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Chapter 5 Robust Performance Tailoring with Tuning - SSL - MIT

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Table 4.1: <strong>Tuning</strong> parameters for SCI development model.<br />

Name Description y0<br />

m1 -x tuning mass 0 kg<br />

m2 +x tuning mass 0 kg<br />

m1 00 11 000 111<br />

00 11 d1 d2 000 111 d2 00 11<br />

000 111<br />

00 11<br />

000 111<br />

00 11<br />

000 111<br />

m 2<br />

E 1 E 1 E 2 E 2<br />

Y<br />

d1<br />

000 111<br />

000 111<br />

000 111<br />

000 111<br />

000 111<br />

To demonstrate the technique the worst-case uncertainty realizations (∆ = 10%)<br />

of the PT and RPT AO designs are tuned using the SA and SQP algorithms. The<br />

nominal, worst-case and tuned performances are listed in Table 4.2. The worst case<br />

PT performance is significantly higher than nominal, and tuning results in a large<br />

improvement. <strong>Tuning</strong> also improves the RPT worst-case designs, but the results are<br />

not as dramatic.<br />

Table 4.2: <strong>Tuning</strong> performance summary for PT and RPT designs.<br />

Algorithm <strong>Performance</strong><br />

<strong>Performance</strong> [µm]<br />

Design nominal worst-case tuned<br />

PT 100.53 1355.5 303.17<br />

RPT AO 263.87 306.86 273.32<br />

In order to evaluate the performance of the different optimization algorithms, tuning<br />

is performed <strong>with</strong> SA-SQP, MC-SQP and an exhaustive search (ES) of the solution<br />

space. The results for the PT and RPT designs are given in Figures 4-1 and 4-2,<br />

respectively. Each figure includes a table of the algorithm performance data as well<br />

as a two-dimensional surface plot of the tuning solution space. In SA-SQP, a feasible<br />

initial guess is chosen randomly for SA, and the resulting design is used as the initial<br />

guess for the SQP algorithm. In MC-SQP ten feasible initial guesses are randomly<br />

111<br />

X

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