美海军研究生院（NPS' Advanced Robotic Systems Engineering Laboratory (ARSENL) ） - 50 Autonomous UAVs in Flight

0. Reference

Ritewing Zephyr II 56" Base Kit
http://www.ritewingrc.com/
- EPO foam wings
- dual Thunder Power 5000 mAh LiPo
- approximately 45-50 minutes

Pixhawk
- 主要使用ArduPlane的控件
- Firmware: flies a lightly-modified branch of ArduPlane
ODroid u3 companion computer
- 机载计算机完成航迹规划、本体控制和信息传递等任务。
- running a stripped-down version of Ubuntu Linux
- based on ROS
- broadcasts pose and status to other planes and to the ground.
- accepts commands from the ground
- payload-directed path planning algorithms
  - kernel: effectively moving a carrot in front of the plane.
  - leader-follower
  - distributed search
  - sequenced landing
Radio
- 主要解决频段分离问题，在紧急时刻切入手动
- 900 MHz telemetry radios
- the default 915-928 MHz band was saturated.
- split our available 902-928 MHz band into three equal-size sub-bands and place an equal number of planes into each sub-band.
- place an equal number of planes into each sub-band.
Wifi
- 作为信息交互主要基于Wifi和MAVLink协议
- primary link with the fleet is an ad hoc 802.11n wireless network
- UDP + MAVLink
- 信号为弱势时，系统从新配置每个分集的sub-band和Net ID
- Each plane broadcasts its pose at roughly 8 Hz
总体配置

Leader-follower模式
- 系统自动将每一组当前位置最靠前，高度最高的飞机作为Leader
自主顺序降落模式
- planes order their landings according to altitude, lowest first, and each plane in sequence begins an autonomous landing
- 在40m高度盘旋，之后进入下滑轨道
- 所有飞机的降落点通过GPS设置为相同位置
- 支撑文章Optimized transit planning and landing of aerial robotic swarms， ICRA2013
轨迹显示
- Visualization in Gazebo using data captured in ROS on each payload
系统构架
- 支撑文章Multi-UAV Software Systems and Simulation Architecture, ICUAS2015
仿真环境设计