DragPlugin values

[JKhan01]

Hello Nishanth,

First of all your work is really impressive, i wanted a from scratch reference for drone simulation on ros without any over dependant libraries and your work is the only resource i could obtain. I tried to simulate my solidworks drone in ros referring your repo, but seems like due to some issue with physical parameters my bot doesn't lifts up though the quadcopter blades are moving in proper sense(Diagonally opposite in same sense). Do you have a reference for setting the values of libliftdrag plugin parameters? I tired setting them from my knowledge but to no avail. If you feel there might be some other issue causing the same please do let me know. Thank you in advance

[NishanthARao]

Thanks for reaching out.

The problem seems to be with one of the parameters of the plugin, which is the center of pressure. The three values that you provide in this . . . command are the coordinates relative to the parent link of the propeller joint. The force generated by the rotating propellers are applied at this coordinate. This coordinate must be present at the child link, which is the propeller itself. In your case, it seems that there is no link (propeller) present at this coordinate. I think if you set the right values just in the command, the issue will be resolved. Make sure to change the value to the total surface area of your propeller. Also, the and commands too, play an important role in lifting your quadcopter. Other than these, I dont think there is any other modifications necessary. For your convenience, I have enclosed some of the resources regarding this. http://gazebosim.org/tutorials?tut=aerodynamics&cat=physics

https://answers.gazebosim.org//question/15331/need-information-on-aerodynamic-parameters-of-lift-drag-plugin/

https://www.youtube.com/watch?v=I-dhwqxV7QM&feature=youtu.be

Let me know if you are facing any other issues.

Thank you.

[smntsc]

Hello Nishanth, i am building a drone looking at your project. By applying a constant speed to all 4 motors of the drone, it takes off but fails to stabilize despite, seeing that the speeds reaching the motors are the same. In your opinion this problem comes from the libliftdrag plugin that I didn't set the parameters well, in particular center of pressure (the drone is slightly different). I hope you can give me advice on how to move forward. Thank you in advance for your reply.