RU2068198C1 - Device for calculation of resource consumption of airframe of airplane - Google Patents

Abstract

FIELD: computer engineering, aviation. SUBSTANCE: device has unit 1 which gathers and inputs flight data, unit 2 which gathers information about fuel rest, board 3 which is used for input and check of internal data, power-independent memory unit 5. Said units are connected to unit 4 which calculates equivalent work load. In addition device has unit 6 which outputs information about calculation results. Results of calculation are displayed on information board of unit 6 which is located in convenient place. In addition results are stored as hard copy. EFFECT: automatic on-board calculation of equivalent workload of constructive members of airframe of airframe using flight data which are received from standard data-gathering unit. 1 dwg

Description

 The invention is intended to determine the loading and accumulation of fatigue damage to structural elements of aircraft and relates to the field of aviation, namely to the field of strength assessment and technical maintenance of aircraft.

Known on-board resource counters, which include special deformation sensors installed in critical areas of the structure, the information from which is fed to computer equipment installed on an airplane [1]
One of the main drawbacks of such a system is the need for special measures for servicing sensors and related equipment, requiring training of technical personnel of operating organizations and complicating the operation of the aircraft. Analysis of the results produced by the counter, in case of doubt in their reliability, failures and malfunctions of sensors, transducers, other elements of the system, crew interference in the operation of the system, exceeding operational restrictions, etc. by testing the system, it is quite laborious and, in addition, requires additional information about flight parameters, crew actions, etc. for example, from regular means of objective control.

 The closest technical solution is equipment based on the processing of information from standard on-board objective monitoring equipment (SOC), containing a device for selecting and entering flight data, a device for inputting information about the remaining fuel, a control panel for entering service parameters and a non-volatile storage device. At the same time, information storage devices are removed from the aircraft after each flight and processed in ground-based data centers. The main disadvantages of such an individual resource accounting system are: a significant increase in labor costs during operation, an increase in the load of computer centers and low efficiency in obtaining information.

 The technical result achieved when using the invention is to automatically account for the equivalent operating time for the entire period of operation.

 The technical result is achieved by the fact that in the device for calculating the resource consumption of the airframe of the aircraft, containing a device for selecting and inputting flight data, a device for inputting fuel information, as well as interconnected control panel for entering service parameters and non-volatile memory, an equivalent calculation unit is additionally introduced operating time and a documenting device connected to its output, and the equivalent operating time calculation unit is made in the form of an input inf filtering unit formation, interconnected unit for calculating equivalent operating time and unit for determining flight mode, as well as a unit for analyzing results and preparing output information interconnected with a control panel and input service parameters and non-volatile storage device, while the first, second and third inputs of the input information filtering unit connected respectively to the first outputs of the device for selection and input of flight data, a device for inputting fuel information and non-volatile storage device, input Lok flight mode determination is coupled to the second output of the fuel entering the information device, and an output connected to the input of calculating unit equivalent to operating time, the output of which is connected to the input analysis unit results and training output data, the output of which is equivalent to the output of the calculator operating time.

 The drawing shows a structural diagram of a device.

 The device comprises a device 1 for selection and input of flight data (USPPD), a device 2 for inputting fuel information (ATF), a remote control 3 for input and control of service parameters (VKVSP), an equivalent operating time calculation unit 4, non-volatile memory 5 (memory), device 6 documentation (UD).

 Block 4 calculation, in turn, consists of block 7 filtering input information (BFVI), block 8 determine the flight mode (BORP), block 9 calculation of equivalent operating time (BREW) and block 10 analysis of the results and preparation of output information (BAPVI).

 The device operates as follows.

On-board means of objective control transmit information to the device 1 selection and input of flight data, which selects the necessary data for the equivalent production of data from the entire information array generated by the standard on-board means of objective control. At the same time, parameters such as:
flight time;
side number of the aircraft;
departure date;
overload at the center of gravity of the aircraft n _y (t);
airspeed V (t);
flight altitude N (t);
airframe configuration (position of wing mechanization elements, wing sweep angle, landing gear position).

 After receiving the necessary information, the device 1 transfers the selected parameter values to the calculator 4. The transfer is carried out by the method of interruption, or direct access to the memory.

The fuel balance data in the form of a parallel binary code is supplied to the fuel information input device 2 from the aircraft fuel system. AIT produces information reception, preliminary processing and memorization. At the command of the calculator 4, the control unit sends him data on the remaining fuel. The remote control 3 control and input of service parameters provides a control mode of the device and input into the non-volatile storage device 5 service parameters, such as:
mass of cargo on board;
calibration characteristics of flight information sensors
the value of the unit dimension of the least significant bit of the flight information sensors of the RNS.

After collecting all the data necessary for the calculations, the calculator 4 proceeds to the solution of the problem; for this, the following algorithms are implemented in its software:
filtering the input data in order to protect against malfunctions and distortions of flight information during the conversion and transmission carried out by the BFVI 7 unit;
calculating the flight mass, consisting of an airplane landing gear, fuel and cargo, carried out in the BREN unit 9;
determination of the flight stage (taxiing, take-off, flight, descent, landing) to make a decision on the beginning (end) of the process of calculating the equivalent operating time of the aircraft structural elements carried out by the BORP 8 unit;
analysis of the calculation results and software support for the process of outputting the results of the calculation of equivalent operating time to the documenting device 6, carried out by the BAPVI unit 10.

 After the decision is made to start the production of calculations of equivalent operating time, the BREN unit 9 of the calculator 4 processes the array of flight data in the following sequence.

1. The extrema of the overload signal are determined at the center of gravity n _i , where i is the serial number of the extremum. The signals of the magnitude of the overload n _y arriving at the initial frequency are compared with each other, while the corresponding extremum n $\genfrac{}{}{0ex}{}{\text{i}}{\text{at}}$ the value of the overload is considered, corresponding to the time instant immediately preceding the moment of changing the sign of the derived value of the overload. After isolation of the next extremum, “filtering” is performed, consisting in the fact that in the implementation of the sequence of extrema only extrema are kept, forming with the previous ranges exceeding the specified value Δf.

где M $\genfrac{}{}{0ex}{}{\text{ctx}}{\text{изг}}$ текущее мгновенное значение изгибающего момента в сечении, K_дин коэффициент динамичности конструкции, Δn_у приращение перегрузки,

постоянная составляющая (нагрузка функционирования), соответствующая условиям невозмущенного полета. Нагрузка функционирования M $\genfrac{}{}{0ex}{}{\text{ctx}}{\text{изг}}$ вычисляется по соотношениям, представляющим собой кусочно-линейные функции. Структура расчета изгибающих моментов (номинальных напряжений) в заранее выбранных "критических" сечениях конструкции, определяющих ее долговечность, предполагает применение метода суперпозиции, поскольку напряженно-деформированное состояние в элементах конструкции самолетов при эксплуатации, как правило, линейное. Тогда

где

изгибающий момент в сечении;

составляющая веса конструкции самолета, как правило, известная константа;

составляющая, учитывающая влияние веса и размещения топлива;

составляющая, учитывающая влияние веса и размещения груза;

составляющая от аэродинамических нагрузок.2. The values of the extrema are converted into the values of bending moments (nominal stresses) at the jth critical point of the structure according to the relations obtained on the basis of the study of the correlation dependences of stresses in elements and overloads in the center of mass. Recalculation is carried out using a relation of the form

where M $\genfrac{}{}{0ex}{}{\text{ctx}}{\text{outcast}}$ the current instantaneous value of the bending moment in the cross section, K _{din is} the dynamic coefficient of the structure, Δn is _the overload increment,

constant component (functioning load) corresponding to the conditions of an unperturbed flight. Functioning load M $\genfrac{}{}{0ex}{}{\text{ctx}}{\text{outcast}}$ calculated by the relations, which are piecewise linear functions. The structure of calculating bending moments (nominal stresses) in pre-selected “critical” sections of a structure that determine its durability requires the use of the superposition method, since the stress-strain state in aircraft structural elements during operation is usually linear. Then

Where

bending moment in section;

component of the weight of the aircraft structure, as a rule, a known constant;

a component that takes into account the influence of weight and fuel placement;

a component that takes into account the influence of weight and cargo placement;

component from aerodynamic loads.

зависит от размещения и порядка выработки топлива и определяется текущим значением остатка топлива по формулам вида

где m $\genfrac{}{}{0ex}{}{\text{1}}{\text{т}}$ , m $\genfrac{}{}{0ex}{}{\text{2}}{\text{т}}$ границы кусочно-линейных участков;
K_1,2. b_1,2. известные константы.Value

depends on the location and order of fuel production and is determined by the current value of the remaining fuel according to formulas of the form

where m $\genfrac{}{}{0ex}{}{\text{1}}{\text{t}}$ , m $\genfrac{}{}{0ex}{}{\text{2}}{\text{t}}$ borders of piecewise linear sections;
K _1,2 . b _1.2 . known constants.

вычисляется по аналогичным формулам.Value

calculated by similar formulas.

 The aerodynamic components of the loads are different for different flight modes. Therefore, the flight mode is first determined. A set of features is used to identify the mode. Here may be: a range of heights, speeds, state of mechanization, compression of the landing gears, etc. Each mode has its own combination of features.

вычисляется одним из способов:
1) по величине полной массы самолета m по формулам типа

где i номер режима полета,
a_i, C_i известные коэффициенты;
2) по величине скоростного напора q и коэффициента подъемной силы C_y:

где е_i, f_i известные коэффициенты, q q_o•q_н,
здесь

; q_н f(V_пр, H),
V_пр, Н приборная скорость и высота.For each mode

calculated by one of the methods:
1) according to the total mass of the aircraft m according to formulas of the type

where i is the flight mode number,
a _i , C _i known coefficients;
2) in terms of velocity head q and lift coefficient C _y :

where e _i , f _{i are} known coefficients, qq _o • q _n ,
here

; q _n f (V _ol , H),
V _ol , N instrument speed and height.

где S_кр площадь крыла.

where S _cr wing area.

In cases where the critical location of the structure under ground conditions is in the compression region, for the correct calculation of damage during the formation of a sequence of extrema at the beginning and end it is necessary to add the values of M $\genfrac{}{}{0ex}{}{\text{ptvkb}}{\text{outcast}}$ corresponding to maximum compressive loads during taxiing take-off run and taxiing mileage, respectively. The calculation of these values of M $\genfrac{}{}{0ex}{}{\text{ptvkb}}{\text{outcast}}$ is possible in two ways: 1) in the calculations according to the formulas above, a fixed value n _{y of the} earth is accepted; 2) when moving on the ground, the value of n _{y of the} earth is monitored and max [n _{y of the} earth] is selected which is used in the calculations.

3. Using a modified algorithm of the "rain" method in real time, sequentially allocated extrema are processed in order to isolate damaging loading cycles and calculate damage for equivalent (according to Odin) cycles using a fatigue curve of the form N (M $\genfrac{}{}{0ex}{}{\text{'rd}}{\text{outcast}}$ ) ⁴ = C and the linear rule for summing damage. A modification of the well-known rain algorithm is associated with the need to ensure operation in almost real time.

The number of extrema read and holding in RAM is limited by the number N _ow . When the end of the sequence is detected, ranges that are not included in the number of selected complete cycles are treated as half-cycles, the damage from which is added to the damage from the selected full cycles.

которая суммируется с предыдущей наработкой.4. At the end of the flight, the resulting damage value ξ _floor refers to the known damage of the "typical resource flight" ξ _etc. , resulting in the value of the equivalent operating time of the j-th critical point of the structure in this flight:

which is summed up with the previous operating time.

In the case of determining the stages of flight, the descent and landing, the computer transfers the results of the calculations to a non-volatile memory and to the documentation device. UD provides registration of the received parameters on a "solid" medium in the form of alphanumeric information visually accessible to the operator. UD registers the following information:
side number of the aircraft;
flight date;
the value of the equivalent operating time of the aircraft in the last flight;
the value of the equivalent operating time of the aircraft for the entire period of operation;
the results of the built-in control of the device and deviations in the onboard RNS.

Claims (1)

 A device for calculating the resource consumption of an airframe of an airplane, comprising a device for selecting and inputting flight data, a device for inputting fuel information, and also an interconnected control panel for entering service parameters and a non-volatile memory device, characterized in that an equivalent operating time calculation unit is additionally introduced into it and a documenting device connected to its output, and the equivalent operating time calculation unit is made in the form of an input information filtering unit, inter the equivalent operating time calculation unit and the flight mode determination unit associated with it, as well as the results analysis and output information preparation unit, interconnected with the control panel and input service parameters and non-volatile storage device, while the first, second and third inputs of the input information filtering unit are connected respectively to the first outputs of the device for selection and input of flight data, a device for inputting fuel information and a non-volatile storage device, the input of the determination unit flight mode is connected to the second output of the fuel information input device, and the output is connected to the input of the equivalent operating time calculation unit, the output of which is connected to the input of the results analysis and preparation of output information, the output of which is the output of the equivalent operating time calculator.