CN100568141C - A kind of unmanned machine rolling leveling control method - Google Patents

Abstract

The invention discloses a kind of unmanned machine rolling leveling control method, level off control aileron controlled quentity controlled variable δ constantly by introducing unmanned plane access lift-over based on the sideslip revised law _X0Come original sideslip modification method is improved, according to formula

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 down wash, 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 strategies 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 yaw angle 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 yaw angle 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)

$M_y^{\mathrm{\β}}\mathrm{\β}+M_y^{{\mathrm{\δ}}_y}{\mathrm{\δ}}_y=0---\left(4\right)$

$M_x^{\mathrm{\β}}\mathrm{\β}+M_x^{{\mathrm{\δ}}_x}{\mathrm{\δ}}_x=0---\left(5\right)$

$M_{z0}+M_z^{\mathrm{\α}}\mathrm{\α}+M_z^{{\mathrm{\δ}}_z}{\mathrm{\δ}}_z=0---\left(6\right)$

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 a motor power, and θ is the angle of pitch, and γ is a roll angle, and α is the angle of attack, and β is a yaw angle, 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 controlled quentity controlled variable, δ _yBe yaw rudder controlled quentity controlled variable, δ _zBe the elevating rudder controlled quentity controlled variable.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 yaw angle 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):

${\mathrm{\δ}}_x=K_{\mathrm{\γ}}\mathrm{\γ}+K_{{\mathrm{\ω}}_x}{\mathrm{\ω}}_x---\left(7\right)$

Wherein, δ _xBe aileron controlled quentity controlled variable, K _γBe the roll angle control coefrficient, Be roll angle rate controlled 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 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 controlled quentity controlled variable 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 controlled quentity controlled variable 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 controlled quentity controlled variable is 0, bring horizontal side stability moment M by yaw angle 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 controlled quentity controlled variable 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 controlled quentity controlled variable 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:

${\mathrm{\δ}}_x=K_{\mathrm{\γ}}\mathrm{\γ}+K_{{\mathrm{\ω}}_x}{\mathrm{\ω}}_x+{\mathrm{\δ}}_{x0}---\left(8\right)$

Wherein, δ _xBe aileron controlled quentity controlled variable, K _γBe the roll angle control coefrficient, γ is a roll angle,

Be roll angle rate controlled 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 controlled quentity controlled variable constantly and can realize leveling off control, and control procedure is simple and reliable;

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

Description of drawings

Fig. 1 a is the course revised law synoptic diagram of aircraft under the crosswind condition;

Fig. 1 b is the sideslip revised law synoptic diagram of aircraft under the crosswind condition;

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

Fig. 2 b is that effect power and equalising torque 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 controlled quentity controlled variable result schematic diagrams among the embodiment;

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 controlled quentity controlled variable 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:

$M_x^{\mathrm{\β}}\mathrm{\β}+M_x^{{\mathrm{\δ}}_x}{\mathrm{\δ}}_{x0}=0---\left(9\right)$

Promptly be somebody's turn to do aileron controlled quentity controlled variable 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:

${\mathrm{\δ}}_x=K_{\mathrm{\γ}}\mathrm{\γ}+K_{{\mathrm{\ω}}_x}{\mathrm{\ω}}_x+{\mathrm{\δ}}_{x0}---\left(10\right)$

Wherein, δ _xBe aileron controlled quentity controlled variable, K _γBe the roll angle control coefrficient, γ is a roll angle,

Be roll angle rate controlled coefficient, ω _xBe roll angle speed.

Because the height of aircraft was lower when control was leveled off in aircraft access lift-over, the time that aircraft levels off ground connection from lift-over is very short, and wind field changes not quite in the consideration during this period of time, and therefore as if guaranteeing the plane nose line up with runway, then the yaw angle of aircraft is constant substantially.Can release thus, the aileron controlled quentity controlled variable that balances each other with it is also constant substantially, is aircraft access lift-over and levels off control aileron controlled quentity controlled variable 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 yaw angle 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 controlled quentity controlled variable and the aileron controlled quentity controlled variable 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 security 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):

${\mathrm{\δ}}_x=K_{\mathrm{\γ}}\mathrm{\γ}+K_{{\mathrm{\ω}}_x}{\mathrm{\ω}}_x$

In this example, K _γ=1.5, $K_{{\mathrm{\ω}}_x}=0.2.$ 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 controlled quentity controlled variable 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 controlled quentity controlled variable 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 controlled quentity controlled variable 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:

${\mathrm{\δ}}_x=K_{\mathrm{\γ}}\mathrm{\γ}+K_{{\mathrm{\ω}}_x}{\mathrm{\ω}}_x+{\mathrm{\δ}}_{x0}---\left(10\right)$

In this example, K _γ=1.5, $K_{{\mathrm{\ω}}_x}=0.2.$ 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 controlled quentity controlled variable 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 security 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:

Described control method is leveled off according to following steps realization lift-over under the cross wind landing situation based on the sideslip revised law:

Step 1: when control is leveled off in aircraft access lift-over, write down the aileron controlled quentity controlled variable δ in this moment _X0, δ _X0≠ 0;

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

${\mathrm{\δ}}_x=K_{\mathrm{\γ}}\mathrm{\γ}+K_{{\mathrm{\ω}}_x}{\mathrm{\ω}}_x+{\mathrm{\δ}}_{x0}$

Wherein, δ _xBe aileron controlled quentity controlled variable, K _γBe the roll angle control coefrficient, γ is a roll angle,

Be roll angle rate controlled 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 controlled quentity controlled variable δ _xWith the aileron controlled quentity controlled variable δ that inserts the moment _X0Substantially equal.

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