National Instruments 370753C-01

Chapter 1 Introduction

Specify the observer poles at [–3 + 3j, –4] and call poleplace( ) again:

op = [-3+3*jay, -4];

L = poleplace(A',C',op)

L (a row vector) = 5.46645 4.67623 9.58

You connect the controller to the observer using lqgcomp( ). L needs to

be a column vector, so you transpose it.

sys_obc = lqgcomp(ssys, Kfsb, L');

You can use names( ) to modify the names of the state estimates to be

more descriptive. To distinguish the estimated states from the “true” states,

you can use the + operator to append the string est to the estimated state

names, as shown in this example.

[,,osNames] = names(sys_obc);

estNames = osNames + [" (est)"," (est)"," (est)"];

estNames'?

ans (a column vector of strings) =

Pitch Rate (est)

Pitch Angle (est)

Horizontal v (est)

You can append these modified names to sys_obc:

sys_obc = system(sys_obc,{stateNames=estNames});

Then you close the loop and verify that the closed-loop poles are all in the

left-half plane.

sys_cl = feedback(ssys, sys_obc);

poles(sys_cl)

ans (a column vector) =

-1 + 1 j

-1 - 1 j

-2

-4

-3 + 3 j

-3 - 3 j