Subscriber in publish_external_position.py is not working in native Ubuntu

[mandelyoni]

Dear Wolfgang,

We're masters students from TAU university. We have been working with your great crazyflie_ros library for quite some time now on a VM (from Bitcraze) and an Optitrack system, and everything worked fine. Lately, we moved to use Ubuntu native 16.04 with ROS Kinetic and installed all libraries according to this GitHub and to the "Flying Multiple UAVs Using ROS" paper. For some reason, the subscriber in publish_external_position_vicon.py is not working (the messages are sent but onNewTransform is not activated). Any idea?

Thank you, Yoni

[mandelyoni]

I'm sorry, it's working now. Thanks, Yoni

[whoenig]

Perhaps you can describe how/what you changed to get it working and close this issue? Thanks for reaching out!

[mandelyoni]

I don't remember but I'll install it on another computer later this week and describe the process here.

[shmpwk]

Hi, I have a similar issue. When I execute roslaunch crazyflie_demo external_position_vrpn.launch Error is ERROR: cannot launch node of type [crazyflie_demo/publish_external_position_vrpn.py]: can't locate node [publish_external_position_vrpn.py] in package [crazyflie_demo]

Here is what I did: In catkin_ws/src, git clone --recursive https://github.com/bitcraze/crazyflie-firmware.git. I changed to ESTIMATOR ?= kalman CONTROLLER ?= Mellinger in Makefile. After that make.

I read #85 #89 #114 as a reference, following the explanation below

you will need to launch external_position_vicon [Which needs to be slightly changed to support Optitrack]. Then, in another terminal, execute python execute_trajectoy.py figure8withTakeoffAndLanding.csv.

a) Adjust the launch file to the vrpn_client b) Adjust topics names in publish_external_position (could simply be set to /tf) c) change frame names (according to motive names) in the high level script.

I've already finished the tutorial below. http://act.usc.edu/publications/Hoenig_Springer_ROS2017.pdf

What should I do to fix it? Thank you.

[mandelyoni]

#shmpwk - try chmod +x on the file

[mandelyoni]

Dear Wolfgang, it was just a topic name problem. We switched to the correct name and it was ok. THANKS FOR ALL YOUR HELP !!!

[shmpwk]

@mandelyoni Thank you for your reply. I tried chmod +x on the file but still have an error. In the first place, I'm not sure whether the process I've done is correct.

[whoenig]

You don't need to build a custom firmware anymore. The scrips switch to the kalman filter automatically; the kalman filter is part of the official firmware. Otherwise your steps seemed ok to me.