DroneShell commands not working properly

[Thusheep]

I encountered several problems using DroneShell. Fistly, when using the "takeoff" command the drone doesn't take off properly as shown in the AirSimDemo Video (https://www.youtube.com/watch?v=HNWdYrtw3f0), but it takes off just a little bit above the ground, rotates around the z-axis and finally stays at that height giving out "using minimum takeoff altitude: 2.5m". In fact the altitude changes from alt=121.59 at the bottom to alt=123.6. When I try "takeoff" again, it tries to correct itself while staying at the same point or it fails and either goes crazy or flies away.

Another problem is when I try to use for example the "movetoposition" command (e.g to move along the x-axis or up the z-axis), the drone just goes crazy by tilting itself abruptly or unrealistically turning around pitch/roll-axis. Then it crashes or flies away giving me the message "RPC Error: rpclib: function 'moveToPosition' threw an exception. (...) lookahead error is continually increasing so we do not have safe control, aborting moveOnPath operation". Does someone has a solution or had the same problem? Is it possible to remove lookahead in the codes?

Also what seemed strange was whenever I hit the play button in UE4, the rotors of the drone are already rotating without having to "arm" it. But when I want to take off or at least try to move it, I have to "arm" it first.

Furthermore, when trying to land with the "land" command, an error emerges, saying "Drone hasn't reported a landing state." Then it flies away or crashes.

An example picture when failing:

Would be very happy if someone can get me some answers.

[lovettchris]

First try removing the camera views, those can slow down the FPS so much that flight goes crazy. Press "0". Second, takeoff will not work well if the altitude is still drifting, which can happen very early on as shown below:

Global position: lat=47.6415, lon=-122.14, alt=122.849 ==||=> arm ==||=> takeoff ==||=> pos Loc==||=> al position: x=-0.025743, y=0.00627603, z=0.224974 Global position: lat=47.6415, lon=-122.14, alt=125.345

In the above case takeoff didn't work, it jumped a bit then landed again. Notice that while it was on the ground the altitude has changed from 122 to 125. Well the default takeoff altitude is only 3 meters, so that's why it is still on the ground. You could change the default takeoff altitude to 10 meters and avoid this problem. That default lives in a method called getTakeoffZ.

But notice, that if I disarm and rearm and try again the following happens:

disarm ==||=> pos Lo==||=> cal position: x=-0.0502019, y=0.0255267, z=-1.55482 Global position: lat=47.6415, lon=-122.14, alt=127.125 pos Lo==||=> cal position: x=-0.0532834, y=0.022402, z=-1.82069 Global position: lat=47.6415, lon=-122.14, alt=127.391 pos Lo==||=> cal position: x=-0.0536345, y=0.0223744, z=-1.88103 Global position: lat=47.6415, lon=-122.14, alt=127.451 pos L==||=> ocal position: x=-0.0541674, y=0.0207134, z=-1.90378 Global position: lat=47.6415, lon=-122.14, alt=127.474

--> Ok, the altitude looks stable at 127, so let's try it:

arm ==||=> takeoff ==||=> pos Lo==||=> cal position: x=-0.037124, y=0.0238937, z=-3.90122 Global position: lat=47.6415, lon=-122.14, alt=129.471 ==||=> pos Lo==||=> cal position: x=-0.0379395, y=0.00927103, z=-4.09609 Global position: lat=47.6415, lon=-122.14, alt=129.666 ==||=> pos Lo==||=> cal position: x=-0.0489082, y=0.00391759, z=-4.12483 Global position: lat=47.6415, lon=-122.14, alt=129.695 ==||=> pos Lo==||=> cal position: x=-0.0465968, y=0.00254618, z=-4.10829 Global position: lat=47.6415, lon=-122.14, alt=129.678

This time it is really flying and hovering at the 3 meter mark.

I do also notice a bit of yaw in the takeoff process, and this needs to be debugged. I suspect it is because the PX4 takeoff command does allow us to pass a target Yaw and we always pass zero, so if the drone is not already pointing north it will try to point north. Perhaps what we should do instead of pass in the "current yaw" so it just stays pointing in the same direction as it is on the ground... That should be an easy fix. In fact I might try that right now :-)

[JohnDing1995]

About the "movetoposition" command and look ahead error, I have same problem with you. I just removed lookahead_error_increasing++; in DronecontrollerBase.cpp. But I must notice you that ,through the airsim will not throw any exception after alterDronecontrollerBase.cpp ,but the drone still gone crazy.

[Thusheep]

@lovettchris. Thank you for the quick response. I changed the default takeoff altitude to 10 meters but unfortunately the problem still exists. When I try what you did this happens:

Global position: lat=47.6415, lon=-122.14, alt=121.439 ==||=> arm ==||=> takeoff ==||=> pos ==||=> Local position: x=-0.0466042, y=0.00448658, z=-1.04317 Global position: lat=47.6415, lon=-122.14, alt=122.535 pos ==||=> Local position: x=0.0183662, y=0.00356221, z=-1.029 Global position: lat=47.6415, lon=-122.14, alt=122.521

It jumps a bit. Then lands and afterwards takes off again and hovers a little bit above ground. (Sometimes it even goes crazy just after the "takeoff" command.) Now when disarming, the position gets confused and won't stay at a specific altitude:

pos ==||=> Local position: x=-0.0947815, y=3.51845, z=4.70571 Global position: lat=47.6415, lon=-122.14, alt=116.801 pos ==||=> Local position: x=-6.81824, y=7.18336, z=14.2944 Global position: lat=47.6414, lon=-122.14, alt=107.212 pos ==||=> Local position: x=-20.381, y=14.0502, z=33.1286 Global position: lat=47.6413, lon=-122.14, alt=88.378 pos Lo==||=> cal position: x=-40.6146, y=23.317, z=69.9199 Global position: lat=47.6411, lon=-122.14, alt=51.705 pos Local posi==||=> tion: x=-65.3946, y=33.6523, z=116.552 Global position: lat=47.6409, lon=-122.14, alt=4.954 pos Local position: x===||=> -97.5509, y=45.8445, z=178.032 Global position: lat=47.6406, lon=-122.14, alt=-56.524 pos Local position: x===||=> -46.3215, y=13.9408, z=70.8558 Global position: lat=47.6411, lon=-122.14, alt=50.65 pos Lo==||=> cal position: x=-76.1005, y=19.8596, z=114.785 Global position: lat=47.6408, lon=-122.14, alt=6.721 pos Lo==||=> cal position: x=-119.27, y=26.7006, z=176.355 Global position: lat=47.6404, lon=-122.14, alt=-54.847

Now if I "arm" again, the drone just goes totally crazy, takes off and flies away. Just by typing "arm".

However once or twice somehow by luck your method worked and the drone properly took off. But when I tried to use "movetoposition" in x or y direction, quickly the lookahead error emerged and drone went crazy (but z-direction worked). Do you have any suggestions?

Now @JohnDing1995. Also thank you for your response. I tried this but it doesn't seem to be the correct solution. The lookahead error came up anyway (after rebuilding) and drone goes crazy.

[clovett]

Those numbers also show unstable x and y, not just altitude, and this would be a real problem. We need to debug that first. It would be interesting to look at the HIL gps mavlink messages being sent to the px4. If you are on windows you can use our logviewer to do that, it is in the repo, we also have docs on that.

[lovettchris]

One more tidbit, to tell the drone to hover after a command completes set this PX4 parameter:

param set COM_OBL_ACT 1

The default is "land". So if the drone keeps landing all the time, this might be the solution.

[Thusheep]

Now I can takeoff and the drone hovers at about 1m above ground but when trying move commands like 'movetoposition' it throws following error: ==||=> Async Error occurred: rpc::timeout: Timeout of 5000ms while calling RPC function 'moveToPosition'

Also the logviewer is not working. This happens when trying to build:

The alternative "click once installer" isn't working either. It just gives me a Windows error.

Also how can reenable the 3 views? I somehow removed them. Or where exactly should I press "0"? Thank you.

[Timebutt]

Hi @Thusheep, I had the same error building the Logviewer project. The problem lies in the difference between using a '.' or ',' as decimal mark. If you are in the US, your compiler defaults to CultureInfo=en-US and will have no problem to build. If you are in Europe - like me - and your culture uses a different decimal mark, the build or program execution will fail.

To solve this, I added these two lines of code in the MeshViewer() constructor (inserted after line 37):

Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
Thread.CurrentThread.CurrentUICulture = new CultureInfo("en-US");

You'll need use these packages to get everything up and running:

using System.Globalization;
using System.Threading;

After that, the solution will build and you'll be able to use the LogViewer.

@clovett, my approach will fix the problems others may have building the LogViewer, but I'm not sure if this is a clean way of fixing the issue at hand? I'm not used to programming in C#, maybe there is a better way to set the CultureInfo fixed to en-US. If this is ok, I'll post a pull-request.

[clovett]

thanks for the fix, I think I found a slightly more localized way to do this since it should only be an issue for parsing the loaded mesh data. See my fix.

[nirmita123]

@Thusheep , it looks like I am facing a similar so if you found a solution for this could you please share it here . Thanks

[tklinterg]

I've got a similar problem. When trying to use the 'MoveToPosition' in the dronehell or the HelleDrone project, the drone goes crazy. Could it be that the sensors detect an obstacle and try to correct the drone somehow and this sends the drone downwards spiral ?

I'm using the PX4 in the SITL mode when running the projects.

Any support is much appreciated.

Thanks.