CN102591348B - Calculation and analysis control method of drag load effect on airplane maneuverability - Google Patents

Abstract

The invention discloses a calculation and analysis control method of drag load effect on airplane maneuverability, which comprises the following steps: (1) collecting and inputting original parameters, which comprise drag limiting velocity VBmax, drag rope limit load FBmax, working height HA of a drag airplane, maximal level flight velocity VAmax of the airplane and working velocity VA; (2) calculating a level flight angle of attack alpha and a drag resistance coefficient CBX; (3) calculating a drag moment MB; (4) calculating a horizontal tail skewness; (5) calculating a joy stick displacement delta WE; and (6) calculating the ratio of the horizontal tail skewness to the joy stick displacement delta WE, comparing the ratio with a preset upper limit, performing alarm prompt if the ratio exceeds a safety range. The method collects and inputs a series of original parameters, calculates the parameters affecting the airplane maneuverability, compares the parameters with the preset limit, analyzes whether to be safe and performs alarm prompt on the unsafe conditions so as to effectively guarantee the flying safety of the airplane.

Description

Method for calculating and analyzing and controlling influence of towing load on airplane maneuvering performance

Technical Field

The invention relates to a method for calculating and analyzing and controlling the influence of a towing load on the maneuvering performance of an airplane.

Background

When the airplane drags the slogan, the flag and the target through the steel cable, the airplane needs to have enough performance to meet various requirements of dragging load, dragging torque, dragging flying radius, airplane manipulation performance, dragging body stability and the like. However, the old model of towed airplane has many problems that are difficult to solve, such as limited geographical location of the operation area due to short range; the dragging body has poor stability and serious swinging due to small thrust; and the towing load causes the airplane to shake obviously, the operation difficulty is increased, and the phenomenon of towing ring falling can occur.

Adopt the aircraft of relative high performance to install towing mechanism additional, solve original series of problems of towing the aircraft: the problem of limited operation area can be solved by a large high-performance aircraft range; meanwhile, the influence of the towing load on the airplane control performance is reduced by the higher performance of the towing load, and the dynamic stability of the towing body and the airplane is ensured; the dragging ring is prevented from falling off by a special structure.

However, during towing, the towing load affects the handling performance of the aircraft, and the handling moment generated by the deflection of the horizontal tail (or elevator) is required to balance the towing moment. The size of the deflection angle of the horizontal tail wing in the process of balancing the drag moment is the problem that the refitting scheme of the towed airplane must be considered firstly, and is an important precondition for ensuring the flight safety of the towed airplane. Therefore, how to provide a method for calculating, analyzing and controlling the influence of the towing load on the airplane maneuvering performance is to calculate, analyze and control the airplane maneuvering performance, calculate and analyze parameters possibly influencing the airplane flight safety in time and guarantee the flight safety.

Disclosure of Invention

The invention provides a method for calculating and analyzing the influence of a towing load on the airplane handling performance, which aims to solve the problem that an effective and reliable method for calculating and analyzing the influence of the towing load on the airplane handling performance does not exist at present, so that certain potential safety hazard exists when an airplane carrying the towing load flies.

In order to solve the technical problems, the invention adopts the following technical scheme:

a method of computational and analytical control of the effect of drag loads on aircraft handling performance, comprising the steps of:

(1) inputting original parameters including drag limiting speed V_BmaxTowing ropeUltimate load F_BmaxWorking altitude H of a towed aircraft_AMaximum flat flying speed V of airplane_AmaxAnd a working speed V_A；

(2) Calculating the plane-flying attack angle alpha and the drag resistance coefficient C_BX；

(3) Calculating drag torque M_B；

(4) Calculating the horizontal tail deviation

(5) Calculating the displacement amount of the joystick_E；

(6) Calculating the ratio of the horizontal tail deflection to the control rod displacement:

and comparing the current value with a preset upper limit value, and if the current value exceeds a safety range, giving an alarm.

Further, in order to clearly display the safety state to the operator, in step (6), if the comparison result is within the safety range, a safety prompt is given.

Preferably, the alarm prompt and the safety prompt can be an audio alarm and/or a photoelectric alarm.

Still further, the method for calculating the flat flight angle of attack α in step (2) is as follows:

judging whether the current ground effect is available or unavailable,

when there is no ground effect, the ground effect is not good,

$\mathrm{\α}=C_y/C_y^a;$

C_yin order to obtain the coefficient of lift of the aircraft,

the slope of the lift coefficient curve;

C_ythe calculation method comprises the following steps: $G=Y=C_y\frac{1}{2}\mathrm{\ρ}{V}^{2}S=C_y\mathrm{qS};$

namely: c_y＝G/qs；

Wherein G is the aircraft weight;

y is aircraft lift force;

ρ is the local air density;

v is the horizontal flight speed;

s is the wing area;

q is rapid pressure;

when the ground effect is good, the plane flying angle of attack alpha is controlled by C_y-alpha curve finding.

Still further, the drag torque M in step (3)_RThe calculation method comprises the following steps:

(31) calculating drag resistance F_B：

$F_B=C_{\mathrm{Bx}}\frac{1}{2}\mathrm{\ρ}{V}^2{S}_B;$

Wherein, C_BXAs drag coefficient, C_BXCalculated by the following way:

$C_{\mathrm{Bx}}=\frac{F_{B\max }}{q_{V_{B\max }}{S}_B};$

is the speed pressure at the drag limit speed;

F_Bmaxis the drag rope limit load;

${q_V}_{B\max }=\frac{1}{2}\mathrm{\ρ}{V}_{B\max }^2;$

V_Bmaxis a mopDrag limit speed;

S_Bis the towed body area;

(32) determining the drag resistance direction;

simply estimating the drag resistance direction by using the given drag body sinking amount;

(33) calculating drag torque;

M_B＝F_BXL_Y-F_BYL_X；

wherein: m_BIs the drag torque;

F_BXis the drag resistance horizontal component;

F_BYis the drag resistance vertical component;

L_Xthe horizontal distance between the acting point of the drag resistance and the gravity center of the airplane;

L_Ythe vertical distance between the point of application of the drag resistance and the center of gravity of the aircraft.

Further, the horizontal tail skewness in the step (4)The calculation method comprises the following steps:

wherein,

the horizontal tail efficiency of the airplane is obtained;

b_ais the average aerodynamic chord.

Still further, the joystick displacement Δ W in step (5)_EAccording to the displacement and the flatness of a steering column of an aircraft control systemAnd calculating the functional relation of the tail deflection angle.

Preferably, the maximum horizontal flying speed V of the airplane is met in the step (1)_AmaxGreater than the drag limit speed V_BmaxWhen the safety range is detected to be exceeded in the step (6), the method also comprises the step of controlling the work speed V to be increased_ASatisfy V_A＞V_BmaxSo as to increase the aerodynamic resistance F of the towed body_B≥F_BmaxThe trailing wire rope is snapped.

Furthermore, if the aircraft towing mechanism is provided with the cold air emergency unlocking system, when the situation that the detected result exceeds the safety range in the step (6), the aircraft towing mechanism further comprises a step of controlling the cold air emergency unlocking system to emergently release the towing load, so that the safety of the aircraft flight is further guaranteed.

Compared with the prior art, the invention has the advantages and positive effects that: the calculation and analysis control method for the influence of the towing load on the airplane maneuvering performance calculates the parameters influencing the airplane maneuvering performance by collecting and inputting a series of original parameters, compares the parameters with the preset limit value, analyzes whether the parameters are safe or not, can give an alarm for unsafe conditions, and effectively guarantees the airplane flight safety.

Other features and advantages of the present invention will become more apparent from the detailed description of the embodiments of the present invention when taken in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a block diagram of the electrical connections of one embodiment of a method for computational and analytical control of the effect of drag loads on aircraft handling performance in accordance with the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of a method for calculating and analyzing control of the effect of towing load on the handling performance of an aircraft according to the present invention;

fig. 3 is a partial structure schematic diagram of the cold air emergency unlocking system in fig. 2.

Detailed Description

Aiming at the problem that an effective and reliable calculation and analysis control method for influence of a towing load on the airplane maneuvering performance does not exist at present, and certain potential safety hazards exist in the flying operation of the airplane carrying the towing load, the invention provides a calculation and analysis control method for influence of the towing load on the airplane maneuvering performance.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

In a first embodiment, the method for calculating and analyzing and controlling the influence of the towing load on the maneuvering performance of the aircraft of the present embodiment includes the following steps:

s1, inputting original parameters including drag limit speed V_BmaxDrag rope limit load F_BmaxWorking altitude H of a towed aircraft_AMaximum flat flying speed V of airplane_AmaxAnd a working speed V_A；

S2, calculating the plane flight angle alpha and the drag resistance coefficient C_BX；

S3, calculating the drag torque M_B；

S4, calculating the horizontal tail deviation

S5, calculating the joystick displacement delta W_E；

S6, calculating the ratio of the horizontal tail deviation degree to the joystick displacement:

and comparing the current value with a preset upper limit value, and if the current value exceeds a safety range, giving an alarm.

In step S6, in order to clearly display the safety state to the operator, it is preferable to present a safety notice when the comparison result is within the safety range. The alarm prompt and the safety prompt can be sound alarm and/or photoelectric alarm, for example, the safety state and the alarm state are distinguished by different sounds, or the two states are distinguished by different LED lamp colors.

In the field of aircraft technology, it is well known to those skilled in the art that level flight is the most basic flight state of an aircraft, that is, the aircraft performs level constant-speed, straight-line flight, called level flight, and in the level flight process of the aircraft, the level flight attack angle is related to the level flight speed. As a specific example, the present embodiment considers the ground effect condition at the same time. Therefore, the method for calculating the flat flight angle α in step S2 is:

judging whether the current ground effect is available or unavailable,

when there is no ground effect, the ground effect is not good,

$\mathrm{\α}=C_y/C_y^a;$

C_yin order to obtain the coefficient of lift of the aircraft,

the slope of the lift coefficient curve;

C_ythe calculation method comprises the following steps: $G=Y=C_y\frac{1}{2}\mathrm{\ρ}{V}^{2}S=C_y\mathrm{qS};$

namely: c_y= G/qs; slope of lift coefficient curve

Equal to a constant, the exact value of each airfoil should be determined experimentally, which is not described herein.

Wherein G is the aircraft weight; is a constant value and can be found from the aircraft almanac.

Y is aircraft lift force;

ρ is the local air density; may be measured by an air density sensor.

V is the horizontal flight speed; the current fly-by speed is a known quantity.

S is the wing area; again being constant.

q is rapid pressure;

when the ground effect is good, the plane flying angle of attack alpha is controlled by C_y-alpha curve finding.

In the present embodiment, the drag torque M in step S3_BThe calculation method comprises the following steps:

s31, calculating drag resistance F_B：

$F_B=C_{\mathrm{Bx}}\frac{1}{2}\mathrm{\ρ}{V}^2{S}_B;$

Wherein, C_BXAs drag coefficient, C_BXCalculated by the following way:

$C_{\mathrm{Bx}}=\frac{F_{B\max }}{{q_V}_{B\max }{S}_B};$

is the speed pressure at the drag limit speed;

F_Bmaxis the drag rope limit load;

${q_V}_{B\max }=\frac{1}{2}\mathrm{\&rho;}{\mathrm{<figure-callout\; id="2"\; label="V\; B\; max"\; filenames="120301155305.png"\; state="\{\{state\}\}">V</figure-callout>}}_{B\max }^{};$

V_Bmaxis the drag limit speed;

S_Bis the towed body area;

s32, determining the drag resistance direction;

simply estimating the drag resistance direction by using the given drag body sinking amount;

s33, calculating the drag torque M_B；

M_B＝F_BXL_Y-F_BYL_X；

Wherein: f_BXIs the drag resistance horizontal component;

F_BYis the drag resistance vertical component;

L_Xthe horizontal distance between the acting point of the drag resistance and the gravity center of the airplane;

L_Ythe vertical distance between the point of application of the drag resistance and the center of gravity of the aircraft.

In the present embodiment, the horizontal tail skewness in step S4The calculation method comprises the following steps:

drag moment M_BAs calculated from the preceding steps, it is possible to calculate,

wherein,

the horizontal tail efficiency of the airplane is obtained;

b_ais the average aerodynamic chord.

The joystick displacement amount Δ W in step S5_EAnd calculating according to the functional relation between the displacement of the steering column of the airplane control system and the horizontal tail deviation angle.

Satisfaction of the aircraft in step S1Maximum flying speed V_AmaxGreater than the drag limit speed V_BmaxWhen the safety-out is detected in step S6, the method further includes controlling the work speed V to be increased_ASatisfy V_A＞V_BmaxSo as to increase the aerodynamic resistance F of the towed body_B≥F_BmaxThe trailing wire rope is snapped.

To further explain the control method of the embodiment, the calculation of the various parameters mentioned above and the sending of the control command are all completed by the control unit, as shown in fig. 1, including the parameter acquisition unit and the control unit, the parameters (such as the flight speed of the aircraft) to be acquired in real time are completed by the corresponding parameter acquisition unit (such as the sensor, etc.), if the aircraft towing mechanism is provided with the cold air emergency unlocking system, when the flight is detected to be out of the safe range in step S6, the method further includes a step of controlling the cold air emergency unlocking system to emergently release the towing load, so as to further ensure the safety of the aircraft flight.

As a specific embodiment, referring to fig. 2 and 3, the aircraft towing mechanism of this embodiment further includes a cold air emergency unlocking system, which includes an electric valve 1, a cold air actuating cylinder 2, and a manual unlocking lever 4, wherein one end of the manual unlocking lever 4 is hinged to the towing hook housing 3.2, the other end is a free end and contacts with the surface of the electric unlocking cam 3.3, and the output end of the cold air actuating cylinder 2 faces the free end of the manual unlocking lever 4. The control unit controls the electric valve 1 and further controls the action of the cold air action cylinder 2.

When the cold air acting cylinder 2 pushes the towing ring 3.1 to open, the cold air acting cylinder 2 extends leftwards → the manual unlocking lever 4 rotates clockwise → the electric unlocking cam 3.3 rotates clockwise → the sector arm 3.6 rotates anticlockwise under the action of the spring 3.11 → the supporting arm 3.7 rotates clockwise to release the upper top arm 3.8 → the upper top arm 3.8 rotates clockwise → the latch hook 3.5 rotates anticlockwise → the latch hook 3.5 releases the towing ring 3.1 → the towing ring 3.1 is dropped.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.

Claims (8)

1. A method for computational and analytical control of the effect of drag loads on the handling performance of an aircraft, comprising the steps of:

(1) collecting and inputting original parameters including drag limiting speed V_BmaxDrag rope limit load F_BmaxWorking altitude H of a towed aircraft_AMaximum flat flying speed V of airplane_AmaxAnd a working speed V_A；

(2) Calculating the plane-flying attack angle alpha and the drag resistance coefficient C_BX；

（3）、Calculating drag moment M_B；

The drag torque M_BThe calculation method comprises the following steps:

(31) calculating drag resistance F_B：

$F_B=C_{\mathrm{Bx}}\frac{1}{2}\mathrm{\&rho;}{V}^2{S}_B;$

Wherein, C_BXIn order to be a drag resistance coefficient,

ρ is the local air density;

v is the horizontal flight speed;

C_BXcalculated by the following way:

$C_{\mathrm{Bx}}=\frac{F_{B\max }}{q_{V_{B\max }}{S}_B};$

is the speed pressure at the drag limit speed;

F_Bmaxis the drag rope limit load;

$q_{V_{B\max }}=\frac{1}{2}\mathrm{\&rho;}{V}_{B\max }^2;$

V_Bmaxis the drag limit speed;

S_Bis the towed body area;

(32) determining the drag resistance direction;

simply estimating the drag resistance direction by using the given drag body sinking amount;

(33) calculating drag torque;

M_B=F_BXL_Y-F_BYL_X；

wherein: m_BIs the drag torque;

F_BXis the drag resistance horizontal component;

F_BYis the drag resistance vertical component;

L_Xthe horizontal distance between the acting point of the drag resistance and the gravity center of the airplane;

L_Ythe vertical distance between the acting point of the drag resistance and the gravity center of the airplane;

(4) calculating the horizontal tail deviation

(5) Calculating the displacement amount of the joystick_E；

(6) Calculating the horizontal tail deviation

And the lever displacement amount DeltaW_EThe ratio of (A) to (B):and comparing the current value with a preset upper limit value, and if the current value exceeds a safety range, giving an alarm.

2. The method for calculating and analyzing the influence of the towed load on the maneuvering characteristics of an aircraft as recited in claim 1, wherein in step (6), a safety prompt is issued if the comparison is within a safe range.

3. The method for the computational and analytical control of the effect of towed loads on aircraft handling performance according to claim 2, wherein said alarm and safety cues are audible and/or electro-optical alarms.

4. The method for calculating and analyzing the influence of the towing load on the maneuvering characteristics of the aircraft according to claim 1, characterized in that the method for calculating the flat flight angle α in step (2) is:

judging whether the current ground effect is available or unavailable,

when there is no ground effect, the ground effect is not good,

$\mathrm{\&alpha;}=C_y/C_y^a;$

C_yin order to obtain the coefficient of lift of the aircraft,

the slope of the lift coefficient curve;

C_ythe calculation method comprises the following steps: $G=Y=C_y\frac{1}{2}\mathrm{\&rho;}{V}^{2}S=C_y\mathrm{qS};$

namely: c_y=G/qs；

Wherein G is the aircraft weight;

y is aircraft lift force;

ρ is the local air density;

v is the horizontal flight speed;

s is the wing area;

q is rapid pressure;

when the ground effect is good, the plane flying angle of attack alpha is controlled by C_y-alpha curve finding.

5. The method for calculating and analytically controlling the effect of towing load on maneuvering characteristics of an aircraft according to claim 1, characterized in that the tail trim in step (4)

The calculation method comprises the following steps:

wherein,the horizontal tail efficiency of the airplane is obtained;

b_ais the average aerodynamic chord.

6. The method for calculating and analytically controlling the effect of towing load on aircraft handling performance of claim 1 wherein in step (5) the stick displacement Δ W is_EAnd calculating according to the functional relation between the displacement of the steering column of the airplane control system and the horizontal tail deviation angle.

7. The towed load pair of claim 1The method for calculating and analyzing and controlling the influence of the maneuvering performance of the airplane is characterized in that the maximum flat flying speed V of the airplane is met in the step (1)_AmaxGreater than the drag limit speed V_BmaxWhen the safety range is detected to be exceeded in the step (6), the method also comprises the step of controlling the work speed V to be increased_ASatisfy V_A＞V_BmaxSo as to increase the aerodynamic resistance F of the towed body_B≥F_BmaxThe trailing wire rope is snapped.

8. The method for calculating and analyzing the effect of towing load on the handling performance of an aircraft as claimed in claim 1, wherein when exceeding the safe range is detected in step (6), further comprising the step of controlling a cold air emergency unlocking system of the aircraft towing mechanism to emergently release the towing load.

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