National Instruments 370757C-01 用户手册
Chapter 2
Robustness Analysis
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2-5
Figure 2-3. SISO Tracking System with Three Uncertainties
The H system will have the reference input as input1 and the error output
as output1 (w and z, respectively, in Figure 2-2). Removing the
as output1 (w and z, respectively, in Figure 2-2). Removing the
δ values will
create inputs 2 through 4 and outputs 2 through 4 (r and q, respectively, in
Figure 2-2).
Figure 2-2).
1.
The A, B, C, D matrices of the state-space system representing H are
as follows:
as follows:
A=[-4,-8;1,0];
B=[8,1,-4,-8;zeros(1,4)];
C=[0,-1;-4,-8;1,0;0,1];
D=[1,0,0,0;8,0,-4,-8;zeros(2,4)];
H = system(A,B,C,D,{inputNames=["reference",
"r1","r2","r3"],outputNames=["error",
"q1","q2","q3"],stateNames=["x1","x2"]});
2.
Specify the uncertainty bounds.
The sensor uncertainty
δ
3
is known to be bounded by l
3
(w), according
to Equation 2-1. Because the position x
2
sensor model is known to be
accurate to 10% up to one radian per second, and very inaccurate at
high frequencies, the l
high frequencies, the l
3
shown in Figure 2-4 is selected.
reference
reference
error
8
K
1
= 4
K
2
= 8
1
s
s
x
1
x
2
+
1
+
+
1
+
+
2
+
+
–
–
+
–
1
s
s