Linearization issues on asbQuadcopter model.

Hi!

I am trying to use the asbQuadcopter template to simulate a drone with different parameters than Mambo or Rolling Spider. However, I am having problems linearizing the airframe plant of this new drone. I am using the trimLinearizeOpPoint function provided in the project but does not seem to give a good result. In fact, if I apply this function for the Mambo parameters, it does not work well either. The state space representation matrices generated this way are totally different to the ones that are by default (linsys) in the model. Therefore, I am wondering how they were calculated in the first place, if the trimLinearizeOpPoint is a reliable function or if there is a better way of linearizing the Nonlinear model.

Thanks in advance.

[Talgat Alimbayev]

Hi Eduardo,

were able to figure out this issue? I'm faced with a very similar task.

Thanks.

Answer 1

[Talgat Alimbayev]

Hi,

I'm probably a bit late with my answer but anyway.

You can build a diagram like in the attached picture (it's basically the same diagram that they use, but now you can follow this tutorial to trim it https://www.mathworks.com/videos/trim-linearization-and-control-design-for-an-aircraft-68880.html

After that you should be able to trim it for different conditions. Don't overcontrain it, if it starts complaining about overconstraining then relax some constraints.

Keep in mind that Cdx (drag coef) is set to zero by default. I think their calculations for drag are wrong but I'm still investigating this. So, don't take my word for it.

Good luck.