CN106410410A - Satellite capturing and tracking method for VSAT (Very Small Aperture Terminal) antenna system with physical level platform - Google Patents

Abstract

The invention proposes a satellite capturing and tracking method for a VSAT (Very Small Aperture Terminal) antenna system with a physical level platform. The method is applicable to a control object such as an antenna system in a direction, pitching and rolling three-axis (A-E-C) pedestal form. The physical level platform is built in the antenna system, a local geographic coordinate system is also built on the physical level platform, thus, the theoretical direction and the pitching angle of an antenna points relative to a fixed local geographic coordinate system are consistent with the direction and the pitching angle of the antenna points relative to a mobile local geographic coordinate system on the physical level platform; and an electric shaft of the antenna is controlled to accurately point a satellite by a mode similar to a fixed antenna on the basis, and the satellite is automatically tracked when a carrier moves. According to the method provided by the invention, heading attitude participation operation is not needed to perform by the carrier in real time during the capturing and tracking process, thus, a shipborne compass system is not needed to install on the carrier, the environment condition requirement of the carrier is reduced, and the method is beneficial for promotion and application in a small-tonnage civil ship or a water carrier with limited equipment budge and equipment resource.

Description

A kind of VSAT antenna system acquiring satellite tracking with physics levelling bench

Technical field

The present invention relates to satellite mobile tracking communication technical field.It is particularly well-suited to the mobile vehicle satellite communication such as boat-carrying A kind of VSAT antenna acquiring satellite and tracking.

Background technology

VSAT is the abbreviation of " Very Small Aperture Terminal ", mean " very small aperture antenna earth station ". And moving VSAT system is exactly that we are usually said " communication in moving " system.Its function is load all kinds of in automobile, naval vessel, aircraft etc. Pass through the communications platforms such as mobile VSAT system real-time tracking Syncom satellite in body motor process, continual for carrier The plurality of communication services such as data, voice and video are provided.Mobile VSAT system provides the Internet to connect as all kinds of motion carriers The end product entering, wide market.At present in the existing more successful application of military and special trade.But due to existing product Product price and communication cost are more high, the problem that civil area yet suffers from being difficult to promote.

The electric axis of fixing VSAT antenna system is pointed to and is controlled in the local geographic coordinate system being to be located based on antenna around orientation The angle of axle and pitch axis is carried out.As long as obtaining the satellite rail of the warp, latitude data and required capture of antenna position Track data, you can accurately calculate azimuth, the angle of pitch and the polarizing angle of electrical boresight of antenna sensing by ripe formula.By watching Take control unit to control orientation, pitching and polarizing angle that antenna points to the point of theory calculating respectively, you can realize defending The capturing and accurately being followed the tracks of of star.But for mobile VSAT system, because the motion of carrier leads to the motion benchmark of antenna Occur to deviate so that above-mentioned tracking mode lost efficacy with local geographic coordinate system.

For solving the above problems, existing mobile VSAT system, typically by the kinematic parameter obtaining carrier, carries out coordinate Conversion, is converted to carrier coordinate system with respect to the azimuth pitch angle of local geographic coordinate system when antenna is pointed to satellite, thus Control antenna accurately to point to satellite, and sensing satellite is remained at the volley by scan tracing or single-pulse track mode. This kind of method needs inertial navigation system or miscellaneous equipment to provide the accurate motion state of carrier.And the scan tracing in tracking technique is Obtain the error in pointing of antenna by the additional scanning action on two-dimensional space, therefore gain has loss and algorithm more Complicated.The tracking accuracy of single-pulse track mode and speed are all higher, but Monopulse feed complex structure, expensive.

Content of the invention

For solving the problems, such as prior art, the present invention proposes a kind of VSAT aerial system with physics levelling bench System acquiring satellite tracking, the control object that the method is suitable for is orientation, pitching, roll three axle (A-E-C) mounting form sky Linear system is united.By setting up a physics levelling bench in antenna system, and local geographic coordinate system is set up thereon, thus Antenna is made to point to respect to the theoretical orientation fixing locality geographic coordinate system, the angle of pitch and the shifting on this physics levelling bench relative The orientation of dynamic locality geographic coordinate system, the angle of pitch are consistent.On this basis in the way of similar with fixed antenna, control antenna electric Axle accurately points to satellite, and the automatic tracking satellite when carrier is mobile.

The technical scheme is that：

A kind of described VSAT antenna system acquiring satellite tracking with physics levelling bench it is characterised in that：Bag Include following steps：

Step 1：To in VSAT antenna system electricity and initialize；

Step 2：The physical platform controlling VSAT antenna system keeps level：Platform stance is had on described physical platform survey Amount unit and servo control unit, servo control unit is with the pitching obliquity sensor in platform stance measuring unit and roll Obliquity sensor output feeds back as position, using the angular rate gyroscope output in respective shaft as velocity feedback, constitutes tool There are incident angle ring and the closed-loop control system of gyro speed ring, control the physical platform of VSAT antenna system to remain water Flat；

Step 3：The geographic position data being given according to the GNSS module of VSAT antenna system and satellite longitude data calculate Go out antenna to point to respect to the theoretical orientation of the earth horizontal coordinates, pitching and polarizing angle：

Wherein θ 1 points to the theoretical azimuth with respect to the earth horizontal coordinates for antenna, and θ 2 points to respect to big for antenna The theoretical angle of pitch of ground horizontal coordinates, θ 3 is theoretical polarizing angle；Ant_longitude is antenna position longitude, Ant_ Latitude is antenna position latitude, and Sat_longitude is satellite longitude；

Step 4：Theoretical orientation, pitching and polarizing angle are pointed to according to calculated antenna；Servo control unit drives sky The each spindle motor of line carries out antenna theory and walks；

Step 5：After the completion of antenna theory walks, servo control unit drives azimuth-drive motor to be scanned, antenna logic master Control unit Real-time Collection satellite signal receiver data, and record corresponding azimuth position during its signal intensity maximum； After the completion of scanning, antenna logic main control unit controls servo control unit that antenna is pointed to return signal maximum of intensity position Put, if antenna points to after being maintained at signal intensity maximum value position can receive locking signal, judge to capture satellite, if Do not receive locking signal after the completion of scanning, then expand sweep limitss and proceed scanning until capturing satellite；

Step 6：After capture satellite, it is tracked using following steps：

Step 6.1：To antenna bearingt servo control unit incoming frequency be f, amplitude be A sinusoidal scanning signal θ= Asin (2 π ft), makes antenna azimuth scan with sinus wave patters, realizes being superimposed frequency in aerial receiver AGC DC level Sinusoidal signal for f；

Step 6.2：According to the positive negative direction of the antenna rotation setting, calculate the AGC direct current of the positive-negative half-cycle of scanning respectively Level average P_average and N_average；

Step 6.3：According to P_average and N_average, determine direction and the size of orientation adjustment：

Δ θ=k (P_average-N_average)

Wherein Δ θ is that antenna bearingt angle is poor；K is proportionality coefficient；

Step 6.4：By antenna bearingt angle difference input antenna bearingt servo-control system, control antenna alignment satellite.

Further preferred version, a kind of described VSAT antenna system acquiring satellite track side with physics levelling bench Method it is characterised in that：In step 2, to the pitching obliquity sensor in platform stance measuring unit and roll obliquity sensor Output be modified using following steps：

Step 2.1：The course that is given according to the GNSS module of VSAT antenna system, speed data, calculate linear acceleration α_tWith centripetal acceleration α_n：

α_t=(V_n-V_n-1)/ΔT

α_n=[(H_n-H_n-1)/ΔT]V_n

Wherein V_nAnd V_n-1For n-th and the speed obtaining of (n-1)th time GNSS module being sampled, H_nAnd H_n-1For n-th with And the course angle (n-1)th time GNSS module sampling being obtained, Δ T is sampling time interval；

Step 2.2：Calculate linear acceleration α_tWith centripetal acceleration α_nPitching inclination angle in platform stance measuring unit passes Component on sensor and roll obliquity sensor sensitive direction

a_c=α_nsin(H-H_n)-α_tcos(H-H_n)

a_e=α_ncos(H-H_n)+α_tsin(H-H_n)

Wherein a_cFor acceleration roll obliquity sensor sensitive direction component, a_eSense at pitching inclination angle for acceleration The component of device sensitive direction, H is antenna theory azimuth；

Step 2.3：Using acceleration roll durection component a_cWith acceleration pitch orientation component a_e, calculate roll and pitching The inclination angle of obliquity sensor sensitive direction relative level：

Θ_c=sin^-1((A_c-a_c)/g)

Θ_e=sin^-1((A_e-a_e)/g)

Wherein Θ_cFor the inclination angle of roll obliquity sensor sensitive direction relative level, Θ_eQuick for pitching obliquity sensor The inclination angle of sense direction relative level, A_cFor roll obliquity sensor sensitive direction specific force value, A_eFor pitching obliquity sensor Sensitive direction specific force value, g is acceleration of gravity.

Further preferred version, a kind of described VSAT antenna system acquiring satellite track side with physics levelling bench Method it is characterised in that：In step 6.2, calculate the value preset of sinusoidal signal positive-negative half-cycle corresponding AGC DC level respectively：

The value preset of positive half cycle corresponding AGC DC level

The value preset of negative half period corresponding AGC DC level

P_Count is the positive half cycle of sinusoidal signal corresponding AGC DC level number, and N_Count is sinusoidal signal negative half period Corresponding AGC DC level number；And after scanning completes a cycle, the AGC unidirectional current being calculated positive-negative half-cycle is average Average

Beneficial effect

The present invention has the effect that：

1st, adopt the method that the present invention provides, the requirement to VSAT antenna system itself and attachment device reduces, need not pacify Fill expensive Monopulse feed and inertial navigation system, thus greatly reducing product cost.

2nd, the coordinate transformation algorithm that the method that the present invention provides need not be complicated, effectively reduces system operations amount, to control Device performance requirement reduces, thus reducing hardware circuit cost.

3rd, the method that the present invention provides, makes scan tracing be down to from traditional two-dimensional scan one-dimensional, effectively reduces scanning The disturbance that antenna is pointed to, improves communication signal quality, so that the software complexity of scan tracing algorithm is reduced simultaneously, thus While improving software reliability, greatly reduce product development cycle.

4th, the method that the present invention provides participates in computing without carrier real-time course attitude during capture, tracking, therefore Without carrier, boat-carrying compass system is installed, the environmental condition of carrier is required to decrease, is conducive in equipment budget and equipment Application on the civilian ship of little tonnage of resource-constrained or water surface carrier.

The additional aspect of the present invention and advantage will be set forth in part in the description, and partly will become from the following description Obtain substantially, or recognized by the practice of the present invention.

Brief description

The above-mentioned and/or additional aspect of the present invention and advantage will become from reference to the description to embodiment for the accompanying drawings below Substantially and easy to understand, wherein：

Fig. 1：The control method flow chart of the present invention.

Specific embodiment

Embodiments of the invention are described below in detail, described embodiment is exemplary it is intended to be used for explaining the present invention, and It is not considered as limiting the invention.

The invention is characterized in that：

1. control object is to have orientation, pitching, the antenna system of roll three axle (A-E-C) mounting form；

2. set up a physics levelling bench in antenna system, and local geographic coordinate system is set up thereon；

3. the azimuth of the local geographic coordinate system set up is carried by the Electronic Megnetic Compass being installed on physics levelling bench For；

4. the initial point of the local geographic coordinate system set up is local geographical coordinate point, is provided by GNSS module；

5. physics levelling bench isolates carrier around the motion of pitch axis and roll axle by control system, remains water Flat；

6. the angle of pitch of antenna and polarizing angle, is calculated and passes through in the formula of earth coordinates by fixing VSAT system Control system controls；

7. due to setting up the Electronic Megnetic Compass azimuth of the local geographic coordinate system on physical platform and theoretical azimuth Have a larger error, need by antenna accurately point to when azimuth on the basis of demarcated；

8. because the Electronic Megnetic Compass azimuth setting up the earth coordinates on physical platform is had relatively with theoretical azimuth Big error, so when antenna movement is to Electronic Megnetic Compass azimuth, also need to capture satellite in azimuth scan mode；

9., due to the motion of carrier, mobile VSAT Systems Theory azimuth is change；So in antenna bearingt control By the way of low-angle sine sweep modulation, obtain the azimuthal error that the electrical boresight of antenna points to, and error is fed back to orientation control System processed, the real-time control electrical boresight of antenna accurately follows the tracks of sensing satellite.

10., due to the motion of carrier, mobile VSAT Systems Theory polarizing angle and the angle of pitch are also required to be become according to geographical position Change is adjusted.Adjustment mode is to make a move using motor to carry out as threshold value through the step pitch that drive mechanism corresponds to each electric axis Adjustment, when the change in GNSS geographical position causes the deviation between new theoretical pitching, polarizing angle and current pitching, polarizing angle big When adjusting threshold value, carry out an active accommodation.Thus ensureing that mobile VSAT antenna system is smart all the time in carrier traveling process Guarantee that holding satellite points to.

Described in detail below：

The control object of the present invention is a kind of orientation, pitching, roll three-axis mount (A-E-C) form parabola antenna, its Middle pitch axis and roll axle are mutually perpendicular to.Platform stance measuring unit is with parallel with pitch axis and can be around the mould of pitch axes Formula connects firmly, and wherein sensor mounting plane is the physics levelling bench of antenna system, and local geographic coordinate system is set up at it On；Two orthogonal micromechanics obliquity sensors are provided with sensor mounting plane, one of obliquity sensor Sensitive direction is vertical with pitch axis, is therefore referred to as pitch inclinometer, and another is then referred to as roll inclinator；Three mutually vertical Straight micromechanical angle rate gyroscope, two of which angular rate gyroscope sensitive axes are sensitive with pitch inclinometer and roll inclinator respectively Direction is vertical, and the sensitive axes of another angular rate gyroscope are vertical with physical platform, are therefore referred to as pitching, roll, side Parallactic angle rate gyroscope；The installation parallel with sensor mounting plane of one two axle Electronic Megnetic Compass, the local geographical coordinate set up The azimuth of system is provided by the Electronic Megnetic Compass being installed on physics levelling bench.Azimuth axis of antenna, pitch axis and roll axle are equal It is connected with brshless DC motor by belt；Polaxis and platform Attitude Measuring Unit sensor plane pitch axis respectively with step Stepper motor is connected.GNSS antenna module is arranged on VSAT antenna parabola top, the local geographic coordinate system set up former Point is local geographical coordinate point, is provided by GNSS module.Satellite signal receiver is arranged in antenna column.

The present invention is used for thering is orientation, pitching, the antenna system of roll three axle (A-E-C) mounting form.Its control section Mainly have：Logic main control unit, platform stance measuring unit, servo control unit, GNSS module and satellite signal receiver.Its Middle logic main control unit, platform stance measuring unit, servo control unit are connected by CAN with satellite signal receiver Connect, to realize the interaction of data and instruction；Logic main control unit be connected by RS-232 with GNSS module realize the speed of a ship or plane, course with And the collection of geographical location information.Servo control unit is connected with two-way motor and three road brshless DC motors, respectively Referred to as antenna points to pitching motor, polarization motor, orientation brshless DC motor, platform pitching, platform roll is brushless Direct current generator, to realize the control to antenna sensing and platform stance；Platform stance measuring unit Zhong tri- road micromechanical angle speed Rate gyro, two-way micromechanics obliquity sensor and two axle Electronic Megnetic Compass, for logic main control unit and SERVO CONTROL Unit provides all kinds of antennas and platform attitude data.

Method for capturing and tracing proposed by the present invention can be divided into five stages, respectively initialization, physics levelling bench set up, Antenna theory angle walks, acquiring satellite and tenacious tracking stage, comprises the following steps that：

Step 1：To in VSAT antenna system electricity and initialize.

Step 2：After initialization success, servo control unit is according to the platform pitching inclination angle of platform stance measuring unit and horizontal stroke Roll inclination data, it is zero that control pitching and the drive pitching of roll brshless DC motor and roll axle move to respective inclination data Position, sets up physics levelling bench, and persistently keeps level, and this is that the present invention realizes capture, the basis followed the tracks of.Detailed process For：Platform stance measuring unit and servo control unit are had on described physical platform, servo control unit is surveyed with platform stance Pitching obliquity sensor in amount unit and roll obliquity sensor output feed back as position, with the angle speed in respective shaft Rate gyro output, as velocity feedback, constitutes and has incident angle ring and the closed-loop control system of gyro speed ring, controls The physical platform of VSAT antenna system remains level；

Because micromechanics obliquity sensor is limited by operation principle, therefore turned in carrier or it is defeated during linear accelerating Going out inclination data will be affected to produce deviation by level or centripetal acceleration, leads to physical platform to lose horizontality, finally makes Antenna deviation is directed correctly to.For this problem, present invention preferably uses the course of GNSS module offer and speed of a ship or plane data calculate Go out linear acceleration and centripetal acceleration, inclination data is modified, draw true inclination data with respect to the horizontal plane.

The output of the pitching obliquity sensor in platform stance measuring unit and roll obliquity sensor is adopted with Lower step is modified：

Step 2.1：The course that is given according to the GNSS module of VSAT antenna system, speed data, calculate linear acceleration α_tWith centripetal acceleration α_n：

α_t=(V_n-V_n-1)/ΔT

α_n=[(H_n-H_n-1)/ΔT]V_n

Wherein V_nAnd V_n-1For n-th and the speed obtaining of (n-1)th time GNSS module being sampled, H_nAnd H_n-1For n-th with And the course angle (n-1)th time GNSS module sampling being obtained, Δ T is sampling time interval；

Step 2.2：Calculate linear acceleration α_tWith centripetal acceleration α_nPitching inclination angle in platform stance measuring unit passes Component on sensor and roll obliquity sensor sensitive direction

a_c=α_nsin(H-H_n)-α_tcos(H-H_n)

a_e=α_ncos(H-H_n)+α_tsin(H-H_n)

Wherein a_cFor acceleration roll obliquity sensor sensitive direction component, a_eSense at pitching inclination angle for acceleration The component of device sensitive direction, H is antenna theory azimuth；

Step 2.3：Using acceleration roll durection component a_cWith acceleration pitch orientation component a_e, calculate roll and pitching The inclination angle of obliquity sensor sensitive direction relative level：

Θ_c=sin^-1((A_c-a_c)/g)

Θ_e=sin^-1((A_e-a_e)/g)

Wherein Θ_cFor the inclination angle of roll obliquity sensor sensitive direction relative level, Θ_eQuick for pitching obliquity sensor The inclination angle of sense direction relative level, A_cFor roll obliquity sensor sensitive direction specific force value, A_eFor pitching obliquity sensor Sensitive direction specific force value, g is acceleration of gravity.

It is ensured that the inclination data of platform stance measuring unit is not added by centripetal acceleration and straight line after above-mentioned correction The impact of speed, makes physical platform remain horizontality in the case of carrier movement.

Step 3：Enter antenna theory angle after physics levelling bench is set up to walk the stage, according to VSAT antenna system The geographic position data that GNSS module is given and satellite longitude data calculate antenna and point to respect to the earth horizontal coordinates Theoretical orientation, pitching and polarizing angle：

Wherein θ 1 points to the theoretical azimuth with respect to the earth horizontal coordinates for antenna, and θ 2 points to respect to big for antenna The theoretical angle of pitch of ground horizontal coordinates, θ 3 is theoretical polarizing angle；Ant_longitude is antenna position longitude, Ant_ Latitude is antenna position latitude, and Sat_longitude is satellite longitude.

Step 4：Theoretical orientation, pitching and polarizing angle are pointed to according to calculated antenna；Servo control unit drives sky The each spindle motor of line carries out antenna theory and walks.Wherein theoretical azimuth is walked and is drawn using the bearing data of Electronic Megnetic Compass Lead, the step pitch of the angle of pitch that antenna points to and the polarizing angle then angle according to the theoretical angle of pitch and polarizing angle and corresponding motor Calculate the step number needing adjustment, walked.Deceleration between the polarization motor of antenna and polaxis in the present embodiment For 75.48, the speed reducing ratio that antenna points to pitching motor and antenna points between the angle of pitch is 10 to ratio, and two motors are equal Postponing original step pitch through two fine distributions is often to walk 0.9 °, and after slowing down, step pitch on polaxis for each step correspondence approximates 0.011924 °, the corresponding step pitch pointed on the angle of pitch in antenna is 0.09 °.And the antenna aperture of KL9002 is 90mm, its half work( Rate angle is 1.87 °, using the precision that walks of motor, the therefore pitching of antenna and polarizing angle disclosure satisfy that antenna is accurately directed to Demand.

Step 5：After the completion of antenna theory walks, enter the acquiring satellite stage.Because Electronic Megnetic Compass is subject to external magnetic field ring There is error in border impact, and external magnetic field is continually changing with carrier movement, is therefore entered using Electronic Megnetic Compass as benchmark After row bearing directing, the true bearing angle of antenna be will be generally offset from and is directed correctly to certain angle it is therefore desirable to be swept by orientation Retouch the search to realize satellite and capture.

Servo control unit drives azimuth-drive motor to be scanned, antenna logic main control unit Real-time Collection satellite signal receiving Machine data, and record corresponding azimuth position during its signal intensity maximum；After the completion of scanning, antenna logic master control list Unit controls servo control unit that antenna is pointed to return signal maximum of intensity position, if antenna points to is maintained at signal intensity Locking signal can be received behind big value position, then judge to capture satellite, if not receiving locking signal after the completion of scanning, Expand sweep limitss and proceed scanning until capturing satellite.

Step 6：Tracking phase is entered after capture satellite.This stage adopts low-angle sine azimuth scan modulation system.Root According to the direction of sinusoidal positive-negative half-cycle receiver signal strength meansigma methodss and the direction of size decision orientation adjustment and size.In antenna Electric axis be aligned lobe center when, the difference of positive-negative half-cycle receiver signal strength meansigma methodss is zero, in this, as to satelloid according to According to making antenna point to the most at last and do small line scanning in lobe immediate vicinity, thus protecting all the time during realizing carrier movement Hold the function of pointing to satellite.Specifically it is tracked using following steps：

Step 6.1：To antenna bearingt servo control unit incoming frequency be f, amplitude be A sinusoidal scanning signal θ= Asin (2 π ft), makes antenna azimuth scan with sinus wave patters, realizes being superimposed frequency in aerial receiver AGC DC level Sinusoidal signal for f.

Step 6.2：According to the positive negative direction of the antenna rotation setting, calculate the AGC direct current of the positive-negative half-cycle of scanning respectively Level average P_average and N_average；Realized by process once：Calculate sinusoidal signal positive-negative half-cycle respectively to correspond to AGC DC level value preset：

The value preset of positive half cycle corresponding AGC DC level

The value preset of negative half period corresponding AGC DC level

P_Count is the positive half cycle of sinusoidal signal corresponding AGC DC level number, and N_Count is sinusoidal signal negative half period Corresponding AGC DC level number；And after scanning completes a cycle, the AGC unidirectional current being calculated positive-negative half-cycle is average Average

Step 6.3：According to P_average and N_average, determine direction and the size of orientation adjustment：

Δ θ=k (P_average-N_average)

Wherein Δ θ is that antenna bearingt angle is poor；K is proportionality coefficient.

Step 6.4：By antenna bearingt angle difference input antenna bearingt servo-control system, control antenna alignment satellite.

Because carrier movement can cause the change of antenna system geographic location, the therefore orientation of antenna sensing, pitching Change with polarizing angle with geographic location is also required to be adjusted.But due in carrier running antenna azimuth pass through little Angle sine scanning modulation tracking makes antenna azimuth remain to be directed correctly to, and therefore need not consider that geographical position changes and bring Azimuthal variation.And polarizing angle and the angle of pitch then need to be adjusted according to geographical change in location, but due to carrier movement away from From highly very little with respect to synchronous satellite orbit, the motion in therefore similar ship this kind of low speed carrier certain time brings Geographical position change is reflected in varying less in pitching and polarizing angle, therefore need not be adjusted in real time.So we are with step The step pitch that stepper motor makes a move through drive mechanism correspondence in electric axis as threshold value, when the change in GNSS geographical position causes newly When deviation between the theoretical angle of pitch calculating and polarizing angle and the current angle of pitch and polarizing angle is more than adjustment threshold value, Motor drive Unit will carry out a pitching and polarizing angle active accommodation.This measure ensure that mobile VSAT antenna system in carrier traveling process In all the time accurately keep satellite point to.

Although embodiments of the invention have been shown and described above it is to be understood that above-described embodiment is example Property it is impossible to be interpreted as limitation of the present invention, those of ordinary skill in the art is in the principle without departing from the present invention and objective In the case of above-described embodiment can be changed within the scope of the invention, change, replace and modification.

Claims (3)

1. a kind of VSAT antenna system acquiring satellite tracking with physics levelling bench it is characterised in that：Including following Step：

Step 1：To in VSAT antenna system electricity and initialize；

Step 2：The physical platform controlling VSAT antenna system keeps level：Platform stance measurement is had on described physical platform single Unit and servo control unit, servo control unit is with the pitching obliquity sensor in platform stance measuring unit and roll inclination angle Sensor output feeds back as position, using the angular rate gyroscope output in respective shaft as velocity feedback, constitutes to have and inclines Angle Position ring and the closed-loop control system of gyro speed ring, control the physical platform of VSAT antenna system to remain level；

Step 3：The geographic position data being given according to the GNSS module of VSAT antenna system and satellite longitude data calculate sky Line points to respect to the theoretical orientation of the earth horizontal coordinates, pitching and polarizing angle：

$\mathrm{\θ}1=arcth\frac{tg(Sat\_longitude-Ant\_longitude)}{\sin (Ant\_latitude)}$

$\mathrm{\θ}2=arcth\frac{\cos (Sat\_longitude-Ant\_longitude)\cos (Ant\_latitude)-0.15127}{\sqrt{1-{\[\cos (Sat\_longitude-Ant\_longitude)\cos (Ant\_latitude)\]}^2}}$

$\mathrm{\θ}3=arctg\frac{\sin (Sat\_longitude-Ant\_longitude)}{tg(Ant\_latitude)}$

Wherein θ 1 points to the theoretical azimuth with respect to the earth horizontal coordinates for antenna, and θ 2 points to respect to the earth water for antenna The theoretical angle of pitch of flat coordinate system, θ 3 is theoretical polarizing angle；Ant_longitude is antenna position longitude, Ant_ Latitude is antenna position latitude, and Sat_longitude is satellite longitude；

Step 4：Theoretical orientation, pitching and polarizing angle are pointed to according to calculated antenna；Servo control unit drives antenna each Spindle motor carries out antenna theory and walks；

Step 5：After the completion of antenna theory walks, servo control unit drives azimuth-drive motor to be scanned, antenna logic master control list First Real-time Collection satellite signal receiver data, and record corresponding azimuth position during its signal intensity maximum；Sweeping After the completion of retouching, antenna logic main control unit controls servo control unit that antenna is pointed to return signal maximum of intensity position, if Antenna points to after being maintained at signal intensity maximum value position and can receive locking signal, then judge to capture satellite, if sweeping Do not receive locking signal after the completion of retouching, then expand sweep limitss and proceed scanning until capturing satellite；

Step 6：After capture satellite, it is tracked using following steps：

Step 6.1：It is f to antenna bearingt servo control unit incoming frequency, amplitude is sinusoidal scanning signal θ=Asin (2 π of A Ft), so that antenna azimuth is scanned with sinus wave patters, realize frequency being superimposed on aerial receiver AGC DC level for f just String signal；

Step 6.2：According to the positive negative direction of the antenna rotation setting, calculate the AGC DC level of the positive-negative half-cycle of scanning respectively Average value P _ average and N_average；

Step 6.3：According to P_average and N_average, determine direction and the size of orientation adjustment：

Δ θ=k (P_average-N_average)

Wherein Δ θ is that antenna bearingt angle is poor；K is proportionality coefficient；

Step 6.4：By antenna bearingt angle difference input antenna bearingt servo-control system, control antenna alignment satellite.

2. a kind of VSAT antenna system acquiring satellite tracking with physics levelling bench according to claim 1, its It is characterised by：Output in step 2, to the pitching obliquity sensor in platform stance measuring unit and roll obliquity sensor Amount is modified using following steps：

Step 2.1：The course that is given according to the GNSS module of VSAT antenna system, speed data, calculate linear acceleration α_tWith to Heart acceleration α_n：

α_t=(V_n-V_n-1)/ΔT

α_n=[(H_n-H_n-1)/ΔT]V_n

Wherein V_nAnd V_n-1For n-th and the speed obtaining of (n-1)th time GNSS module being sampled, H_nAnd H_n-1For n-th and The course angle that n-1 time obtains to GNSS module sampling, Δ T is sampling time interval；

Step 2.2：Calculate linear acceleration α_tWith centripetal acceleration α_nPitching obliquity sensor in platform stance measuring unit And the component on roll obliquity sensor sensitive direction

a_c=α_nsin(H-H_n)-α_tcos(H-H_n)

a_e=α_ncos(H-H_n)+α_tsin(H-H_n)

Wherein a_cFor acceleration roll obliquity sensor sensitive direction component, a_eQuick in pitching obliquity sensor for acceleration The component in sense direction, H is antenna theory azimuth；

Step 2.3：Using acceleration roll durection component a_cWith acceleration pitch orientation component a_e, calculate roll and pitching inclination angle The inclination angle of sensor sensing direction relative level：

Θ_c=sin^-1((A_c-a_c)/g)

Θ_e=sin^-1((A_e-a_e)/g)

Wherein Θ_cFor the inclination angle of roll obliquity sensor sensitive direction relative level, Θ_eFor pitching obliquity sensor sensitivity side To the inclination angle of relative level, A_cFor roll obliquity sensor sensitive direction specific force value, A_eSensitive for pitching obliquity sensor Direction specific force measured value, g is acceleration of gravity.

3. a kind of VSAT antenna system acquiring satellite tracking with physics levelling bench according to claim 1, its It is characterised by：In step 6.2, calculate the value preset of sinusoidal signal positive-negative half-cycle corresponding AGC DC level respectively：

The value preset of positive half cycle corresponding AGC DC level

$P\_Sum=\underset{i=1}{\overset{P\_Count}{\Σ}}{\mathrm{AGC}}_i(\mathrm{\θ}>0)$

The value preset of negative half period corresponding AGC DC level

$N\_Sum=\underset{j=1}{\overset{N\_Count}{\&Sigma;}}{\mathrm{AGC}}_j(\mathrm{\&theta;}<0)$

P_Count is the positive half cycle of sinusoidal signal corresponding AGC DC level number, and N_Count corresponds to for sinusoidal signal negative half period AGC DC level number；And after scanning completes a cycle, it is calculated the AGC DC level meansigma methodss of positive-negative half-cycle

$P\_average=\frac{P\_Sum}{P\_Count}$

$N\_average=\frac{N\_Sum}{N\_Count}.$