Method for tracking target, device and system
Technical field
The present invention relates to unmanned vehicle technical field, relate in particular to a kind of method for tracking target, dressPut and system.
Background technology
Unmanned vehicle (also referred to as unmanned plane, unmanned vehicle etc.) is a kind of with wireless remotecontrolOr the unmanned aircraft under autonomous, half independent procedure control. Because its cost is lower, unmannedMember's injures and deaths risk, the advantage such as mobility is good, its all kinds of Aerial photographies, geological survey, line data-logging,The fields such as emergency management and rescue are widely used. Wherein, unmanned plane relies on its unique outmaneuver, widely appliesIn Aerial photography. Along with intellectualized technology development, people have proposed the intelligent function of unmanned vehicleHigher requirement, as require unmanned plane to target subject from motion tracking etc.
In general, aircraft is by vision sensor or fixed based on GPS standard to the tracking of targetRealize position. For example the scheme of patent application CN105100728A, patent CN103149939B, all makesWith vision sensor as target following sensor. The scheme of patent application CN104965522A be based onGPS standard setting realizes.
But existing video recognition system forms complicated, be blocked in short-term or target high speed in sight lineIn the situation of motion, algorithm meeting lose objects, has certain limitation. Adopt vision sensor as targetTracking transducer, its track algorithm is tediously long, is unfavorable for the unmanned aerial vehicle onboard system integration. Locate based on GPSTarget Tracking System location and tracking accuracy not high, be difficult to realize the shadow of target subject in capture apparatusRing steady lock.
Summary of the invention
Technical problem
In view of this, the technical problem to be solved in the present invention is, provide a kind of new method for tracking target,Equipment and system, can improve location and the tracking accuracy of unmanned plane in shooting process.
Solution
In order to solve the problems of the technologies described above, the invention provides a kind of method for tracking target, comprising:
Set up reference frame according to the positional information of target subject and aircraft, obtain described with reference to sittingPrimary importance vector from described target subject to described aircraft under mark system;
According to the current attitude information of described aircraft, calculate under described reference frame from described flightThe aerial position of device is to the direction vector of The Cloud Terrace position;
According to direction vector described in described primary importance vector, calculate under described reference frame from instituteState the second place vector of target subject to described The Cloud Terrace position, and described second place vector is converted toThe targeted attitude information of described aircraft;
According to the current attitude information of described aircraft and targeted attitude information, obtain target control amount, instituteState target control amount and be used to indicate the adjustment amount to The Cloud Terrace motion control.
For said method, in a kind of possible implementation, according to the position of target subject and aircraftThe information of putting is set up reference frame, obtains flying to described from described target subject under described reference frameThe primary importance vector of row device, comprising:
Obtain the position of described target subject under geographic coordinate system from the GNSS beacon of described target subjectInformation;
Obtain described aircraft under geographic coordinate system from the GNSS receiver of described aircraft and antennaPositional information;
According to described target subject and described aircraft, the positional information under described geographic coordinate system is set upDescribed reference frame, obtains described primary importance vector.
For said method, in a kind of possible implementation, according to described target subject and described in flyThe positional information of row device under described geographic coordinate system set up described reference frame, obtains described firstPut vector, comprising:
Positional information P according to described target subject under described geographic coordinate systemt(lont,latt,heit),With the positional information P under geographic coordinate system described in described aircraftu(lonu,latu,heiu), adopt following formula 1Set up described reference frame with formula 2, obtain described primary importance vector A1(x1,y1,z1),
x1=(lonu-lont)*cos(latt) * lon0 formula 1,
y1=(latu-latt) * lat0 formula 2,
z1=heiu-heitFormula 3,
Wherein, lon0=2* π * a/360, lat0=(2* π * c+4* (a-c))/360, π is pi, a is groundBall major axis radius, c is earth minor axis radius, lon represents that longitude, lat represent that dimension, hei represent height,T represents described target subject, and u represents described aircraft, and cos () represents cosine function, x1、y1、z1TableShow the coordinate figure under described reference frame.
For said method, in a kind of possible implementation, according to the current attitude of described aircraftInformation, calculates the direction from the aerial position of described aircraft to The Cloud Terrace position under described reference frameVector, comprising:
Obtain the current attitude information of described aircraft from attitude transducer;
According to the current attitude information of described aircraft, calculate under described reference frame from described flightThe antenna phase center of device is to the centrostaltic direction vector of The Cloud Terrace.
For said method, in a kind of possible implementation, according to the current attitude of described aircraftInformation, calculates under described reference frame from the antenna phase center of described aircraft to The Cloud Terrace motionThe direction vector of the heart, comprising:
According to the current attitude information Atti of described aircraftu(Pitchu,Rollu,Yawu),, adopt following formula 3To formula 5, calculate the antenna phase center from described aircraft under described reference frame and move to The Cloud TerraceThe direction vector dA ' at center (dx ', dy ', dz '),
dx’=dx(cos(Rollu)cos(Yawu)-sin(Pitchu)sin(Rollu)sin(Yawu))-dy(cos(Pitchu)sin(Yawu))+dz(sin(Rollu)cos(Yawu)+sin(Pitchu)cos(Rollu)sin(Yawu)) formula 3,
dy’=dx(cos(Rollu)sin(Yawu)-sin(Pitchu)sin(Rollu)cos(Yawu))-dy(cos(Pitchu)cos( Yawu))+dz(sin(Rollu)sin(Yawu)+sin(Pitchu)cos(Rollu)cos(Yawu)) formula 4,
dz’=dx(-cos(Pitchu)sin(Rollu))-dy(sin(Pitchu)+dz(cos(Pitchu)cos(Rollu)) formula 5,
Wherein, PitchuRepresent the current angle of pitch of aircraft u, RolluRepresent the current rolling of aircraft uAngle, YawuThe current yaw angle that represents aircraft u, sin () represents SIN function;
DA (dx, dy, dz) represents that antenna phase center flies described to the centrostaltic direction vector of The Cloud TerraceCoordinate figure under the body axis system of row device.
For said method, in a kind of possible implementation, according to described primary importance vector instituteState direction vector, calculate under described reference frame from described target subject to described The Cloud Terrace position theTwo position vectors, and described second place vector is converted to the targeted attitude information of described aircraft, bagDraw together:
According to described primary importance vector A1(x1,y1,heiu-heit) and described direction vectorDA ' (dx ', dy ', dz '), calculate from described target subject to the centrostaltic second place vector of The Cloud Terrace A2=(x2,y2,z2)=(A1+dA’);
Adopt following formula 6, by described second place vector be converted to described aircraft under body axis systemTargeted attitude information Attic(Pitchc,Rollc,Yawc):
Attic(Pitchc,Rollc,Yawc)=(arcsin(x2/|A2|),arcsin(y2/|A2|),arcsin(z2/|A2|)) formula 6,
Wherein, arcsin () is arcsin function.
For said method, in a kind of possible implementation, according to the current attitude of described aircraftInformation and targeted attitude information, obtain target control amount, comprising:
According to the current attitude information Atti of described aircraftu(Pitchu,Rollu,Yawu) and targeted attitudeInformation, employing following formula 7 obtains the target control amount Output of three axle The Cloud Terraces,
Output=(Pitchc-Pitchu,Rollc-Rollu,Yawc-Yawu) formula 7.
The present invention also provides a kind of target tracker, comprising:
Primary importance vector module, for setting up with reference to sitting according to the positional information of target subject and aircraftMark system, obtains the primary importance from described target subject to described aircraft under described reference frame and vowsAmount;
Direction vector module, for according to the current attitude information of described aircraft, calculates in described referenceDirection vector from the aerial position of described aircraft to The Cloud Terrace position under coordinate system;
Second place vector module, for according to direction vector described in described primary importance vector, in instituteState the second place vector of calculating from described target subject to described The Cloud Terrace position under reference frame, and willDescribed second place vector is converted to the targeted attitude information of described aircraft;
Controlled quentity controlled variable module, for according to the current attitude information of described aircraft and targeted attitude information, obtainsTo target control amount, described target control amount is used to indicate the adjustment amount to The Cloud Terrace motion control.
For said apparatus, in a kind of possible implementation, described primary importance vector module is also usedIn obtain the position letter of described target subject under geographic coordinate system from the GNSS beacon of described target subjectBreath; Obtain described aircraft under geographic coordinate system from the GNSS receiver of described aircraft and antennaPositional information; The positional information under described geographic coordinate system according to described target subject and described aircraftSet up described reference frame, obtain described primary importance vector.
For said apparatus, in a kind of possible implementation, described primary importance vector module is also usedIn the positional information P under described geographic coordinate system according to described target subjectt(lont,latt,heit), andPositional information P described in described aircraft under geographic coordinate systemu(lonu,latu,heiu), adopt following formula 1 HeFormula 2 is set up described reference frame, obtains described primary importance vector A1(x1,y1,heiu-heit),
x1=(lonu-lont)*cos(latt) * lon0 formula 1,
y1=(latu-latt) * lat0 formula 2,
z1=heiu-heitFormula 3,
Wherein, lon0=2* π * a/360, lat0=(2* π * c+4* (a-c))/360, π is pi, a is groundBall major axis radius, c is earth minor axis radius, lon represents that longitude, lat represent that dimension, hei represent height,T represents described target subject, and u represents described aircraft, and cos () represents cosine function, x1、y1、z1TableShow the coordinate figure under described reference frame.
For said apparatus, in a kind of possible implementation, described direction vector module also for fromAttitude transducer obtains the current attitude information of described aircraft; According to the current attitude letter of described aircraftBreath, calculates under described reference frame from the antenna phase center of described aircraft to the The Cloud Terrace centre of motionDirection vector.
For said apparatus, in a kind of possible implementation, described direction vector module is also for rootAccording to the current attitude information Atti of described aircraftu(Pitchu,Rollu,Yawu),, adopt following formula 3 to formula 5,Calculating antenna phase center from described aircraft under described reference frame is centrostaltic to The Cloud TerraceDirection vector dA ' (dx ', dy ', dz '),
dx’=dx(cos(Rollu)cos(Yawu)-sin(Pitchu)sin(Rollu)sin(Yawu))-dy(cos(Pitchu)sin(Yawu))+dz(sin(Rollu)cos(Yawu)+sin(Pitchu)cos(Rollu)sin(Yawu)) formula 3,
dy’=dx(cos(Rollu)sin(Yawu)-sin(Pitchu)sin(Rollu)cos(Yawu))-dy(cos(Pitchu)cos(Yawu))+dz(sin(Rollu)sin(Yawu)+sin(Pitchu)cos(Rollu)cos(Yawu)) formula 4,
dz’=dx(-cos(Pitchu)sin(Rollu))-dy(sin(Pitchu)+dz(cos(Pitchu)cos(Rollu)) formula 5,
Wherein, PitchuRepresent the current angle of pitch of aircraft u, RolluRepresent the current rolling of aircraft uAngle, YawuThe current yaw angle that represents aircraft u, sin () represents SIN function;
DA (dx, dy, dz) represents that antenna phase center flies described to the centrostaltic direction vector of The Cloud TerraceCoordinate figure under the body axis system of row device.
For said apparatus, in a kind of possible implementation, described second place vector module is also usedAccording to described primary importance vector A1(x1,y1,heiu-heit) and described direction vectorDA ' (dx ', dy ', dz '), calculate from described target subject to the centrostaltic second place vector of The Cloud Terrace A2=(x2,y2,z2)=(A1+ dA '); Adopt following formula 6, described second place vector is converted to described aircraftThe targeted attitude information Atti under body axis systemc(Pitchc,Rollc,Yawc):
Attic(Pitchc,Rollc,Yawc)=(arcsin(x2/|A2|),arcsin(y2/|A2|),arcsin(z2/|A2|)) formula 6,
Wherein, arcsin () is arcsin function.
For said apparatus, in a kind of possible implementation, described controlled quentity controlled variable module is also for basisThe current attitude information Atti of described aircraftu(Pitchu,Rollu,Yawu) and targeted attitude information, adoptFollowing formula 7 obtains the target control amount Output of three axle The Cloud Terraces,
Output=(Pitchc-Pitchu,Rollc-Rollu,Yawc-Yawu) formula 7.
The present invention also provides a kind of Target Tracking System of unmanned vehicle, comprises and is arranged at described nothingThe cradle head controllor of people's beam riding device and the positioner that is arranged at target subject, wherein, described The Cloud TerraceController, the target tracker of any one structure in the employing embodiment of the present invention.
For said system, in a kind of possible implementation, the positioner of described target subject isGNSS beacon, described GNSS beacon is for obtaining the positional information of described target subject;
Described Target Tracking System also comprises:
Airborne GNSS receiver and antenna, by nolo flight described in reception GNSS signal acquisitionThe positional information of device;
Attitude transducer, for detection of the attitude information of described unmanned vehicle;
The Cloud Terrace and capture apparatus, described The Cloud Terrace is for controlling the bat that is installed on the capture apparatus on described The Cloud TerraceTake the photograph attitude;
Described cradle head controllor and described GNSS receiver and antenna, described GNSS beacon and described attitudeSensor communicates, for from unmanned vehicle described in described GNSS receiver and antenna receptionPositional information, receives the positional information of described target subject, from attitude transducer from described GNSS beaconReceive the attitude information of described unmanned vehicle;
Described cradle head controllor is also connected with described The Cloud Terrace, for sending target control amount to described The Cloud Terrace,To control the shooting attitude of the described capture apparatus on described The Cloud Terrace.
Beneficial effect
The present invention is according to obtained positional information calculation space points relationship, simultaneously in conjunction with unmanned planeThe attitude of flight vehicle that airborne sensor obtains, determine the The Cloud Terrace output of capture apparatus, realizes target subjectFollow the tracks of, owing to having considered the impact of fuselage height on track algorithm, tracking accuracy is high, can realize whole dayWait autonomous tracking.
In addition, the present embodiment utilizes high-precision GNSS positioning result to obtain the essence of target subject and unmanned planeTrue positional information, can ensure further to improve the accuracy of calculating.
According to below with reference to accompanying drawing to detailed description of illustrative embodiments, further feature of the present invention and sideIt is clear that face will become.
Brief description of the drawings
The accompanying drawing being included in description and form a part for description shows together with descriptionExemplary embodiment of the present invention, feature and aspect, and for explaining principle of the present invention.
Fig. 1 illustrates the structure of the Target Tracking System of unmanned vehicle according to an embodiment of the inventionSchematic diagram;
Fig. 2 a illustrates the schematic flow sheet of method for tracking target according to an embodiment of the invention;
Fig. 2 b illustrates the principle schematic of method for tracking target according to an embodiment of the invention
Fig. 3 illustrates the schematic flow sheet of method for tracking target according to another embodiment of the present invention;
Fig. 4 illustrates the structural representation of target tracker according to an embodiment of the invention.
Detailed description of the invention
Describe various exemplary embodiments of the present invention, feature and aspect in detail below with reference to accompanying drawing. AttachedThe identical same or analogous element of Reference numeral presentation function in figure. Although enforcement shown in the drawingsThe various aspects of example, but unless otherwise indicated, needn't draw in proportion accompanying drawing.
Here special word " exemplary " means " as example, embodiment or illustrative ". Here conduct" exemplary " illustrated any embodiment needn't be interpreted as being better than or being better than other embodiment.
In addition, for better explanation the present invention, in detailed description of the invention below, provided numerousDetail. It will be appreciated by those skilled in the art that and there is no some detail, the present invention equally canImplement. In some instances, method, means, element and the circuit known for those skilled in the artBe not described in detail, so that highlight purport of the present invention.
Embodiment 1
In order to improve positioning precision, in Target Tracking System, can adopt GNSS (GlobalNavigationSatelliteSystem, global location navigational satellite system) technology obtains positional information. ExcellentSelection of land, can adopt PPP (PrecisePointPositioning, single-point precision positioning) technology, obtainsPositional information can reach decimeter grade, or even the high accuracy of Centimeter Level. The present invention is based on GNSS skillArt is conducive to realize precision positioning.
Fig. 1 illustrates the structure of the Target Tracking System of unmanned vehicle according to an embodiment of the inventionSchematic diagram. As shown in Figure 1, the Target Tracking System of this unmanned vehicle mainly comprises: be arranged atThe cradle head controllor 114 of unmanned vehicle 11 (abbreviation unmanned plane) and be arranged at target subject 13Positioner. The concrete function of cradle head controllor 114 can referring in embodiment 2,3 about target followingThe associated description of method. Wherein, cradle head controllor 114 can be independent of the controller setting of unmanned plane,The function that also can realize by the controller of unmanned plane cradle head controllor, the present invention does not limit thisFixed.
Particularly, the unmanned plane target tracking system of the present embodiment, comprising: GNSS beacon 131, logicalLetter equipment 133,113, airborne GNSS receiver and antenna 111, The Cloud Terrace 112, cradle head controllor 114,Attitude transducer 115, capture apparatus 116.
Wherein, GNSS beacon 131 is equipped in target subject 13, can utilize GNSS to obtain order being shotTarget exact position. Airborne GNSS receiver and antenna 111, The Cloud Terrace 112, cradle head controllor 114, appearanceState sensor 115, capture apparatus 116, arrange on the target tracker 11 based on unmanned plane. GNSSBeacon 131 communicates by communication equipment 133 and the communication equipment 113 of target tracker 11, thereby toCradle head controllor 114 provides the real-time precise position information of target subject 13. Communication equipment 113, communication are establishedStandby 133 can think a kind of two ends of communication equipment, for realizing GNSS beacon 131 and cradle head controlThe communication of device 114, aerial by for example 433MHz radio signal realization communication. Particularly, arrangeEach component function in unmanned plane is as follows:
Airborne GNSS receiver and antenna 111 are connected with cradle head controllor 114, by receiving GNSS signalObtain the exact position of unmanned plane, the space that this exact position can actual corresponding reception antenna phase centerPosition.
The Cloud Terrace 112 is preferably by the motor of some frees degree or steering wheel and forms, and can control to be installed onCapture apparatus carries out multivariant swing.
Cradle head controllor 114 is preferably by microcontroller and peripheral circuit thereof, horizontal stage electric machine drive circuit structureBecome, receive the information that transmits of each several part and carry out controlling The Cloud Terrace after computing and swing.
Attitude transducer 115 is preferably by MEMS sensor and forms, for cradle head controllor 114 provides unmannedPitch (angle of pitch), the Roll (roll angle) of machine, the attitude information of three directions of Yaw (yaw angle).
Capture apparatus 116 is preferably by camera or video camera and forms. Attitude transducer 115 and cradle head controllor114 be connected, for detection of and provide unmanned plane current attitude information. For example camera of capture apparatus 116 is solidOn The Cloud Terrace 112, thereby cradle head controllor 114 is controlled the bat of the swing control capture apparatus of The Cloud Terrace 112Take the photograph attitude, realize the tracking to target subject.
Embodiment 2
Fig. 2 a illustrates the schematic flow sheet of method for tracking target according to an embodiment of the invention. As Fig. 2 a instituteShow, this method for tracking target specifically can comprise the following steps:
Step 201, set up reference frame according to the positional information of target subject and aircraft, obtainPrimary importance vector from described target subject to described aircraft under described reference frame;
Step 202, according to the current attitude information of described aircraft, calculate under described reference frameDirection vector from the aerial position of described aircraft to The Cloud Terrace position;
Step 203, according to direction vector described in described primary importance vector, calculate described with reference to sitSecond place vector from described target subject to described The Cloud Terrace position under mark system, and by the described second placeVector is converted to the targeted attitude information of described aircraft;
Step 204, according to the current attitude information of described aircraft and targeted attitude information, obtain targetControlled quentity controlled variable, described target control amount is used to indicate the adjustment amount to The Cloud Terrace motion control.
Particularly, as shown in Figure 2 b, airborne GNSS receiver is set above the body of unmanned plane 41And antenna 43, The Cloud Terrace 45 and capture apparatus (not shown) are set below the body of unmanned plane 41,Capture apparatus is loaded on The Cloud Terrace 45 conventionally. From target subject 47 to antenna phase center (for example antennaGeometric center) primary importance vector be A1, from antenna phase center for example, to the The Cloud Terrace centre of motion (cloudThe pivot of platform) direction vector be dA ', from target subject 47 to the centrostaltic second of The Cloud TerracePutting vector is A2. Proofread and correct by described direction vector the second place vector that primary importance vector draws,For the vector representation of the actual The Cloud Terrace centre of motion and target subject, can eliminate GNSS antenna and The Cloud Terrace fortuneIn esse position difference is being installed at moving center.
In a kind of possible implementation, step 201 can comprise:
Step 2011, obtain described target subject at geographical coordinate from the GNSS beacon of described target subjectPositional information under system;
Step 2012, obtain described aircraft at geography from GNSS receiver and the antenna of described aircraftPositional information under coordinate system;
Step 2013, according to described target subject and described aircraft the position under described geographic coordinate systemInformation is set up reference frame, obtains at described primary importance vector.
In a kind of possible implementation, step 2013 can comprise:, exist according to described target subjectPositional information P under described geographic coordinate systemt(lont,latt,heit), and geographical seat described in described aircraftPositional information P under mark systemu(lonu,latu,heiu), adopt following formula 1 and formula 2 to set up reference frame,For example cartesian coordinate system, obtains under described reference frame from described target subject to described aircraftPrimary importance vector A1(x1,y1,heiu-heit),
x1=(lonu-lont)*cos(latt) * lon0 formula 1,
y1=(latu-latt) * lat0 formula 2,
z1=heiu-heitFormula 3,
Wherein, lon0=2* π * a/360, lat0=(2* π * c+4* (a-c))/360, π is pi, a is groundBall major axis radius, c is earth minor axis radius, lon represents that longitude, lat represent that dimension, hei represent height,T represents described target subject, and u represents described aircraft, and cos () represents cosine function, x1、y1、z1TableShow the coordinate figure under reference frame.
In a kind of possible implementation, step 202 can comprise:
Step 2021, obtain the current attitude information of described aircraft from attitude transducer;
Step 2022, according to the current attitude information of described aircraft, calculate under described reference frameFrom the antenna phase center of described aircraft to the centrostaltic direction vector of The Cloud Terrace.
In a kind of possible implementation, step 2022 can comprise: current according to described aircraftAttitude information Attiu(Pitchu,Rollu,Yawu),, adopt following formula 3 to formula 5, calculate described with reference to sittingMark under system from the antenna phase center of described aircraft to the centrostaltic direction vector of The Cloud TerracedA’(dx’,dy’,dz’),
dx’=dx(cos(Rollu)cos(Yawu)-sin(Pitchu)sin(Rollu)sin(Yawu))-dy(cos(Pitchu)sin(Yawu))+dz(sin(Rollu)cos(Yawu)+sin(Pitchu)cos(Rollu)sin(Yawu)) formula 3,
dy’=dx(cos(Rollu)sin(Yawu)-sin(Pitchu)sin(Rollu)cos(Yawu))-dy(cos(Pitchu)cos(Yawu))+dz(sin(Rollu)sin(Yawu)+sin(Pitchu)cos(Rollu)cos(Yawu)) formula 4,
dz’=dx(-cos(Pitchu)sin(Rollu))-dy(sin(Pitchu)+dz(cos(Pitchu)cos(Rollu)) formula 5,
Wherein, PitchuRepresent the current angle of pitch of aircraft u, RolluRepresent the current rolling of aircraft uAngle, YawuThe current yaw angle that represents aircraft u, sin () represents SIN function; DA (dx, dy, dz) representsAntenna phase center is sat under the body axis system of described aircraft to the centrostaltic direction vector of The Cloud TerraceScale value.
In a kind of possible implementation, step 203 can comprise:
Step 2031, according to described primary importance vector A1(x1,y1,heiu-heit) and described direction vectorDA ' (dx ', dy ', dz '), calculate from described target subject to the centrostaltic second place vector of The Cloud Terrace A2=(x2,y2,z2)=(A1+dA’);
Step 2032, adopt following formula 6, by described second place vector be converted to described aircraft at machineTargeted attitude information Atti under body coordinate systemc(Pitchc,Rollc,Yawc):
Attic(Pitchc,Rollc,Yawc)=(arcsin(x2/|A2|),arcsin(y2/|A2|),arcsin(z2/|A2|)) formula 6.
Wherein, arcsin () is arcsin function.
In a kind of possible implementation, step 204 can comprise: current according to described aircraftAttitude information Attiu(Pitchu,Rollu,Yawu) and targeted attitude information, adopt following formula 7 to obtain three axle cloudsThe target control amount Output of platform,
Output=(Pitchc-Pitchu,Rollc-Rollu,Yawc-Yawu) formula 7.
The method for tracking target of the present embodiment points to and closes according to obtained positional information calculation spaceSystem, the attitude of flight vehicle simultaneously obtaining in conjunction with unmanned aerial vehicle onboard sensor, determines the output of camera The Cloud Terrace,Realize the tracking of target subject, owing to having considered the impact of fuselage height on track algorithm, tracking accuracy is high,Can realize round-the-clock autonomous tracking.
In addition, the present embodiment utilizes high-precision GNSS positioning result to obtain the essence of target subject and unmanned planeTrue positional information, obtains the accurate relative position of target and camera optical axis by succinct computational methodsRelation, and carry out close coupling with the sensor information of unmanned plane, realize the control to camera pan-tilt, energyEnough accuracy that ensures further to improve calculating, realize the tracking to target.
Embodiment 3
Fig. 3 illustrates the schematic flow sheet of method for tracking target according to another embodiment of the present invention. As Fig. 3 instituteShow, when the present embodiment, describe as an example of GNSS technology realization shooting tracking example, in the present embodimentThe formula identical with enforcement 2 has identical implication, do not repeat them here. This method for tracking target is concreteCan comprise the following steps:
Step 301:GNSS beacon receives GNSS signal and carries out precision positioning, acquisition target subjectPosition Pt(lont,latt,heit) (lat conventionallyt,lontUnit is degree, heitUnit is rice).
Step 302: communication equipment is encoded the position of target subject and to be modulated to 433MHz wirelessOn the signal of telecommunication, launch;
Step 303: the position P of the target subject that cradle head controllor received communication equipment transmitst, obtain simultaneouslyObtain the unmanned plane position P that airborne GNSS receiver and antenna transmitu(lonu,latu,heiu),Pt、PuForCoordinate figure under geographic coordinate system. Then, with PtFor round dot, set up right-handed scale (R.H.scale) taking positive east orientation as x axleSystem's (now can suppose that target subject and unmanned plane moving region are plane instead of ellipsoid), this seatMark system also can be called local cartesian coordinate system.
Referring to above-mentioned formula 1 and formula 2, a=6378137.0 under WGS-84 coordinate system, c=6356752.3,Calculate gained lat0=111183.865, lon0=111319.491, thus vow the position that can obtain unmanned planeAmount is A1(x1,y1,heiu-heit), wherein:
x1=(lonu-lont)*cos(latt) * 111319.491 formula 1-1,
y1=(latu-latt) * 111183.865 formula 2-1,
Parameter in above formula also can adopt with other standards like WGS-84 standard class for example Xi'an 54,Beijing 84, CGCS2000 etc., the numerical value possibility that adopts various criterion to calculate is slightly different, the present inventionDo not limit concrete calculating standard.
Step 304: cradle head controllor obtains the attitude of flight vehicle Atti that attitude transducer recordsu(Pitchu,Rollu,Yawu), can be transported to The Cloud Terrace by antenna phase center in airborne GNSS receiver and Anneta moduleThe expression of the direction vector at moving center under aircraft coordinate system: dA (dx, dy, dz) (installs on by aircraftDetermining positions), in the coordinate system that this direction vector is set up in step 303, can be expressed as:DA ' (dx ', dy ', dz '), wherein the computational methods of dA ' (dx ', dy ', dz ') can be referring to the formula of embodiment 23.
Step 305: by step 303 gained A1DA ' can calculate target subject with step 304 gainedTo The Cloud Terrace centre of motion direction vector, The Cloud Terrace centre of motion position vector is A2=(x2,y2,z2)=(A1+ dA '), further can calculate this direction vector represented under body axis systemTargeted attitude information Attic(Pitchc,Rollc,Yawc)=(arcsin(x2/|A2|),arcsin(y2/|A2|),arcsin(z2/|A2|))。
Step 306: according to step 305 gained AtticWith Atti in step 304uCan draw three axle The Cloud TerracesTarget control amount Output=(Pitchc-Pitchu,Rollc-Rollu,Yawc-Yawu)。
By cradle head controllor, this target control amount is outputed to horizontal stage electric machine by for example second order control loop,Realize the tracking to target.
The method for tracking target of the present embodiment, can utilize high-precision GNSS location technology, for example PPPTechnology is obtained the exact position of target subject and unmanned plane, then calculates space points relationship, simultaneously knotClose the attitude of flight vehicle that unmanned aerial vehicle onboard sensor obtains, determine the output of camera The Cloud Terrace, realize order being shotTarget is followed the tracks of, and has tracking accuracy high, can realize round-the-clock autonomous tracking. Follow compared to existing visionTrack technology has the features such as simple, real-time is high, applied environment is wide of calculating; Compared to having based on GPSThe method for tracking target of location, have tracking accuracy high, follow the tracks of stable feature.
Embodiment 4
Fig. 4 illustrates the structural representation of target tracker according to an embodiment of the invention. As Fig. 4 instituteShow, this target tracker can, comprising:
Primary importance vector module 51, for setting up reference according to the positional information of target subject and aircraftCoordinate system, obtains the primary importance from described target subject to described aircraft under described reference frameVector;
Direction vector module 53, for according to the current attitude information of described aircraft, calculates in described ginsengExamine under coordinate system the direction vector from the aerial position of described aircraft to The Cloud Terrace position;
Second place vector module 55, for according to direction vector described in described primary importance vector,Under described reference frame, calculate the second place vector from described target subject to described The Cloud Terrace position, andDescribed second place vector is converted to the targeted attitude information of described aircraft;
Controlled quentity controlled variable module 57, for according to the current attitude information of described aircraft and targeted attitude information,Obtain target control amount, described target control amount is used to indicate the adjustment amount to The Cloud Terrace motion control.
In a kind of possible implementation, described primary importance vector module 51 is also for from described being shotThe GNSS beacon of target obtains the positional information of described target subject under geographic coordinate system; Fly from describedThe GNSS receiver of row device and antenna obtain the positional information of described aircraft under geographic coordinate system; RootAccording to described target subject and described aircraft, the positional information under described geographic coordinate system is set up described ginsengExamine coordinate system, obtain described primary importance vector.
In a kind of possible implementation, described primary importance vector module 51 is also for according to described quiltTake the photograph the positional information P of target under described geographic coordinate systemt(lont,latt,heit), and described aircraft instituteState the positional information P under geographic coordinate systemu(lonu,latu,heiu), adopt described in following formula 1 and formula 2 foundationReference frame, obtains described primary importance vector A1(x1,y1,heiu-heit),
x1=(lonu-lont)*cos(latt) * lon0 formula 1,
y1=(latu-latt) * lat0 formula 2,
z1=heiu-heitFormula 3,
Wherein, lon0=2* π * a/360, lat0=(2* π * c+4* (a-c))/360, π is pi, a is groundBall major axis radius, c is earth minor axis radius, lon represents that longitude, lat represent that dimension, hei represent height,T represents described target subject, and u represents described aircraft, and cos () represents cosine function, x1、y1、z1TableShow the coordinate figure under described reference frame. Concrete example under WGS-84 coordinate system can referring onState formula 1-1 and formula 2-1. Certainly, can adopt other standards to calculate, the present invention does not limit tool yetBody calculates standard.
In a kind of possible implementation, described direction vector module 53 is also for obtaining from attitude transducerObtain the current attitude information of described aircraft; According to the current attitude information of described aircraft, calculate in instituteState under reference frame from the antenna phase center of described aircraft to the centrostaltic direction vector of The Cloud Terrace.
In direction vector module 53 described in a kind of possible implementation also for according to described aircraftCurrent attitude information Attiu(Pitchu,Rollu,Yawu),, adopt following formula 3 to formula 5, calculate describedUnder reference frame from the antenna phase center of described aircraft to the centrostaltic direction vector of The Cloud TerracedA’(dx’,dy’,dz’),
dx’=dx(cos(Rollu)cos(Yawu)-sin(Pitchu)sin(Rollu)sin(Yawu))-dy(cos(Pitchu)sin(Yawu))+dz(sin(Rollu)cos(Yawu)+sin(Pitchu)cos(Rollu)sin(Yawu)) formula 3,
dy’=dx(cos(Rollu)sin(Yawu)-sin(Pitchu)sin(Rollu)cos(Yawu))-dy(cos(Pitchu)cos(Yawu))+dz(sin(Rollu)sin(Yawu)+sin(Pitchu)cos(Rollu)cos(Yawu)) formula 4,
dz’=dx(-cos(Pitchu)sin(Rollu))-dy(sin(Pitchu)+dz(cos(Pitchu)cos(Rollu)) formula 5,
Wherein, PitchuRepresent the current angle of pitch of aircraft u, RolluRepresent the current rolling of aircraft uAngle, YawuThe current yaw angle that represents aircraft u, sin () represents SIN function;
DA (dx, dy, dz) represents that antenna phase center flies described to the centrostaltic direction vector of The Cloud TerraceCoordinate figure under the body axis system of row device.
In a kind of possible implementation, described second place vector module 55 is also for according to describedOne position vector A1(x1,y1,heiu-heit) and described direction vector dA ' (dx ', dy ', dz '), calculate from instituteState target subject to the centrostaltic second place vector of The Cloud Terrace A2=(x2,y2,z2)=(A1+ dA '); AdoptFollowing formula 6, is converted to the described second place vector target appearance under body axis system of described aircraftState information Attic(Pitchc,Rollc,Yawc):
Attic(Pitchc,Rollc,Yawc)=(arcsin(x2/|A2|),arcsin(y2/|A2|),arcsin(z2/|A2|)) formula 6.
In a kind of possible implementation, described controlled quentity controlled variable module 57 is also for according to described aircraftCurrent attitude information Attiu(Pitchu,Rollu,Yawu) and targeted attitude information, adopt following formula 7 to obtain threeThe target control amount Output of axle The Cloud Terrace,
Output=(Pitchc-Pitchu,Rollc-Rollu,Yawc-Yawu) formula 7.
Each module of the target tracker of the present embodiment can be come by the cradle head controllor of unmanned plane realExisting, according to obtained positional information calculation space points relationship, pass in conjunction with unmanned aerial vehicle onboard simultaneouslyThe attitude of flight vehicle that sensor obtains, determines the output of camera The Cloud Terrace, realizes the tracking of target subject, due toConsidered the impact of fuselage height on track algorithm, tracking accuracy is high, can realize round-the-clock autonomous tracking.
Utilize high-precision GNSS positioning result to obtain the accurate positional information of target subject and unmanned plane,Can ensure further to improve the accuracy of calculating.
The above be only the specific embodiment of the present invention, but protection scope of the present invention is not limited toIn this, any be familiar with those skilled in the art the present invention disclose technical scope in, can be easilyExpect changing or replacing, within all should being encompassed in protection scope of the present invention. Therefore, protection of the present inventionScope should be as the criterion with the protection domain of described claim.