Position Hold flights at High Altitude with the OptiFlow Tricopter (OFT) v1

Successful high altitude (>100m AGL) position hold tests flights with an optical flow sensor on a Tricopter (OFT) UAV.
Tests flights:
1) Fast climb rate to about 100 m AGL in hold position mode with only the throttle command.
2) At 100 m AGL, a 360° turn has been done (wind 14 km/h from SE) with only the yaw command.
3) Fast descend from 100 m AGL whith the horizontal stabilisation active.

All the tests flights have been recorded with a GoPro HD Wide video camera

More infos at:

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  • Developer
    Yes, but this is only a lens problem...
  • Moderator
    From the video clips of Flymentor I get the feeling that it only works weel at less then 2-3 feet.
  • Developer

    Hello Brent, yes one of the key of the success is the tuning of the lens... You need to change the original lens by a better quality lens and conducting a fine tuning of the focus. For the primary test a good contrast is required and a strong sun light too.

    Regards, Jean-Louis

  • Nice work, did you replace the lens with a better quality one or just adjust the focus of the current one? Never had consistent results with the FM position hold and suspected the lens focus was bad. Would love to be able to correct that as it is a nice unit.

  • Developer

    You will find another low cost (74 $) Optical Flow system (equivalent to the Helicommand) which can also be used (and tuned) HERE.


    Regards, Jean-Louis


  • Developer

    Hello Randy, the setup is very simple because I use a ready made Optical Flow system which is used in a flight stabilizer for helicopter "Helicommand Rigid" mad by Captron. This is a low cost system that I have previously used in my RC helicopter. I have simply improved the optical system (the lens) of the CCD sensor so as to increase its accuracy at high altitude and also I have conducted a very fine tuning of the Helicommand setup and its parameters.

    There are two stages in the stabilisation process:

    1) the low level stage is done by the KKmulticontroller board and it firmware (XXcontroller_KR_v1_5b (JLN version)). This is now one of the best and very simple (but very efficient) stabilisation system that I have ever tested in various weather conditions. With this stage, the tricopter or the quadcopter can be compared to a common and basic rc bi-rotor helicopter and can be piloted by any Newbie...

    2) the high level stage is actutally done by the Optical Flow system from the Helicommand.

    This is a very simple setup which use common parts and which can be replicated by anyone. This was one of the purpose of my test...

    See the diagram below:


    Regards, Jean-Louis

  • Developer

    very interesting.  Can you share more details on the tech you use?  i.e. what camera?  What converted the image into direction information that you could counter?  for the horizontal position control, do you counter for roll/pitch of the quad?


    @Hai Tran - you're right - arducopter does need optical flow too.

  • Developer

    Here a new video of tests flights done on the same day at another place:

    Position Hold flights at High Altitude with the OptiFlow Tricopter ...



  • Developer

    Hello abey, Thanks for your comments. You proposal is interesting.

    You will find below a high altitude Position Hold test with optical flow done by another guy with a camera downward. He has used setup than the mine but set on a helicopter. After that I have seen this video, I have decided to conduct the same experiment with my Tricopter.

    HeliCommand 3A - Modified Position Hold

    Regards, Jean-Louis

  • Interesting work. Any chance to have the same flights with the the camera pointed downward? It would better illustrate the lateral stabilisation achieved by the optic flow sensors.
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