@Chambana, that change is sitting in my precland12 branch. I'm not sure if I'll include it in Copter-3.4 or not. I need to be sure that it's an improvement. I haven't been able to finish that off because I'm working on some architectural changes with Leonard to make the motors library use -1 ~ +1 inputs instead of the current (slightly strange) -4500 ~ +4500 and 0 ~ 1000 ranges.
@Chambana Let me know if you try out Randy's precland12 branch. I played around with it a bit after making some modifications. I like how Randy arranged the code ...... Conceptually, it is a move in the right direction, but it hasn't undergone the same amount of testing as the existing position controller.
I'll give it a shot. I find that I'm getting the same level of precision with IR lock as I am with opencv derived landing_target messages, so I think I may be pushing the limit of the flight controller code in master.
@Chambana Thanks for the feedback..... After much testing, I think a critical issue is that the altitude and angle-to-target readings become less reliable at low-altitude... Lidar Lite has a minimum range of 20cm, and the camera sensor is not as useful when the target is at super-close range.
@ThomasSFL Another factor is the quality of your loiter. Per above, I’ve been flying with optical flow indoors. I changed the surface flooring to a more detailed/textured surface and it significantly improved my precision landing using IR Lock. I dont know if I’ll be able to replicate that level of precision outdoors using GPS though. At this point, I dont think the EKF will fuse optical flow with GPS.
@a7scenario Thanks for the update. :) Yes, you are exactly correct. The precision landing cannot perform any better that the loiter performance (using the existing control method) .... The loiter performance depends on the velocity measurements. So if your optical flow is providing better velocity readings than IMU+GPS, your results make perfect sense.
@a7scenario However, one of my concerns is the robustness of the optical flow measurements. Have you had a good experience using optical flow? ... It is suppose to be able to work outdoors as well.
@ThomasSFL When using the PX4Flow indoors with a large amount of incandescent light, focused lens, and a highly textured floor, the optical flow provides a very stable loiter. With an untextured surface, it performs horribly. With a “semi textured” surface, it seems to have a similar loiter to what GPS can provide. It’s a hell of a lot cheaper than a motion capture system, but it’s (one of) the first things to impact the ground on a crash and I’ve had the sensors crack on me. Also, if you have anything dangling from your quad, using the px4flow will end up causing your quad to veer into the nearest wall. I really wish there was an off-the-shelf platform (like the solo) that had working optical flow , as px4flow takes some time to configure. I think the bebop 2 will eventually support optical flow on ardupilot, but not sure what the status is on that. Between the LIDAR lite, PX4Flow, and whatever you’re trying to accomplish on your companion computer, you’ll spend quite a bit of time “fiddling” with cables and settings trying to get your indoor platform back up and running after a crash.
That's right. Our EKF doesn't fuse GPS and optical flow.. it can fail over from GPS to optical flow but it doesn't use both at once.
It would be possible of course, someone just needs to sweet talk Paul Riseborough
@a7scenario Thanks for the candid reply. :) I have a long list of IR-LOCK users working toward more reliable precision landing controls. The velocity estimation is a fundamental component of the controls performance, so Paul's work is very important. And it is interesting that you may have got better velocity estimations with optical flow ... However, I do a lot of outdoor development, so I probably can't rely on optical flow very much (unless it is automatically fused, as Randy mentioned).
@a7scenario ... also, if you are using optical flow indoors, the controls can behave much better due to the absence of wind.
@ThomasSFL Saw your post on diydrones. Awesome work on the “guaranteed" precision landing. Is the modified firmware available yet?
We ordered a Volta 4Gmetry III a couple of weeks ago, and it arrived today. After unpacking it, I realized that we could just ordered the ODROID-XU4 and save some money. The Volta doesn't even include a power supply and the available documentation is really bad and out of date. You are pretty much paying over $200 more for just an USB chinese cable adapted with a DF13 connector to connect to the Pixhawk. Ouch! For security reasons here in the US, we cannot even use 4G for our project. Grazie Mile, Silvio!
Trying to find getting started guides. Or any sort of documentation. Any help?
hmm, I can't seem to see docs.valtarobots.com:
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Hello, Has anyone used the 4Gemetry with a Pixhawk 2 ? I would like to try it while also using the uAvionix Ping 2020 transceiver. Thanks
Hi Silvio. I have done it with both Pixhawk 2 AND Qualcomm Snapdragon Flight. I am presently a QUALCOMM DEVELOPER ADVOCATE for Qualcomm Flight, as well as other new products in the pipeline. We just did a 1000 flight test using 4G LTE Control. https://www.qualcomm.com/news/onq/2017/05/03/qualcomm-technologies-releases-lte-drone-trial-results I've sort of become an expert in the subject. If you need any more information please ask and I can provide you with a copy of your test result report when it is published.
@billrock that is really cool to hear about. Can I contact you for more information? My email address is email@example.com
Hi, I'm considering to buy 4Gmetry to connect remotely to my rover. My question is Has 4Gmetry any restrictions about internet dataplans? I would like to use a Tmobile unlimited dataplan for smartphones.
I'm not sure if this chat group is very active. It may take a little while to get your answer.