RU2344460C1 - Method of longitudinal control of airplane - Google Patents

Abstract

FIELD: physics, aviation.

SUBSTANCE: additional correcting signal is generated requiring no correction of factors of airplane control laws proportionality in all operating ranges of the flight altitude and speed changes. Note here that there is no necessity in controlling the flying aircraft centering variations.

EFFECT: expanded performances.

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Description

The invention relates to automatic flight control systems and can be used to control the longitudinal movement of aircraft.

A known method of controlling the angular movement of an aircraft (Automatic control system SAU-23A series 2. Purpose, principle of operation, control laws. Technical description 6A2.550.045-4TO (in four parts. Part one). Edition I-77) - [1, p.20], which measure the normal overload n _y , the angular velocity relative to the transverse axis ω _z and the pressure head q, set the required value of the normal overload n _{at the rear} , and also form a control signal of the form

where T ₁₃ , T ₁₁ - filter time constants, p - Laplace operator, i _ny - constant coefficient of proportionality; µ _z (q), µ _z1 (q) are proportionality coefficients that vary depending on the pressure head q.

Correction of the proportionality coefficients is carried out to obtain the same transient rates for normal overload when the values of the dynamic coefficients of the aircraft change when changing the mode of movement. Correction of proportionality coefficients complicates the scheme, reduces the reliability of the control system, and in a wide range of changes in the motion parameters it may turn out to be unrealizable with sufficient accuracy. In this case, the correction of the proportionality coefficients for the velocity head is ineffective when the position of the center of mass of the aircraft changes during the flight and does not allow for the same transient performance.

, а также формируют сигнал управления рулем высоты согласно формулеThere is a method of longitudinal control of an airplane (Mikhalev I.A., Okoyemov B.N., Chikulaev M.S. Automatic control systems for an airplane. M: Engineering, 1987, 240 p.) - [2, p.136], according to which measure the angular velocity relative to the transverse axis ω _z and the normal overload increment Δn _y , set the normal overload increment

, and also form a steering signal according to the formula

where Δδ _B is the angle of deviation of the elevator from the balancing position,

Δn _y is the increment of normal overload,

Δn _y = n _y -1,

n _y - normal overload,

- заданное приращение нормальной перегрузки,

- specified increment of normal overload,

ω _z is the angular velocity relative to the transverse axis,

k _ny , µ, q _ny are constant transmission coefficients.

This machine does not allow to obtain optimal transient performance due to the use of constant values of the proportionality coefficients in a wide range of changes in speeds and altitudes and when the centering of the aircraft changes during movement.

The technical result, to which the claimed invention is directed, is to provide optimal transient performance for normal overload, not requiring correction of the proportionality coefficients of the laws governing the longitudinal movement of the aircraft over the entire operational range of changes in flight speeds and altitudes, as well as when the centering of the aircraft in process of movement.

, а также формируют сигнал управления рулем высоты согласно формулеThe technical result is achieved by the fact that by the method of longitudinal control of an airplane, by which the angular velocity relative to the transverse axis ω _z and the increment of the normal overload Δn _y are measured, the increment of the normal overload is set

, and also form a steering signal according to the formula

where Δδ _B is the angle of deviation of the elevator from the balancing position,

Δn _y is the increment of normal overload,

Δn _y = n _y -1,

n _y - normal overload,

- заданное приращение нормальной перегрузки,

- specified increment of normal overload,

ω _z is the angular velocity relative to the transverse axis,

k _ny , µ, q _ny - constant transmission coefficients,

form an additional signal of the form

Where

where T is the filter time constant, p is the Laplace operator,

k₁, k₂, k₃ - постоянные коэффициенты, которыми дополняют сигнал управления рулем высоты.i _x1 , i _x2 , i _qx ,

k ₁ , k ₂ , k ₃ are constant coefficients that complement the elevator control signal.

The invention is illustrated in figure 1-figure 4:

figure 1 is a block diagram of a longitudinal control machine that implements the inventive method,

figure 2 is a block diagram of a unit for setting the dynamics of longitudinal overload,

figure 3 - graphs of transients of an aircraft with a longitudinal control machine without a unit for specifying the dynamics of longitudinal overload when changing the centering of the aircraft,

figure 4 - graphs of transients of an aircraft with a longitudinal control unit with a unit for setting the dynamics of longitudinal overload when changing the centering of the aircraft.

The longitudinal control machine contains:

1 - sensor increment normal overload Δn _y ;

2 - the first adder;

3 - the first integrator;

4 - the first summing amplifier;

5 - elevator drive;

6 - sensor angular velocity relative to the transverse axis ω _z ;

;7 - adjuster increment normal overload

;

8 - unit for setting the dynamics of longitudinal overload.

The following notation is accepted:

Δδ _B is the angle of deviation of the elevator from the balancing position,

Δn _y is the increment of normal overload,

- заданное приращение нормальной перегрузки,

- specified increment of normal overload,

ω _z is the angular velocity relative to the transverse axis,

U _add - an additional signal.

7, датчик приращения нормальной перегрузки Δn_y 1, первый сумматор 2, первый вход которого соединен с выходом датчика приращения нормальной перегрузки Δn_y 1, а второй, инвертирующий, вход соединен с выходом задатчика приращения нормальной перегрузки

7, первый интегратор 3, вход которого соединен с выходом первого сумматора 2, первый суммирующий усилитель 4, входы которого соединены соответственно с выходами первого сумматора 2, первого интегратора 3 и датчика угловой скорости относительно поперечной оси ω_z 6, а выход соединен с входом привода руля высоты 5, а также блок задания динамики продольной перегрузки 8, входы которого соединены соответственно с выходами датчика приращения нормальной перегрузки Δn_y 1, датчика угловой скорости относительно поперечной оси ω_z 6, задатчика приращения нормальной перегрузки

7, а выход соединен с первым суммирующим усилителем 4.The longitudinal control machine comprises an angular velocity sensor relative to the transverse axis ω _z 6, a normal overload increment adjuster

7, the normal overload increment sensor Δn _y 1, the first adder 2, the first input of which is connected to the output of the normal overload increment sensor Δn _y 1, and the second inverting input is connected to the output of the normal overload increment knob

7, the first integrator 3, the input of which is connected to the output of the first adder 2, the first summing amplifier 4, whose inputs are connected respectively to the outputs of the first adder 2, the first integrator 3 and the angular velocity sensor relative to the transverse axis ω _z 6, and the output is connected to the input of the drive elevator 5, as well as a unit for specifying the dynamics of longitudinal overload 8, the inputs of which are connected respectively to the outputs of the normal overload increment sensor Δn _y 1, the angular velocity sensor relative to the transverse axis ω _z 6, the increment adjuster n normal overload

7, and the output is connected to the first summing amplifier 4.

The unit for setting the dynamics of longitudinal overload 8 contains:

9 - filter;

10 - second adder;

11 - the third summing amplifier;

12 - third integrator;

13 - computer;

14 - second integrator;

15 is a second summing amplifier.

The following notation is accepted:

- сигнал на выходе вычислителя 13;

- a signal at the output of a calculator 13;

η is the signal at the output of the third summing amplifier 11.

The unit for setting the dynamics of longitudinal overload contains a calculator 13, the first and second inputs of which are respectively the first and second inputs of the control unit for setting the dynamics of longitudinal overload 8,

the second integrator 14, the input of which is connected to the output of the calculator 13, the second adder 10, the first input of which is connected to the first input of the calculator 13, the second inverting input is connected to the output of the filter 9. the input of which is the third input of the unit for setting the dynamics of longitudinal overload 8,

the third integrator 12, the input of which is connected to the output of the second adder 10,

the third summing amplifier 11, the inputs of which are connected respectively to the outputs of the second adder 10, the third integrator 12 and the second integrator 14, the output is connected to the third input of the calculator 13, the second summing amplifier 15, the first input of which is connected to the second input of the calculator 13, the second, inverting, the input is with the output of the second integrator 14, and the output is the output of the unit for setting the dynamics of longitudinal overload 8.

.The system operates as follows. The signal from the sensor of the increment of the normal overload Δn _y 1 is fed to the first input of the first adder 2, to the second, inverting, the input of which receives the specified increment of the normal overload. From the output of the first adder 2, the generated signal is fed to the first input of the first summing amplifier 4 and to the input of the first integrator 3. From the output of the first integrator 3, the signal goes to the second input of the first summing amplifier 4, the third input of which receives a signal from the angular velocity sensor relative to the transverse axis 6. ω _z to the input of reference speakers longitudinal overload 8 respectively receives the increment signals normal overload Δn _y, the angular velocity about a transverse axis and ω _z holes predetermined increment cial overload

.

The calculator 13 of the unit for setting the dynamics of the longitudinal overload 8 operates in accordance with the equation

where Δn _y , ω _z , η are the signals, respectively, at the first, second and third inputs of the calculator,

k ₁ , k ₂ , k ₃ - constant coefficients,

- сигнал на выходе вычислителя.

- signal at the output of the calculator.

From the output of the calculator 13, the signal is supplied to the second integrator 14, operating in accordance with the algorithm

поступающий на третий вход блока задания динамики продольной перегрузки 8, проходит через фильтр 9 с передаточной функцией видаSignal of the specified increment of normal overload

arriving at the third input of the unit for setting the dynamics of longitudinal overload 8, passes through a filter 9 with a transfer function of the form

where T is the time constant, p is the Laplace operator,

and enters the second, inverting, input of the second adder 10, the first input of which is connected to the first input of the calculator 13. At the output of the second adder 10, a signal is generated

The introduction of a filter 9 reduces overshoot when it reaches a set point of normal overload.

From the output of the second adder 10, the signal is fed to the input of the third integrator 12, the output of which forms a signal of the form

The introduction of the third integrator 12 allows you to eliminate the static error of the increment of the load when the alignment of the aircraft during the flight.

At the output of the third summing amplifier 11, a signal of the form

where i _x1 , i _x2 , i _qx - constant gear ratios.

From the output of the third summing amplifier 11, the generated signal η is supplied to the third input of the calculator 13.

The output of the unit for setting the dynamics of longitudinal overload 8 is the output of the second summing amplifier 15, where an additional signal of the form

- постоянные передаточные числа,Where

- constant gear ratios,

- сигналы соответственно на первом и втором входах.ω _z

- signals, respectively, at the first and second inputs.

From the output of the unit for setting the dynamics of longitudinal overload 8, the generated additional signal is fed to the input of the first summing amplifier 4, the output of which is connected to the elevator wheel drive 5.

An additional signal generated in the unit for setting the dynamics of longitudinal overload 8 allows you to provide additional steering deviation necessary to compensate for changes in the dynamic motion parameters of the aircraft that occur when the flight mode changes. Compensation of changes in the dynamic parameters of the aircraft’s movement allows us to provide optimal transient processes for the aircraft in the entire operational range of changes in flight speeds and altitudes, as well as when the aircraft’s centering changes during movement.

The effectiveness of the use of the unit for setting the dynamics of longitudinal overload 8 is confirmed by figure 3-figure 4. Figure 3-figure 4 shows graphs of transients of an aircraft with an automatic longitudinal control in the presence (figure 4) and absence (figure 3) of the unit for setting the dynamics of longitudinal overload 8 when the center of mass of the aircraft is shifted. A light aircraft was adopted as an aircraft. The transition curve 1 corresponds to the displacement of the center of mass of the aircraft back along the wing chord relative to the calculated value. Transient curve 2 corresponds to the optimal control system setting for the calculated value of the center of mass position. The transition curve 3 corresponds to the displacement of the center of mass of the aircraft forward along the wing chord relative to the calculated value. The transition curve 4 corresponds to the displacement of the center of mass of the aircraft back beyond the point of application of the lifting force (the aircraft is statically unstable).

From figure 3 it is seen that the displacement of the center of mass of the aircraft with a longitudinal control machine without a unit for specifying the dynamics of longitudinal overload 8 leads to a significant change in transients. At the same time, the required quality indicators of transient processes corresponding to the transient process at the calculated position of the center of mass of the aircraft are not maintained.

Figure 4 shows that the introduction of the unit for setting the dynamics of longitudinal overload 8 in the longitudinal control machine ensures that the transients are close to optimal when the center of mass of the aircraft is shifted.

The proposed longitudinal control machine provides optimal transient performance that does not require correction of the proportionality coefficients of laws in the entire operational range of changes in flight speeds and altitudes, as well as when the aircraft centering changes during movement.

Claims (1)

The longitudinal control method of an airplane, according to which the angular velocity relative to the transverse axis ω _z and the normal overload increment Δn _y are measured, specify the normal overload increment

and also form a steering signal according to the formula

where Δδ _In - the angle of deviation of the elevator from the balancing position;
Δn _y is the increment of normal overload;
Δn _y = n _y -1;
n _y - normal overload;

- specified increment of normal overload;
ω _z is the angular velocity relative to the transverse axis;
k _ny , µ, q _ny - constant transmission coefficients,
characterized in that they form an additional signal of the form

Where

where T is the filter time constant, p is the Laplace operator,
i _x1 , i _x2 , i _qx ,

k ₁ , k ₂ , k ₃ are constant coefficients that complement the elevator control signal.

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