the message time counter reaches a set time length T1, a message sending instruction is sent, the message time counter is restarted, and whether the current vibration value continuously exceeds the limit is judged:

if so, sending a message data acquisition instruction again after the vibration event message serial number is + 1;

if not, the driving program returns to the searching state to continuously monitor the vibration value;

the T1 value is set according to the capacity limit of a single message.

The ACMS vibration warning message data acquisition module respectively performs instantaneous acquisition and time window acquisition after receiving the data acquisition instruction;

the method comprises the steps of instantaneously acquiring data for explaining the general condition characteristics of the engine vibration overrun event, wherein the data comprises the vibration event starting time, the vibration event message sequence number, the vibration event overrun code and the like recorded by the ACMS vibration monitoring logic module;

the time window is used to collect data describing the development of an engine vibration event over a set duration T2, T1-T2.

The device continuously monitors any vibration event, and segments a continuous vibration overrun event according to ACARS message capacity limitation through the cooperation of the ACMS vibration monitoring logic module, the ACMS vibration warning message data acquisition module and the ACMS vibration warning message transmission module, so that the ACARS message capacity limitation is avoided while the whole overrun event development process is recorded, and the requirement of timely downloading of vibration data is met.

The engine vibration value monitored by the engine vibration overrun capturing module comprises a fan vibration value and a core machine vibration value, the core machine vibration value is preferentially monitored, and the fan vibration value is judged only after the core machine vibration value is not overrun.

The threshold value range of the fan vibration value and the core machine vibration value monitored by the engine vibration overrun capturing module is 1.0CU or more and is not more than 5.0CU or less than the threshold value. The ECAM warning only monitors the situation when the vibration value is larger than 5CU, the threshold value is recommended to be valued within the range of 1.0-5.0 CU, and under certain conditions, vibration events with the vibration value being smaller than or equal to 1.0CU and smaller than or equal to 5.0CU are worth to arouse the alert of engineers and can be used as a data source for preventive maintenance.

The engine vibration overrun capture module monitors whether the vibration value is overrun by:

the input module is used for continuously acquiring a vibration value of a monitored parameter;

the signal verification module is used for verifying the monitored parameter vibration value input by the input module by calling a signal verification statement of the ACMS;

the delay module is used for acquiring historical data of the monitored parameter vibration value currently input by the input module;

the threshold comparison module is used for comparing the current vibration value of the monitored parameter input by the input module with the historical vibration value of the current monitored parameter input by the delay module with the threshold thereof;

the logic AND gate is used for performing AND operation on the outputs of the signal validation module and the threshold comparison module;

and the overrun judgment result output module is used for judging whether the vibration value of the monitored parameter is overrun or not according to the operation result of the logic AND gate, and outputting overrun only when the acquired data is valid and all the data are greater than corresponding threshold values.

On the aspect of judging the vibration value is out of limit, the invention combines the methods of data verification and multi-time-point sampling comparison, and on the premise of ensuring the effectiveness of the collected data, the occurrence of false alarm can be greatly reduced by using historical data and current data to carry out comparison judgment.

The historical data selects the sampling data from T3 seconds ago to the current time, and T3 is more than or equal to2 and less than or equal to 5. Historical data should not be collected too much, otherwise the sensitivity of the warning is reduced.

After the ACMS vibration warning message data acquisition module receives the message data acquisition instruction, the acquired time window is set as follows: the total duration from the time when the message data acquisition instruction is received to the time when the message data acquisition instruction is received is T2, the advance time is more than T3 seconds, and more than 1 or 2 seconds is recommended generally.

Due to the participation of historical data in the vibration overrun judgment, a certain lag exists in the judgment of the occurrence of the vibration overrun event, and the starting point of the data acquisition time window is set before the real occurrence time point of the vibration event, so that an engineer receiving a message can observe the evolution of the event from the overrun state to the overrun state.

The parameters acquired by the time window acquisition mode comprise:

N1A1P；N2A1P；FFP1；FFRP1；VB1P1；VB2P1；OITP1；OIPP1；OIQP1；EGT1P；FFAN1P；FVN11P；FVN21P；N1COM1P；RFAN1P；RVN11P；RVN21P；ODP1P；UTCSS。

the parameters acquired by the instantaneous acquisition mode comprise:

FLTNUM；TATP；ALTP；CASP；MNP；GWP；CGP；CPU2VER；ENGTYPE；ENGVERP；ACID1REP；ACID2REP；ACID3REP；ACID4REP；ACID5REP；ACID6REP；FROM1；FROM2；FROM3；FROM4；TO1；TO2；TO3；TO4；QSW42161；DATEYY；DATEMM；DATEDD；UTCHH；UTCMM；UTCSS；PHNUMPRT；PFLP；PFRP；ADW1B111；QSW30181；QSW31181；ICESW272；ICESW282；BMCW4152；BMCW4172；BMCW5151；BMCW5172；0VERHW；RPTCNT47；RPTCD947；CZMDV1T1；CZMDV2T1；CZMDUTC1；CZMDSRC1；ESNL1；ESNL2；ESNL3；ESNL4；ESNL5；ESNL6；EHRS1P1；ECYC1P1；BAFP1；HPCTC1P；LPCTC1P；NF1P；PB1P；SVAP1；TLA1P；VSVA1P；ODM5F1；ODM6F1；ODM7F1；B251P。

the device also comprises an MCDU vibration parameter adjusting and displaying program module which is integrated in the MCDU and is realized by developing a vibration monitoring related page and associating threshold parameters, is used for acquiring the current vibration threshold of each vibration monitoring sub-module and displaying the vibration threshold on an MCDU display screen, has different parameter names, and adjusts each threshold parameter through the MCDU vibration monitoring related page to realize the capability of respectively setting monitoring thresholds for the fan and the rotor of different engines of different airplanes, thereby meeting the actual engineering requirements of fine monitoring changes caused by the individual differences of airplane equipment.

Compared with the prior art, the invention has the following beneficial effects:

1) the invention can capture the vibration overrun event of the aircraft engine in real time and send the vibration warning information of the engine to the ground system in time

At present, engine vibration warning information of an airplane can only remind a pilot in real time through an ECAM/EICAS airborne system, or inform ground maintenance personnel after the end of the flight through an after-flight fault message and QAR data. The device of the invention provides a method for monitoring the vibration condition of the engine in real time and sending warning information to the ground system in real time through airborne software monitoring, ACARS message sending and ground system analysis, so that a ground engineer can master the vibration overrun condition of the engine in real time, and the problems of untimely information transmission, incomplete transmitted information and even inaccuracy and the like in the prior art are solved;

2) recording the progress of a vibration overrun event

The invention segments a vibration event lasting for a long time according to the ACARS message capacity limit by matching the timing trigger data acquisition, instruction sending and instantaneous and time window data acquisition modes, records the whole vibration overrun event development process, avoids the ACARS message capacity limit and meets the requirement of timely downloading the vibration data; the invention also enables an engineer to observe the evolution process of the event from the non-overrun state to the overrun state through the setting of the time window acquisition time;

3) according to the invention, on the basis of judgment of the vibration value overrun, a data verification and multi-time-point sampling comparison method is combined, on the premise of ensuring the effectiveness of the collected data, historical data and current data are used for comparison and judgment, so that the occurrence of false alarm can be greatly reduced;

4) the engine vibration related parameters recorded by the invention are accurate and comprehensive, and are beneficial to the ground engineers to analyze the cause of the engine failure and arrange the maintenance work in advance;

5) airline configuration capability to implement vibration warning thresholds for individual engines on-board

According to the invention, through the method for setting the MCDU vibration threshold value, the differential setting of the trigger threshold value aiming at the vibration warning message of each engine of each airplane is realized, and the purpose of enabling the engine vibration monitoring scheme to be more flexible and convenient is achieved.

Drawings

FIG. 1 is a schematic diagram of the general concept of the present embodiment;

FIG. 2 shows VB1 data collection interface 1;

FIG. 3 shows VB1 data collection interface 2;

FIG. 4 is a VB1 data acquisition interface 3;

FIG. 5 shows VB2 data collection interface 1;

FIG. 6 shows VB2 data collection interface 2;

FIG. 7 is a VB2 data collection interface 3;

FIG. 8 is a diagram of the overall architecture of the monitoring logic;

FIG. 9 vibration monitoring submodule state machine;

FIG. 10 is an engine vibration overrun capture module;

FIG. 11 captures a vibration overrun handling mechanism;

FIG. 12 the vibration monitor module is embedded in the ACMS trigger;

FIG. 13 is a schematic view of a data structure for instantaneous acquisition;

FIG. 14 setting 1 of instantaneous acquisition data on ACMS;

FIG. 15 setting 2 of instantaneous acquisition data on ACMS;

FIG. 16 time window acquisition mode description;

FIG. 17 setting 1 of time window acquisition data on ACMS;

FIG. 18 setting 2 of time window acquisition data on ACMS;

FIG. 19 message ACARS Format overview;

FIG. 20 illustrates the ACARS format structure of the message;

FIG. 21 message ACARS Format setting 1 on ACMS;

FIG. 22 message ACARS Format setup 2 on ACMS;

FIG. 23 message print format overview;

FIG. 24 setting 1 of message printing format on ACMS;

FIG. 25 setting 2 of message printing format on ACMS;

FIG. 26 setup of routing function on ACMS;

fig. 27 setting up the message download path on ACMS;

figure 28 setting of message transmission number on ACMS;

fig. 29 MCDU message editing interface;

fig. 30 MCDU message parameter editing interface;

FIG. 31 is a diagram of an MCDU vibration message parameter adjustment interface;

fig. 32 shows an on-board MCDU vibration alert message triggering a threshold setting interface;

33B-8368 Default vibration message alert thresholds;

34B-8368 vibration message alert threshold revision values;

FIG. 35 vibration message subscription interface-message type;

FIG. 36 vibration message subscription interface-aircraft number selection;

FIG. 37 vibration message subscription interface-subscription rule set;

FIG. 38 a vibration message subscription interface-subscription check;

FIG. 39 vibration message subscription interface-mail recipient settings;

FIG. 40 real-time alert mail alert case;

FIG. 41 alert mail content;

FIG. 42 FIADA vibration message query interface;

FIG. 43 is a drawing of a FIADA vibration message printing format display interface;

FIG. 44 FIADA vibration message time window data query;

fig. 45 FIADA vibration message time window data curve and mathematical statistics.

Detailed Description

The general idea of this embodiment is shown in fig. 1, and it is described in the background art that when a high vibration condition occurs, an electronic central monitoring system (ECAM/EICAS) of an aircraft automatically generates a high vibration warning and reminds a pilot, but during a navigation phase, a ground engineer is informed that the flight crew can only relay the warning through a satellite phone or an aviation telegraph, and this way, not only is a large delay, but also the quality of the transmitted information is not high. In the embodiment, an autonomous monitoring logic for monitoring the vibration condition of the aircraft engine is added in the airborne ACMS system, when the monitoring logic is triggered due to the occurrence of a high vibration condition, the airborne ACMS system automatically collects relevant parameter information, and timely reminds a ground engineer in a mode of descending an ACARS message to a ground system, so that the vibration condition of the engine can be monitored and analyzed in real time at an airborne terminal and a ground terminal.

The specific implementation of the above scheme will be described in detail below by taking an air passenger a32X Neo PW engine series aircraft as an example.

The utility model provides an aircraft engine advanced vibration monitoring devices, at aircraft circular telegram stage, it realizes the setting of aircraft engine vibration condition detection, control and relevant function through following module:

1. ACMS engine vibration parameter acquisition module

The module is used as an engine vibration data input interface module of the device of the embodiment, and collects vibration values of a fan and a rotor of an Engine Electronic Controller (EEC) in real time through an ARINC 429 bus, wherein the vibration values are consistent with a vibration warning data source of an airplane electronic central monitoring system (ECAM/EICAS) received by a pilot. This vibration value will be passed as output data to the ACMS vibration monitoring logic module in the following.

1.1 introduction of vibration parameters of Engine

Taking the PW1100G-JM engine as an example, the vibration behavior of the PW1100G-JM engine is mainly inferred by analyzing the vibrations of the low-pressure spool and the high-pressure spool. Because the low-pressure rotor acts on the low-pressure compressor and the low-pressure turbine, the high-pressure rotor acts on the high-pressure compressor and the high-pressure turbine, and the central monitoring system of the airplane judges the vibration conditions of the two rotating shafts by acquiring a fan vibration value (VB1) and a core machine vibration value (VB 2).

The main characteristics of these two vibration values are shown in table 1.

TABLE 1 main characteristics of vibration values

The vibration value of any engine exceeding 5CU is a serious event and needs to be monitored immediately. The stop-down maintenance caused by the vibration value being more than 5CU 3 times will cause huge profit loss and detection and repair cost for the operation unit. In addition, a vibration event with a vibration value between 1CU and 5CU may also be worth alerting engineers in some cases, and may serve as a data source for preventive maintenance. Therefore, it is recommended to set the engine vibration overrun determination threshold between 1CU and 5CU, which is preferably adjusted according to the engine specification.

Since there are 2 parameters above for each engine, there are 4 vibration parameters to monitor for each aircraft, and the different engines are distinguished by labeling "1" and "2" after the vibration parameter identifier. For example, VB11 represents the value of the fan vibration of shot 1, VB12 represents the value of the fan vibration of shot 2, VB21 represents the value of the core engine vibration of shot 1, and VB22 represents the value of the core engine vibration of shot 2.

1.2, fan vibration value (VB1) acquisition

The module uses an airborne embedded programmable system ACMS to realize data acquisition, and achieves the aim of accurately acquiring the vibration value of the fan by setting a data acquisition standard so as to meet the requirements of frequency, precision, data format and the like required by monitoring logic.

By analyzing the monitoring logic requirements, the VB1 parameter at least needs to meet the following parameter characteristic collection criteria, as shown in table 2.

TABLE 2 VB1 parameter characteristic Collection Standard

Type of data acquisition	Precision of acquisition	Acquisition frequency	Time of buffer	Acquisition source
					DITS	At least 0.1CU	At least 1Hz	At least 20 seconds	EIU1

For ARINC 429 bus data transmission, the following standard is adopted, as shown in Table 3.

TABLE 3 VB1 parameter characteristic Collection Standard

According to the above acquisition requirements, the setting of the parameter acquisition is implemented in ACMS software, which takes engine number 1 as an example, and is specifically shown in fig. 2, 3 and 4.

1.3, collecting vibration value (VB2) of core machine

As with the VB1 collection concept, the VB2 parameters at least satisfy the following parameter characteristic collection criteria, as shown in table 4.

TABLE 4 VB2 Collection Standard

Type of data acquisition	Precision of acquisition	Acquisition frequency	Time of buffer	Acquisition source
					DITS	At least 0.1CU	At least 1Hz	At least 20 seconds	EIU2

For ARINC 429 bus data transmission, the following standard is adopted, as shown in Table 5.

TABLE 5 VB2 parameter characteristic Collection Standard

According to the above acquisition requirements, the setting of the parameter acquisition is implemented in ACMS software, which takes engine number 1 as an example, and is specifically shown in fig. 5, 6 and 7.

2. ACMS vibration monitoring program module

The module receives the engine vibration value output by the ACMS engine vibration parameter acquisition module, filters and monitors the engine vibration value, and triggers an ACARS (aircraft communication addressing and reporting system) warning message according to specific logic. The module continuously monitors any vibration event and segments a continuous vibration overrun event according to ACARS capacity limit so as to record the development process of the whole overrun event.

2.1 general structural introduction

The module is used as a core module of the device of the embodiment, is connected with each function module in the upstream and downstream in series, and is responsible for overall monitoring of vibration overrun events, triggering and forwarding of data of downlink warning messages and feeding back data required by a human-computer interaction interface.

This module carries out independent control to2 engines, sends out vibration control submodule independent execution by 1/2 respectively, and mutual noninterference satisfies the control engineering demand that the high vibration condition takes place simultaneously of two. The vibration monitoring logic of each engine is the same, the difference is only the input real-time acquisition parameters, and the method can be regarded as two independent examples of the same type of method.

The module acquires real-time vibration data from the ACMS engine vibration parameter acquisition module and respectively transmits the real-time vibration data to2 independent sub-modules. The threshold value display and adjustment of each sub-module can be independently completed through an MCDU vibration parameter adjustment display program module, and the respective triggered activation message command can also be independently transmitted to a downstream ACMS vibration warning message data acquisition module. The overall architecture of the monitoring logic of the module is shown in fig. 8.

In addition, the operation of the module covers the whole power-on stage of the airplane, so that vibration events in flight can be monitored, and instant information can be obtained aiming at the vibration problems occurring in ground test or sliding.

The operation of the vibration monitoring logic will be described below by introducing a 1-pin vibration monitoring submodule, using engine number 1 as an example.

2.2 vibration monitoring submodule

The vibration monitoring routine for each engine can be described by 3 state machines, namely, the search state, the captured VB2 vibration overrun state and the captured VB1 vibration overrun state, represented by the parameter CZMADPPR 1 (here, 1 is taken as an example, and 2 is referred to as CZMADPPR 2), corresponding to three values of 0, 1 and 2, respectively, as shown in FIG. 9. The last 2 states are also referred to as capture states, and can be expressed by the same logic mechanism. If the program does not enter any capture state, the sub-module will execute every second in the order of FIG. 9.

After the initialization process of switching the power-off state of the airplane to the power-on state is finished, the monitoring program automatically enters a searching state to monitor the acquired vibration value. Since the vibration of the core (VB2) is more important than the vibration of the fan (VB1), the program will monitor the vibration of VB2 preferentially and determine the vibration of VB1 only after the vibration of VB2 has not exceeded.

The vibration determination process is implemented by the engine vibration overrun capture module for both VB2 and VB 1. If the monitored vibration value does not reach the preset threshold value or the threshold value is manually input through the MCDU, the monitoring program is continuously in the searching state.

Once the program enters the capture state for a certain vibration value (at this point, czmaadpr 1 is 1 or 2), the program will continuously monitor that vibration value and send a corresponding warning message until the corresponding vibration value meets a threshold below which it will exit the search state or wait for the aircraft to power down.

2.2.1 engine vibration overrun capture module

The overrun judgment of the overrun capture module on VB1 and VB2 combines a data check and multi-time-point sampling comparison method, and on the premise that the collected data is effective, the occurrence of false alarms can be greatly reduced by using historical data for comparison and judgment. Meanwhile, historical data is not collected too much, otherwise the sensitivity of warning is reduced. The structure of this module is shown in fig. 10.

The overrun capture module is mainly divided into 6 parts, namely input, signal check, delay, threshold comparison, logic AND gate and output.

Real-time vibration parameters VB1 or VB2 acquired by the vibration monitoring submodule from the ACMS engine vibration parameter acquisition module are used as input quantities to enter the overrun capture module. The process can only judge one input quantity at a time, but the process can be called for many times within one processing period (1 second) of the vibration monitoring submodule, for example, the vibration monitoring submodule calls the process to judge the VB2, the result is not over-limit, and the process can be continuously called to judge the VB 1.

The output of the module is an overrun judgment result, is discrete quantity of 0 or 1 and represents that the output is not overrun or overrun. The result will be described with respect to fig. 9 as affecting the status of the vibration monitoring submodule.

And the process checks the vibration value by calling a signal check statement of the ACMS, the check result is discrete quantity and is input to the logic AND gate, and the check failure means that the output of the whole process is 0, namely the process is not overrun.

Meanwhile, the input quantity is processed by the delayer and participates in the future overrun judgment. In this way, the data of a plurality of time sampling points (2 seconds before the current time, 1 second before the current time and the current data) can be simultaneously determined when the program runs each time.

The current vibration data and the delayed data are respectively compared with the vibration threshold parameter, the discrete quantity result is also input into the logic AND gate, and the output of the 'overrun' result is possible only when all the data are greater than the corresponding vibration threshold. The oscillation threshold parameter CZMDV2T1 represents a threshold for an oscillation value VB11 (VB1 on issue 1), and CZMDV1T1 represents a threshold for VB21 (VB2 on issue 1). As shown in fig. 10, these thresholds can be displayed and set by the MCDU vibration parameter adjustment display module.

The logic AND gate part ensures that the data passes the verification and the current data and the historical data both meet the condition of triggering the overrun.

2.2.2 captured vibration overrun processing Module

After the vibration monitoring submodule finds that a certain vibration value is overrun through the overrun capture module, the program enters a capture state of the corresponding vibration value, and the logic of the program can be described through fig. 11. Due to the size limitation of the ACARS message, the description of the vibration event cannot be completed with a large probability in the capacity of one message. The device of the embodiment sets a message to describe a vibration process of 20 seconds according to the message capacity, so that the processing mechanism for capturing the vibration overrun processing module is 20 seconds per cycle. The following describes the processing mechanism by dividing it into 3 parts, namely "first time capture state", "time count state", and "message continuous trigger judgment state", according to the time evolution sequence.

A) First entering Capture State

When the program is switched into the capture state from the search state, namely the vibration event of the current round enters the capture state for the first time, various information of the vibration event is initialized and recorded, and a timer is triggered to start. The following are descriptions of the parameters:

the "vibration event start time" parameter records the time when the vibration occurs, and since a vibration overrun event may be continuously described by a plurality of ACARS messages, the parameter can help the messages to determine to which vibration event the vibration process represented by the message belongs.

The "vibration event message sequence number" parameter indicates that the message belongs to the messages in the vibration event which are arranged in time sequence.

The "vibration event overrun code" parameter describes which vibration value of which engine generated the event, and the specific relationship is shown in table 6.

TABLE 6 vibration event overrun trigger code

Vibration event overrun code	Description of the invention
		3021	1-shot VB2 overrun
3011	1-shot VB1 overrun
		3022	2-shot VB2 overrun
3012	2-shot VB1 overrun

The "message time counter" parameter is used to count the time required to trigger the sending of a message. After entering the capture state for the first time, the program starts a timer count from 0, counting 1 time per second.

And the program sends an instruction to the ACMS vibration warning message data acquisition module, and starts the data acquisition of the vibration message with the current serial number of 1.

At this point, the process of first entering the capture state ends, the time counter is incremented by 1, and the routine is executed again until the next second.

B) Time counter state

After the counter is started, in 0 to 20 seconds, the program only detects whether the counter reaches 20, and does not execute other operations.

C) Message continuous trigger judging state

When the time counter reaches 20, it will be reset and send instruction to ACMS vibration warning message transmission program module, triggering it to send the message data formed in 20 seconds. Until the relevant instructions of the segment of the message are completely finished.

Thereafter, the routine continues to determine whether the vibration value that previously triggered the warning continues to overrun.

If the program continues to overrun, the program will trigger a new data acquisition instruction to the ACMS vibration warning message data acquisition module, start the next 20-second data acquisition, and at the same time, the parameter "vibration event message sequence number" will be incremented to mark the sequence position of the next message in the vibration event series message. The program continues to enter the time counter state.

If the vibration value is no longer exceeded, the program will exit the capture state, return to the search state, and have monitored the next vibration event.

2.3 implementation of the Module

The ACMS vibration monitoring program module is realized by a Trigger 'Trigger CSNMADV' implanted into the ACMS. The trigger is automatically executed in all operating phases in the power-on state, and the execution frequency is 1 Hz.

An example of an ACMS trigger segment after implantation of a vibration monitor module is shown in fig. 12.

3. ACMS vibration warning message data acquisition module

After receiving a message data collection instruction sent by the ACMS vibration monitoring logic module, the module collects data according to a preset rule. The data collection work can be performed independently for two engine messages, and the two engine messages do not interfere with each other, and the following description takes the operation process of 1 engine as an example.

According to the acquisition mode, the data is divided into 2 modes of instantaneous acquisition and time window acquisition. Through the cooperation of the two data acquisition modes, the module maximally transfers data useful for fault analysis under the condition of capacity limitation. The data collected by the 2 modes are transmitted to a downstream ACMS vibration warning message transmission module after the data are collected.

3.1, instantaneous acquisition

The data obtained at the moment of receiving the data acquisition instruction is used for explaining the general situation characteristics of the vibration overrun event, and is mainly divided into 3 parts, namely flight information, vibration event information and flight state overview. Fig. 13 shows the data acquired instantaneously in the message printing format as an example.

A) Flight information

Including aircraft number, flight date, current time of flight (UTC), take-off and landing airport, and flight number.

B) Vibration event information

The method comprises the steps of monitoring a software version, a vibration event occurrence flight phase, a vibration message total number (the accumulated number of all vibration messages is 999 and is reset to zero), a vibration event overrun code, a VB1 vibration threshold value, a VB2 vibration threshold value, vibration event starting time and a vibration event message sequence number.

C) Overview of flight status

The flight control system comprises 24 state parameters such as total temperature, altitude, airspeed, Mach number, gross weight and engine cycle number, and reflects the flight at the moment of receiving a data acquisition command and the total instantaneous state of an engine.

The specific parameter names, formats and descriptions of the above data are seen in table 7.

TABLE 7 instantaneous acquisition data List

The above parameters are implemented by adding to the ACMS message data collection function to establish an instantaneous collection group. The attribute of the parameter acquisition group is set to "Request Time", i.e., instantaneous acquisition. The settings on ACMS are shown in fig. 14 and 15.

3.2 time window acquisition

Another type of data is data describing the progress of the vibration event, where each message collects 20 seconds of continuous time window data, with a collection frequency of 1Hz, ranging from the first 3 seconds to the last 16 seconds of receiving the data collection instructions, as shown in fig. 16.

This time point arrangement is used because the triggering of any vibration event requires a continuous 3 second vibration value to reach the threshold. The actual occurrence time point of the vibration event has been lagged by 2 seconds at the time of the trigger acquisition data command. And the time point 3 seconds before the acquisition command is triggered is just the critical point of the exceeding of the vibration value. In this way, engineers receiving the message can observe the evolution of the event from an un-overrun to an overrun condition.

The data collected every second has the same content, mainly the vibration related parameters of the engine, such as vibration value, low-pressure rotating speed, high-pressure rotating speed and the like, and the specific data are shown in a table 8. After the data acquisition for 20 seconds is finished, the module can automatically transmit the data to the ACMS vibration warning message transmission module for message sending. If the ACMS vibration monitoring program module judges that the vibration event continues to occur, the module receives a new data acquisition instruction and repeats the previous data acquisition work.

TABLE 8 continuous time Window acquisition data List

The parameters are added to the ACMS message data acquisition module, so that a time window acquisition group is established. The attribute of the parameter acquisition group is set as "Time Series", that is, Time window acquisition, and the acquisition is started from the first 3 seconds of message activation (Time when a data acquisition instruction is received) and ended for 20 seconds, and is performed once every 1 second. The setting of the time window acquisition data on ACMS is shown in detail in fig. 17 and 18.

4. ACMS vibration warning message transmission module

Data acquired by the ACMS vibration warning message data acquisition module are formatted into a message in an ACARS format for transmission, the message can be decoded through the same rule on the ground, and the message data are structured and then stored in a database. Meanwhile, the data can also be sent to a printer through a printing format for a pilot or a ground engineer to read. In addition, the cache and route forwarding mechanism of the warning message are set by the module.

4.1, ACARS message Format

The message consists of 66 lines of characters, the first two characters of each line are line numbers, and the line numbers are used for quickly positioning data with specific meanings. Each row can carry at most 40 characters, and commas are used for dividing data. The version is shown in fig. 19.

The structure of the message format is mainly composed of 3 major parts, see fig. 20.

The first section describes basic information such as flight information, software version information, event trigger codes, vibration warning thresholds and event sequence numbers, belonging to the instantaneous acquisition data, by the CC and CD lines.

The second section, from CE to EA, describes the overall aircraft state information, such as total temperature, altitude, airspeed, and mach number, among other parameters, as well as the instantaneous collected data.

The third section describes the progression of a vibration event through the lines FA to YC. The part has 60 lines, 1 group of every 3 lines, and 20 groups in total, and respectively corresponds to the states from3 seconds before message activation to 16 seconds after message activation. Each set of recording parameters consists of three lines of A/B/C, and the same structure is formed among the sets.

This format is implemented by ACMS message format setting function, which creates a hard copy (Hardcopy) "CSN ENGINE MECH ADV1 ACARS" and edits the above format, as shown in fig. 21 and 22.

4.2 print message Format

The printing format structure of the message is similar to the ACARS overall structure, except that an annotation with parameter meaning is directly added to each row of data, for example, as shown in fig. 23, an annotation in the word "a/C ID" exists above the data in the "AAAAAA" format of the CC row, indicating that the data is the registration number of the airplane.

This format is implemented by ACMS message format setting function, which creates a new hard copy (Hardcopy) "CSN ENGINE MECHANICAL advesory REPORT" and edits the above format, as shown in fig. 24 and 25.

4.3, data transmission route submodule

The sub-modules define the path, mode and number of message transmission.

A) Route setup

The sub-module displays the transmission of different purposes by setting different routing modes. Fig. 26 shows the implementation of this sub-module in the ACMS message Routing function (Routing).

The total number of route settings is 6 major categories (Loader, ACARS, Printer, Ethernet, Recorder and Integrated Disk), 3 ways (Automatic, Manual and Formatted).

The Loader is a handheld data Loader, and by means of the arrangement, the message can be directly transmitted to the Loader after being generated. The ACARS is a message air-to-ground transmission mode. Printer represents a Printer, and the message can be directly printed through this setting after being generated. Ethernet is a network connection. The Recorder represents an OQAR, and the message can be backed up in a QAR file medium and can be downloaded to a ground server through a wireless QAR. The Integrated Disk corresponds to a PCMCIA (personal computer memory card) which is installed in a DMU device of an airplane.

The Automatic mode is that a message is sent immediately after a vibration event is triggered, but the message cannot be sent immediately because the vibration event needs to acquire time window data. Manual is a Manual message sending mode, and a message sending behavior is generated only after a specific instruction is received. The device of the embodiment is controlled by an ACMS vibration monitoring program module. The Formatted approach represents the transfer of data in a band format, such as the format described in fig. 19 and 23, and if transmitted in a non-Formatted format, all the data will be concatenated without gaps.

The submodule adopts the Manual and Formatted modes of Loader, ACARS and Printer according to the actual application requirement.

B) ACARS download path setup

As shown in fig. 27, through the ACMS message download function (Downlinks), an additional fixed forwarding address may be added to the address (Addresses) column, and if the address is blank, the forwarding address set by the ATSU is selected by default.

A user of the sub-module can define an ACARS sending path (Destination) of the message according to the self requirement by analyzing a data supplier tariff scheme, and can select a VHF single path, a satellite single path or a VHF priority satellite leakage repairing mode. Meanwhile, deletion wrapping can be set to save transmission flow.

C) Number of transmissions

In addition, the sub-module can set the maximum storage quantity of the message in the onboard equipment (sometimes the message cannot be sent out immediately due to the delay and blockage of the ACARS network) and the maximum sending quantity of each segment, so that the message flow expense can be reduced in certain specific situations, or the occurrence of message storm can be prevented.

Fig. 28 shows the implementation of this sub-module by the ACMS message Retention function (Retention). "Max Copies Total" indicates that the message is reserved for 50 Copies at most. "Max Copies per Flight" indicates that each Flight segment of the message is reserved for 50 Copies at most, and the next Flight segment will clear up more than 50 records. "Number of Flight Legs" indicates that the data is stored in the aircraft for up to 50 Flight segments. "Keep Last" indicates if the message of the excess capacity restriction appears, delete the earlier time of occurrence, Keep the later.

5. MCDU vibration parameter adjustment display module

Through the module, airline personnel or engine engineers can adjust the threshold value triggered by the warning message for a certain engine of a certain airplane, and independent control according to requirements is realized. The module is integrated in an onboard multifunctional control display Module (MCDU), and the functions can be realized by developing corresponding pages and associating threshold parameters.

An entry of a vibro-messaging threshold parameter adjustment interface is added to a blank on the right side of a message editing interface, and is associated to a corresponding page by setting a line option, as shown in fig. 29.

Then, an entry of the vibration monitoring message is created on the message parameter editing interface, as shown in fig. 30.

The vibration message parameter adjustment interface can set 4 threshold parameters in total, see fig. 31 specifically, and see table 9 for the explanation of the parameters. These parameters will directly act on the comparison process in the over-limit capture process above.

TABLE 9 vibratory report threshold parameter description

The parameters can be displayed on a screen in real time after being input by a numeric keyboard on the MCDU, the numerical value in the interface STATUS is displayed as a result of real-time refreshing at the frequency of 1Hz, and related personnel can immediately confirm whether the setting is successful after the adjustment is finished.

The above threshold parameters are stored in non-volatile memory and will be valid unless the software is reloaded. The software is reset to the default value after being reinstalled.

Single machine differential monitoring

Through the MCDU vibration parameter adjusting and displaying module of the device, each engine of each airplane has the function of realizing differential monitoring. For example, state engineers set a vibration warning threshold for B-8368. The engineer enters the threshold setting interface through the path described in the previous MCDU vibration data display module, as shown in fig. 32, and fig. 33 is a document scan of this interface printed by the cockpit printer. By inputting 2.9 'on the keyboard and selecting the corresponding vibration threshold row selection key, 4 vibration thresholds of 2 engines can be changed to 2.9', and fig. 34 shows that the change is effective after a document scanning piece printed by a cockpit printer is changed.

6. Ground system

After the warning message is transmitted to a ground gateway of an airline company through an ACARS link, the message is decoded through a message processing and message subscribing system of an airplane remote diagnosis system and is compared with subscribing conditions preset by an engineer, and the successfully matched subscription is presented to a desktop real-time terminal (RTT) or is sent to an electronic mailbox of a worker in a subscribing mail mode. Meanwhile, various maintenance personnel can inquire all history messages of the vibration warning and the mathematical statistical characteristics and the variation curve of various vibration related parameters related in the message content through an inquiry terminal (FIADA) of the airplane remote diagnosis system. The specific introduction is as follows:

6.1 ground subscription vibration warning message

The airline can subscribe to the message in real time by RTT (terrestrial IT integration system). The method is as follows:

A) ACMS-REP947 or REP948 is selected in the subscription message category as shown in figure 35.

B) An aircraft registration number to be monitored is selected as shown in fig. 36.

C) And writing trigger logic of the ground warning notification by using data fields acquired by an ACMS vibration warning message data acquisition module. For example, the following settings are that a flight originates or arrives at an airport as the sheng yangtao fairy airport, and the VB1 overrun initial state is 3.0CU or more or the VB2 overrun initial state is 3.0CU or more, as shown in fig. 37.

D) Vibration event subscription verification and alert address settings. Through which it can be verified whether the priority level of the subscription and the subscription status are active. After the subscription is selected, the Setting of the alert mail receiving address is completed by Setting "Setting RSS Acceptors". As shown in fig. 38 and 39.

6.2 real-time vibration warning reception and vibration message data viewing

A) Real-time alert mail reminders

After the ground system is successfully subscribed, once the onboard equipment monitors the occurrence of the vibration event, the subscription mailbox of the engineer receives a real-time warning mail, and the message printing format exists in the mail in an attachment form, wherein the vibration key parameters VB1/VB2 and N1/N2 change processes are directly presented in the mail body.

FIG. 40 illustrates a number of engine vibration overrun events occurring on the CZ6403 flight on month 25B-8545 of 2019. And 5 vibration events occur on the flight in total through the real-time vibration warning mail, and the phenomenon that the vibration value falls back after repeated overrun of the engine is shown. In the 5 overrun events, the shortest one together has only 1 message, namely the vibration overrun time is less than 20 seconds, the longest one together has up to 8 continuous messages, and the vibration overrun lasts 160 seconds. If the aircraft is not provided with the software device of the invention, the ground system can not receive the engine vibration warning message in real time, and can not have corresponding real-time warning so as to conveniently inform an engineer, and can only wait for the satellite telephone notification of a pilot, or know the occurrence of the vibration event through post-aircraft fault message printing and QAR data decoding.

Any one of the early warning mails contains an attachment in the message printing format, so that the subscriber can conveniently and visually read the development and change of all the parameters, see fig. 41. In addition, the mail also comprises subscribed key information (such as the subscription name, airplane number, flight number and subscription summary) so as to facilitate the subscribers to subscribe to the content in the conference. Meanwhile, the underlying data information in the warning message can also guide and help the developer to troubleshoot.

And each early warning mail can automatically and directly present the variation trend of the subscribed engine vibration key parameters in the mail text in a form of a series according to the subscription condition of the subscriber, and simultaneously give mathematical statistics.

In the final part of the mail, the subscriber can check and verify the pre-warning logic rules set up by the subscriber.

B) FIADA (ground IT Integrated System) vibration message data lookup

And inquiring in the FIADA according to the airplane number, the flight number, the vibration event trigger code, the message sending time and the like. The query results may be ordered by various types of fields. Meanwhile, the engineer can view the ACARS Format (click on RawDetail) and the Print Format (click on Print Format) of the message and Print the contents thereof if necessary. The FIADA vibration message query interface is shown in fig. 42.

For example, the second row of records of FIG. 42 shows that 2 vibration overrun events occurred in 2019, 8, 28, day B-8670. Fig. 43 shows the message print format content thereof.

Clicking on the A/B/C data in EVENT LINE may view the vibration related parameters as shown in FIG. 44.

Clicking any parameter can check the variation trend and the mathematical statistic characteristics of the parameter. For example, looking at the variation track of VB2, VB2P1 (the parameter name corresponding to the VB2 value in the ACMS vibration warning message data collection module) may be clicked, as shown in fig. 45. It is very intuitive from this plot that the VB2 vibration value begins to recover slowly within seconds of overrun. This continuous data comes from the time window data acquisition mechanism. These sets of parameters constitute real-time continuous data, i.e., data segments corresponding to vibrations in the QAR, but are transmitted to the surface system already when the vibrations occur, without waiting for post-flight decoding of the QAR data.