GeoFence Polygon Fence could be used as a Cable Cam function

A cable cam mode is something that I’ve always thought would be amazing to have. In the simplest implementation you would define and fly between two defined points, limiting the quad to fly a straight line between them. Speed along the line controlled by forward pitch with unrestricted yaw movement.

In the test flight video showing Daniel Rickette’s code you can slide along the fence boundary using forward stick with a little yaw in the direction you want to go. I could see how the fence boundary could be used to define the cable run and forward pitch controlling the speed. Yaw is the only limiting factor (using Poly Fence) for camera orientation but I could see a possible segway to a new mode!

I have to give this a try.


I have thought about this before. I think the cable cam would be a great add to the firmware.

I don’t think that the fence is a good way to go about it. Getting the fence where you want it is hit or miss setting it through mission planer or what have you. What we really need is a flight mode that is like auto but can control the progression of the mission the a knob on chan 7 or pitch on the controller. Moving though the mission speeding up lowwing down reversing would be very useful to getting great shots with the copter.

If we had something like this we could save waypoints with a switch on the controller then switch to “cable? mode” and move through the mission with rc input.

I Dont have a deep understanding of how the mission work but I think it would be hard to implement. I know you can do a jump from one waypoint to another but toi Dont have fine grain control. You either have 0 or 100% between waypoints.

Maybe the devs can chime in to explain what it would take to get something like this implemented.

Good points Tim… I’m using MP.

I was just thinking that maybe some Daniel’s concepts and work creating Poly Fence could be reused as a starting point for a real Cable Cam mode. Maybe, maybe not… as I also have very limited knowledge of what it takes to create or modify code into a new mode.
Your thoughts of being able to manipulate the mission (between two or even multiple points… speed and direction) with a knob or controller pitch would be good way to implement.
In it’s simplest form, I envision establishing 2 points (‘A’ and ‘B’) in Flight Plan and then switching to ‘Auto’ having the quad fly to a point between ‘A’ and ‘B’. Then the fun starts… The mode then would change into a simi auto control, keeping the flight path restricted to a straight line between points ‘A’ and ‘B’ but allowing speed, direction (between the two points) and yaw to be changed by the pilot (using perhaps your idea’s), Now we are talking a flexible Cable Cam for incredible shots.
Finally… I would love to get the take of the developers. Could they borrow from Daniel’s efforts with Poly Fence? Would they even want to? Sure would be interesting to hear what they would say.


While a cable cam mode might have similar behavior to a vehicle along the fence boundary, I doubt there would be any code shared between the two modes. However, I think it would be relatively easy to implement a cable cam mode because the position controller in ardupilot is so good. You would simply have to figure out how stick positions control movement along the cable. For example, does pitch position correspond directly to a speed along the cable? An acceleration? Is roll completely ignored? Once you figure this out, I think the implementation would be relatively easy.

HI Daniel… I sent you a PM… Please give me a call or respond to the private e-mail address I listed to talk over some ideas…


My reply to an email from Ralph,

Hi Ralph,

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My thoughts are to make a mode based on the existing mission navigation system. You would do a normal mission setup but instead of the aircraft traveling along the mission at maximum speed, the speed would be controlled by the throttle stick. So you could adjust the speed and heading.

We could also make the throttle stick go both positive and negative so you are able to move backwards along the path as well. This would require more work on the code though.

So I read through the chat. Using the channel 7 knob instead of the throttle is also good. Depends what people want to see.

Chat soon,

Hello, I’m trying to use the polygon fence. I draw the polygon and uploaded it but Mission planner, in Config/Tuning, doesn’t show me the polygon word in the drop-down fence menu.
What can I do to solve this problem, please?

INfo: Pixhawk Ac3.4.2, Mission planner 1.3.41.

Best regards