1.FPGAbaedplatforms（Field－ProgrammableGateArray）即现场可编程门阵列
1)PhenixPro(RobSenseTech公司开发,固件开源为：基于自主定制的无人机实时操作系统（UOS）)
Itisbuiltonreconfigurable(可重构)SystemonaChip(SoC)designedanddevelopedbyRobSenseTech,foundedin2015andlocatedinHangzhouChina.
Theflightcontrollerisequippedwiththereal-timeoperatingsystemandLinux-basedRobotOperatingSystem(ROS).Theflightplatformsupports20+interfacesincludeingon-boardsensors,mmWaveradar,thermalcamera,ultra-visionHDvideotransceiverviasoftwaredefinedradio,etc.Inaddition,itshardware(FPGA)acceleration(硬件加速能力)enablescomputervisionandDeepNeuralNetworkalgorithmsapplications.ItrunsFreeRTOSbasedUAVreal-timeoperatingsystem(PhenOS)thatcontainsabuiltinmulti-taskscheduling,andROSforintelligentalgorithmsandhardwareresourcesmanagement.Fig.2-ashowsPhenixProflightcontrollerandFig.2-bshowsitscircuitboard.Theschematicofthisplatformisclosed-source,however,theproject'ssoftwareisopenunderTheGNUGeneralPublicLicense(GPL)v3license.
PhenixPro搭载业界首创的基于SoC（ARM+FPGA）架构的无人机实时操作系统（UOS）和优秀的飞行控制算法。ARM双核处理器提供实时的自动控制与人机交互性能的同时，FPGA可以实现计算机视觉、卷积神经网络等算法的硬件加速并降低功耗。三余度IMU+三余度GPS.
2)OcPoC(OctagonalPilotonChip):(Aerotenna公司开发,运行固件为APM)
ItisdevelopedbyAerotennaCompany,foundedin2015andlocatedinBioscienceandTechnologyBusinessCenter,UniversityofKansas,USA.OcPoCexpandsitsinputandoutputcapabilitiestoincludefullyprogrammablePWM,PPM,andGPIOpinstointegratewithavastnumberofdifferentsensoradditions.Italsoincludemanyotherstandardizedconnectorsforperipherals(外围设备)suchasGPS,CSIcameralink,andSDcard.ItrunsArduPilotsoftwareplatform.
Fig.3-ashowsOcPoCflightcontrollerandFig.3-bshowsitscircuitboard.Theschematicofthisplatformisclosed-source.
2.ARM-basedplatforms
1)PIXHAWK/PX4:(苏黎世大学的ComputerVisionandGeometryLabandAutonomousSystemLab，固件为PX4和APM)
ItisacomputervisionresearchbasedflightcontroldesignedbyComputerVisionandGeometryLabofETHZurichandAutonomousSystemLab.ItisanevolutionofthePX4flightcontrollersystem(i.e.,enclosure(密集化)andperhapsmodifiedconnections(改进接口)).ItconsistsofaPX4-FlightManagementUnit(FMU)controllerandaPX4-IOintegrated(集成)onasingleboardwithadditionalIO,Memoryandotherfeatures.Inaddition,itworkscloselywiththeLinuxFoundationDroneCodeproject.
Fig.4-ashowsPIXHAWKflightcontrollerandFig.4-bshowsitsmaincircuitboard;PX4.TheprojectisavailableundertheBerkeleySoftwareDistribution(BSD)license.
2)PIXHAWK2:(PX4andArduPilot团队，固件为PX4和APM)
ItgrowsfromthePixhawkHardwareProjectanddoneasagroupeffortbythePX4andArduPilotteams.Itisasmallcube,hastripleredundant(三倍冗余)IMU's,andupto3GPSmodules.Allconnection(I/Os)tothecubeisinonesingleDF17connector.ItscarrierhasaninterfacetoIntelEdition(worksasacompanioncomputer(伴随的电脑)).重点
Fig.5-ashowsPIXHAWK2enclosureandFig.5-bshowsitscircuitboard.ThePixhawk2schematics(电路图)areopenundertheCC-BY-SA-3.0license.
3)Paparazzi&Chimera:(ENACLab，固件为Paparazziautopilotsystem)
Itisthefirstandtheoldestopen-sourcedronehardwareandsoftewareproject.ItisdevelopedinEcoleNationaledeI'AviationCivil(ENAC)UAVLabsince2003.Itencompasses(集成)autopilotsystemsandgroundstationsoftwareformulticopters/multirotors,fixed-wing,helicoptersandhybridaircrafe("FlexibleopenarchitectureforUASsintegration(集成)intotheairspace:Paparazziautopilotsystem",in2016IEEE/A-IAA35thDigitalAvionicsSystemsConference(DASC),Sept2016,pp.1-7.).InMarch2017,ENACLabreleasedanewautopilotnamedChimerathatisbasedonthelatestSTM32F7MicrocontrollerUnit(MCU).(配备ARMCortex-M7内核的超高性能STM32F7系列)Fig.6showsPaparazziChimeracircuitboard.ThehardwareandsofewareoftheprojectareavailableundertheGPLlicence.
4)CC3D&Atom:(OpenPilot/LibraPilot公司，固件为：OpenPilot/LibraPilotfirmware)
Theyaretwoflightcontrollershavethesamefunctionalitiesbutdefferentinsize.TheyaredevelopedbyOpenPilotwhichbecameLibraPilotrecently.TheCC3DandAtomflightcontrollershavealltypesofstabilizationshardwarewhichruntheOpenPilot/LibraPilotfirmware.Theycanbeconfigured(安装配置)toflyanyairframefromfixed-wingtoanoctocopterusingtheOpenPilot/LibraPilot.ThehardwareandthesofewareoftheprojectareavailableundertheGPLv3license.Fig.7-aandbshowCC#DandAtomcircuitboards,respectively.
3.Atmel-basedplatforms
1)ArdupilotMega(APM):(DIYDronescommunity开发，运行固件为ArduPilot)
ItisanArduinoMega-basedautopilotsystemdevelopedbyDIYDronescommunityasanupgradeofArduPilotflightcontrol.Itisabletocontrolautonomousmulticopters,fixed-wingaircraft,traditionalhelicopters,groundroversandantennatrackers.Fig.8-ashowsArduPilotMega(APM)v2.8unitandFig.8-bshowsitscircuitboard.TheprojectisopenunderGPLv3license.
ThedesignofFlyMapleisbasedonthemaple,whichisanArduinostyleARMprocessor.Fig.9showsFlymapleflightcontrollerboard.TheprojectisunderGPLv3license.
4.RaspberryPibasedplatforms(由ErleRobotics公司开发)
1)Erle-Brain3:
ItisLinuxbasedopenpilotfordronesdevelopedbyErleRobotics,Spain.ItcombinesanembeddedLinuxcomputer(RaspberryPi)andadaughterboard(PXFmini)containingseveralsensors,IOandpowerelectronics.ThePXFminiisanopenhardwareautopilotshieldformakingrobotsanddronesmeantfortheRaspberryPifamily.ItisbuildontopoftheDronecodeFoundationtechnologies.
Fig.10-ashowsErle-Brain3autopilotandFig.10-bshowsltsparts(PXFmini+RaspberryPi).ThePXFminischematicsareopenundertheCreativeCommonsAttribution-NonCommercial-ShareAlike(CCBY-NC_SA)license.
重要信息提取：
1.STM32F7MicrocontrollerUnit(MCU).(配备ARMCortex-M7内核的超高性能STM32F7系列)。
2.FPGA（Field－ProgrammableGateArray），即现场可编程门阵列，非常先进的技术。
1)PhenixPro便是基于该处理器，运行固件为基于SoC（ARM+FPGA）架构的无人机实时操作系统（UOS）。
2)ARM双核搭配FPGA硬件加速，令计算机视觉、神经网络等人工智能技术在无人机上实时运算成为可能，效能比超GPU同类型方案两个数量级以上。
3)PhenixPro支持智能感知环境、闪避障碍物、全自主飞行。
4)PhenixPro可以轻松兼容20种以上不同设备（传感器）同时接入。
3.PIXHAWK/PX4:ItisacomputervisionresearchbasedflightcontroldesignedbyComputerVisionandGeometryLabofETHZurichandAutonomousSystemsLab.竟然是基于飞控的计算机视觉研究，并没有发现这点，之后在仔细研究一下，究竟是哪个地方体现了计算机视觉。
4.PIXHAWK2:
1)Allconnection(I/Os)tothecubeisinonesingleDF17connector.(只有一个接口).
2)ItscarrierboardhasaninterfacetoIntelEdison(worksasacompanioncomputer).(竟然还可以附带一个微型计算机IntelEdison)
运行Linux系统！运行Linux系统！运行Linux系统！重要的事说三遍，我好像看到了什么！