Mathematical modeling of a feedback control system

[dpk707]

My system is a compound pendulum hinged at some distance from one end and have a propeller mounted dc motor at the other end. I wish to position the pendulum with the help of motor propeller system.
I tried but i am unable to get a mathematical model for it. I am getting a non linear model that has terms of sin and cos. I am taking theta(the angle) as the output and current as input.
Please also suggest the approach i should follow.

 

[f95toli]

A system like this will always be non-linear unless you restrict your model to a very small range of angles, so there isn't much you can do about it. The "solution" is simply to use numerical methods.