3D Robotics

Proposed next T3 round: simulations

Gary Mortimer and I are leaning towards a simulation round for the next T3 contest, but I need some feedback about what would work best.

There are two kinds of simulations: "open loop" and "closed loop".

Open loop means that you connect the output of the simulator to the input of the autopilot. The simulation drives the autopilot with synthetic GPS coordinates and sometimes synthetic attitude data, essentially replacing the autopilot's sensors. This basically fools the autopilot into thinking that it is flying, and you can watch how it responds. This is typically done by having the simulator output data via the serial port and feed that into the autopilot.

Closed loop means that you also connect the output of the autopilot to the input of the simulator, so that the autopilot is "flying" the aircraft on screen. This usually requires a relatively complicated bit of hardware that converts the PWM servo output of the autopilot into what amount to joystick commands via USB or serial that steer the plane in the simulator. It can also be done entirely in software on the host PC, as in the case of Matlab simulations being driven by a flight simulator.

Here are some blog posts that show examples:

--Curt Olson's FlightGear demo

--Faisal Shah closes the loop, Part 1

--Faisal Shah closes the loop, Part 2

Here's a proposed contest structure:

Two sets of winners:

Both must write "DIY" (in cursive) over a place of their choosing.

--Group One: Open loop (video showing you mirroring the airplanes control surfaces with the arrow keys): First six to complete this win a $25 gift certificate to the DIY Drones store.

--Group Two: Closed loop (aircraft controls the flight simulator): First three to complete this win a $50 gift certificate.

What do you think? Is this doable?

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  • does anyone know another flight simulator that can be used as I have downloaded flight gear and installed it in all three computers plus laptop in my house and it runs really badly.

    I may be doing something wrong because it does not run smoothly at all.
  • T3
    It's a little too easy for some of us http://www.vimeo.com/10525732
  • 3D Robotics
    @Curt, great news about the code/tutorial on using ArduPilot as a closed-loop PWM reader. Can't wait for that!

    In the meantime, we could of course tweak the code to send the PWM commands (in whatever format FlightGear needs) out via serial. It's an easy thing, just taking a line or two of code.
  • Moderator
    Ah I did'nt see the points based conversations, I was going to bring in the people that have volunteered to help this time and have a committee decision!

    No doubt several;people have already got their simulations ready to enter just waiting for the official thread.

    Perhaps we should reward everybody that enters successfully with 4 points as Brian suggests.

    Maybe the top prize should goto somebody that properly documents how they went about it and creates a useful section for others to use afterwards.

    I was all for having a simulation of all the T3 rounds so far.but that might have been a bridge too far, still if anyone managed that and a good explanation it might be good ;-)
  • Moderator
    Oh bring that aeromatic option Curt, that would be very handy, especially for wings!
  • T3
    What about using time to complete the run or size of lettering?
  • Chris,
    I think that the success or lack of such for most of the things we do with UAVs are often best measured in terms of quality, not quantity. I therefore think we need to include evaluation of quality in some way, even if there will be a problem with regard to objectivity. A way to minimize the impact of subjectivity could be to let the participants give points to each other - according to one or more pre-defined criterias. (Would reduse the blame on Gary and you as well).
  • Moderator
    I think it would be best to base the winners on quality and not speed, however rewards should be added for the first ppl to complete a simulation. for example give bonus points to the first few people who have completed a system first, and then after all the entries are in compare them all to find the best overall?

    for example rate each simulation out of 20 or some other number as appropriate
    then give the first person to completion a bonus of say 5 points
    second person to completion 4
    third 3 or something like that?
  • T3
    This could be more an exhibition round. 4 points to everyone who does an open loop sim and 6 to everyone that does a closed loop. Maybe shorten the time as well to 2 or three weeks? Of course Gary always has the right to add "style points" to those who do something extra.
  • 3D Robotics

    You're right--I haven't figured out how to make it a real competition in any way other than "completion is victory". Can you think of a way to allow people to compete in simulations in a way that's fair and verifiable? I'd love to tweak the competition to include that..
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