a Problem In LQR controller

[shellp70]

Hi guys!!

Does anyone know anything about LQR method? I have a problem in my code to gain a correct k-gains!!

 

[xnuke]

Plenty of people know things about the LQR method. Please be more specific with your question.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[shellp70]

In fact, I have a uniform beam with piezo actuator/sensor film and I want to control it based on LQR controller method.
For gaining accurate results and convergence, I have to use at least 4 mode shapes in my numerical method. As a result, as I increase my mode shape in my code, the number of final states, which I want to control, will increase. For example, I have 2 states: W and U. If I use only first mode shape ( n=1 ), my final states will be 2 and I will have 2 k-gains for them. If I use 4 mode shapes ( n=4 ), I will have 8 states and k-gains.

I don't know what I should do to have both accurate answer and only 2 k-gain ?!

I hope I could explain my problem clear.

Thank you in advance.