CN105353772A - Visual servo control method for unmanned aerial vehicle maneuvering target locating and tracking - Google Patents

Abstract

The invention belongs to the technical field of unmanned aerial vehicle flight control and machine visual intersection fusion, and particularly relates to a visual servo control method for unmanned aerial vehicle maneuvering target locating and tracking. The method comprises the steps that a geodetic coordinate system, a body coordinate system, a camera coordinate system, an image coordinate system and a body and geodetic transition coordinate system are established; and target locating and calculation of an attitude angle given value of target tracking and an attitude angle given value of course tracking are performed via the relationship between the established coordinate systems according to target imaging sequences so that visual servo control is completed. Target imaging is performed by using a single fixed camera only, and high-precision continuous locating and tracking of maneuvering targets are realized by controlling the attitude of an unmanned aerial vehicle. According to the method, a tracking holder or laser range finding equipment is not required so that load volume and cost can be effectively reduced and reconnaissance concealment can be enhanced.

Description

A kind of Visual servoing control method in UAV Maneuver target locating

Technical field

The invention belongs to the technical field of UAV Flight Control and machine vision mixing together, be specifically related to a kind of Visual servoing control method in UAV Maneuver target locating.

Background technology

And have man-machine compared with, unmanned plane has that volume is little, cost is low, maneuverability, easy to use and to plurality of advantages such as requirement for environmental conditions are lower.From being born from unmanned plane, its just constantly progress along with improving constantly of scientific and technological level, and be progressively widely used in the various fields such as military, civilian, police, performed task comprises: target reconnaissance, trace and monitor, target hit, injure assessment, rescue and relief work, personnel's search and rescue, terrain prospecting etc.The function of unmanned plane in daily life, value are shown up prominently; Effect in modernized war, status just progressively improve, and have become indispensable tactical weapon, and by means of the unique advantage of battlefield zero injures and deaths, its important air armament becoming future battlefield is unquestionable.Therefore in recent years, the growth momentum of domestic and international unmanned air vehicle technique is very swift and violent.

The location of maneuvering target and tracking are that unmanned plane scouts one of critical function followed the tracks of.Target localization is exactly by unmanned plane during flying parameter and load information, calculates the coordinate figure of impact point under earth coordinates; Target following is then according to locating information, is locked in all the time among unmanned plane load visual field by maneuvering target, and calculates the movable information of target by design con-trol strategy.The technology utilizing view data to carry out target identification reaches its maturity, and how to utilize the positioning result of target identification design servo control strategy carry out efficient target tracking be still domestic and international unmanned plane research focus and difficult point.

Due to small-sized limited with Small and micro-satellite load-carrying ability, in reconnaissance mission, general use carries out imaging reconnaissance without monopod video camera, video camera itself does not have tracking power, to realize target following function, need to utilize image information design con-trol algorithm, the position of control unmanned plane and attitude, by target lock-on heart region in the picture, realize location and the tracking of the maneuvering target of view-based access control model servo.

The inventive method can in military operation, and realize target is accurately located, the task such as surveillance and tracking and precision strike; In Multi computer cooperation, be conducive to collaborative finishing the work; In disaster relief, realize rapid rescue and treatment of the wounded etc.Therefore, the accurate locating and tracking of maneuvering target has important Research Significance and wide application prospect.

Summary of the invention

The present invention proposes a kind of Visual servoing control method in UAV Maneuver target locating, by carrying out Visual servoing control to unmanned plane, by target lock-on among camera field of view, reaching precision target location and tracking effect.

Concrete technical scheme of the present invention is as follows: the first step, determine the equipment states such as unmanned plane, GPS, Inertial Measurement Unit, video camera, determines camera intrinsic parameter and setting angle; Vector of unit length i on definition optical axis, obtains vector of unit length in the earth coordinates { expression under G} by coordinate system relation ^gp _i, the optical axis asked by aircraft altitude and collinear image formation principle and ground intersection point A are in { the expression under G} ^gp _a, and then try to achieve the expression of A under body axis system ^bp _a;

Second step, according to scouting imaging select target point, by impact point t coordinate figure in the picture ( ⁱx _t, ⁱy _t) and camera intrinsic parameter, obtain impact point at the camera coordinate system { coordinate figure under C} ^cp _t, in conjunction with camera installation locations, angle, the current longitude of aircraft, latitude, height and attitude angle, obtain impact point at the earth coordinates { coordinate of G} ^gp _t, then resolved by earth model and obtain impact point longitude and latitude, realize target is accurately located;

3rd step, in conjunction with target localization result last time, according to the flight information of the time interval, aircraft, obtain the motion state that target is current, and estimate maneuvering target subsequent time position

4th step, with picture centre ⁱp _afor maneuvering target desired locations in the picture ⁱp _tr, then target is at { the desired locations under G} ^gp _trfor ^gp _a, according to error delta ^gp _t= ^gp _tr- ^gp _tequation obtains attitude angle set-point θ _t, φ _tand ψ _t;

5th step, by aircraft desired locations in flight track with aircraft current location ^gp _bOerror delta ^gp _bO, obtain attitude angle set-point φ respectively according to horizontal side direction control law and Longitudinal Control Law _rand θ _r.In conjunction with attitude angle set-point in task weight and the 4th step, obtain the total specified rate of each attitude angle, with each relevant rudder face of this servocontrol unmanned plane, the maximized Visual servoing control of stability margin in realize target locating and tracking process.

Beneficial effect: the present invention only needs to use single fixed camera to target imaging, by controlling UAV position and orientation, realize following the tracks of the high precision consecutive tracking of maneuvering target, the method is without the need to following the tracks of The Cloud Terrace and Laser Distance Measuring Equipment, significantly reduce volume and the cost of load, improve the disguise of scouting.The method is generally applicable to the target localization and tracking system of unmanned plane, is especially loaded with the SUAV (small unmanned aerial vehicle) of fixed cameras and the UAS of The Cloud Terrace motion failures.The method has important practical significance and having broad application prospects to unmanned plane (with other similar topworkies) high precision target locating, opens up certain guiding function to new location method.

Accompanying drawing explanation

Fig. 1 is the device connection diagram that unmanned plane target positioning and tracing method relates to;

Fig. 2 is each coordinate system used in Positioning and Tracking of Maneuvering Target process;

Fig. 3 is that under earth model, longitude and latitude and coordinate system represent relation schematic diagram;

Fig. 4 is the lower moving targets location tracing process schematic diagram of unmanned aerial vehicle flight path flight.

Embodiment

Below in conjunction with accompanying drawing, the UAV Maneuver target locating method embodiment of a kind of view-based access control model servo that the present invention proposes is described in detail.

1 unmanned aerial vehicle platform and coordinate system definition

For scouting UAS, unmanned aerial vehicle platform involved in the present invention comprises the parts such as aircraft subsystem, flight-control computer, pattern process computer, video camera, aircraft subsystem includes the equipment such as Inertial Measurement Unit and GPS, is used for measuring UAV Attitude and position.Main device connection diagram as shown in Figure 1.

In Positioning and Tracking of Maneuvering Target process, as shown in Figure 2, each coordinate system is defined as follows each coordinate system used:

{ G}: start to carry out the target locating moment with unmanned plane, the projection of center of gravity on ground is as overall changeless geodetic coordinates origin, and X-axis is parallel to warp, and Y-axis is parallel to parallel, and Z axis points to the earth's core perpendicular to XOY plane for earth coordinates.

Body axis system { B}: with unmanned plane center of gravity for initial point, be connected on unmanned plane, X-axis is parallel to design orientation of its axis head in unmanned plane symmetrical plane, and Y-axis is pointed on the right side of body perpendicular to unmanned plane symmetrical plane, and Z axis points to below fuselage perpendicular to X-axis in symmetrical plane.

{ C}: with video camera photocentre for initial point, X-axis and Y-axis are parallel to the vertical and horizontal straight line of image to camera coordinate system respectively, and Z axis is camera optical axis, vertical with the plane of delineation.Definition camera optical axis is with { the XOY plane angle of B} is angular altitude α, and optical axis is just on plane; Optical axis is with { the XOZ plane included angle of B} is azimuthal angle beta, and optical axis is just on the right side of plane.

{ I}: with image upper left angle point for initial point two-dimensional coordinate system, X-axis is parallel to the longitudinal pixel line in the image leftmost side to image coordinate system, and Y-axis is parallel to pixels across line, and coordinate figure x and y represents line number and the columns of pixel respectively.

{ GB}: with unmanned plane center of gravity for initial point, each axle of X, Y, Z is parallel to earth coordinates { G} in body the earth interim coordinate system.

In unmanned plane reconnaissance flight process, any time body axis system { relative to earth coordinates, { pose of G} represents B}, is uniquely determined by the longitude of aircraft, latitude, height and attitude angle.According to earth coordinates, { { longitude of B}, latitude and height, earth model can solve that { B} initial point is at { the coordinate under G} as shown in Figure 3 for G} and body axis system ^gp _bO=( ^gx _bO, ^gy _bO, ^gz _bO) ^t, can obtain in conjunction with the pitching angle theta of body, crab angle ψ, roll angle φ that { B} is in { the expression under G} { B} is in { the expression under G}

$T_B^G=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-s\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& {x_G}_{BO}\\ c\mathrm{\θ}s\mathrm{\ψ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& {y_G}_{BO}\\ -s\mathrm{\θ}& c\mathrm{\θ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& {z_G}_{BO}\\ 0& 0& 0& 1\end{array}\right]---\left(1\right)$

$T_G^B=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& c\mathrm{\θ}s\mathrm{\ψ}& -s\mathrm{\θ}& -{x_G}_{BO}\\ s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-s\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& c\mathrm{\θ}s\mathrm{\φ}& -{y_G}_{BO}\\ s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& -{z_G}_{BO}\\ 0& 0& 0& 1\end{array}\right]---\left(2\right)$

Defined can be drawn by coordinate system, { B} is in { the expression under GB} { B} is in { the expression under GB} for:

$T_B^{GB}=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-s\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& 0\\ c\mathrm{\θ}s\mathrm{\ψ}& s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& 0\\ -s\mathrm{\θ}& c\mathrm{\θ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& 0\\ 0& 0& 0& 1\end{array}\right]---\left(3\right)$

$T_{GB}^B=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& c\mathrm{\θ}s\mathrm{\ψ}& -s\mathrm{\θ}& 0\\ s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-s\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& c\mathrm{\θ}s\mathrm{\φ}& 0\\ s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& 0\\ 0& 0& 0& 1\end{array}\right]---\left(4\right)$

{ C} is relative to { pose of B} is by video camera fixed position for camera coordinate system ^bp _cO=( ^bx _cO, ^by _cO, ^bz _cO) ^t, current angular altitude α and azimuthal angle beta determine, after setting angle is fixing, and C} the expression under B} immobilizes:

$T_C^B=\left[\begin{array}{cccc}c\mathrm{\α}c\mathrm{\β}& -s\mathrm{\β}& s\mathrm{\α}c\mathrm{\β}& {x_B}_{CO}\\ c\mathrm{\α}s\mathrm{\β}& c\mathrm{\β}& s\mathrm{\α}s\mathrm{\β}& {y_B}_{CO}\\ -s\mathrm{\α}& 0& c\mathrm{\α}& {z_B}_{CO}\\ 0& 0& 0& 1\end{array}\right]---\left(5\right)$

Image coordinate system and camera coordinate system relation are determined by camera intrinsic parameter, and camera intrinsic parameter comprises picture centre coordinate ⁱp _icent=( ⁱx _icent, ⁱy _icent, 1) ^t, focal distance f, proportionality factors lambda etc.From perspective projection model, at camera coordinate system, { under C}, coordinate is expressed as picture centre pixel coordinate ^cp _icent=(0,0, f) ^t, then I} being expressed as under C}:

$T_I^C=\left[\begin{array}{cccc}\mathrm{\λ}& 0& 0& -{\mathrm{\λ}}^I{x}_{Icent}\\ 0& \mathrm{\λ}& 0& -{\mathrm{\λ}}^I{y}_{Icent}\\ 0& 0& 0& f\\ 0& 0& 0& 1\end{array}\right]---\left(6\right)$

According to the relation between above-mentioned each coordinate system, under can obtaining a certain coordinate system easily, arbitrfary point represents at the coordinate of other coordinate systems.

2 maneuvering targets are accurately located

When unmanned plane flies to scouting region, open load video camera and start to scout, the intersection point on note optical axis and ground is A.According to the relation between each coordinate system mentioned above, vector of unit length i on definition camera light axis, then its at camera coordinate system, { homogeneous coordinates under C} are ^cp _i=(0,0,1,1) ^t, according to the pose of video camera by formula (5), the body axis system { expression under B} can be obtained ^bp _i:

${P_B}_i=T_C^B\·{P_C}_i---\left(7\right)$

According to the pose of aircraft by formula (1), try to achieve the earth coordinates { expression under G} ^gp _i:

${P_G}_i=T_B^G\·{P_B}_i=T_B^G\·T_C^B\·{P_C}_i---\left(8\right)$

According to perspective imaging principle and imaging triangular relationship, calculated by aircraft altitude and obtain optical axis and ground intersection point A at the { coordinate under G} ^gp _a.Obtain according to formula (2) again ^bp _a, use in subsequent calculations.(by earth model and the current longitude and latitude of aircraft, by ^bp _aa point longitude and latitude can be obtained.The initial point of earth coordinates can be got a certain moment platform information according to the method and calculate, also desirable known point.)

After unmanned plane finds target, select interesting target point, by selected impact point t in the image coordinate system { homogeneous coordinates under I} according to reconnaissance mission ⁱp _t=( ⁱx _t, ⁱy _t, 1,1) ^t, draw according to formula (6) ^cp _t, then can obtain successively ^bp _t, ^gp _t:

${P_G}_t=T_B^G\·{P_B}_t=T_B^G\·T_C^B\·{P_C}_t=T_B^G\·T_C^B\·T_I^C\·{P_I}_t---\left(9\right)$

By earth model and longitude and latitude relation, obtain the longitude and latitude high information of impact point t, realize target is accurately located.For maneuvering target, the method can according to twice positioning states estimating target motion information.Usual pattern process computer processing speed quickly, according to the time interval of twice target localization, the flight information of aircraft, obtains the motion state that target is current, and estimates maneuvering target subsequent time position thus system hit rate is improved in maneuvering target hits.

Maneuvering target tracking under 3 unmanned plane Visual servoing control

In unmanned plane autonomous surveillance flight course, it is desirable to keep impact point in the center of image, to obtain maximum stability margin.For the scouting load having The Cloud Terrace, after providing unmanned plane reconnaissance route or trajectory planning, tracking and positioning can rely on the servocontrol lock onto target heart position in the picture of The Cloud Terrace.When load The Cloud Terrace motion failures or when there is no The Cloud Terrace, maximizing for realizing stability margin, can realize by controlling UAV Attitude, specific as follows:

According to the derivation of formula (7) and (8), convolution (3) and above required by ^bp _a, can try to achieve respectively ^gp _twith ^gBp _tr= ^gp _a, then error is Δ ^gp _t= ^gp _tr- ^gp _t, system of equations obtains attitude angle set-point θ thus _t, φ _tand ψ _t;

By aircraft desired locations in flight track with aircraft current location ^gp _bOerror roll angle set-point φ is obtained according to horizontal side direction control law _r

${\mathrm{\φ}}_r=K_{\mathrm{\φ}}({\tilde{y}_G}_{BO}-{y_G}_{BO})+{K_{d\mathrm{\φ}}}^G{\stackrel{\·}{y}}_{BO}---\left(10\right)$

Angle of pitch set-point θ is obtained respectively according to Longitudinal Control Law _r

${\mathrm{\θ}}_r=K_{\mathrm{\θ}}({\tilde{z}_G}_{BO}-{z_G}_{BO})---\left(11\right)$

In conjunction with task weight λ _mdistribute the attitude angle set-point of target following and course line tracking, always exported

θ＝λ _mθ _t+(1-λ _m)φ _r

φ＝λ _mφ _t+(1-λ _m)φ _r(12)

ψ＝ψ _t

The inner ring controlled in this, as flight is given, each relevant rudder face of servocontrol unmanned plane, the maximized Visual servoing control of stability margin in realize target locating and tracking process.

Claims (7)

1. the Visual servoing control method in UAV Maneuver target locating, is characterized in that, described method application unmanned plane carries out Visual servoing control, by target lock-on among camera field of view.

2. the Visual servoing control method in a kind of UAV Maneuver target locating according to claim 1, it is characterized in that, described method establishment earth coordinates, body axis system, camera coordinate system, image coordinate system, body the earth interim coordinate system, by the relation between the coordinate system of above-mentioned foundation, carry out the calculating of the attitude angle set-point that the location of target and the attitude angle set-point of target following and course line are followed the tracks of, complete Visual servoing control.

3. the Visual servoing control method in a kind of UAV Maneuver target locating according to claim 2, is characterized in that, said method comprising the steps of:

A) equipment state and the device parameter of locating device on unmanned plane, Inertial Measurement Unit and video camera is determined, the device parameter of described video camera comprises camera intrinsic parameter and setting angle, point to according to camera intrinsic parameter and setting angle determination optical axis, the positional representation on unmanned plane body axis system by mutual relationship determination optical axis between each coordinate system and ground intersection point;

B) according to the scouting imaging of video camera, select target point, determines the coordinate position of impact point in camera coordinate system, then draws the position location of impact point on earth model in conjunction with the device parameter of video camera;

C) according to positioning result, in conjunction with the flight information of unmanned plane, obtain the motion state that impact point is current, and estimate the position at impact point lower a moment;

D) using the desired locations of picture centre as impact point, the attitude angle set-point of target following is gone out according to error calculation;

E) by the error of aircraft desired locations and aircraft current location in unmanned aerial vehicle flight path, the attitude angle set-point followed the tracks of in course line is obtained respectively according to horizontal side direction control law and Longitudinal Control Law, according to the attitude angle set-point that attitude angle set-point and the course line of target following are followed the tracks of, obtain the total specified rate of each attitude angle, with the relevant rudder face of this servocontrol unmanned plane, the maximized Visual servoing control of stability margin in realize target locating and tracking process.

4. the Visual servoing control method in a kind of UAV Maneuver target locating according to claim 3, it is characterized in that, described earth coordinates { G}: start to carry out the target locating moment with unmanned plane, the projection of center of gravity on ground is as overall changeless geodetic coordinates origin, X-axis is parallel to warp, Y-axis is parallel to parallel, and Z axis points to the earth's core perpendicular to XOY plane;

Body axis system { B}: with unmanned plane center of gravity for initial point, be connected on unmanned plane, X-axis is parallel to design orientation of its axis head in unmanned plane symmetrical plane, and Y-axis is pointed on the right side of body perpendicular to unmanned plane symmetrical plane, and Z axis points to below fuselage perpendicular to X-axis in symmetrical plane;

Camera coordinate system C}: with video camera photocentre for initial point, X-axis and Y-axis are parallel to the vertical and horizontal straight line of image respectively, and Z axis is camera optical axis, vertical with the plane of delineation; Definition camera optical axis is with { the XOY plane angle of B} is angular altitude α, and optical axis is just on plane; Optical axis is with { the XOZ plane included angle of B} is azimuthal angle beta, and optical axis is just on the right side of plane;

Image coordinate system I}: with image upper left angle point for initial point two-dimensional coordinate system, X-axis is parallel to the longitudinal pixel line in the image leftmost side, and Y-axis is parallel to pixels across line, and coordinate figure x and y represents line number and the columns of pixel respectively;

{ GB}: with unmanned plane center of gravity for initial point, each axle of X, Y, Z is parallel to earth coordinates { G} in body the earth interim coordinate system.

5. the Visual servoing control method in a kind of UAV Maneuver target locating according to claim 4, it is characterized in that, the relation between described coordinate system comprises:

Obtain according to locating information and earth model that { B} initial point is at { the coordinate under G} ^gp _bO=( ^gx _bO, ^gy _bO, ^gz _bO) ^t, obtain in conjunction with the pitching angle theta of body, crab angle ψ, roll angle φ that { B} is in { the expression under G} { B} is in { the expression under G}

$T_B^G=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& {x_G}_{BO}\\ c\mathrm{\θ}s\mathrm{\ψ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& {y_G}_{BO}\\ -s\mathrm{\θ}& c\mathrm{\θ}s\mathrm{\ψ}& c\mathrm{\θ}c\mathrm{\φ}& {z_G}_{BO}\\ 0& 0& 0& 1\end{array}\right]---\left(1\right)$

$T_G^B=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& c\mathrm{\θ}s\mathrm{\ψ}& -s\mathrm{\θ}& -{x_G}_{BO}\\ s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& c\mathrm{\θ}s\mathrm{\φ}& -{y_G}_{BO}\\ s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& -{z_G}_{BO}\\ 0& 0& 0& 1\end{array}\right]---\left(2\right)$

Defined by coordinate system and draw, { B} is in { the expression under GB} { B} is in { the expression under GB} for:

$T_B^{GB}=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& 0\\ c\mathrm{\θ}s\mathrm{\ψ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& 0\\ -s\mathrm{\θ}& c\mathrm{\θ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& 0\\ 0& 0& 0& 1\end{array}\right]---\left(3\right)$

$T_{GB}^B=\left[\begin{array}{cccc}c\mathrm{\θ}c\mathrm{\ψ}& c\mathrm{\θ}s\mathrm{\ψ}& -s\mathrm{\θ}& 0\\ s\mathrm{\θ}c\mathrm{\ψ}s\mathrm{\φ}-c\mathrm{\ψ}c\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}s\mathrm{\φ}+c\mathrm{\ψ}c\mathrm{\φ}& c\mathrm{\θ}s\mathrm{\φ}& 0\\ s\mathrm{\θ}c\mathrm{\ψ}c\mathrm{\φ}+s\mathrm{\ψ}s\mathrm{\φ}& s\mathrm{\θ}s\mathrm{\ψ}c\mathrm{\φ}-c\mathrm{\ψ}s\mathrm{\φ}& c\mathrm{\θ}c\mathrm{\φ}& 0\\ 0& 0& 0& 1\end{array}\right]---\left(4\right)$

{ C} is relative to { pose of B} is by video camera fixed position for camera coordinate system ^bp _cO=( ^bx _cO, ^by _cO, ^bz _cO) ^t, angular altitude α and azimuthal angle beta determine, C} being expressed as under B}:

$T_C^B=\left[\begin{array}{cccc}c\mathrm{\α}c\mathrm{\β}& -s\mathrm{\β}& s\mathrm{\α}c\mathrm{\β}& {x_B}_{CO}\\ c\mathrm{\α}s\mathrm{\β}& c\mathrm{\β}& s\mathrm{\α}s\mathrm{\β}& {y_B}_{CO}\\ -s\mathrm{\α}& 0& c\mathrm{\α}& {z_B}_{CO}\\ 0& 0& 0& 1\end{array}\right]---\left(5\right)$

Image coordinate system and camera coordinate system relation are determined by camera intrinsic parameter, and camera intrinsic parameter comprises picture centre coordinate ⁱp _icent=( ⁱx _icent, ⁱy _icent, 1) ^t, focal distance f, proportionality factors lambda; From perspective projection model, at camera coordinate system, { under C}, coordinate is expressed as picture centre pixel coordinate ^cp _icent=(0,0, f) ^t, then I} being expressed as under C}:

$T_I^C=\left[\begin{array}{cccc}\mathrm{\λ}& 0& 0& -{\mathrm{\λ}}^I{x}_{Icent}\\ 0& \mathrm{\λ}& 0& -{\mathrm{\λ}}^I{y}_{Icent}\\ 0& 0& 0& f\\ 0& 0& 0& 1\end{array}\right]---\left(6\right).$

6. the Visual servoing control method in a kind of UAV Maneuver target locating according to claim 5, it is characterized in that, the optical axis of described video camera and the intersection point on ground are A, and to be i, i in the homogeneous coordinates of camera coordinate system be the vector of unit length on camera light axis ^cp _i=(0,0,1,1) ^t, according to the pose of video camera by formula (5), the body axis system { expression under B} can be obtained ^bp _i:

${P_B}_i=T_C^B\·{P_C}_i---\left(7\right)$

According to the pose of aircraft by formula (1), try to achieve the earth coordinates { expression under G} ^gp _i:

${P_G}_i=T_B^G\·{P_B}_i=T_B^G\·T_C^B\·{P_C}_i---\left(8\right)$

According to perspective imaging principle and imaging triangular relationship, calculated by aircraft altitude and obtain optical axis and ground intersection point A at the { coordinate under G} ^gp _a, then obtain according to formula (2) ^bp _a;

After unmanned plane finds target, by selected impact point t in the image coordinate system { homogeneous coordinates under I} ⁱp _t=( ⁱx _t, ⁱy _t, 1,1) ^t, draw according to formula (6) ^cp _t, then can obtain successively ^bp _t, ^gp _t:

${P_G}_t=T_B^G\·{P_B}_t=T_B^G\·T_C^B\·{P_C}_t=T_B^G\·T_C^B\·T_I^G\·{P_I}_t---\left(9\right).$

7. the Visual servoing control method in a kind of UAV Maneuver target locating according to claim 6, is characterized in that, according to formula (7) and (8), and convolution (3) and trying to achieve ^bp _a, try to achieve respectively ^gp _twith ^gBp _tr= ^gp _a, then error is Δ ^gp _t= ^gp _tr- ^gp _t, system of equations obtains attitude angle set-point θ thus _t, φ _tand ψ _t;

By aircraft desired locations in flight track with aircraft current location ^gp _bOerror roll angle set-point φ is obtained according to horizontal side direction control law _r

${\mathrm{\φ}}_r=K_{\mathrm{\φ}}({\tilde{y}_G}_{BO}-{y_G}_{BO})+K_{d\mathrm{\φ}}{\stackrel{\·}{y}_G}_{BO}---\left(10\right)$

Angle of pitch set-point θ is obtained respectively according to Longitudinal Control Law _r

${\mathrm{\θ}}_r=K_{\mathrm{\θ}}({\tilde{z}_G}_{BO}-{z_G}_{BO})---\left(11\right)$

In conjunction with task weight λ _mdistribute the attitude angle set-point of target following and course line tracking, always exported

θ＝λ _mθ _t+(1-λ _m)φ _r

φ＝λ _mφ _t+(1-λ _m)φ _r(12)

ψ＝ψ _t

The inner ring controlled in this, as flight is given, each rudder face of servocontrol unmanned plane, the Visual servoing control in realize target locating and tracking process.