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patrickelectric / bluerov_ros_playground

Scripts to help BlueRov integration with ROS
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Nature of the values given to /BlueRov2/thruster_command for gazebo #45

Open GabrielWellander opened 3 weeks ago

GabrielWellander commented 3 weeks ago

Hello, I am currently trying to understand what kind of value the thruster_command accepts. Is it PWM, voltage, force, thrust force or something else? I saw in the BlueRov2_thrusters.urdf that the minimum value is -40.18 and maximal 49.98 . Are those the values that bounds the values put in thruster_command? Secondly, when I give the thruster_command an effort, I can see that according to the rostopic BlueRov2/thruster_use it is seen as position. Can someone help me understand this? Thanks in advance !

GabrielWellander commented 3 weeks ago

I saw that there is a link in the README file to the conversion from thrustforce(kgf) to PWM . According to the graph in the Google Colab sheet, the thrustforce is limited between -4 to 5. The PWM between 1100 and 1900 both according to the colab and the thruster data on the Bluerobotics website. But why are the thrusters in the BlueRov2_thrusters capped between the limits thrustforce*10 ?

As for now I have published directly to /BlueRov2/thruster_command in my code when using the gazebo.launch option. I have published thrustforce as effort in to the system but will switch to PWM. Is there anything I have missed?