Publishing online setpoints

[yanrui89]

Hi, would like to ask if anyone has any experiences with publishing setpoints in an online fashion, ie continuously publishing setpoints as Crazyflie is flying. I did notice that there's a function cmdFullState ('https://github.com/IMRCLab/crazyswarm2/blob/main/crazyflie_py/crazyflie_py/crazyflie.py#L502') and cmdPosition ('https://github.com/IMRCLab/crazyswarm2/blob/main/crazyflie_py/crazyflie_py/crazyflie.py#L618'). I tried to use them with the simulator but it didn't seem to be able to command the simulated Crazyflie to the defined setpoint.

I also noticed that the rostopic 'cmd_position' https://github.com/IMRCLab/crazyswarm2/blob/main/crazyflie_py/crazyflie_py/crazyflie.py#L192 is not available upon running the launch file ros2 launch crazyflie launch.py backend:=sim. The topic is only visible when running an example script for example 'ros2 run crazyflie_examples figure8 --ros-args -p use_sim_time:=True`. There also seemed to be no subscribers to the 'cmd_position' topic. While 'cmd_full_state' has a subscriber, however, even after calling the function cmdFullState, the drone did not move at all.

Thank you

[whoenig]

There is an example script for cmdFullState in https://github.com/IMRCLab/crazyswarm2/blob/main/crazyflie_examples/crazyflie_examples/cmd_full_state.py, which should work both with real flight and "simulation". Note that the current simulator just visualizes the setpoint (there is no notion of physics and a controller), so the crazyflie might jump if the setpoint jumps. cmdPosition is not supported in the simulator, yet, see https://imrclab.github.io/crazyswarm2/overview.html#support-functionality-with-backends (under manual control).

[whoenig]

Depends on the update rate you need to send the commands at. Shouldn't be a problem if 10 Hz suffice, but for 100 Hz you probably need at least 3 radios.

[Kaijun101]

I noticed that the script took setpoints from a csv file. What about if I want to publish different setpoints to multiple drones in real time, without the use of csv file?

[whoenig]

We have no example for this yet. Perhaps https://github.com/USC-ACTLab/crazyswarm/blob/master/ros_ws/src/crazyswarm/scripts/backgroundComputation.py can be an inspiration?

[yanrui89]

Hi! Sorry this has nothing to do with Crazyswarm but I was just wondering how was the figure8.csv file generated? Is the trajectory optimized for time? Would you be able to direct me to the appropriate package used to generate the figure8 trajectories? Thank you.

[whoenig]

We used https://github.com/whoenig/uav_trajectories. This does not optimize for time. Once can stretch a polynomial trajectory for slower/faster movement. With motion capture and Mellinger controller, the fastest practical factor is 0.8.