Need Attitude Control: Issues with /setpoint_attitude/attitude and /setpoint_attitude/thrust

PX4 Autopilot Flight Controllers 💻
1

Hi all,

I am trying to send attitude and thrust commands in simulation but (as per the title) I have been unable to do so. In offboard mode, I am publishing thrust and attitude commands to /setpoint_attitude/attitude and /setpoint_attitude/thrust. I have a controller that determines the attitude to apply a desired force on the quadrotor. Since the attitude commands must be quaternions, I am converting the euler angles (from my controller) to quaternions using the tf.transformation library. I should note that the parameter /mavros/setpoint_attitude/use_quaternion is set to true.

I have two main issues:

  1. Cannot find throttle at hover.
  2. Attitude commands are seemingly doing nothing.

I am mostly concerned about the first point. How have people done this in the past? I have a script which makes the quadrotor hover at a desired height for 20 seconds. I save this throttle value and start publishing it to /setpoint_attitude/thrust alongside my attitude commands. However, the quadrotor immediately plummets and then hovers at around 0.5m above ground…

I have checked and I am publishing commands to the correct topics.

If anyone has got this to work, could you share some insights?

Thanks in advance!

2

is there an urge using thrust setpoints instead of position setpoints? You may try that.

Logs could also be helpful.

3

@mwbb I am trying to follow this work by Klausen to minimize oscillations when the quadrotor is carrying a suspended payload. It works by determining the desired attitude along a smooth path. I need the thrust setpoints as they are needed alongside the attitude commands.

If there was a way to hold altitude while sending attitude commands, this would be ideal. However, I haven’t been able to find anything online where that is the case - at least not a real solution.

Logs could also be helpful.

Also, I am fairly new to ROS and all this. I am using rosbag to keep track of the thrust cmds and position of my quadrotor. Is this what you mean by this?