RoboBoat 2019 Drone Retrospective

The Frankendrone from RoboBoat 2019 had a rough start and was not able to fly in competition. Eric was able to finally get it steady in the air before the end of the week of competition. Hardware must work before software can work properly.

Takeaways:

  • Software
    • ArduPilot and PX4 flight stacks both have useful features
      • Ardupilot is simpler to set up and has better stability, compatible with most voltage step-down modules
      • PX4 is more difficult on setup but may *possibly* have more simulation support.
      • Calibrate over USB, not telemetry
      • Properly configure radio telemetry Net ID, more below
    • An onboard companion computer is recommended going forward for camera and ROS integration (Raspberry Pi, Jetson Nano, etc)
    • Various ground control software exist. For this iteration, we used QGroundControl and Mission Planner
    • For PX4 find CBRK_SUPPLY_CHK parameter to override battery check in case of issues (User discretion advised, potential safety hazard)
    • Simulation: Gazebo + PX4 flight stack has been tested with ROS Kinetic. Use ROS Melodic if possible due to more recent support. Do not run inside of ADePT-ROS.
  • Hardware
    • 4 ESC systems are nice if you have lots of the same ESC for replacement parts
    • 4-in-1 ESCs may save on weight
    • Keep cable management in mind, especially when designing a power bus
    • Bring more than 1 battery, and make sure batteries are essentially the same
    • Use a lightweight camera, not a bulky webcam, if possible
    • Potential frame idea: modular with zip-ties for part attachments which allow for breakage without damaging the frame
    • Order spare props
    • Parrot Bebop should be a RTF drone compatible with PX4 and thus MAVROS
  • Debugging
    • Test systems independently
    • Check for hardware issues: ESCs and other electronics can easily interfere with GPS
    • Know how to tune the PIDs
  • Safety
    • Be mindful of the fact that other teams may be on the same telemetry frequency, so make sure that there will be no interference
      • Check/change RADIO TELEMETRY NET ID, avoid default ID of 25, or else there WILL BE INTERFERENCE with other teams
      • RFD900 Tools suggested by an Embry-Riddle professor for configuring radio telemetry (Especially Net ID)
    • Take props off before doing any sort of modifications or debugging IF YOU LIKE HAVING FINGERS
    • Make the drone waterproof
    • REGISTER WITH THE FAA, FOLLOW SAFETY PROTOCOLS
  • Judging
    • Drone fail-safes were of concern. Know how to ensure a safe mode of failure
      • Potential solution: mount electronics in a waterproof container to lower CoM below main frame to ensure fall stability