Chapter 1 Introduction
Xmath Control Design Module 1-16 ni.com
You can choose to scale the system output here for zero steady-state error
in the step response. This is accomplished in an intuitive manner, dividing
the system sys_cl by the desired scaling factor.
sys_cl = sys_cl/51.76;
v_obc = step(sys_cl, 0:.1:10);
plot (v_obc, {xlab = "Time", ylab = "Magnitude"})
In Figure 1-9 the step response shows zero-steady-state error, little
overshoot, and a response time of less than sevenseconds.
Figure 1-9. Step Response for Observer-Based Design
The system response is quite good, implying that your state estimates were
satisfactory. You can do some further simulation, this time returning all the
states directly from the original plant, and get a graphical picture of how the
estimates track the actual states. First, you need to create the closed-loop
system with all states available.
The abcd( ) function extracts the A, B, C, and D matrices from a system
object. When you call it here, all you are interested in is the closed-loop
A matrix, so you do not need to extract the other state-space matrices.
A_cl = abcd(sys_cl);