Not many people know but we have an piece of open source software for controlling an Antenna Tracker. It's been built by Tridge (Arduplane lead developer) for use in the outback challenge.
Sadly we have no documentation and, as far as I know, nobody except Tridge has used it. Still given Tridge's track record on building great software I suspect it works well and if it doesn't, I'm sure we can fix it. So to not let this piece of code go to waste, I'd like some help from people who are interested to give it a try and help me figure out how it works.
Here's the little that I know:
- It runs on any of our supported board (APM1, APM2, PX4, Pixhawk, Flymaple and perhaps VRBrain)
- For APM1/APM2 users building the code is as easy as opening our hacked ArduinoIDE and selecting File > SketchBook > Tools > AntennaTracker and then building in the normal way. For PX4/Pixhawk, our autobuilder doesn't automatically build a binary but I can provide one if people are interested.
- It can control a Pan and Tilt gimbal like this or this found on servocity.com.
- It may or may not require a GPS
- It must somehow receive vehicle position updates from the ground station which has the telemetry radio that is connected to the vehicle. Maybe through a USB cable. Tridge probably uses the python ground station, MAVProxy, to passthrough the vehicle position data to the AT but perhaps we can get MichaelO to build out a similar feature in Mission Planner.
- I imagine this antenna tracker could also be used to keep a camera focused on the vehicle which might be good for easing the burden on creating videos of our vehicles.
So if you want to give it a try please do and stick any findings, questions or issues below. Alternatively Issues can go into the issues list.
I'll start sticking things into the wiki as they become clear.
Replies
Hi all,
i want to test my AntennaTracker with SITL and i am wondering if anybody did this successfully ?
I have connected a second pair of 3DR radios to my computer and loaded the mavproxy tracker module.
Started SITL (ArduCopter) and with a `tracker start` it opens the correct device, i can configure the tracker in the console.
But it insists to track my virtual Copter. Dialing PID's down and up it at most behaved erratically shaking back/forth on yaw axis.
I am Using a HK micro apm on the tracker and standard servos with last AntennaTracker version or even compiled from master a few weeks ago i think.
Am i on the right track or should i better try outdoors with a real vehicle ?
Cheers
Linus
I used SITL a lot when I played around with firmware. I didn't use MAVProxys tracker module since it didn't work for me. Instead I just add an additional output to SITLs MAVProxy - in SITL manual search for "output add" command. That way I can feed virtual data into an actual tracker to see it in action just as Ted P described.
Ted - if the procedure you described doesn't work for you try uploading a simple mission with takeoff command and switch it into AUTO mode. You can do it either via MAVProxy or Mission Planner provided you add an output for it (output add x.x.x.x:14550). When you have Mission Planner connected to SITL you can use it to takeoff and fly around.
thanks for the hint Jakub,i tried that once but then found the tracker module.
Cheers
It's not clear if you are using a virtual tracker or not, but for my setup I am successfully using a SITL Arduplane with a REAL tracker. Depending on your tracker configuration there might be other parameters to tweak on the TRACKER. I also think that many people make the mistake of using the tracker too close to the vehicle. If your tracker has a GPS, then it will have "noise" on it making the vehicle appear to move relative to the tracker. In the worst case condition, if your vehicle GPS is on top of your tracker GPS, you've created a "singularity" where any small noise on the GPS location can make the tracker go crazy.
Thanks Ted for verifying!
Im using a real tracker and it was indeed a setup issue.
It came to life shortly after posting :)
Hi Linus,
I'm glad it worked for you. I've been meaning to test the tracker out with a virtual copter since it's possible to have the vehicle "fix" the location. I am trying to troubleshoot possible offsets in the tracker versus setting PID values. It's hard to do so on a plane vehicle since the plane has to always be moving.
I've never flown a copter before -- is the SITL procedure for copter the same as it is for plane? I.e. compile the code per http://dev.ardupilot.com/wiki/setting-up-sitl-on-linux/? For the plane, I just start it with "$ARDUPILOT_PATH/Tools/autotest/sim_vehicle.sh -L <mylocation> -v ArduPlane -w --aircraft <myplane>", issue an "ARM THROTTLE", and then a set rc 3 to something like 1400 to take off.
Thanks
-Ted
Copter works similar in SITL, i tried plane as well.
Here what i do usually:
sim_vehicle.sh -L EDDH -v ArduCopter --map --console --load-module=tracker --aircraft trackertest/
proceed with:
wp clear, wp list, wp draw, arm throttle, rc 3 1666, auto, tracker start, tracker calpress
My tracker works fine on yaw axis now but pitch does not work so far.
hi all is there a minimum distance before it works my one never points to the quad on testing at home
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