Using Multiple Instances of ardrone_autonomy

[parcon]

I am curently working to get multiple ardrones flying at the same time from a single desktop. I've built a simple launch file to create an instance of ardrone_autonomy in a namespace called "quad1". I also pass in ip arguments and a statement to handle which controller each drone is to be commanded from. My question is this: Even with compiling a second copy of ardrone_driver and attempting to run it along side the first instance of ardrone_autonomy, the second ardrone_driver fails. Does anyone know a way to resolve this error?

I see this error message:

[quad1/ARdrone-1] restarting process
process[quad1/ARdrone-1]: started with pid [17386]
Using custom ip address 192.168.1.10
Wait authentification
Wait authentification
Wait authentification
===================+> 192.168.1.10
[ INFO] [1360280789.946051099]: Root Frame is: 0
[ INFO] [1360280789.947098353]: ~cov/imu_la set to [0.1, 0, 0, 0, 0.1, 0, 0, 0, 0.1]
[ INFO] [1360280789.948039719]: ~cov/imu_av set to [1, 0, 0, 0, 1, 0, 0, 0, 1]
[ INFO] [1360280789.949083298]: ~cov/imu_or set to [1, 0, 0, 0, 1, 0, 0, 0, 100000]
[ WARN] [1360280789.949989201]: Automatic IMU Caliberation is active.
[ INFO] [1360280789.950096522]: using default calibration URL
[ INFO] [1360280789.950166558]: camera calibration URL: file:///home/parcon/.ros/camera_info/ardrone_front.yaml
[ INFO] [1360280789.953101752]: using default calibration URL
[ INFO] [1360280789.953193572]: camera calibration URL: file:///home/parcon/.ros/camera_info/ardrone_bottom.yaml
Deleting Profile -cea48d22
Deleting Application -e182b69b
Input device Teleop added
Starting thread video_stage
Starting thread update_ros

video stage thread initialisation

Video multisocket : init 2 sockets
Video multisocket : connecting socket 0 on port 5555 UDP
Thread update_ros started

• Connection failed
  Video multisocket : connecting socket 1 on port 5555 TCP
  Failed to open AT
  Starting thread navdata_update
  Starting thread ardrone_control
  VP_Com : Failed to open socket for navdata
  PA : Start thread thread_academy_download
  Academy download stage resumed
  MEMORY SPACE ALLOWED : 40 MB
  Start thread thread_academy
  Start thread thread_academy_upload
  • Connection failed

video stage thread ended

Academy download stage paused
[ INFO] [1360280795.015007096]: SEND: CAT_COMMON/altitude_max = 2500.000000 (DEFAULT = 3000.000000)
[ INFO] [1360280795.015084296]: SEND: CAT_COMMON/enemy_colors = 2.000000 (DEFAULT = 1.000000)
[ INFO] [1360280795.015169021]: SEND: CAT_APPLI/navdata_options = 268435456.000000 (DEFAULT = 65537.000000)
[ INFO] [1360280795.015248827]: SEND: CAT_USER/euler_angle_max = 0.087000 (DEFAULT = 0.209440)
[ INFO] [1360280795.015302954]: SEND: CAT_USER/control_yaw = 1.750000 (DEFAULT = 1.745329)
[ INFO] [1360280795.015363624]: SEND: CAT_APPLI/bitrate = 4000.000000 (DEFAULT = 1000.000000)
[ INFO] [1360280795.015419406]: SEND: CAT_SESSION/max_bitrate = 4000.000000 (DEFAULT = 1000.000000)
[ INFO] [1360280795.015475310]: SEND: CAT_SESSION/detections_select_h = 32.000000 (DEFAULT = 0.000000)
[quad1/ARdrone-1] process has died [pid 17386, exit code -11].
log files: /home/parcon/.ros/log/7240ab1e-717e-11e2-a955-1c6f65c6b0bc/quad1-ARdrone-1*.log
respawning...
[quad1/ARdrone-1] restarting process
process[quad1/ARdrone-1]: started with pid [17607]
Using custom ip address 192.168.1.10

[tomh05]

I'm trying to do the same thing and get the same error. If I run them directly using rosrun (re-exporting the ROS-NAMESPACE variable) it also crashes, but displays it as a Segmentation Fault.

[richardw347]

Hi guys, I've been messing around trying to get this to work too. I've managed to get it working but not completely. I started just adding some good old fashioned print statements to figure out what was causing the second ardrone_driver to crash.

I found that commenting out the shared_raw_navdata->navdata_demo.bat line in the initialization part of the main loop and just giving it a dummy value (e.g. 99 ):

 ROS_INFO("Successfully connected to '%s' (AR-Drone %d.0 - Firmware: %s) - Battery(\%): %d",
                         ardrone_control_config.ardrone_name,
                         (IS_ARDRONE1) ? 1 : 2,
                         ardrone_control_config.num_version_soft,
                         /*shared_raw_navdata->navdata_demo.vbat_flying_percentage*/99);

And setting the realtime_navdata parameter to true for the second driver works up to a point. I can now run two drivers at the same time and am getting video back from both drones but I'm only getting navdata from the first (unaltered) driver.

I'll keep working on it but maybe someone with a little more experience with C++ (I've only been using it for a few months) and the drone navdata could chime in on this?

[richardw347]

Looked into this a bit further and the problem seems to be with opening UDP ports as the second driver fails to open the ports for both NavData and AT commands. So unfortunately it looks like a bug within the SDK when I have more time I'll get all the details together and post this as an issue on the Parrot boards. In the meantime though I've been looking at the work of Jaroslav Halgašík, he's managed to get control of multiple drones from a single computer (without video). His blog has more details (warning it's in Czech):

http://yerrix.blogspot.cz/search/label/AR.Drone

Alternatively they've written a conference paper on the work (in english):

http://aa4cc.dce.fel.cvut.cz/sites/default/files/downloads/publications/ardrone-ecc2013.pdf

So perhaps for multi-drone support we could forget about the sdk and just handle the navdata and at commands in the driver?

[pathammer]

Hi everybody!
Just wondering if there has been any progress on this issue? Mani Monajjemi was kind enough to point me to AR Drone Node.js where apparently they have control of several drones by the same machine. I tried linking ardrone_autonomy with the latest ARDroneLib files but got the same result - first drone works, second cannot launch. I would still prefer an integrated ROS solution over node.js. Thanks!

[pusnik]

Any progress on this? Has anyone had any success flying multiple drones with ROS driver?

[pathammer]

I tried recompiling with the latest version of the ARDrone SDK but it did
not help. Since then I have been controlling using one computer per ARDrone.
On Apr 19, 2013 4:02 AM, "pusnik" notifications@github.com wrote:

Any progress on this? Has anyone had any success flying multiple drones
with ROS driver?

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/56#issuecomment-16640693
.

[pusnik]

I have some great news regarding this issue. I am now able to fly multiple drones with 1 PC.
The issue is in the ArDrone SDK in the file vp_com_socket.c around line 100.
The problem is when the second drone node tries to bind client's IP (PC) with the socket, so that the drone can constantly send navdata to it. Here the error is received, and node crashes.
Binding cannot be done, because the socket is already taken and binded by the first drone. So there is no need to bind it again.

This is the quick and ugly fix that should get multiple drones running. I already notified Parrot so I hope that they will fix this issue soon in the SDK.

case VP_COM_SERVER:
name.sin_addr.s_addr = INADDR_ANY;
int bind_err = bind( s, (struct sockaddr*)&name, sizeof(struct sockaddr));
if (bind_err < 0 ){
//res = VP_COM_ERROR;
res = VP_COM_OK;
}

More testing will be done on friday. I will post some result.

[mani-monaj]

@pusnik That is a really good news.Please update this thread with your new results.

[pusnik]

I performed a simple testing controlling 2 drones from 1 pc. Reading navdata and publishing commands worked perfectly. I didn't try if the video feed is working from both, but I expect it does.

[pathammer]

I can also confirm this fix works. Drove two drones under continuous cmd_vel control simultaneously

[tomh05]

I can't get this to work on my Ubuntu Fuerte setup - still reports the original error message. I've changed that file, deleted old builds in Soft/Build/targets_versions, and rerun build_sdk and rosmake. Am I missing something? Thanks.

[pusnik]

I am guessing the updated file didn't compile. Check if you really compiled it. Simple printf statements in modified file should do it.

[tomh05]

Yup, you're right - a fresh checkout did the trick. Video feeds work great too. Thank you for your help!

[sananeji]

hi i'm new in this and i don't know to make the change that you do. i'm using the package of ardrone_autonomy and i can't connect to parrot because this make a mistake when i connect the second drone

[mikeclement]

Hi All, I'm curious to know if any further work has been done on this. After applying the advice given above to bba0028, I was getting negative results on two quads joined to an access point. The first quad would come up fine (control, video, and navdata) running ardrone_driver with vanilla parameters. Then, running a second instance using the '-ip' parameter, I would get full connectivity to the second quad but lose connectivity to the first quad. Perhaps the previously-posted solution no longer works in light of more recent SDK versions?

I've done some further analysis and put together a solution based on UDP port remapping that appears to work fine for control, navdata, and video for multiple quads (tested on up to four v1.0's at once); my notes are posted here:

http://hacked10bits.blogspot.com/2014/02/multiple-ardrones-from-single-computer.html

Anyway, I've reached out to a couple people on this thread individually for feedback, but wanted to find out from the larger user community if anyone is having success using another approach. If not, is there interest in contributing this back into master (or groovy-devel, etc)? Cheers!