SingleCopter and CoaxCopter

Warning

Warning the SingleCopter (available since AC3.1) and CoaxCopter (available since AC3.2) are not regularly used and have not been extensively tested!

As this is VERY new many of the Single copters shown here use either mil-spec or very simple stabilize mode controllers.

The First Video of a SingleCopter using an APM 2.5

https://vimeo.com/77850133

SingleCopter

  • A SingleCopter is an aerial vehicle with one central rotating propeller thrusting downward past 4 controllable vanes.

  • The 4 control vanes (one in each quadrant) permits the control of the vehicles roll, pitch and yaw.

  • The vanes also permit real time compensation for the motors direction of rotation.

  • Altitude is controlled by adjusting the motor / propeller speed.

    vtolcustom2

An innovative and quite successful hobbyist SingleCopter

../_images/P1060929.jpg

Connecting the Flight Controller to the SingleCopter:

  • Connect the APM, PX4 or Pixhawk servo output channels 1-4 to the SingleCopters 4 control fins as shown.
  • Connect the APM, PX4 or Pixhawk servo output channel 7 to the ESC for the brushless motor that powers the main single rotor
  • The 4 fins are attached to four arms and it’s a bit like a Plus quad.
  • Looking down on the APM from above as in the attached diagram. “servo1” would be attached to the APM’s output channel #1, etc.
../_images/SingleCopterBothView1.jpg

Load the Firmware

  • For the time being, the user needs to compile the source code themselves.
  • Add this line to the APM_Config.h: #define FRAME_CONFIG SINGLE_FRAME
  • In the near future this will be added as a downloadable binary to firmware.ardupilot.org and likely as a Mission Planner loadable icon.

Configuration

If digital servos are used the SV_SPEED parameter can be set to 125 (or even higher). If slower analog servos are used set this parameter to 50.

CoaxCopter

  • A CoaxCopter is an aerial vehicle with two counter rotating central propellers thrusting downward past 2 controllable vanes (one side to side and the other from front to back) that permit control of roll and pitch.
  • Yaw is controlled by varying top and bottom propeller speeds relative to each other.
  • There are two variant motor configurations of the CoaxCopter:
    • A contra-rotating motor pair with both Propellers on top and the shaft of the bottom motor passing up through the hollow shaft of the top motor
    • And two motors mounted back to back with one propeller above and the other beneath with appropriate support struts.
    • Both variations are illustrated below.
../_images/vtol.jpg ../_images/mav_electric.jpg

Connecting the Flight Controller to the CoaxCopter:

  • Connect the APM, PX4 or Pixhawk servo output channels 1 and 2 to the CoaxCopters two control fins servos as shown (Note: the diagram below is incorrect, “Servo3” should be “Servo1” and “Servo4” should be “Servo2”).
  • Connect the APM, PX4 or Pixhawk servo output channel 3 and 4 to the ESC for the brushless motors that power the main dual rotors.
  • The two wide fins are attached to two cross arms and works a bit like the elevator and ailerons of a fixed wing plane.
  • Below is an illustration looking down on an APM/Pixhawk mounted on the frame. Note the warning re Servo3 and Servo4 being mislabelled.
../_images/CoaxCopterTopView1.jpg

Load the Firmware

  • For the time being, the user needs to compile the source code themselves.
  • Add this line to the APM_Config.h: #define FRAME_CONFIG COAX_FRAME
  • In the near future this will be added as a downloadable binary to firmware.ardupilot.org and likely as a Mission Planner loadable icon.

And a Video of a Research SingleCopter in action: