Chapter 3 Building System Connections
Xmath Control Design Module 3-10 ni.com
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Algorithm
For the feedback system shown in Example 3-3, you can write the
following system equations:
Combining these equations with the equation for the positive feedback
input term:
and multiplying by the input and output gains M and N, you obtain the
following state-space equations describing the entire system between input
u and output y. If you do not specify any values for the gain matrices,
Kdefaults to zero (no feedback) and M and N default to appropriately-sized
identity matrices (unity gain on the input and output).
This algorithm assumes that the closed-loop system is well posed to ensure
that Sys will be proper. The (I–KD1) term must be invertible, and a
warning appears if the condition estimate of the term (refer to rcond) is
less than eps.
x
·A1xB
1u1
+= y1C1xD
1u1
+=
u1Ky1Mu+=
x
·A1B1IKD
1
–()
1–KC1
+()xB
1IKD
1
–()
1–Mu+=
yNIKD
1
–()
1–C1xND
1IKD
1
–()
1–Mu+=