LQG control

Is it possible to obtain better accuracy in turbo pmac by the usage of alternative control strategies such as LQG control or H∞ control ? I understand that turbo pmac is flexible enough to implement these by the way of bypassing the existing firmware pmac PID filter and replacing it by user written servo algorithms.

 

Can I get some practical guidelines for implementing advanced servo algorithms on turbo pmac ? I am not much initiated in advanced control strategies. I only know the mechanism of open servo.

First, LQG, LTR, H2, Hinf, Mu synthesis, pole placement, classical loop shaping etc. are controller design techniques for LTI systems. Provided that you have a good (accurate) model of your system, you can design a controller using the above techniques. You may use user written servo to implement these controllers (you have to discretize unless you use direct digital design), however for a nth order system, as an example for LQG implemented in compensator form will be nth order, for hinf it's going to be more than this due to frequency weighting filters. Even omitting truncation due to the word size effects and fixed point aritmaticm the user written servo will take most of the Turbo Pmac's cpu time. The best way is to write the code in assembly language but it's really time consuming. This is why I strongly recommend you to use Power PMAC instead of Turbo Pmac to implement high order controllers, since it uses full floating point arithmetic, faster cpu and you can write your own user written servo in C language. Even you may use Matlab Simulink Embedded Coder to generate C code from your designed controller in Matlab Simulink ad use it as a user written servo in Power Pmac.