RU2531706C2 - Canard control (versions) - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aircraft engineering. Canard control incorporates version of all-moving feathering front horizontal canard. In compliance with first version, said front horizontal canard features the following twist of fins: fin support root section positive angle of attack is larger than that at support ends. In compliance with second version, said front horizontal canard features variable relative thickness of fins: larger nearby root of fins and smaller nearby the ends of supports. In compliance with third version, said front horizontal canard features weather vane shaped to regular triangle, isosceles triangle, skew-side triangle or skew-side rhomb. In compliance with fourth version, said front horizontal canard incorporates electrical remote control that allows smooth decreased in transmission factor in transmission line from pilot master to actuator "angle between front horizontal canard and weather vane" or smooth input of negative shift in said angle. In compliance with fifth version, it is equipped with computer system. System processor receives the signal from control master, from transducer of angle between weather vane and fins, signals of pitch, speed and height while processor output is connected with vertical rudder actuator.

EFFECT: better anti-spin properties.

14 cl, 5 dwg

Description

The invention relates to the control of elevators of flight or combat aircraft and other aircraft with aerodynamic rudders.

Known control aircraft "Management" duck "(options)", see patent No. RU 2410286, which provides weathervane control all-rotational PGO (front horizontal tail), including regressive. This control allows you to get better pitch maneuverability than conventional control, and the regression version has increased longitudinal stability.

The objective and technical result of the invention is to increase the anti-tearing properties of control, more precisely, to “soften” them, that is, more smooth independent departure of the aircraft from dangerous from the point of view of flow stall on the wing modes.

As you know, the center of mass of an aircraft with normal stability in order to avoid uncontrolled corkscrew should be ahead of the aerodynamic focus. And to balance this diving moment, the ZGO creates a negative lift, moreover, a rather large one. That is, the ZGO steals from the main wing its lift - about 10-15%, depending on centering. In contrast, the PGO (that is, the "duck") is free from this drawback, but has poor longitudinal stability, especially when the alignment is deviated. The invention of the “Regressive Weather Vane Duck” (a variant of the mentioned patent) combines the advantages of both variants and is free from both disadvantages.

Moreover, the regressive weathervane duck forgives all the pilot's mistakes - for a given marginal difference in the angle between the wind vane and the fully rotating PGO, the pilot, with all desire, will not be able to bring the PGO to supercritical angles of attack (say, 12 degrees), no matter how inexperienced he is. When delivering aircraft to less developed countries, this is not the last factor.

And when you set a certain degree of regressive control, the pilot, with all desire, will not be able to bring the wing to supercritical angles of attack (for example, when zeroing the angle of the PGO relative to the stream when it is positioned relative to the fuselage down by 14-15 degrees).

The anti-corking qualities of the duck are well known. You can also apply a positive or negative twist PGO, this additionally gives it other opposing qualities. Usually, a decrease in the angle of attack at the root of the steering wheel is used - this delays the moment of flow stall.

OPTION 1. But if you do the opposite, then the flow will stall earlier, but gradually. And this, combined with a higher specific load of the rudders than that of the main wing, will make it possible to strengthen anti-tearing qualities - if the pilot, ignoring the thrust capabilities, starts scorching and stupidly bulging his nose, then the aircraft will gradually, precisely, gradually lower its nose and gain safe speed . Such actions of the aircraft, by the way, give the pilot a signal to increase engine thrust and reduce pitch.

So, this control has the following twist PGO: at the root of the steering wheel consoles, the positive angle of attack is greater than at the ends of the consoles. The amount of twist can reach 10-11 degrees.

Of course, if the goal is to break the plane at a low altitude and at a decent speed, take the helm abruptly, then the plane will not save anything (a parachute can save a pilot).

EXAMPLE: at the root of the consoles of the front rudders of the aircraft, the positive angle of attack is greater than at the ends of the consoles.

This option works as follows: if the rudders are too large upward (this mode is dangerous from the point of view of stalling), the root part of the rudders is interrupted by the flow, which, however, does not extend to the entire surface of the rudders. The lifting force of the rudders is somewhat reduced, which prevents further growth of vertical sliding. Thus, the plane corrects the error of the pilot.

OPTION 2. It is possible to “soften” anti-tearing qualities in another way: to choose a profile of PGO of variable relative thickness - from the ends there are more. Then the flow stall will first come on a thinner profile - at the root of the rudder - and only then will it gradually begin to move to an increasingly large part of the rudder.

OPTION 3. You can “soften” anti-tearing qualities in the following way: by choosing a shape in terms of a weather vane so that flow stall does not affect its lifting force, for example, the shape of a regular triangle (more exotic forms are possible: an isosceles triangle, an oblique triangle, an oblique diamond, etc.). And to choose a specific load on it more than on PGO. Then the stall will begin with a weather vane and the plane will gently lower its nose.

OPTION 4. With remote control, it is possible to “soften” anti-tearing qualities as follows: by electronically interfering with the transmission of the signal from the pilot’s commander to the “angle between PGO and weather vane” execution unit, it is possible to reduce the transmission coefficient or introduce a negative bias with a drop in speed. Of course, this must be done smoothly, otherwise the aircraft will bite its nose, which is unacceptable.

The principle of operation of any servo system is that at the input to the amplifier the signals from the control dial and from the position sensor of the controlled body (in this case, the angle between the weather vane and the rudders) are compared and the resulting positive or negative difference signal is amplified and fed to the actuator, which by its action, it matches the sensor signal with the setpoint signal. In this regard, in this embodiment, two sub-options are possible.

OPTION 4-a. Between the master and the amplifier is a controlled signal divider (for example, a conventional controlled resistive voltage divider). In this case, the amplifier “seems” that the setpoint generates a weaker signal, and it reduces the rudder angle so that the signal from the sensor decreases accordingly.

OPTION 4-b. Between the sensor and the amplifier is a controlled signal amplifier (for example, a conventional voltage amplifier). In this case, the amplifier “seems” that the sensor produces a stronger signal, and it reduces the angle of the rudders so that the signal from the sensor decreases accordingly.

OPTION 4-c. The previous two options reduced the angle of the wind vane relative to the rudders N times depending on the speed drop, and this N with the speed drop grew from zero to a significant maximum, almost zeroing the control signal. That is, the control system generally removed the inexperienced pilot from the pitch control - no matter how the pilot pulled the helm, the rudders will become in neutral position (which is preselected when installing the sensor) and the aircraft will gradually lower its nose and gain speed.

In this sub-option, with a decrease in speed, an offset signal is supplied, for which purpose the signal from a controlled signal source (for example, from a controlled voltage divider, if the signal from a DC sensor, or from a controlled generator, if the signal from the AC sensor). In this case, the plane obeys the rudders, but only in one direction - in the direction of decreasing pitch. This control system is better for an experienced pilot, who can lower his nose very sharply, and with a good angle of attack, he can again sharply raise his nose to an acceptable level. But for a low-skilled pilot, the 4-a and 4-b systems are better.

OPTION 5. And finally, all the functions for preventing a corkscrew can be taken over by a computer. In this case, the already mentioned signal from the control knob, the signal from the angle sensor between the vane and the rudders, the pitch, speed, altitude signals and, possibly, the vertical slip and pitch sensors are fed to the processor input, and the processor output is connected to the vertical rudder actuator. The higher the speed and altitude (preferably not above sea level, but above the surface of the earth), the more freedom a computer (processor) can allow for pitch. In this case, two options are possible for the processor to process speed and altitude signals.

OPTION 5-a. The speed and altitude signals are added, one of the signals may have a positive or negative coefficient.

OPTION 5-b. Signals of speed and altitude are multiplied, and one of the signals can be raised to a power greater or less than unity.

Vertical slip is more likely negative, therefore, the signal from the slip sensor, if there is a sensor, should be subtracted from the sum according to option 5-a or from the product according to option 5-b with a small coefficient. Or vice versa - multiplied by the amount or added to the product.

The presence of pitch can make a different impact - if it is negative (down), then a sharp movement of the helm on itself is only welcome and vice versa. Therefore, its influence on the results of calculations for options 5-a, 5-b is as follows: the pitch sensor signal is subtracted with its sign from the sum in option 5-a (pitch down - negative, pitch up - positive), or multiplied by the product according to option 5 -b with a coefficient greater than one if the pitch is negative, and with a coefficient less than one if the pitch is positive (horizontal position, of course, gives a coefficient equal to one). It is possible and vice versa - it is multiplied by the amount or added to the product.

Perhaps a combination of options 5-a and 5-b.

All variants of “mitigation” of anti-corking qualities can be combined, except for option 5 - it does not need combinations. But he needs duplication, preferably triple.

In FIG. Figure 1 shows how whimsical the optimal shape of the weather vane 1 may turn out to be (a similar shape expanding toward the ends in aviation is called the “butterfly wing”). Moreover, it is possible that the relative thickness of the cross section of the weather vane is unstable - behind rod 2, where the flow is perturbed, the relative thickness is smaller and the stall will occur earlier, while the ends of the “butterfly wing” will still operate in continuous flow mode.

In FIG. Figures 2, 3, 4, 5 show variants 4-a, 4-b, 4-c and 5, respectively. In these block diagrams, 3-ZD is a control knob associated with the pilot's helm, 4-US is a control amplifier, 5- IM is the actuator (steering machine), 6-D is the angle sensor between the wind vane and the rudders (if “scissors” of the rudders are provided, then the signal from the two rudders is fed in half weakened form). These are common elements for all circuits.

In FIG. 2, the output of the 3-ZD master is connected to the input of the 7-DL divider, which is controlled by an 8-C speed sensor. The signal from the divider goes further to the 4-US amplifier, and from it to the 5-IM actuator, and the 6-D sensor informs the amplifier about the angle between the wind vane and the rudders.

The scheme works as follows: at a safe speed, the amplifier gives a voltage to the actuator according to the error signal between the setpoint and the sensor. When the speed drops, the divider weakens the setpoint signal and the steering angle decreases (up or down - anyway).

In FIG. 3, the 6-D sensor is connected to the input of the 4-US amplifier through an intermediate controlled 9-U amplifier, the signal from which in turn is fed to the input of the 4-US amplifier, and the signal from the 3-ZD setpoint goes directly to the amplifier.

This scheme works as follows: when the speed drops, the signal from the 6-D sensor increases, as if the rudders are deflected too much, and the amplifier and actuator reduce the angle of installation of the rudders relative to the wind vane.

In FIG. 4, a signal from a 10-G controlled generator is supplied to the amplifier input, which, when the speed drops, introduces an offset corresponding to the rudder deviation up. And the wheels actually deviate below the position that the pilot asked them.

In FIG. 5 shows the control by means of an 11-PR processor, the input of which, in addition to the signals mentioned in the previous diagrams from the 3-ZD encoder, 6-D sensor and 8-C speed sensor, also receives signals from a 12-V height sensor, a 13-A slip sensor (angle of attack) and with a 14-T pitch sensor. The processor processes them according to the above algorithms and issues a control signal to the actuator.

Claims (14)

1. Management "duck", containing a fully rotated vane front horizontal tail (PGO) and characterized in that it has the following twist of the rudders: the root of the consoles of the rudders has a positive angle of attack than at the ends of the consoles. 2. The “duck” control, which contains an all-turning weathervane VGO and characterized in that the profile of the rudders of variable relative thickness — at the root part of the rudders it is smaller, and at the ends of the consoles - more. 3. The “duck” control, which contains an all-turning weathervane VGO and differs in that it has a shape in terms of a weather vane such that flow stall has little effect on its lifting force — for example, the shape of a regular triangle, an isosceles triangle, an oblique triangle, an oblique rhombus. 4. The “duck” control, which contains an all-rotational weather vane with a VGA and characterized in that with electrical remote control, it is possible to gradually decrease the transmission coefficient in the transmission line of the signal from the pilot's gear to the execution unit “angle between the VGA and the weather vane” or to smoothly enter a negative offset into this corner. 5. The control according to claim 4, characterized in that between the setpoint and the amplifier is a controlled signal divider. 6. The control according to claim 4, characterized in that between the sensor and the amplifier is a controlled signal amplifier. 7. The control according to claim 4, characterized in that the signal from a controlled signal source, for example, from a controlled voltage divider, if the signal from a DC sensor, or from a controlled generator, is additionally fed to the same input of the amplifier to which the signal from the sensor is supplied if the signal from the AC sensor. 8. The control "duck", containing a fully rotary weather vane PGO and characterized in that the control is equipped with a computer system, the input of the processor of which is fed a signal from the control knob, a signal from the angle sensor between the vane and rudders, pitch, speed and height signals, and the processor output connected to the actuator vertical rudders. 9. The control of claim 8, characterized in that the input of the processor is additionally supplied with the signals of the vertical slip sensor and pitch sensor. 10. The control of claim 8, wherein the speed and altitude signals are added, one of the signals may have a positive or negative coefficient. 11. The control of claim 10, wherein the pitch sensor signal is subtracted with its sign from the sum of claim 10 or multiplied by this sum. 12. The control of claim 8, wherein the speed and altitude signals are multiplied, and one of the signals can be raised to a power greater or less than one. 13. The control according to claim 12, characterized in that the pitch sensor signal is multiplied by the product according to claim 12 with a coefficient greater than one if the pitch is negative, and with a coefficient less than one if the pitch is positive, or added to the product with its own sign. 14. The control of claim 8, wherein the signal from the slip sensor with a certain coefficient is subtracted from the sum of speed and height signals, one of these signals can have a positive or negative coefficient, or the signal from the slip sensor with a certain coefficient is subtracted from the product of speed and altitude signals, or vice versa, is multiplied by the said amount or added to the said product.

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