RU2430858C1 - Aircraft bank angle bank angular speed limiting automatic control system - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aircraft bank angle automatic control systems. Proposed system comprises bank angle setter and autopilot computer, servo drive with its output signal defining angle of aileron deflection angle, bank angle transducer, bank angle maximum angular speed setter, bank angle angular speed limitation automatic device computer, and algebraic selector of maximum signal. Aircraft bank angle transducer output is connected to second input of bank angle autopilot computer. Aircraft bank angle transducer output is connected to third input of bank angle autopilot computer. Maximum signal selector output is connected to servo drive input. Bank angle angular speed limitation automatic device computer second input is connected with bank angle angular speed transducer output. Bank angle autopilot computer output is connected with second input of algebraic selector of maximum signal.

EFFECT: higher accuracy of bank angular speed.

2 dwg

Description

The invention relates to the field of automatic control systems (ACS) roll angle of the aircraft (LA).

Known self-propelled guns, providing the development of a given angle of heel of the aircraft using autopilot, affecting the angle of deviation of the ailerons of the aircraft [1. Bodner V.A. Control systems for aircraft. - M.: Mechanical Engineering, 1973. - 506 p. Page 1116, fig. 3.22; 2. Krasovsky A.A. Automatic flight control systems and their analytical design. - M .: Nauka, 1973. - 560 p. Page 184, Fig. 5.5; 3. Mikhalev I.A., Okoyemov B.N., Chikulaev M.S. Automatic aircraft control systems. - M.: Mechanical Engineering, 1987. - p. 240. Page 212, Fig. 15.2].

The closest technical result achieved, chosen as a prototype, is taken by self-propelled guns with a roll angle of LA, which implements an astatic control law with high-speed feedback, containing serially connected roll angle adjuster and a roll angle autopilot calculator, a servo drive, the output signal of which determines the angle of deviation of the ailerons of the aircraft , the roll angle sensor of the aircraft having an output connected to the second input of the roll angle calculator autopilot, the roll angle sensor and an aircraft having an output connected to the third input of a roll angle calculator autopilot [V. Bodner Control systems for aircraft. - M. Mechanical Engineering, 1973. - 506 p. P.116, Fig. 3.22].

This ACS provides good static and dynamic characteristics of the aircraft roll angle control channel, but does not allow limiting the value of the angular roll speed, which can lead to unacceptable overloads when rotating the aircraft relative to the longitudinal axis.

In addition, as is known, intensive roll rotation (ω _x ≠ 0), due to aeroinertial interaction of longitudinal and lateral motion, leads to a decrease in the degree of stability of the aircraft at small and moderate angles of attack. At sufficiently large so-called critical angular roll velocities ω _хкр stability is lost and movement develops with a sharp change in the angles of attack and slip, a large amplitude of the load acting on the plane, and an increase in the angular velocity ω _{x itself} . This form of movement is called aero-inertia rotation and is characteristic of high-speed aircraft. To prevent access to aero-inertial self-rotation in flight, allowable angular velocities ω _xd . [Aircraft mechanics: Flight dynamics / Ed. A.F. Bochkarev and V.V. Andrievsky. - M.: Mechanical Engineering, 1985. - 360 p. Pages 343-344.].

The task to be solved by the claimed invention is directed, is to provide the necessary accuracy of limiting the angular velocity of the roll by including in the self-propelled guns the roll angle of the aircraft LA of the automatic limiting machine using an algebraic selector of the maximum signal.

The problem is achieved by the fact that in the system of automatic control of the angle of roll and limitation of the angular velocity of the roll of the aircraft, containing a series-connected roll angle adjuster and a calculator of autopilot roll angle, a servo drive, the output signal of which determines the angle of deviation of the ailerons of the aircraft, the roll angle sensor of the aircraft, having an output connected to the second input of the calculator of the autopilot roll angle, the sensor of angular roll speed of the aircraft, having an output, connect directed to the third input of the roll angle autopilot calculator, in contrast to the prototype, a series-connected roll angular maximum speed adjuster, a roll angular velocity limiting calculator and an algebraic maximum signal selector, the output of which is connected to the servo input, and the second input of the angular speed limiting automat calculator are additionally introduced the roll is connected to the output of the roll angular velocity sensor, the output of the calculator of the autopilot roll angle is connected to the second input of the algebraic Elector maximum signal.

The invention is illustrated by drawings.

Figure 1 presents the structural diagram of the inventive system of automatic control of the angle of heel and limit the angular velocity of the roll of the aircraft.

Figure 2 presents the results of the simulation of transients: 2a - graphs of transients in self-propelled guns with a roll angle γ without an automatic machine for limiting angular velocity ω _x , 2b - graphs of transients in self-propelled guns with a roll angle γ _x with automatic machine for limiting angular velocity ω _x .

A system for automatically controlling the angle of roll and limiting the angular velocity of the roll of the aircraft, comprising serially connected roll angle adjuster 1 and an autopilot calculator of roll angle 2, a servo drive 3, the output signal of which determines the angle of deviation of the ailerons of the aircraft 4, a roll angle sensor 5 of the aircraft 4, having an output connected to the second input of the calculator of the autopilot roll angle 2, the angular velocity sensor 6 roll of the aircraft 4, having an output connected to the third input of the calculation dividing the autopilot roll angle 2, according to the invention contains a serially connected maximum angle roll speed adjuster 7, a calculator of the automatic roll angular speed limiter 8 and an algebraic selector of the maximum signal 9, the output of which is connected to the input of the servo drive 3, and the second input of the roll automatic speed limit calculator 8 connected to the output of the roll angular velocity sensor 6, the output of the autopilot calculator of the roll angle 2 is connected to the second input of the algebraic selector of the maximum signal 9.

The limitation of the angular roll velocity in the reduced system is achieved by introducing into its structure an automaton of limiting the angular roll velocity and the algebraic selector of the maximum signal.

The system of automatic control of the roll angle and limitation of the angular velocity of the roll of the aircraft operates as follows.

The signal of the set roll angle γ _ass from the output of the roll angle adjuster 1 is fed to the first input of the autopilot calculator of roll angle 2, the second input of which receives the signal of the current roll angle γ from the output of the roll angle sensor 5, and the third input receives the signal of the current value of the angular velocity roll ω _x = pγ from the output of the roll angular velocity sensor 6. A signal is generated at the output of the autopilot calculator of the roll angle 2

,

,

arriving at one of the inputs of the algebraic selector of the maximum signal 9.

The signal of the set maximum angular velocity of the roll ω _hogr from the output of the master _{unit of} the maximum angular velocity of the heel 7 is fed to the first input of the calculator of the automatic machine of the angular angular velocity control 8, the second input of which receives the signal of the current value of the angular angular velocity ω _x from the output of the angular angular velocity sensor 6. On the output of the calculator of the machine for limiting the angular velocity of the roll 8, a signal is formed

,

,

arriving at the other of the two inputs of the algebraic selector of the maximum signal 9.

To build self-propelled guns with limited parameters of aircraft, you can use logical devices that implement algorithms for algebraic channel selection. Typically, the principle of selection is applied, according to which the parameter of the multidimensional control object is adjusted, which is closest to the value determined by the control program [Integrated systems for automatic control of aircraft power plants / Ed. A.A.Shevyakova. - M.: Mechanical Engineering, 1983. - 283 p. Page 110-111]. Such selection is implemented using algebraic selectors.

In order for the adjustable parameters not to exceed the maximum allowable values (upper limit), the selector must skip the control signal corresponding to the minimum value of the control signal. Such selection is called minimum selection, and the selector is called the minimum control signal selector.

If the minimum parameter values are limited (lower limit), preference is given to the parameter regulator, which requires the highest control signal to be maintained, i.e. selection is carried out to the maximum. In this case, the maximum control signal selector is used.

Such a classification of algebraic selectors is valid if the transmission coefficient of the control object is greater than zero. If the transmission coefficient of the control object is less than zero, the logic of the algebraic selector must be the opposite. As is known, the minus sign when the angle of deviation of the ailerons δ _e is included in the equations and transfer functions of the aircraft with respect to the angle of heel and the angular velocity of the heel [1. Bodner V.A. Control systems for aircraft. - M.: Mechanical Engineering, 1973. - 506 p. P. 115; 2. Krasovsky A.A. Automatic flight control systems and their analytical design. - M .: Nauka, 1973 - 560 p. P. 50]. Therefore, the algebraic selector of the maximum signal 9 should be used in the system under consideration.

Regarding the difference of the input signals ε = U ₁ -U _{2, the} expression describing the operation of the algebraic selector of two quantities is converted using the module selection operation as follows:

where µ = 1 for the selector of the maximum signal; µ = -1 for the minimum signal selector.

Selectors are introduced into the ACS for smooth switching of control channels and provide in all operating conditions the control action of only one of several control channels that are included in the work depending on the operating mode of the control object. Moreover, each of the control channels operates autonomously and its parameters are usually selected without regard to interaction with other channels. This allows you to maintain the static accuracy and stability margins inherent in individual control channels.

Consequently, the algebraic selector ensures smooth switching from one channel to another, for example, from autopilot to automatic control and back to autopilot.

The output signal U of the algebraic selector of the maximum signal 9 is fed to the input of the astatic servo 3 with the transfer function

,

,

changing the angle of deviation of ailerons δ _e aircraft 4

δ _e = W _sp (p) U

Here is the synthesis of the automatic control system of the roll angle and the limitation of the angular velocity of the roll of the aircraft.

Analytical synthesis of the gear ratios of the autopilot and automatic control based on the specified quality of self-propelled guns is conveniently carried out using the standard transient response method [V. Petunin Synthesis of autopilot pitch control channel laws // Vestnik of Ufa State Aviation Technical University, series "Control, computer engineering and informatics". 2007. Volume 9, No 2 (20). S.25-31]. In this case, the equality of the transfer functions of the original Φ (p) and the desired systems Φ * (p) should be satisfied:

Φ (p) = Φ * (p)

The transfer function of the aircraft along the angle of heel γ when controlling ailerons δ _e [V. Bodner Control systems for aircraft. - M.: Mechanical Engineering, 1973. - 506 p. Page 115]:

Law of control of astatic autopilot roll angle with high-speed feedback

,

,

,

- передаточные числа автопилота.where k _γ ;

,

- gear ratios of autopilot.

Transfer function of a closed system in roll angle

.

.

Desired transfer function of the closed loop angle

Then autopilot gear ratios

The transfer function of the aircraft in terms of roll angular velocity ω _x when controlling ailerons δ _e

The control law of the roll angular velocity limiting machine

,

,

- передаточные числа автомата ограничения.where k _ω ;

- gear ratios of the automatic restriction.

The transfer function of a closed system in angular roll speed

Desired transfer function of a closed system according to the angular roll speed

Then the gear ratios of the constraint

k _ω = ω ² / n _e ;

The synthesis results are confirmed by the results of modeling transients in the inventive system of automatic control of the angle of heel and limiting the angular velocity of the heel of the aircraft, presented in figure 2, where the defining effects of the channels: γ _ass = 1; ω _hogr = 0.5. The transients 2a obtained in the self-propelled guns with a roll angle without an automatic roll angular velocity limiting machine are unsatisfactory, since they have a roll over the roll angular velocity. The transients 2b obtained in the self-propelled guns with a roll angle with a roll angle limiting automat are satisfactory, since they show the necessary accuracy of the limitation ω≤ω _hogr = 0.5 and good control quality in the channel switching modes of the system.

So, the claimed invention allows, due to the introduction of a roll angle control machine of the automatic control system of the roll angle control using the algebraic selector of the maximum signal, to ensure the accuracy of the roll angle control and smooth transition processes when switching channels.

Claims (1)

A system for automatically controlling the angle of roll and limiting the angular velocity of the roll of the aircraft, comprising a roll angle adjuster and an autopilot calculator of the roll angle, a servo drive whose output signal determines the angle of deviation of the ailerons of the aircraft, and a roll angle sensor of the aircraft having an output connected to the second input calculator of autopilot roll angle; sensor of angular roll velocity of an aircraft having an output connected to the third input of the calculator heel angle meter, characterized in that it further comprises a serially connected maximum angular velocity adjuster, a calculator of the automatic angular velocity limiter and an algebraic maximum signal selector, the output of which is connected to the input of the servo, and the second input of the automatic angular velocity limiter calculator is connected to the output of the sensor angular roll speed, the output of the autopilot calculator roll angle is connected to the second input of the algebraic selector of the maximum signal.

Images