用于小型无人机定向天线的主动平衡支架的开发

1、The Development of Active Gimbal System for Directional Antenna on a Small Remote Piloted Aircraft (RPA) Yangzi (Frank) GuoDr Stephen D. Prior Email: yangzi.guosoton.ac.ukAddress: Engineering Centre of Excellence, Building 176Boldrewood Campus, University of SouthamptonSO16 7QF, UK共十八页StructureBackg

2、roundConcept DesignImplementationTestConclusion共十八页BackgroundSmall Remotely Piloted Aircraft (RPA)Communication SystemRemote control and sensing.Around 2 kg.On a RPAReceive: commands.Transmit: video, sensor data. 共十八页BackgroundWhat people do?Better modulation technology.Circular polarized antennae.

3、Higher microwave frequency. Get licence for higher transmitter power.Higher sensitivity receiver.High gain directional antenna and autonomous tracker (AAT) on the ground.Develop a light weight, low cost active gimbal system for the directional antenna on small RPAs.My research question: High gain di

4、rectional antenna and gimbal on the RPAs?MassAccuracy?For small RPAsLong range technology is restricted Satellite repeaterSmart antennaFurther & Clearer共十八页Concept Design Structure- Concern of degree of freedoms (DOFs)xyz“Home” PointXYZ3 planar movement.3 rotation.3 DOF gimbal- 360yaw,90pitch,90roll

5、.共十八页Concept Design Structure- Concern of degree of freedoms (DOFs)xr doesnt count in a polar coordinate system. Planar movements: 2 angles. Circular polarized antennae.Rotation: ignore the roll of the antenna.2 DOF Gimbal Yaw and pitch.共十八页Concept Design Structure- Concern of degree of freedoms (DO

6、Fs)Distance900“Home” PointPitch of antenna: + .Steady flight, ignore .Fixed mission altitude.Longer distance, slower change of .Nearer to the home point, less important is .Fix and optimize the value.1 DOF Gimbal only yaw. 共十八页Control StrategyDistanceAltitude“Home” Point+XY+ “Home” PointHorizontal p

7、lanar angle: Vertical planar angle: Antenna gimbal:In Example 1, Yaw:+ - Stepper motorIn Example 2, pitch:+ - Servo motorRoll: - Servo motor*Note: Red arm: direction of front.Accelerometer (RPA):Acceleration along 3 axis. GPS:LongitudeLatitudeAltitudeYaw: Pitch:Roll: calculatecalculateprocess共十八页Imp

8、lementation-2 DOF structureThe stepper motor and a pair of 1: 1 gears.The big servo motor.The bearing.Antenna platform with small constant angle.Base for antenna platform. A locker to fix the slip ring.Slip ring for RF. Models built in SolidWorks.共十八页The Control System & The Video Communication Syst

9、emMyFlyDream Telefly OSDTxAccelerometerGPSArduino MicroSet “Home” ButtonThe top layer.Bottom of the top layer and the second layer.AATAAT DriverMonitor ScreenPatch AntennaReceiverGround station.*FPV: First Person View*OSD: On screen display*AAT: Autonomous antenna tracker共十八页Connection of the System

10、RPAVideo SignalAudio SignalData & CommandGround Station共十八页Test Results and AnalysisPositionFnctionality Mass (g)Bottom Layer360 Rotation170Second Layer90 Tilt190Top layerController Board140Total mass500Total height260 mmMass of RPA: 1.2 kg.RPA Maximum Payload: 1 kg.RPA Total MTOM: 2.2 kg.Total mass

11、: half of the payload.共十八页Test Results and AnalysisTolerance of radiation pattern.GPS accuracy: 5-10 m3 dBi Beam width of directional antenna main lobe: 70- 90Control system: suitable for long range application.共十八页Cost AnalysisComponentsPrice/Cost ()CommentsArduino Micro Board18Compared with the RP

12、A and the video system, the cost of this gimbal system is reasonable.Compared with smart antenna, the price of the mechanical solution is really cheap. Accelerometer20GPS module21Helical directional antenna52Stepper motor5Servo43Laser cutting and rapid prototyping.freeTotal Cosst159Ready to fly RPA

13、platform950This is the basic flight platform.The MFD antenna tracker pack204These components are for extra function of FPV.Video system, including: camera, Tx, Rx, patch antenna and monitor screen.180Circular Polarized Omnidirectional antenna20共十八页ConclusionThe mechanical design is light weight and

14、satisfactory to all the movement requirements.All the modules of the control system can work properly. This system has the capability of being a low-cost solution to improve the communication of small RPAs.共十八页Future WorkThe mechanical design could be further miniaturized. The control strategy could be modified to prevent drifting.A full fly test will be operated to test the overall performance.共十八页Thank you!共十八页内容摘要The Development of Active Gimbal System for Directional Antenna on a Small Remo