CN101264797A - Unmanned machine rolling leveling control method - Google Patents

Abstract

The invention discloses an unmanned aircraft rolling flattening control method based on sideslip correction method, which is characterized in that a intrinsical sideslip correction method is improved by introducing an aileron controlled variable of unmanned aircraft rolling flattening control time Delta <SUB>x0</SUB>, according to the formula, the unmanned aircraft is processed with rolling flattening control using Delta <SUB>x</SUB>=K<SUB>r</SUB>r+K<SUB>w number-[x</SUB>]Omega<SUB>x</SUB>+ Delta <SUB>xo</SUB>. The invention is particularly suitable for the unmanned aircraft control which has high requirement to landing rolling flattening while the side wind is strong. The aileron controlled variable in rolling flattening accessing time is only needed to record applying the control method of the invention, and the flattening control can be realized; the control process is simple and reliable; the airplane can be grounded in smaller roll angle; in the same side wind situation, the unmanned aircraft can be landed in near zero degree by applying the control method in the invention, which can greatly increase the landing safety of unmanned aircraft.

Description

A kind of unmanned machine rolling leveling control method

Technical field

The invention belongs to the UAV Flight Control field, specifically, be meant a kind of control method of unmanned machine rolling leveling.

Background technology

The sudden change of weather, the invasion and attack of little downwash, and the flight under IFR conditions, forced landing etc. all might make unmanned plane suffer from crosswind.Fly in crosswind, if unmanned aerial vehicle flight path is not revised, the flight path of aircraft will depart from the plane of symmetry of aircraft, and unmanned plane is moved to cross-wind direction.Crosswind is big more, and the sidesway of generation is just big more.When approach ran into crosswind, if the influence that untimely crab the wind effectively brings, unmanned plane just was difficult to align runway ground connection.

Be the influence of antagonism crosswind, two kinds of control policies are generally arranged: a kind of for the course revised law, shown in Fig. 1 (a), make head deflection cross-wind direction, i.e. air speed among Fig. 1 a Direction, select drift angle Δ ψ flight, air speed is consistent with axon, makes air speed

With wind speed

Synthetic ground velocity

Consistent with runway heading, utilize yaw rudder to make head put back runway heading in ground connection moment.Another kind is the sideslip revised law, and shown in Fig. 1 (b), heading is along runway, air speed V _kVector equals drift angle with the angle of side slip β of axon, makes air speed

With wind speed

Synthetic ground velocity

Consistent with runway heading.The sideslip revised law is to utilize yaw rudder to keep the head course consistent with the runway axis direction, and utilizes the aileron balance because the rolling moment that angle of side slip produces.

Fig. 2 has provided the power and the moment that act on aboard when adopting the sideslip revised law to land automatically following equilibrium relation, shown in (1)～(6):

Gcosθcosγ＝Y (1)

Gsinθ+P＝X (2)

Gcosθsinγ＝Z (3)

$M_y^{\mathrm{\&beta;}}\mathrm{\&beta;}+M_y^{{\mathrm{\&delta;}}_y}{\mathrm{\&delta;}}_y=0---\left(4\right)$

$M_x^{\mathrm{\&beta;}}\mathrm{\&beta;}+M_x^{{\mathrm{\&delta;}}_x}{\mathrm{\&delta;}}_x=0---\left(5\right)$

$M_{z0}+M_z^{\mathrm{\&alpha;}}\mathrm{\&alpha;}+M_z^{{\mathrm{\&delta;}}_z}{\mathrm{\&delta;}}_z=0---\left(6\right)$

Wherein, G is an aircraft weight, and Y is a lift, and X is a resistance, and Z is a side force, and P is an engine thrust, and θ is a pitch angle, and γ is a roll angle, and α is the angle of attack, and β is an angle of side slip, M _y ^βBe the course static derivative,

Be yaw rudder efficient, M _x ^βBe the lift-over static derivative,

Be effectiveness of aileron, M _z ^αBe vertical static derivative,

Be elevating rudder efficient, δ _xBe aileron controlling quantity, δ _yBe yaw rudder controlling quantity, δ _zBe the elevating rudder controlling quantity.By formula (1)～(6) as can be known, stable decline when breakking away, aileron, yaw rudder and elevating rudder need to control respectively to make unmanned plane reach the balance of power and moment.Specify for: control aileron can make bank attitude control moment

With horizontal side stability moment M _x ^βThe β balance, to keep roll angle γ constant, the control yaw rudder can make directional control moment With weathercocking moment M _y ^βThe β balance is to keep angle of side slip β constant; The control elevating rudder can make pitch control moment

With zero lift moment M _Z0, pitching stability moment M _z ^αThe α balance is to keep angle of attack α constant.

It should be noted that when adopting the sideslip revised law to land automatically, downslide with roll angle will appear when aircraft flies under the crosswind condition, will cause the danger that aircraft enters will have wing to contact to earth behind the low latitude like this, therefore moment before ground contact, must carry out the action that lift-over is leveled off.The direct approach that the lift-over of common control aircraft is leveled off is an aileron, and the roll angle that promptly utilizes aileron to control aircraft is 0.Common control law is as the formula (7):

${\mathrm{\&delta;}}_x=K_{\mathrm{\&gamma;}}\mathrm{\&gamma;}+K_{{\mathrm{\&omega;}}_x}{\mathrm{\&omega;}}_x---\left(7\right)$

Wherein, δ _xBe aileron controlling quantity, K _γBe the roll angle control coefficient,

Be roll angle speed control coefficient, ω _xBe roll angle speed.When roll angle appears in aircraft, to handle the corresponding angle of aileron movement and make the reverse lift-over of aircraft eliminate roll angle, the feedback of introducing roll angle speed mainly plays shock damping action.By the control law in the formula (7) as can be known, when control stabilization, promptly roll angle and roll angle speed are at 0 o'clock, and the aileron controlling quantity also is 0.But the equilibrium relation of power and moment as can be known when being landed automatically by above-mentioned employing sideslip revised law, and the aileron controlling quantity made bank attitude control moment before lift-over was leveled off

With horizontal side stability moment M _x ^ββ balance, lift-over are leveled off the back if the aileron controlling quantity is 0, bring horizontal side stability moment M by angle of side slip β _x ^ββ will make aircraft produce lift-over again, and the roll angle behind final the stablizing must not be 0, and aircraft safety is landed to have a negative impact.

Summary of the invention

The objective of the invention is to propose a kind of unmanned machine rolling leveling control method based on the sideslip revised law, insert lift-over and level off control aileron controlling quantity constantly and come original sideslip modification method is improved by introducing unmanned plane, method provided by the invention is particularly useful for when crosswind is big the control of requirement than higher unmanned plane being leveled off in the landing lift-over.

Unmanned plane cross wind landing lift-over leveling control method of the present invention is realized by following steps:

Step 1: when control is leveled off in aircraft access lift-over, write down the aileron controlling quantity δ in this moment _X0

Step 2: after control is leveled off in aircraft access lift-over, carry out lift-over according to following formula and level off control:

${\mathrm{\&delta;}}_x=K_{\mathrm{\&gamma;}}\mathrm{\&gamma;}+K_{{\mathrm{\&omega;}}_x}{\mathrm{\&omega;}}_x+{\mathrm{\&delta;}}_{x0}---\left(8\right)$

Wherein, δ _xBe aileron controlling quantity, K _γBe the roll angle control coefficient, γ is a roll angle,

Be roll angle speed control coefficient, ω _xBe roll angle speed.

The advantage of the unmanned plane cross wind landing lift-over leveling control method that the present invention proposes is:

(1) using control method of the present invention can be so that aircraft can be with less roll angle ground connection;

(2) the present invention only need write down lift-over and levels off and insert aileron controlling quantity constantly and can realize leveling off control, and control process is simple and reliable;

(3) under identical crosswind condition, use control method of the present invention and can make unmanned plane land the landing safety that has improved unmanned plane greatly with roll angle near 0 degree.

Description of drawings

Fig. 1 a is the course revised law scheme drawing of aircraft under the crosswind condition;

Fig. 1 b is the sideslip revised law scheme drawing of aircraft under the crosswind condition;

Fig. 2 a is that effect power and moment balance aboard concerns schematic rear view when adopting the sideslip revised law to land automatically;

Fig. 2 b is that effect power and moment balance aboard concerns schematic side view when adopting the sideslip revised law to land automatically

Fig. 3 a adopts different lift-over leveling control method roll angle result schematic diagrams among the embodiment;

Fig. 3 b adopts different lift-over leveling control method aileron controlling quantity result schematic diagrams among the embodiment;

The specific embodiment

Below in conjunction with accompanying drawing and instantiation a kind of unmanned machine rolling leveling control method based on the sideslip revised law of the present invention is described further.

Unmanned machine rolling leveling control method of the present invention is realized by following steps:

Step 1: when control is leveled off in aircraft access lift-over, write down the aileron controlling quantity δ in this moment _X0

When adopting the sideslip revised law to land automatically, effect power and moment aboard has in the following equilibrium relation, by formula (5) as can be known:

$M_x^{\mathrm{\&beta;}}\mathrm{\&beta;}+M_x^{{\mathrm{\&delta;}}_x}{\mathrm{\&delta;}}_{x0}=0---\left(9\right)$

Promptly be somebody's turn to do aileron controlling quantity δ constantly _X0Can satisfy bank attitude control moment With horizontal side stability moment M _x ^βThe β equilibrium relation.

Step 2: after control is leveled off in aircraft access lift-over, carry out lift-over according to following formula and level off control:

${\mathrm{\&delta;}}_x=K_{\mathrm{\&gamma;}}\mathrm{\&gamma;}+K_{{\mathrm{\&omega;}}_x}{\mathrm{\&omega;}}_x+{\mathrm{\&delta;}}_{x0}---\left(10\right)$

Wherein, δ _xBe aileron controlling quantity, K _γBe the roll angle control coefficient, γ is a roll angle, Be roll angle speed control coefficient, ω _xBe roll angle speed.

The height of aircraft is lower because aircraft inserts lift-over when leveling off control, and it is very short that aircraft levels off the connected to chassis time from lift-over, consider during this period of time in wind field change not quite, therefore if guarantee the plane nose line up with runway, then the angle of side slip of aircraft is constant substantially.Can release thus, the aileron controlling quantity that balances each other with it is also constant substantially, is aircraft access lift-over and levels off control aileron controlling quantity δ constantly _X0At this moment, if with δ _X0Be retained to lift-over and level off the stage, then mean after aircraft inserts lift-over and levels off control, a part of aileron control amount continues to serve as the effect that the horizontal side stability moment that produces with angle of side slip balances each other, and the roll angle that another part is used for controlling aircraft is 0.When control reached stable state, roll angle and roll angle speed were 0, aileron controlling quantity and the aileron controlling quantity δ that inserts the moment _X0Substantially equal, the balance on the lift-over direction of aircraft is not broken, and the assurance aircraft can have been guaranteed the safety of aircraft landing with less roll angle ground connection.

Embodiment:

In this example, the unmanned plane downslide stage adopts the sideslip revised law to carry out horizontal side direction control, has added the positive crosswind of normal value of 3m/s in the simulation process.When control is leveled off in the access lift-over, directly utilize the middle control method of formula mentioned in the background technology (7) respectively and utilize lift-over leveling control method provided by the present invention to compare explanation.

Control method is in the formula (7):

${\mathrm{\&delta;}}_x=K_{\mathrm{\&gamma;}}\mathrm{\&gamma;}+K_{{\mathrm{\&omega;}}_x}{\mathrm{\&omega;}}_x$

In this example, K _γ=1.5, $K_{{\mathrm{\&omega;}}_x}=0.2.$ Shown in Fig. 3 a, 3b, insert lift-over since 1892.6 seconds in the emulation and level off control, dotted line is the simulation result of the control method of utilizing formula (7) among Fig. 3 (a) and Fig. 3 (b), has provided the roll angle and the corresponding aileron controlling quantity of aircraft respectively.By Fig. 3 a as can be seen, insert lift-over and level off before the control, because the influence of crosswind, the roll angle of aircraft about with-3.5 degree done to break away and revised flight, and corresponding aileron controlling quantity is about 2.5 degree.Insert lift-over and level off after the control, roll angle finally is stable at 1.5 degree under the effect of aileron, roll angle is not controlled to 0 degree.

Carry out lift-over by method provided by the invention below and level off control.

Step 1: when control is leveled off in aircraft access lift-over, write down the aileron controlling quantity δ in this moment _X0

δ _x0＝2.5

Step 2: after control is leveled off in aircraft access lift-over, carry out lift-over according to formula (10) and level off control:

${\mathrm{\&delta;}}_x=K_{\mathrm{\&gamma;}}\mathrm{\&gamma;}+K_{{\mathrm{\&omega;}}_x}{\mathrm{\&omega;}}_x+{\mathrm{\&delta;}}_{x0}---\left(10\right)$

In this example, K _γ=1.5, $K_{{\mathrm{\&omega;}}_x}=0.2.$ Solid line is the simulation result curve of lift-over leveling control method provided by the present invention among Fig. 3 (a) and Fig. 3 (b), has provided the roll angle and the corresponding aileron controlling quantity of aircraft respectively.By Fig. 3 b as can be seen, utilize lift-over leveling control method provided by the present invention, insert lift-over and level off after the control, about roll angle under the effect of aileron was near 0 degree, aircraft can have been guaranteed the safety of aircraft landing with less roll angle ground connection.

Claims (1)

1, a kind of unmanned machine rolling leveling control method is characterized in that:

Step 1: when control is leveled off in aircraft access lift-over, write down the aileron controlling quantity δ in this moment _X0

Step 2: after control is leveled off in aircraft access lift-over, carry out lift-over according to following formula and level off control:

${\mathrm{\&delta;}}_x=K_{\mathrm{\&gamma;}}\mathrm{\&gamma;}+K_{{\mathrm{\&omega;}}_x}{\mathrm{\&omega;}}_x+{\mathrm{\&delta;}}_{x0}$

Wherein, δ _xBe aileron controlling quantity, K _γBe the roll angle control coefficient, γ is a roll angle,

Be roll angle speed control coefficient, ω _xBe roll angle speed; Under the effect of aileron, when control reaches stable state, roll angle γ and roll angle speed ω _xBe 0, aileron controlling quantity δ _xWith the aileron controlling quantity δ that inserts the moment _X0Substantially equal.

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