4 crazyflies 2 crazyradio LPS with ROS

Discussions about autonomous flight in general, regardless of positioning method
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lorenzo92
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Posts: 2
Joined: Fri Oct 12, 2018 9:54 am

4 crazyflies 2 crazyradio LPS with ROS

Post by lorenzo92 » Fri Oct 12, 2018 10:44 am

Hi,
I'm using ROS on a virtual machine of linux 16.04
I would like to autonomously drive 4 CF's with the help of LPS (6 anchors) in ROS environment, but I got stuck.
I've followed the: https://www.bitcraze.io/getting-started ... yflie-2-0/ to update the firmware of all the 4 crazyflies.
I've followed the: https://www.bitcraze.io/getting-started ... ng-system/ for setting the Loco Positioning System in the right way.
I've launch the: dwm_loc_ekf_hover.launch with a 6 anchors setup in both TWR and TdOA mode, and it works!
In TdOA I've even tryed with 2 CF's and it works!
Now I'm trying to launch the: dwm_loc_ekf_swarm_hover.launch with 4 CF's but I found necessary to add another Crazyradio.
So I' ve put 2 CF's on one Crazyradio and 2 CF's on the other Crazyradio changing the dwm_loc_ekf_swarm_hover.launch with the appropriate URI:

<arg name="uri0" default="radio://0/80/2M/E7E7E7E701"/>
<arg name="uri1" default="radio://1/70/2M/E7E7E7E702"/>
<arg name="uri2" default="radio://1/70/2M/E7E7E7E703"/>
<arg name="uri3" default="radio://0/80/2M/E7E7E7E704"/>


Unexpectedly the result was something like this:
Schermata 2018-10-12 alle 10.55.32.png
Could anyone help me in find what could be the problem?
Thank you very much.

P.S:
I'm pretty sure that the previous URI setup is correct because implementing it in the multi_teleop_xbox360.launch (https://github.com/whoenig/crazyflie_ros) I could manually drive the 4 CF's.

arnaud
Bitcraze
Posts: 1752
Joined: Tue Feb 06, 2007 12:36 pm

Re: 4 crazyflies 2 crazyradio LPS with ROS

Post by arnaud » Wed Oct 17, 2018 8:33 am

There error look like you have not recompiled your ros workspace correctly: the service checksum error appears when the C and Python parts are out of sync. You can make sure everything is in sync by running catkin_make in your workspace root and making sure you are sourcing devel/setup.bash from the right Workspace in all your terminals.

lorenzo92
Beginner
Posts: 2
Joined: Fri Oct 12, 2018 9:54 am

Re: 4 crazyflies 2 crazyradio LPS with ROS

Post by lorenzo92 » Wed Oct 17, 2018 9:19 am

Hi arnaud,
Thanks for reply,
I've already tried to catkin_make the ws in a "clean" way (I've deleted both build and devel directory and I've done catkin_make).
I' ve the following line in my .bashrc:
source /opt/ros/kinetic/setup.bash
source ~/crazyflie_ws/devel/setup.bash
So I think this is correct.
The very strange thing is that with the same: dwm_loc_ekf_swarm_hover.launch with 2 CF's works everything, the issue is when I add the 3rd (and 4th) CF's.
Any other idea on what could be the problem?
Thanks a lot for helping me.

arnaud
Bitcraze
Posts: 1752
Joined: Tue Feb 06, 2007 12:36 pm

Re: 4 crazyflies 2 crazyradio LPS with ROS

Post by arnaud » Thu Oct 18, 2018 8:25 am

Hi,
Unfortunately I do not have any more ideas other than the checksum error message should definitely not happen in a well configured and compiled ros workspace. You could try to post a ticket on the crazyflie_ros git repos, they might have an idea of what could be happening.

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