1. FPGA baed platforms（Field－Programmable Gate Array）即現場可編程門陣列
1)Phenix Pro(RobSense Tech公司開發, 固件開源為：基於自主定制的無人機實時操作系統（UOS）)
It is built on reconfigurable (可重構) System on a Chip (SoC) designed and developed by RobSense Tech, founded in 2015 and located in Hangzhou China.
The flight controller is equipped with the real-time operating system and Linux-based Robot Operating System(ROS).The flight platform supports 20+ interfaces includeing on-board sensors, mmWave radar, thermal camera,ultra-vision HD video transceiver via software defined radio,etc. In addition,its hardware(FPGA) acceleration(硬件加速能力) enables computer vision and Deep Neural Network algorithms applications. It runs FreeRTOS based UAV real-time operating system(PhenOS) that contains a built in multi-task scheduling, and ROS for intelligent algorithms and hardware resources management. Fig. 2-a shows Phenix Pro flight controller and Fig. 2-b shows its circuit board. The schematic of this platform is closed-source, however, the project's software is open under The GNU General Public License(GPL)v3 license.
Phenix Pro 搭載業界首創的基於SoC（ARM+FPGA）架構的無人機實時操作系統（UOS）和優秀的飛行控制算法。ARM雙核處理器提供實時的自動控制與人機交互性能的同時，FPGA可以實現計算機視覺、卷積神經網絡等算法的硬件加速並降低功耗。三余度IMU+三余度GPS.
2)OcPoC(Octagonal Pilot on Chip):(Aerotenna公司開發, 運行固件為APM)
It is developed by Aerotenna Company, founded in 2015 and located in Bioscience and Technology Business Center, University of Kansas, USA. OcPoC expands its input and output capabilities to include fully programmable PWM, PPM, and GPIO pins to integrate with a vast number of different sensor additions. It also include many other standardized connectors for peripherals(外圍設備) such as GPS, CSI camera link, and SD card. It runs ArduPilot software platform.
Fig. 3-a shows OcPoC flight controller and Fig. 3-b shows its circuit board. The schematic of this platform is closed-source.
2. ARM-based platforms
1) PIXHAWK/PX4:(蘇黎世大學的 Computer Vision and Geometry Lab and Autonomous System Lab，固件為PX4和APM)
It is a computer vision research based flight control designed by Computer Vision and Geometry Lab of ETH Zurich and Autonomous System Lab. It is an evolution of the PX4 flight controller system(i.e., enclosure(密集化) and perhaps modified connections(改進接口)). It consists of a PX4-Flight Management Unit(FMU) controller and a PX4-IO integrated(集成) on a single board with additional IO, Memory and other features. In addition, it works closely with the Linux Foundation DroneCode project.
Fig. 4-a shows PIXHAWK flight controller and Fig. 4-b shows its main circuit board; PX4. The project is available under the Berkeley Software Distribution(BSD) license.
2) PIXHAWK 2:(PX4 and ArduPilot 團隊，固件為PX4和APM)
It grows from the Pixhawk Hardware Project and done as a group effort by the PX4 and ArduPilot teams. It is a small cube , has triple redundant(三倍冗余) IMU's, and up to 3 GPS modules. All connection (I/Os) to the cube is in one single DF17 connector. Its carrier has an interface to Intel Edition (works as a companion computer(伴隨的電腦)).重點
Fig. 5-a shows PIXHAWK 2 enclosure and Fig. 5-b shows its circuit board. The Pixhawk 2 schematics(電路圖) are open under the CC-BY-SA-3.0 license.
3) Paparazzi & Chimera:(ENAC Lab，固件為 Paparazzi autopilot system)
It is the first and the oldest open-source drone hardware and softeware project. It is developed in Ecole Nationale de I'Aviation Civil (ENAC) UAV Lab since 2003. It encompasses(集成) autopilot systems and ground station software for multicopters/multirotors, fixed-wing, helicopters and hybrid aircrafe ("Flexible open architecture for UASs integration(集成) into the airspace: Paparazzi autopilot system", in 2016 IEEE/A-IAA 35th Digital Avionics Systems Conference(DASC), Sept 2016, pp.1-7.). In March 2017, ENAC Lab released a new autopilot named Chimera that is based on the latest STM32F7 Microcontroller Unit (MCU). (配備ARM® Cortex®-M7內核的超高性能STM32F7系列)Fig. 6 shows Paparazzi Chimera circuit board. The hardware and sofeware of the project are available under the GPL licence.
4) CC3D & Atom:(OpenPilot/LibraPilot公司，固件為：OpenPilot/LibraPilot firmware)
They are two flight controller s have the same functionalities but defferent in size. They are developed by OpenPilot which became LibraPilot recently. The CC3D and Atom flight controllers have all types of stabilizations hardware which run the OpenPilot/LibraPilot firmware. They can be configured (安裝配置) to fly any airframe from fixed-wing to an octocopter using the OpenPilot/LibraPilot. The hardware and the sofeware of the project are available under the GPLv3 license. Fig. 7-a and b show CC#D and Atom circuit boards, respectively.
3. Atmel-based platforms
1) Ardupilot Mega(APM):(DIY Drones community開發，運行固件為ArduPilot)
It is an Arduino Mega-based autopilot system developed by DIY Drones community as an upgrade of ArduPilot flight control. It is able to control autonomous multicopters, fixed-wing aircraft, traditional helicopters, ground rovers and antenna trackers. Fig. 8-a shows ArduPilot Mega(APM) v2.8 unit and Fig. 8-b shows its circuit board. The project is open under GPLv3 license.
2) FlyMaple:(來源於Maple Project)
The design of FlyMaple is based on the maple, which is an Arduino style ARM processor. Fig. 9 shows Flymaple flight controller board. The project is under GPLv3 license.
4. Raspberry Pi based platforms(由Erle Robotics公司開發)
1) Erle-Brain 3:
It is Linux based open pilot for drones developed by Erle Robotics, Spain. It combines an embedded Linux computer (Raspberry Pi) and a daughter board (PXFmini) containing several sensors, IO and power electronics. The PXFmini is an open hardware autopilot shield for making robots and drones meant for the Raspberry Pi family. It is build on top of the Dronecode Foundation technologies.
Fig. 10-a shows Erle-Brain 3 autopilot and Fig. 10-b shows lts parts (PXFmini + Raspberry Pi). The PXFmini schematics are open under the Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC_SA) license.
重要信息提取：
1. STM32F7 Microcontroller Unit (MCU). (配備ARM® Cortex®-M7內核的超高性能STM32F7系列)。
2. FPGA（Field－Programmable Gate Array），即現場可編程門陣列，非常先進的技術。
1) Phenix Pro便是基於該處理器，運行固件為基於SoC（ARM+FPGA）架構的無人機實時操作系統（UOS）。
2) ARM雙核搭配FPGA硬件加速，令計算機視覺、神經網絡等人工智能技術在無人機上實時運算成為可能，效能比超GPU同類型方案兩個數量級以上。
3) Phenix Pro支持智能感知環境、閃避障礙物、全自主飛行。
4) Phenix Pro可以輕松兼容20種以上不同設備（傳感器）同時接入。
3. PIXHAWK/PX4: It is a computer vision research based flight control designed by Computer Vision and Geometry Lab of ETH Zurich and Autonomous Systems Lab.竟然是基於飛控的計算機視覺研究，並沒有發現這點，之后在仔細研究一下，究竟是哪個地方體現了計算機視覺。
4. PIXHAWK 2:
1) All connection (I/Os) to the cube is in one single DF17 connector.(只有一個接口).
2) Its carrier board has an interface to Intel Edison (works as a companion computer). (竟然還可以附帶一個微型計算機Intel Edison)
3) Edison 由一枚雙核 Quark SOC 的芯片驅動，運行 Linux 系統，支持 Wi-Fi 和藍牙連接。
運行Linux系統！運行Linux系統！運行Linux系統！重要的事說三遍，我好像看到了什么！
5. Dronecode Community
The community provides software for OSH PIXHAWK, FlyMaple, Erle Brain 2, etc. The software is available in "https://www.dronecode.org/".
最后是兩個圖，分別是現今的開源飛控硬件和軟件列表：
