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<title>Effect on the control system of each stages on the vibration of the station</title>
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<h1 class="title">Effect on the control system of each stages on the vibration of the station</h1>
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<div id="table-of-contents">
<h2>Table of Contents</h2>
<div id="text-table-of-contents">
<ul>
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<li><a href="#org90c65f2">1. Effect of all the control systems on the Sample vibrations</a>
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<ul>
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<li><a href="#org440b68a">1.1. Experimental Setup</a></li>
<li><a href="#orgd930ba3">1.2. Load data</a></li>
<li><a href="#orgaf61ea2">1.3. Analysis - Time Domain</a></li>
<li><a href="#org3f46904">1.4. Analysis - Frequency Domain</a>
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<ul>
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<li><a href="#org6cda42c">1.4.1. Vibrations at the sample location</a></li>
<li><a href="#orga943462">1.4.2. Vibrations on the marble</a></li>
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</ul>
</li>
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<li><a href="#orgeca50d8">1.5. Conclusion</a></li>
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</ul>
</li>
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<li><a href="#org1592cd8">2. Effect of all the control systems on the Sample vibrations - One stage at a time</a>
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<ul>
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<li><a href="#orgf7f587e">2.1. Experimental Setup</a></li>
<li><a href="#org3554496">2.2. Load data</a></li>
<li><a href="#org5b2dc21">2.3. Voltage to Velocity</a></li>
<li><a href="#orga044f95">2.4. Analysis - Time Domain</a></li>
<li><a href="#org2132360">2.5. Analysis - Frequency Domain</a>
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<ul>
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<li><a href="#orgf096039">2.5.1. Vibrations at the sample location</a></li>
<li><a href="#org2457465">2.5.2. Vibrations on the marble</a></li>
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</ul>
</li>
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<li><a href="#org2a3582c">2.6. Conclusion</a></li>
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</ul>
</li>
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<li><a href="#org8e41411">3. Effect of the Symetrie Driver</a>
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<ul>
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<li><a href="#org2c71144">3.1. Experimental Setup</a></li>
<li><a href="#org86d2cac">3.2. Load data</a></li>
<li><a href="#org8866dd0">3.3. Analysis - Time Domain</a></li>
<li><a href="#org42b0b80">3.4. Analysis - Frequency Domain</a>
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<ul>
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<li><a href="#org327f014">3.4.1. Vibrations at the sample location</a></li>
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</ul>
</li>
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<li><a href="#org19a7dad">3.5. Conclusion</a></li>
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</ul>
</li>
</ul>
</div>
</div>
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<p>
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This file is organized as follow:
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</p>
<ul class="org-ul">
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<li>Section <a href="#orgf43e1ad">1</a>:
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<ul class="org-ul">
<li>One geophone on the marble and one at the sample location</li>
<li>Each stage is turned on one by one</li>
</ul></li>
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<li>Section <a href="#org2896ac0">2</a>:
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<ul class="org-ul">
<li>One geophone on the marble and one at the sample location</li>
<li>Each stage is turned on one at a time</li>
</ul></li>
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<li>Section <a href="#org01c82bb">3</a>:
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<ul class="org-ul">
<li>We check if the Symetrie driver induces some vibrations when placed on the marble</li>
</ul></li>
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</ul>
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<div id="outline-container-org90c65f2" class="outline-2">
<h2 id="org90c65f2"><span class="section-number-2">1</span> Effect of all the control systems on the Sample vibrations</h2>
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<div class="outline-text-2" id="text-1">
<p>
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<a id="orgf43e1ad"></a>
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</p>
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<div class="note" id="org09dadc9">
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<p>
All the files (data and Matlab scripts) are accessible <a href="data/effect_control_all.zip">here</a>.
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</p>
</div>
</div>
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<div id="outline-container-org440b68a" class="outline-3">
<h3 id="org440b68a"><span class="section-number-3">1.1</span> Experimental Setup</h3>
<div class="outline-text-3" id="text-1-1">
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<p>
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We here measure the signals of two L22 geophones:
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</p>
<ul class="org-ul">
<li>One is located on top of the Sample platform</li>
<li>One is located on the marble</li>
</ul>
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<p>
The signals are amplified with voltage amplifiers with the following settings:
</p>
<ul class="org-ul">
<li>gain of 60dB</li>
<li>AC/DC option set on AC</li>
<li>Low pass filter set at 1kHz</li>
</ul>
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<p>
The signal from the top geophone does not go trought the slip-ring.
</p>
<p>
First, all the control systems are turned ON, then, they are turned one by one.
Each measurement are done during 50s.
</p>
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<table id="orgfda8785" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
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<caption class="t-above"><span class="table-number">Table 1:</span> Summary of the measurements and the states of the control systems</caption>
<colgroup>
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="org-left">Ty</th>
<th scope="col" class="org-left">Ry</th>
<th scope="col" class="org-left">Slip Ring</th>
<th scope="col" class="org-left">Spindle</th>
<th scope="col" class="org-left">Hexapod</th>
<th scope="col" class="org-left">Meas. file</th>
</tr>
</thead>
<tbody>
<tr>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><code>meas_003.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><code>meas_004.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><code>meas_005.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><code>meas_006.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><code>meas_007.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><code>meas_008.mat</code></td>
</tr>
</tbody>
</table>
<p>
Each of the <code>mat</code> file contains one array <code>data</code> with 3 columns:
</p>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="org-right" />
<col class="org-left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="org-right">Column number</th>
<th scope="col" class="org-left">Description</th>
</tr>
</thead>
<tbody>
<tr>
<td class="org-right">1</td>
<td class="org-left">Geophone - Marble</td>
</tr>
<tr>
<td class="org-right">2</td>
<td class="org-left">Geophone - Sample</td>
</tr>
<tr>
<td class="org-right">3</td>
<td class="org-left">Time</td>
</tr>
</tbody>
</table>
</div>
</div>
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<div id="outline-container-orgd930ba3" class="outline-3">
<h3 id="orgd930ba3"><span class="section-number-3">1.2</span> Load data</h3>
<div class="outline-text-3" id="text-1-2">
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<p>
We load the data of the z axis of two geophones.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">d3 = load(<span class="org-string">'mat/data_003.mat'</span>, <span class="org-string">'data'</span>); d3 = d3.data;
d4 = load(<span class="org-string">'mat/data_004.mat'</span>, <span class="org-string">'data'</span>); d4 = d4.data;
d5 = load(<span class="org-string">'mat/data_005.mat'</span>, <span class="org-string">'data'</span>); d5 = d5.data;
d6 = load(<span class="org-string">'mat/data_006.mat'</span>, <span class="org-string">'data'</span>); d6 = d6.data;
d7 = load(<span class="org-string">'mat/data_007.mat'</span>, <span class="org-string">'data'</span>); d7 = d7.data;
d8 = load(<span class="org-string">'mat/data_008.mat'</span>, <span class="org-string">'data'</span>); d8 = d8.data;
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</pre>
</div>
</div>
</div>
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<div id="outline-container-orgaf61ea2" class="outline-3">
<h3 id="orgaf61ea2"><span class="section-number-3">1.3</span> Analysis - Time Domain</h3>
<div class="outline-text-3" id="text-1-3">
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<p>
First, we can look at the time domain data and compare all the measurements:
</p>
<ul class="org-ul">
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<li>comparison for the geophone at the sample location (figure <a href="#org2d0b601">1</a>)</li>
<li>comparison for the geophone on the granite (figure <a href="#orgb35182d">2</a>)</li>
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</ul>
<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(d3(<span class="org-type">:</span>, 3), d3(<span class="org-type">:</span>, 2), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry, Ty'</span>);
plot(d4(<span class="org-type">:</span>, 3), d4(<span class="org-type">:</span>, 2), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry'</span>);
plot(d5(<span class="org-type">:</span>, 3), d5(<span class="org-type">:</span>, 2), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR'</span>);
plot(d6(<span class="org-type">:</span>, 3), d6(<span class="org-type">:</span>, 2), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz'</span>);
plot(d7(<span class="org-type">:</span>, 3), d7(<span class="org-type">:</span>, 2), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa'</span>);
plot(d8(<span class="org-type">:</span>, 3), d8(<span class="org-type">:</span>, 2), <span class="org-string">'DisplayName'</span>, <span class="org-string">'All OFF'</span>);
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hold off;
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xlabel(<span class="org-string">'Time [s]'</span>); ylabel(<span class="org-string">'Voltage [V]'</span>);
xlim([0, 50]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'bestoutside'</span>);
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</pre>
</div>
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<div id="org2d0b601" class="figure">
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<p><img src="figs/time_domain_sample.png" alt="time_domain_sample.png" />
</p>
<p><span class="figure-number">Figure 1: </span>Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location</p>
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</div>
<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(d3(<span class="org-type">:</span>, 3), d3(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry, Ty'</span>);
plot(d4(<span class="org-type">:</span>, 3), d4(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry'</span>);
plot(d5(<span class="org-type">:</span>, 3), d5(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR'</span>);
plot(d6(<span class="org-type">:</span>, 3), d6(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz'</span>);
plot(d7(<span class="org-type">:</span>, 3), d7(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa'</span>);
plot(d8(<span class="org-type">:</span>, 3), d8(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'All OFF'</span>);
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hold off;
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xlabel(<span class="org-string">'Time [s]'</span>); ylabel(<span class="org-string">'Voltage [V]'</span>);
xlim([0, 50]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'bestoutside'</span>);
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</pre>
</div>
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<div id="orgb35182d" class="figure">
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<p><img src="figs/time_domain_marble.png" alt="time_domain_marble.png" />
</p>
<p><span class="figure-number">Figure 2: </span>Comparison of the time domain data when turning off the control system of the stages - Geophone on the marble</p>
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</div>
</div>
</div>
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<div id="outline-container-org3f46904" class="outline-3">
<h3 id="org3f46904"><span class="section-number-3">1.4</span> Analysis - Frequency Domain</h3>
<div class="outline-text-3" id="text-1-4">
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</div>
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<div id="outline-container-org6cda42c" class="outline-4">
<h4 id="org6cda42c"><span class="section-number-4">1.4.1</span> Vibrations at the sample location</h4>
<div class="outline-text-4" id="text-1-4-1">
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<p>
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">[px3, f] = pwelch(d3(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px4, <span class="org-type">~</span>] = pwelch(d4(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px5, <span class="org-type">~</span>] = pwelch(d5(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px6, <span class="org-type">~</span>] = pwelch(d6(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px7, <span class="org-type">~</span>] = pwelch(d7(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px8, <span class="org-type">~</span>] = pwelch(d8(<span class="org-type">:</span>, 2), win, [], [], Fs);
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</pre>
</div>
<p>
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And we compare all the signals (figures <a href="#orgfad1dca">3</a> and <a href="#orgbb85235">4</a>).
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</p>
<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(f, sqrt(px3), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry, Ty'</span>);
plot(f, sqrt(px4), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry'</span>);
plot(f, sqrt(px5), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR'</span>);
plot(f, sqrt(px6), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz'</span>);
plot(f, sqrt(px7), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa'</span>);
plot(f, sqrt(px8), <span class="org-string">'DisplayName'</span>, <span class="org-string">'All OFF'</span>);
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hold off;
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<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'xscale'</span>, <span class="org-string">'log'</span>);
<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'yscale'</span>, <span class="org-string">'log'</span>);
xlabel(<span class="org-string">'Frequency [Hz]'</span>); ylabel(<span class="org-string">'Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$'</span>)
xlim([0.1, 500]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'southwest'</span>);
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</pre>
</div>
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<div id="orgfad1dca" class="figure">
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<p><img src="figs/psd_sample_comp.png" alt="psd_sample_comp.png" />
</p>
<p><span class="figure-number">Figure 3: </span>Amplitude Spectral Density of the signal coming from the top geophone</p>
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</div>
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<div id="orgbb85235" class="figure">
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<p><img src="figs/psd_sample_comp_high_freq.png" alt="psd_sample_comp_high_freq.png" />
</p>
<p><span class="figure-number">Figure 4: </span>Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)</p>
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</div>
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<div id="org3ad8776" class="figure">
<p><img src="figs/cas_sample_comp.png" alt="cas_sample_comp.png" />
</p>
</div>
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</div>
</div>
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<div id="outline-container-orga943462" class="outline-4">
<h4 id="orga943462"><span class="section-number-4">1.4.2</span> Vibrations on the marble</h4>
<div class="outline-text-4" id="text-1-4-2">
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<p>
Now we plot the same curves for the geophone located on the marble.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">[px3, f] = pwelch(d3(<span class="org-type">:</span>, 1), win, [], [], Fs);
[px4, <span class="org-type">~</span>] = pwelch(d4(<span class="org-type">:</span>, 1), win, [], [], Fs);
[px5, <span class="org-type">~</span>] = pwelch(d5(<span class="org-type">:</span>, 1), win, [], [], Fs);
[px6, <span class="org-type">~</span>] = pwelch(d6(<span class="org-type">:</span>, 1), win, [], [], Fs);
[px7, <span class="org-type">~</span>] = pwelch(d7(<span class="org-type">:</span>, 1), win, [], [], Fs);
[px8, <span class="org-type">~</span>] = pwelch(d8(<span class="org-type">:</span>, 1), win, [], [], Fs);
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</pre>
</div>
<p>
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And we compare the Amplitude Spectral Densities (figures <a href="#orge409077">6</a> and <a href="#orgf19188f">7</a>)
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</p>
<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(f, sqrt(px3), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry, Ty'</span>);
plot(f, sqrt(px4), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR, Ry'</span>);
plot(f, sqrt(px5), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz, SR'</span>);
plot(f, sqrt(px6), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa, Rz'</span>);
plot(f, sqrt(px7), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa'</span>);
plot(f, sqrt(px8), <span class="org-string">'DisplayName'</span>, <span class="org-string">'All OFF'</span>);
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hold off;
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<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'xscale'</span>, <span class="org-string">'log'</span>);
<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'yscale'</span>, <span class="org-string">'log'</span>);
xlabel(<span class="org-string">'Frequency [Hz]'</span>); ylabel(<span class="org-string">'Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$'</span>)
xlim([0.1, 500]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'northeast'</span>);
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</pre>
</div>
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<div id="orge409077" class="figure">
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<p><img src="figs/psd_marble_comp.png" alt="psd_marble_comp.png" />
</p>
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<p><span class="figure-number">Figure 6: </span>Amplitude Spectral Density of the signal coming from the top geophone</p>
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</div>
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<div id="orgf19188f" class="figure">
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<p><img src="figs/psd_marble_comp_high_freq.png" alt="psd_marble_comp_high_freq.png" />
</p>
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<p><span class="figure-number">Figure 7: </span>Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)</p>
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</div>
</div>
</div>
</div>
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<div id="outline-container-orgeca50d8" class="outline-3">
<h3 id="orgeca50d8"><span class="section-number-3">1.5</span> Conclusion</h3>
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<div class="outline-text-3" id="text-1-5">
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<div class="important" id="org3e2d674">
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<ul class="org-ul">
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<li>The control system of the Ty stage induces a lot of vibrations of the marble above 100Hz</li>
<li>The hexapod control system add vibrations of the sample only above 200Hz</li>
<li>When the Slip-Ring is ON, white noise appears at high frequencies. This is studied <a href="../slip-ring-electrical-noise/index.html">here</a></li>
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</ul>
</div>
</div>
</div>
</div>
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<div id="outline-container-org1592cd8" class="outline-2">
<h2 id="org1592cd8"><span class="section-number-2">2</span> Effect of all the control systems on the Sample vibrations - One stage at a time</h2>
<div class="outline-text-2" id="text-2">
<p>
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<a id="org2896ac0"></a>
</p>
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<div class="note" id="orgdf47cc5">
<p>
All the files (data and Matlab scripts) are accessible <a href="data/effect_control_one.zip">here</a>.
</p>
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</div>
</div>
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<div id="outline-container-orgf7f587e" class="outline-3">
<h3 id="orgf7f587e"><span class="section-number-3">2.1</span> Experimental Setup</h3>
<div class="outline-text-3" id="text-2-1">
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<p>
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We here measure the signals of two geophones:
</p>
<ul class="org-ul">
<li>One is located on top of the Sample platform</li>
<li>One is located on the marble</li>
</ul>
<p>
The signal from the top geophone does go trought the slip-ring.
</p>
<p>
All the control systems are turned OFF, then, they are turned on one at a time.
</p>
<p>
Each measurement are done during 100s.
</p>
<p>
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The settings of the voltage amplifier are shown on figure <a href="#orgd8f9a31">8</a>:
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</p>
<ul class="org-ul">
<li>gain of 60dB</li>
<li>AC/DC option set on DC</li>
<li>Low pass filter set at 1kHz</li>
</ul>
<p>
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A first order low pass filter with a cut-off frequency of 1kHz is added before the voltage amplifier.
</p>
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<table id="org2eb327f" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
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<caption class="t-above"><span class="table-number">Table 2:</span> Summary of the measurements and the states of the control systems</caption>
<colgroup>
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
<col class="org-left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="org-left">Ty</th>
<th scope="col" class="org-left">Ry</th>
<th scope="col" class="org-left">Slip Ring</th>
<th scope="col" class="org-left">Spindle</th>
<th scope="col" class="org-left">Hexapod</th>
<th scope="col" class="org-left">Meas. file</th>
</tr>
</thead>
<tbody>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><code>meas_013.mat</code></td>
</tr>
<tr>
<td class="org-left"><b>ON</b></td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><code>meas_014.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><code>meas_015.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><code>meas_016.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left">OFF</td>
<td class="org-left"><code>meas_017.mat</code></td>
</tr>
<tr>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left">OFF</td>
<td class="org-left"><b>ON</b></td>
<td class="org-left"><code>meas_018.mat</code></td>
</tr>
</tbody>
</table>
<p>
Each of the <code>mat</code> file contains one array <code>data</code> with 3 columns:
</p>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="org-right" />
<col class="org-left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="org-right">Column number</th>
<th scope="col" class="org-left">Description</th>
</tr>
</thead>
<tbody>
<tr>
<td class="org-right">1</td>
<td class="org-left">Geophone - Marble</td>
</tr>
<tr>
<td class="org-right">2</td>
<td class="org-left">Geophone - Sample</td>
</tr>
<tr>
<td class="org-right">3</td>
<td class="org-left">Time</td>
</tr>
</tbody>
</table>
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<div id="orgd8f9a31" class="figure">
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<p><img src="./img/IMG_20190507_101459.jpg" alt="IMG_20190507_101459.jpg" width="500px" />
</p>
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<p><span class="figure-number">Figure 8: </span>Voltage amplifier settings for the measurement</p>
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</div>
</div>
</div>
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<div id="outline-container-org3554496" class="outline-3">
<h3 id="org3554496"><span class="section-number-3">2.2</span> Load data</h3>
<div class="outline-text-3" id="text-2-2">
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<p>
We load the data of the z axis of two geophones.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">d_of = load(<span class="org-string">'mat/data_013.mat'</span>, <span class="org-string">'data'</span>); d_of = d_of.data;
d_ty = load(<span class="org-string">'mat/data_014.mat'</span>, <span class="org-string">'data'</span>); d_ty = d_ty.data;
d_ry = load(<span class="org-string">'mat/data_015.mat'</span>, <span class="org-string">'data'</span>); d_ry = d_ry.data;
d_sr = load(<span class="org-string">'mat/data_016.mat'</span>, <span class="org-string">'data'</span>); d_sr = d_sr.data;
d_rz = load(<span class="org-string">'mat/data_017.mat'</span>, <span class="org-string">'data'</span>); d_rz = d_rz.data;
d_he = load(<span class="org-string">'mat/data_018.mat'</span>, <span class="org-string">'data'</span>); d_he = d_he.data;
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</pre>
</div>
</div>
</div>
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<div id="outline-container-org5b2dc21" class="outline-3">
<h3 id="org5b2dc21"><span class="section-number-3">2.3</span> Voltage to Velocity</h3>
<div class="outline-text-3" id="text-2-3">
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<p>
We convert the measured voltage to velocity using the function <code>voltageToVelocityL22</code> (accessible <a href="file:///home/thomas/Cloud/thesis/meas/srcindex.html">here</a>).
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</p>
<div class="org-src-container">
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<pre class="src src-matlab">gain = 60; <span class="org-comment">% [dB]</span>
d_of(<span class="org-type">:</span>, 1) = voltageToVelocityL22(d_of(<span class="org-type">:</span>, 1), d_of(<span class="org-type">:</span>, 3), gain);
d_ty(<span class="org-type">:</span>, 1) = voltageToVelocityL22(d_ty(<span class="org-type">:</span>, 1), d_ty(<span class="org-type">:</span>, 3), gain);
d_ry(<span class="org-type">:</span>, 1) = voltageToVelocityL22(d_ry(<span class="org-type">:</span>, 1), d_ry(<span class="org-type">:</span>, 3), gain);
d_sr(<span class="org-type">:</span>, 1) = voltageToVelocityL22(d_sr(<span class="org-type">:</span>, 1), d_sr(<span class="org-type">:</span>, 3), gain);
d_rz(<span class="org-type">:</span>, 1) = voltageToVelocityL22(d_rz(<span class="org-type">:</span>, 1), d_rz(<span class="org-type">:</span>, 3), gain);
d_he(<span class="org-type">:</span>, 1) = voltageToVelocityL22(d_he(<span class="org-type">:</span>, 1), d_he(<span class="org-type">:</span>, 3), gain);
d_of(<span class="org-type">:</span>, 2) = voltageToVelocityL22(d_of(<span class="org-type">:</span>, 2), d_of(<span class="org-type">:</span>, 3), gain);
d_ty(<span class="org-type">:</span>, 2) = voltageToVelocityL22(d_ty(<span class="org-type">:</span>, 2), d_ty(<span class="org-type">:</span>, 3), gain);
d_ry(<span class="org-type">:</span>, 2) = voltageToVelocityL22(d_ry(<span class="org-type">:</span>, 2), d_ry(<span class="org-type">:</span>, 3), gain);
d_sr(<span class="org-type">:</span>, 2) = voltageToVelocityL22(d_sr(<span class="org-type">:</span>, 2), d_sr(<span class="org-type">:</span>, 3), gain);
d_rz(<span class="org-type">:</span>, 2) = voltageToVelocityL22(d_rz(<span class="org-type">:</span>, 2), d_rz(<span class="org-type">:</span>, 3), gain);
d_he(<span class="org-type">:</span>, 2) = voltageToVelocityL22(d_he(<span class="org-type">:</span>, 2), d_he(<span class="org-type">:</span>, 3), gain);
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</pre>
</div>
</div>
</div>
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<div id="outline-container-orga044f95" class="outline-3">
<h3 id="orga044f95"><span class="section-number-3">2.4</span> Analysis - Time Domain</h3>
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<div class="outline-text-3" id="text-2-4">
<p>
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First, we can look at the time domain data and compare all the measurements:
</p>
<ul class="org-ul">
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<li>comparison for the geophone at the sample location (figure <a href="#orgcae4035">9</a>)</li>
<li>comparison for the geophone on the granite (figure <a href="#orgece9ecc">10</a>)</li>
<li>relative displacement of the sample with respect to the marble (figure <a href="#orgece9ecc">10</a>)</li>
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</ul>
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<div id="orgcae4035" class="figure">
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<p><img src="figs/time_domain_sample_lpf.png" alt="time_domain_sample_lpf.png" />
</p>
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<p><span class="figure-number">Figure 9: </span>Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location</p>
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</div>
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<div id="orgece9ecc" class="figure">
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<p><img src="figs/time_domain_marble_lpf.png" alt="time_domain_marble_lpf.png" />
</p>
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<p><span class="figure-number">Figure 10: </span>Comparison of the time domain data when turning off the control system of the stages - Geophone on the marble</p>
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</div>
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<div id="org68dbb45" class="figure">
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<p><img src="figs/time_domain_relative_disp.png" alt="time_domain_relative_disp.png" />
</p>
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<p><span class="figure-number">Figure 11: </span>Relative displacement of the sample with respect to the marble</p>
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</div>
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</div>
</div>
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<div id="outline-container-org2132360" class="outline-3">
<h3 id="org2132360"><span class="section-number-3">2.5</span> Analysis - Frequency Domain</h3>
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<div class="outline-text-3" id="text-2-5">
2019-05-09 09:13:10 +02:00
<div class="org-src-container">
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<pre class="src src-matlab">dt = d_of(2, 3) <span class="org-type">-</span> d_of(1, 3);
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Fs = 1<span class="org-type">/</span>dt;
win = hanning(ceil(10<span class="org-type">*</span>Fs));
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</pre>
</div>
</div>
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<div id="outline-container-orgf096039" class="outline-4">
<h4 id="orgf096039"><span class="section-number-4">2.5.1</span> Vibrations at the sample location</h4>
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<div class="outline-text-4" id="text-2-5-1">
2019-05-09 09:13:10 +02:00
<p>
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">[px_of, f] = pwelch(d_of(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px_ty, <span class="org-type">~</span>] = pwelch(d_ty(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px_ry, <span class="org-type">~</span>] = pwelch(d_ry(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px_sr, <span class="org-type">~</span>] = pwelch(d_sr(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px_rz, <span class="org-type">~</span>] = pwelch(d_rz(<span class="org-type">:</span>, 2), win, [], [], Fs);
[px_he, <span class="org-type">~</span>] = pwelch(d_he(<span class="org-type">:</span>, 2), win, [], [], Fs);
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</pre>
</div>
<p>
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And we compare all the signals (figures <a href="#orgc1c0a30">12</a> and <a href="#orga1e7d03">13</a>).
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</p>
<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(f, sqrt(px_of), <span class="org-string">'DisplayName'</span>, <span class="org-string">'All OFF'</span>);
plot(f, sqrt(px_ty), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Ty ON'</span>);
plot(f, sqrt(px_ry), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Ry ON'</span>);
plot(f, sqrt(px_sr), <span class="org-string">'DisplayName'</span>, <span class="org-string">'S-R ON'</span>);
plot(f, sqrt(px_rz), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Rz ON'</span>);
plot(f, sqrt(px_he), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Hexa ON'</span>);
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hold off;
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<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'xscale'</span>, <span class="org-string">'log'</span>);
<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'yscale'</span>, <span class="org-string">'log'</span>);
xlabel(<span class="org-string">'Frequency [Hz]'</span>); ylabel(<span class="org-string">'Amplitude Spectral Density $\left[\frac{m/s}{\sqrt{Hz}}\right]$'</span>)
xlim([0.1, 500]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'southwest'</span>);
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</pre>
</div>
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<div id="orgc1c0a30" class="figure">
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<p><img src="figs/psd_sample_comp_lpf.png" alt="psd_sample_comp_lpf.png" />
</p>
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<p><span class="figure-number">Figure 12: </span>Amplitude Spectral Density of the sample velocity</p>
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</div>
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<div id="orga1e7d03" class="figure">
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<p><img src="figs/psd_sample_comp_high_freq_lpf.png" alt="psd_sample_comp_high_freq_lpf.png" />
</p>
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<p><span class="figure-number">Figure 13: </span>Amplitude Spectral Density of the sample velocity (zoom at high frequencies)</p>
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</div>
</div>
</div>
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<div id="outline-container-org2457465" class="outline-4">
<h4 id="org2457465"><span class="section-number-4">2.5.2</span> Vibrations on the marble</h4>
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<div class="outline-text-4" id="text-2-5-2">
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<p>
Now we plot the same curves for the geophone located on the marble.
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And we compare the Amplitude Spectral Densities (figures <a href="#org76a7420">14</a> and <a href="#org9dda36a">15</a>)
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</p>
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<div id="org76a7420" class="figure">
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<p><img src="figs/psd_marble_comp_lpf.png" alt="psd_marble_comp_lpf.png" />
</p>
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<p><span class="figure-number">Figure 14: </span>Amplitude Spectral Density of the marble velocity</p>
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</div>
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<div id="org9dda36a" class="figure">
<p><img src="figs/psd_marble_lpf_high_freq.png" alt="psd_marble_lpf_high_freq.png" />
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</p>
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<p><span class="figure-number">Figure 15: </span>Amplitude Spectral Density of the marble velocity (zoom at high frequencies)</p>
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</div>
</div>
</div>
</div>
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<div id="outline-container-org2a3582c" class="outline-3">
<h3 id="org2a3582c"><span class="section-number-3">2.6</span> Conclusion</h3>
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<div class="outline-text-3" id="text-2-6">
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<div class="important" id="org0b59337">
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<ul class="org-ul">
<li>The Ty stage induces vibrations of the marble and at the sample location above 100Hz</li>
<li>The hexapod stage induces vibrations at the sample position above 220Hz</li>
</ul>
</div>
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</div>
</div>
</div>
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<div id="outline-container-org8e41411" class="outline-2">
<h2 id="org8e41411"><span class="section-number-2">3</span> Effect of the Symetrie Driver</h2>
<div class="outline-text-2" id="text-3">
<p>
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<a id="org01c82bb"></a>
</p>
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<div class="note" id="orgbddd3ee">
<p>
All the files (data and Matlab scripts) are accessible <a href="data/effect_symetrie_driver.zip">here</a>.
</p>
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</div>
</div>
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<div id="outline-container-org2c71144" class="outline-3">
<h3 id="org2c71144"><span class="section-number-3">3.1</span> Experimental Setup</h3>
<div class="outline-text-3" id="text-3-1">
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<p>
We here measure the signals of two geophones:
</p>
<ul class="org-ul">
<li>One is located on top of the Sample platform</li>
<li>One is located on the marble</li>
</ul>
<p>
The signal from the top geophone does go trought the slip-ring.
</p>
<p>
All the control systems are turned OFF except the Hexapod one.
</p>
<p>
Each measurement are done during 100s.
</p>
<p>
The settings of the voltage amplifier are:
</p>
<ul class="org-ul">
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<li>gain of 60dB</li>
<li>AC/DC option set on DC</li>
<li>Low pass filter set at 1kHz</li>
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</ul>
<p>
A first order low pass filter with a cut-off frequency of 1kHz is added before the voltage amplifier.
</p>
<p>
The measurements are:
</p>
<ul class="org-ul">
<li><code>meas_018.mat</code>: Hexapod&rsquo;s driver on the granite</li>
<li><code>meas_019.mat</code>: Hexapod&rsquo;s driver on the ground</li>
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</ul>
<p>
Each of the <code>mat</code> file contains one array <code>data</code> with 3 columns:
</p>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="org-right" />
<col class="org-left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="org-right">Column number</th>
<th scope="col" class="org-left">Description</th>
</tr>
</thead>
<tbody>
<tr>
<td class="org-right">1</td>
<td class="org-left">Geophone - Marble</td>
</tr>
<tr>
<td class="org-right">2</td>
<td class="org-left">Geophone - Sample</td>
</tr>
<tr>
<td class="org-right">3</td>
<td class="org-left">Time</td>
</tr>
</tbody>
</table>
</div>
</div>
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<div id="outline-container-org86d2cac" class="outline-3">
<h3 id="org86d2cac"><span class="section-number-3">3.2</span> Load data</h3>
<div class="outline-text-3" id="text-3-2">
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<p>
We load the data of the z axis of two geophones.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">d_18 = load(<span class="org-string">'mat/data_018.mat'</span>, <span class="org-string">'data'</span>); d_18 = d_18.data;
d_19 = load(<span class="org-string">'mat/data_019.mat'</span>, <span class="org-string">'data'</span>); d_19 = d_19.data;
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</pre>
</div>
</div>
</div>
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<div id="outline-container-org8866dd0" class="outline-3">
<h3 id="org8866dd0"><span class="section-number-3">3.3</span> Analysis - Time Domain</h3>
<div class="outline-text-3" id="text-3-3">
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<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(d_19(<span class="org-type">:</span>, 3), d_19(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Driver - Ground'</span>);
plot(d_18(<span class="org-type">:</span>, 3), d_18(<span class="org-type">:</span>, 1), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Driver - Granite'</span>);
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hold off;
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xlabel(<span class="org-string">'Time [s]'</span>); ylabel(<span class="org-string">'Voltage [V]'</span>);
xlim([0, 50]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'bestoutside'</span>);
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</pre>
</div>
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<div id="org3b49fad" class="figure">
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<p><img src="figs/time_domain_hexa_driver.png" alt="time_domain_hexa_driver.png" />
</p>
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<p><span class="figure-number">Figure 16: </span>Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location</p>
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</div>
</div>
</div>
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<div id="outline-container-org42b0b80" class="outline-3">
<h3 id="org42b0b80"><span class="section-number-3">3.4</span> Analysis - Frequency Domain</h3>
<div class="outline-text-3" id="text-3-4">
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<div class="org-src-container">
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<pre class="src src-matlab">dt = d_18(2, 3) <span class="org-type">-</span> d_18(1, 3);
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Fs = 1<span class="org-type">/</span>dt;
win = hanning(ceil(10<span class="org-type">*</span>Fs));
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</pre>
</div>
</div>
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<div id="outline-container-org327f014" class="outline-4">
<h4 id="org327f014"><span class="section-number-4">3.4.1</span> Vibrations at the sample location</h4>
<div class="outline-text-4" id="text-3-4-1">
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<p>
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
</p>
<div class="org-src-container">
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<pre class="src src-matlab">[px_18, f] = pwelch(d_18(<span class="org-type">:</span>, 1), win, [], [], Fs);
[px_19, <span class="org-type">~</span>] = pwelch(d_19(<span class="org-type">:</span>, 1), win, [], [], Fs);
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</pre>
</div>
<div class="org-src-container">
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<pre class="src src-matlab"><span class="org-type">figure</span>;
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hold on;
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plot(f, sqrt(px_19), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Driver - Ground'</span>);
plot(f, sqrt(px_18), <span class="org-string">'DisplayName'</span>, <span class="org-string">'Driver - Granite'</span>);
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hold off;
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<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'xscale'</span>, <span class="org-string">'log'</span>);
<span class="org-type">set</span>(<span class="org-variable-name">gca</span>, <span class="org-string">'yscale'</span>, <span class="org-string">'log'</span>);
xlabel(<span class="org-string">'Frequency [Hz]'</span>); ylabel(<span class="org-string">'Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$'</span>)
xlim([0.1, 500]);
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legend(<span class="org-string">'Location'</span>, <span class="org-string">'southwest'</span>);
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</pre>
</div>
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<div id="org6757aa8" class="figure">
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<p><img src="figs/psd_hexa_driver.png" alt="psd_hexa_driver.png" />
</p>
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<p><span class="figure-number">Figure 17: </span>Amplitude Spectral Density of the signal coming from the top geophone</p>
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</div>
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<div id="orga4175a1" class="figure">
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<p><img src="figs/psd_hexa_driver_high_freq.png" alt="psd_hexa_driver_high_freq.png" />
</p>
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<p><span class="figure-number">Figure 18: </span>Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)</p>
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</div>
</div>
</div>
</div>
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<div id="outline-container-org19a7dad" class="outline-3">
<h3 id="org19a7dad"><span class="section-number-3">3.5</span> Conclusion</h3>
<div class="outline-text-3" id="text-3-5">
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<div class="important" id="org73be6df">
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<p>
Even tough the Hexapod&rsquo;s driver vibrates quite a lot, it does not generate significant vibrations of the granite when either placed on the granite or on the ground.
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</p>
</div>
</div>
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</div>
</div>
</div>
<div id="postamble" class="status">
<p class="author">Author: Dehaeze Thomas</p>
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<p class="date">Created: 2020-11-12 jeu. 10:27</p>
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</div>
</body>
</html>