Add some simscape plots
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| "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> | ||||
| <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"> | ||||
| <head> | ||||
| <!-- 2019-01-21 lun. 23:32 --> | ||||
| <!-- 2019-01-21 lun. 23:44 --> | ||||
| <meta http-equiv="Content-Type" content="text/html;charset=utf-8" /> | ||||
| <meta name="viewport" content="width=device-width, initial-scale=1" /> | ||||
| <title>Control in a rotating frame</title> | ||||
| @@ -275,75 +275,75 @@ for the JavaScript code in this tag. | ||||
| <h2>Table of Contents</h2> | ||||
| <div id="text-table-of-contents"> | ||||
| <ul> | ||||
| <li><a href="#orgee97b77">1. Introduction</a></li> | ||||
| <li><a href="#orge01a725">2. System</a> | ||||
| <li><a href="#org0a89915">1. Introduction</a></li> | ||||
| <li><a href="#org123b9ca">2. System</a> | ||||
| <ul> | ||||
| <li><a href="#org91f4ea0">2.1. System description</a></li> | ||||
| <li><a href="#org481ba4a">2.2. Equations</a></li> | ||||
| <li><a href="#org174395f">2.3. Numerical Values for the NASS</a></li> | ||||
| <li><a href="#orgea07d45">2.4. Euler and Coriolis forces - Numerical Result</a></li> | ||||
| <li><a href="#org394681f">2.5. Negative Spring Effect - Numerical Result</a></li> | ||||
| <li><a href="#org62563d6">2.6. Limitations due to coupling</a> | ||||
| <li><a href="#org9aa32bf">2.1. System description</a></li> | ||||
| <li><a href="#orgc0c2859">2.2. Equations</a></li> | ||||
| <li><a href="#org0ff8b08">2.3. Numerical Values for the NASS</a></li> | ||||
| <li><a href="#org361651b">2.4. Euler and Coriolis forces - Numerical Result</a></li> | ||||
| <li><a href="#orgd2c08cb">2.5. Negative Spring Effect - Numerical Result</a></li> | ||||
| <li><a href="#org3d790d8">2.6. Limitations due to coupling</a> | ||||
| <ul> | ||||
| <li><a href="#org890c28a">2.6.1. Numerical Analysis</a></li> | ||||
| <li><a href="#org041128a">2.6.1. Numerical Analysis</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| <li><a href="#orgd4adbe6">2.7. Limitations due to negative stiffness effect</a></li> | ||||
| <li><a href="#org11f0d9f">2.7. Limitations due to negative stiffness effect</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| <li><a href="#org680ba84">3. Control Strategies</a> | ||||
| <li><a href="#org6ae3c88">3. Control Strategies</a> | ||||
| <ul> | ||||
| <li><a href="#orga9b261d">3.1. Measurement in the fixed reference frame</a></li> | ||||
| <li><a href="#org8823cd3">3.2. Measurement in the rotating frame</a></li> | ||||
| <li><a href="#orgbf1698b">3.1. Measurement in the fixed reference frame</a></li> | ||||
| <li><a href="#orgf37122a">3.2. Measurement in the rotating frame</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| <li><a href="#org837c5c4">4. Multi Body Model - Simscape</a> | ||||
| <li><a href="#org3b55a8d">4. Multi Body Model - Simscape</a> | ||||
| <ul> | ||||
| <li><a href="#orgd9921e4">4.1. Identification in the rotating referenced frame</a> | ||||
| <li><a href="#orgd50d938">4.1. Identification in the rotating referenced frame</a> | ||||
| <ul> | ||||
| <li><a href="#org6737d1b">4.1.1. Piezo and Voice coil</a></li> | ||||
| <li><a href="#org3a97e8d">4.1.2. Low rotation speed and High rotation speed</a></li> | ||||
| <li><a href="#org2ede09d">4.1.1. Piezo and Voice coil</a></li> | ||||
| <li><a href="#orgbb666ab">4.1.2. Low rotation speed and High rotation speed</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| <li><a href="#org2dbda82">4.2. Identification in the fixed frame</a></li> | ||||
| <li><a href="#orgffd87f4">4.3. Identification from actuator forces to displacement in the fixed frame</a></li> | ||||
| <li><a href="#org19541fc">4.4. Effect of the rotating Speed</a> | ||||
| <li><a href="#org3ecccf8">4.2. Identification in the fixed frame</a></li> | ||||
| <li><a href="#orga260738">4.3. Identification from actuator forces to displacement in the fixed frame</a></li> | ||||
| <li><a href="#orge0b7f4f">4.4. Effect of the rotating Speed</a> | ||||
| <ul> | ||||
| <li><a href="#org1a2f75c">4.4.1. <span class="todo TODO">TODO</span> Use realistic parameters for the mass of the sample and stiffness of the X-Y stage</a></li> | ||||
| <li><a href="#orgf132002">4.4.2. <span class="todo TODO">TODO</span> Check if the plant is changing a lot when we are not turning to when we are turning at the maximum speed (60rpm)</a></li> | ||||
| <li><a href="#orgd25182f">4.4.1. <span class="todo TODO">TODO</span> Use realistic parameters for the mass of the sample and stiffness of the X-Y stage</a></li> | ||||
| <li><a href="#org0368be9">4.4.2. <span class="todo TODO">TODO</span> Check if the plant is changing a lot when we are not turning to when we are turning at the maximum speed (60rpm)</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| <li><a href="#org5693368">4.5. Effect of the X-Y stage stiffness</a> | ||||
| <li><a href="#org8ddc330">4.5. Effect of the X-Y stage stiffness</a> | ||||
| <ul> | ||||
| <li><a href="#org542840b">4.5.1. <span class="todo TODO">TODO</span> At full speed, check how the coupling changes with the stiffness of the actuators</a></li> | ||||
| <li><a href="#orgd282a96">4.5.1. <span class="todo TODO">TODO</span> At full speed, check how the coupling changes with the stiffness of the actuators</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| </ul> | ||||
| </li> | ||||
| <li><a href="#org6384d1d">5. Control Implementation</a> | ||||
| <li><a href="#orgdfc37fb">5. Control Implementation</a> | ||||
| <ul> | ||||
| <li><a href="#org2123335">5.1. Measurement in the fixed reference frame</a></li> | ||||
| <li><a href="#org5ed4967">5.1. Measurement in the fixed reference frame</a></li> | ||||
| </ul> | ||||
| </li> | ||||
| </ul> | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orgee97b77" class="outline-2"> | ||||
| <h2 id="orgee97b77"><span class="section-number-2">1</span> Introduction</h2> | ||||
| <div id="outline-container-org0a89915" class="outline-2"> | ||||
| <h2 id="org0a89915"><span class="section-number-2">1</span> Introduction</h2> | ||||
| <div class="outline-text-2" id="text-1"> | ||||
| <p> | ||||
| The objective of this note it to highlight some control problems that arises when controlling the position of an object using actuators that are rotating with respect to a fixed reference frame. | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| In section <a href="#org51ce00f">2</a>, a simple system composed of a spindle and a translation stage is defined and the equations of motion are written. | ||||
| In section <a href="#org725c7e8">2</a>, a simple system composed of a spindle and a translation stage is defined and the equations of motion are written. | ||||
| The rotation induces some coupling between the actuators and their displacement, and modifies the dynamics of the system. | ||||
| This is studied using the equations, and some numerical computations are used to compare the use of voice coil and piezoelectric actuators. | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| Then, in section <a href="#orgc98e361">3</a>, two different control approach are compared where: | ||||
| Then, in section <a href="#orgc886060">3</a>, two different control approach are compared where: | ||||
| </p> | ||||
| <ul class="org-ul"> | ||||
| <li>the measurement is made in the fixed frame</li> | ||||
| @@ -351,27 +351,27 @@ Then, in section <a href="#orgc98e361">3</a>, two different control approach are | ||||
| </ul> | ||||
| 
 | ||||
| <p> | ||||
| In section <a href="#org8965ea1">4</a>, the analytical study will be validated using a multi body model of the studied system. | ||||
| In section <a href="#org889e9c9">4</a>, the analytical study will be validated using a multi body model of the studied system. | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| Finally, in section <a href="#org5ea3930">5</a>, the control strategies are implemented using Simulink and Simscape and compared. | ||||
| Finally, in section <a href="#orgaa1e82e">5</a>, the control strategies are implemented using Simulink and Simscape and compared. | ||||
| </p> | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orge01a725" class="outline-2"> | ||||
| <h2 id="orge01a725"><span class="section-number-2">2</span> System</h2> | ||||
| <div id="outline-container-org123b9ca" class="outline-2"> | ||||
| <h2 id="org123b9ca"><span class="section-number-2">2</span> System</h2> | ||||
| <div class="outline-text-2" id="text-2"> | ||||
| <p> | ||||
| <a id="org51ce00f"></a> | ||||
| <a id="org725c7e8"></a> | ||||
| </p> | ||||
| </div> | ||||
| <div id="outline-container-org91f4ea0" class="outline-3"> | ||||
| <h3 id="org91f4ea0"><span class="section-number-3">2.1</span> System description</h3> | ||||
| <div id="outline-container-org9aa32bf" class="outline-3"> | ||||
| <h3 id="org9aa32bf"><span class="section-number-3">2.1</span> System description</h3> | ||||
| <div class="outline-text-3" id="text-2-1"> | ||||
| <p> | ||||
| The system consists of one 2 degree of freedom translation stage on top of a spindle (figure <a href="#orge344748">1</a>). | ||||
| The system consists of one 2 degree of freedom translation stage on top of a spindle (figure <a href="#org492a56d">1</a>). | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| @@ -384,7 +384,7 @@ The measurement is either the \(x-y\) displacement of the object located on top | ||||
| </p> | ||||
| 
 | ||||
| 
 | ||||
| <div id="orge344748" class="figure"> | ||||
| <div id="org492a56d" class="figure"> | ||||
| <p><img src="./Figures/rotating_frame_2dof.png" alt="rotating_frame_2dof.png" /> | ||||
| </p> | ||||
| <p><span class="figure-number">Figure 1: </span>Schematic of the mecanical system</p> | ||||
| @@ -418,19 +418,19 @@ Indices \(u\) and \(v\) corresponds to signals in the rotating reference frame ( | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org481ba4a" class="outline-3"> | ||||
| <h3 id="org481ba4a"><span class="section-number-3">2.2</span> Equations</h3> | ||||
| <div id="outline-container-orgc0c2859" class="outline-3"> | ||||
| <h3 id="orgc0c2859"><span class="section-number-3">2.2</span> Equations</h3> | ||||
| <div class="outline-text-3" id="text-2-2"> | ||||
| <p> | ||||
|   <a id="org4a7f9d5"></a> | ||||
| Based on the figure <a href="#orge344748">1</a>, we can write the equations of motion of the system. | ||||
|   <a id="org07b8498"></a> | ||||
| Based on the figure <a href="#org492a56d">1</a>, we can write the equations of motion of the system. | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| Let's express the kinetic energy \(T\) and the potential energy \(V\) of the mass \(m\): | ||||
| </p> | ||||
| \begin{align} | ||||
| \label{orgae08e6a} | ||||
| \label{org97ab84a} | ||||
| T & = \frac{1}{2} m \left( \dot{x}^2 + \dot{y}^2 \right) \\ | ||||
| V & = \frac{1}{2} k \left( x^2 + y^2 \right) | ||||
| \end{align} | ||||
| @@ -439,7 +439,7 @@ V & = \frac{1}{2} k \left( x^2 + y^2 \right) | ||||
| The Lagrangian is the kinetic energy minus the potential energy. | ||||
| </p> | ||||
| \begin{equation} | ||||
| \label{org30a9182} | ||||
| \label{org5b05ded} | ||||
| L = T-V = \frac{1}{2} m \left( \dot{x}^2 + \dot{y}^2 \right) - \frac{1}{2} k \left( x^2 + y^2 \right) | ||||
| \end{equation} | ||||
| 
 | ||||
| @@ -448,7 +448,7 @@ L = T-V = \frac{1}{2} m \left( \dot{x}^2 + \dot{y}^2 \right) - \frac{1}{2} k \le | ||||
| The partial derivatives of the Lagrangian with respect to the variables \((x, y)\) are: | ||||
| </p> | ||||
| \begin{align*} | ||||
| \label{orgbf13b01} | ||||
| \label{orgf971d6e} | ||||
| \frac{\partial L}{\partial x} & = -kx \\ | ||||
| \frac{\partial L}{\partial y} & = -ky \\ | ||||
| \frac{d}{dt}\frac{\partial L}{\partial \dot{x}} & = m\ddot{x} \\ | ||||
| @@ -518,11 +518,11 @@ We can then subtract and add the previous equations to obtain the following equa | ||||
| </p> | ||||
| <div class="important"> | ||||
| \begin{equation} | ||||
| \label{orgb7e67f4} | ||||
| \label{orge8fa8fd} | ||||
|  m \ddot{d_u} + (k - m\dot{\theta}^2) d_u = F_u + 2 m\dot{d_v}\dot{\theta} + m d_v\ddot{\theta} | ||||
| \end{equation} | ||||
| \begin{equation} | ||||
| \label{orgda77d65} | ||||
| \label{orge386db1} | ||||
|  m \ddot{d_v} + (k - m\dot{\theta}^2) d_v = F_v - 2 m\dot{d_u}\dot{\theta} - m d_u\ddot{\theta} | ||||
| \end{equation} | ||||
| 
 | ||||
| @@ -548,8 +548,8 @@ The resulting effect of those forces should then be higher when using softer act | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org174395f" class="outline-3"> | ||||
| <h3 id="org174395f"><span class="section-number-3">2.3</span> Numerical Values for the NASS</h3> | ||||
| <div id="outline-container-org0ff8b08" class="outline-3"> | ||||
| <h3 id="org0ff8b08"><span class="section-number-3">2.3</span> Numerical Values for the NASS</h3> | ||||
| <div class="outline-text-3" id="text-2-3"> | ||||
| <p> | ||||
| Let's define the parameters for the NASS. | ||||
| @@ -612,8 +612,8 @@ Let's define the parameters for the NASS. | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orgea07d45" class="outline-3"> | ||||
| <h3 id="orgea07d45"><span class="section-number-3">2.4</span> Euler and Coriolis forces - Numerical Result</h3> | ||||
| <div id="outline-container-org361651b" class="outline-3"> | ||||
| <h3 id="org361651b"><span class="section-number-3">2.4</span> Euler and Coriolis forces - Numerical Result</h3> | ||||
| <div class="outline-text-3" id="text-2-4"> | ||||
| <p> | ||||
| First we will determine the value for Euler and Coriolis forces during regular experiment. | ||||
| @@ -624,10 +624,10 @@ First we will determine the value for Euler and Coriolis forces during regular e | ||||
| </ul> | ||||
| 
 | ||||
| <p> | ||||
| The obtained values are displayed in table <a href="#orgd27b775">1</a>. | ||||
| The obtained values are displayed in table <a href="#org87d7458">1</a>. | ||||
| </p> | ||||
| 
 | ||||
| <table id="orgd27b775" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <table id="org87d7458" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <caption class="t-above"><span class="table-number">Table 1:</span> Euler and Coriolis forces for the NASS</caption> | ||||
| 
 | ||||
| <colgroup> | ||||
| @@ -661,22 +661,22 @@ The obtained values are displayed in table <a href="#orgd27b775">1</a>. | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org394681f" class="outline-3"> | ||||
| <h3 id="org394681f"><span class="section-number-3">2.5</span> Negative Spring Effect - Numerical Result</h3> | ||||
| <div id="outline-container-orgd2c08cb" class="outline-3"> | ||||
| <h3 id="orgd2c08cb"><span class="section-number-3">2.5</span> Negative Spring Effect - Numerical Result</h3> | ||||
| <div class="outline-text-3" id="text-2-5"> | ||||
| <p> | ||||
| The negative stiffness due to the rotation is equal to \(-m{\omega_0}^2\). | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| The values for the negative spring effect are displayed in table <a href="#org08ea861">2</a>. | ||||
| The values for the negative spring effect are displayed in table <a href="#orgda1ded2">2</a>. | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| This is definitely negligible when using piezoelectric actuators. It may not be the case when using voice coil actuators. | ||||
| </p> | ||||
| 
 | ||||
| <table id="org08ea861" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <table id="orgda1ded2" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <caption class="t-above"><span class="table-number">Table 2:</span> Negative Spring effect</caption> | ||||
| 
 | ||||
| <colgroup> | ||||
| @@ -704,15 +704,15 @@ This is definitely negligible when using piezoelectric actuators. It may not be | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org62563d6" class="outline-3"> | ||||
| <h3 id="org62563d6"><span class="section-number-3">2.6</span> Limitations due to coupling</h3> | ||||
| <div id="outline-container-org3d790d8" class="outline-3"> | ||||
| <h3 id="org3d790d8"><span class="section-number-3">2.6</span> Limitations due to coupling</h3> | ||||
| <div class="outline-text-3" id="text-2-6"> | ||||
| <p> | ||||
| To simplify, we consider a constant rotating speed \(\dot{\theta} = {\omega_0}\) and thus \(\ddot{\theta} = 0\). | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| From equations \eqref{orgb7e67f4} and \eqref{orgda77d65}, we obtain: | ||||
| From equations \eqref{orge8fa8fd} and \eqref{orge386db1}, we obtain: | ||||
| </p> | ||||
|  \begin{align*} | ||||
|  (m s^2 + (k - m{\omega_0}^2)) d_u &= F_u + 2 m {\omega_0} s d_v \\ | ||||
| @@ -766,26 +766,26 @@ Then, coupling is negligible if \(|-m \omega^2 + (k - m{\omega_0}^2)| \gg |2 m { | ||||
| </p> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org890c28a" class="outline-4"> | ||||
| <h4 id="org890c28a"><span class="section-number-4">2.6.1</span> Numerical Analysis</h4> | ||||
| <div id="outline-container-org041128a" class="outline-4"> | ||||
| <h4 id="org041128a"><span class="section-number-4">2.6.1</span> Numerical Analysis</h4> | ||||
| <div class="outline-text-4" id="text-2-6-1"> | ||||
| <p> | ||||
| We plot on the same graph \(\frac{|-m \omega^2 + (k - m {\omega_0}^2)|}{|2 m \omega_0 \omega|}\) for the voice coil and the piezo: | ||||
| </p> | ||||
| <ul class="org-ul"> | ||||
| <li>with the light sample (figure <a href="#orgc6849b2">2</a>).</li> | ||||
| <li>with the heavy sample (figure <a href="#org8cac42a">3</a>).</li> | ||||
| <li>with the light sample (figure <a href="#org7303972">2</a>).</li> | ||||
| <li>with the heavy sample (figure <a href="#org3386e78">3</a>).</li> | ||||
| </ul> | ||||
| 
 | ||||
| 
 | ||||
| <div id="orgc6849b2" class="figure"> | ||||
| <div id="org7303972" class="figure"> | ||||
| <p><img src="Figures/coupling_light.png" alt="coupling_light.png" /> | ||||
| </p> | ||||
| <p><span class="figure-number">Figure 2: </span>Relative Coupling for light mass and high rotation speed</p> | ||||
| </div> | ||||
| 
 | ||||
| 
 | ||||
| <div id="org8cac42a" class="figure"> | ||||
| <div id="org3386e78" class="figure"> | ||||
| <p><img src="Figures/coupling_heavy.png" alt="coupling_heavy.png" /> | ||||
| </p> | ||||
| <p><span class="figure-number">Figure 3: </span>Relative Coupling for heavy mass and low rotation speed</p> | ||||
| @@ -801,17 +801,17 @@ Coupling is higher for actuators with small stiffness. | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orgd4adbe6" class="outline-3"> | ||||
| <h3 id="orgd4adbe6"><span class="section-number-3">2.7</span> Limitations due to negative stiffness effect</h3> | ||||
| <div id="outline-container-org11f0d9f" class="outline-3"> | ||||
| <h3 id="org11f0d9f"><span class="section-number-3">2.7</span> Limitations due to negative stiffness effect</h3> | ||||
| <div class="outline-text-3" id="text-2-7"> | ||||
| <p> | ||||
| If \(\max{\dot{\theta}} \ll \sqrt{\frac{k}{m}}\), then the negative spring effect is negligible and \(k - m\dot{\theta}^2 \approx k\). | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| Let's estimate what is the maximum rotation speed for which the negative stiffness effect is still negligible (\(\omega_\text{max} = 0.1 \sqrt{\frac{k}{m}}\)). Results are shown table <a href="#orgd3c38a0">3</a>. | ||||
| Let's estimate what is the maximum rotation speed for which the negative stiffness effect is still negligible (\(\omega_\text{max} = 0.1 \sqrt{\frac{k}{m}}\)). Results are shown table <a href="#org3a5730b">3</a>. | ||||
| </p> | ||||
| <table id="orgd3c38a0" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <table id="org3a5730b" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <caption class="t-above"><span class="table-number">Table 3:</span> Maximum rotation speed at which negative stiffness is negligible (\(0.1\sqrt{\frac{k}{m}}\))</caption> | ||||
| 
 | ||||
| <colgroup> | ||||
| @@ -860,10 +860,10 @@ The system can even goes unstable when \(m \omega^2 > k\), that is when the cent | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| From this analysis, we can determine the lowest practical stiffness that is possible to use: \(k_\text{min} = 10 m \omega^2\) (table <a href="#orgef973e2">4</a>) | ||||
| From this analysis, we can determine the lowest practical stiffness that is possible to use: \(k_\text{min} = 10 m \omega^2\) (table <a href="#org9464a39">4</a>) | ||||
| </p> | ||||
| 
 | ||||
| <table id="orgef973e2" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <table id="org9464a39" border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> | ||||
| <caption class="t-above"><span class="table-number">Table 4:</span> Minimum possible stiffness</caption> | ||||
| 
 | ||||
| <colgroup> | ||||
| @@ -892,15 +892,15 @@ From this analysis, we can determine the lowest practical stiffness that is poss | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org680ba84" class="outline-2"> | ||||
| <h2 id="org680ba84"><span class="section-number-2">3</span> Control Strategies</h2> | ||||
| <div id="outline-container-org6ae3c88" class="outline-2"> | ||||
| <h2 id="org6ae3c88"><span class="section-number-2">3</span> Control Strategies</h2> | ||||
| <div class="outline-text-2" id="text-3"> | ||||
| <p> | ||||
| <a id="orgc98e361"></a> | ||||
| <a id="orgc886060"></a> | ||||
| </p> | ||||
| </div> | ||||
| <div id="outline-container-orga9b261d" class="outline-3"> | ||||
| <h3 id="orga9b261d"><span class="section-number-3">3.1</span> Measurement in the fixed reference frame</h3> | ||||
| <div id="outline-container-orgbf1698b" class="outline-3"> | ||||
| <h3 id="orgbf1698b"><span class="section-number-3">3.1</span> Measurement in the fixed reference frame</h3> | ||||
| <div class="outline-text-3" id="text-3-1"> | ||||
| <p> | ||||
| First, let's consider a measurement in the fixed referenced frame. | ||||
| @@ -923,11 +923,11 @@ Finally, the control low \(K\) links the position errors \([\epsilon_u, \epsilon | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| The block diagram is shown on figure <a href="#orgc60aeca">4</a>. | ||||
| The block diagram is shown on figure <a href="#org8698ee9">4</a>. | ||||
| </p> | ||||
| 
 | ||||
| 
 | ||||
| <div id="orgc60aeca" class="figure"> | ||||
| <div id="org8698ee9" class="figure"> | ||||
| <p><img src="./Figures/control_measure_fixed_2dof.png" alt="control_measure_fixed_2dof.png" /> | ||||
| </p> | ||||
| <p><span class="figure-number">Figure 4: </span>Control with a measure from fixed frame</p> | ||||
| @@ -943,19 +943,19 @@ One question we wish to answer is: is \(G(\theta) J(\theta) = G(\theta_0) J(\the | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org8823cd3" class="outline-3"> | ||||
| <h3 id="org8823cd3"><span class="section-number-3">3.2</span> Measurement in the rotating frame</h3> | ||||
| <div id="outline-container-orgf37122a" class="outline-3"> | ||||
| <h3 id="orgf37122a"><span class="section-number-3">3.2</span> Measurement in the rotating frame</h3> | ||||
| <div class="outline-text-3" id="text-3-2"> | ||||
| <p> | ||||
| Let's consider that the measurement is made in the rotating reference frame. | ||||
| </p> | ||||
| 
 | ||||
| <p> | ||||
| The corresponding block diagram is shown figure <a href="#org21df845">5</a> | ||||
| The corresponding block diagram is shown figure <a href="#org6f71235">5</a> | ||||
| </p> | ||||
| 
 | ||||
| 
 | ||||
| <div id="org21df845" class="figure"> | ||||
| <div id="org6f71235" class="figure"> | ||||
| <p><img src="./Figures/control_measure_rotating_2dof.png" alt="control_measure_rotating_2dof.png" /> | ||||
| </p> | ||||
| <p><span class="figure-number">Figure 5: </span>Control with a measure from rotating frame</p> | ||||
| @@ -968,16 +968,16 @@ The loop gain is \(L = G K\). | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org837c5c4" class="outline-2"> | ||||
| <h2 id="org837c5c4"><span class="section-number-2">4</span> Multi Body Model - Simscape</h2> | ||||
| <div id="outline-container-org3b55a8d" class="outline-2"> | ||||
| <h2 id="org3b55a8d"><span class="section-number-2">4</span> Multi Body Model - Simscape</h2> | ||||
| <div class="outline-text-2" id="text-4"> | ||||
| <p> | ||||
| <a id="org8965ea1"></a> | ||||
| <a id="org889e9c9"></a> | ||||
| </p> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orgd9921e4" class="outline-3"> | ||||
| <h3 id="orgd9921e4"><span class="section-number-3">4.1</span> Identification in the rotating referenced frame</h3> | ||||
| <div id="outline-container-orgd50d938" class="outline-3"> | ||||
| <h3 id="orgd50d938"><span class="section-number-3">4.1</span> Identification in the rotating referenced frame</h3> | ||||
| <div class="outline-text-3" id="text-4-1"> | ||||
| <p> | ||||
| We initialize the inputs and outputs of the system to identify. | ||||
| @@ -1000,8 +1000,8 @@ io<span style="color: #707183;">(</span><span style="color: #D0372D;">4</span><s | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org6737d1b" class="outline-4"> | ||||
| <h4 id="org6737d1b"><span class="section-number-4">4.1.1</span> Piezo and Voice coil</h4> | ||||
| <div id="outline-container-org2ede09d" class="outline-4"> | ||||
| <h4 id="org2ede09d"><span class="section-number-4">4.1.1</span> Piezo and Voice coil</h4> | ||||
| <div class="outline-text-4" id="text-4-1-1"> | ||||
| <p> | ||||
| We start we identify the transfer functions at high speed with the light sample. | ||||
| @@ -1026,6 +1026,12 @@ Gvc_light.OutputName = <span style="color: #707183;">{</span><span style="color: | ||||
| </pre> | ||||
| </div> | ||||
| 
 | ||||
| 
 | ||||
| <div class="figure"> | ||||
| <p><img src="Figures/coupling_simscape_light.png" alt="coupling_simscape_light.png" /> | ||||
| </p> | ||||
| </div> | ||||
| 
 | ||||
| <p> | ||||
| And then with the heavy sample. | ||||
| </p> | ||||
| @@ -1049,13 +1055,31 @@ Gvc_heavy.OutputName = <span style="color: #707183;">{</span><span style="color: | ||||
| </pre> | ||||
| </div> | ||||
| 
 | ||||
| 
 | ||||
| <div class="figure"> | ||||
| <p><img src="Figures/coupling_simscape_heavy.png" alt="coupling_simscape_heavy.png" /> | ||||
| </p> | ||||
| </div> | ||||
| 
 | ||||
| <p> | ||||
| Plot the ratio between the main transfer function and the coupling term: | ||||
| </p> | ||||
| 
 | ||||
| <div class="figure"> | ||||
| <p><img src="Figures/coupling_ration_simscape_light.png" alt="coupling_ration_simscape_light.png" /> | ||||
| </p> | ||||
| </div> | ||||
| 
 | ||||
| 
 | ||||
| <div class="figure"> | ||||
| <p><img src="Figures/coupling_ration_simscape_heavy.png" alt="coupling_ration_simscape_heavy.png" /> | ||||
| </p> | ||||
| </div> | ||||
| </div> | ||||
| <div id="outline-container-org3a97e8d" class="outline-4"> | ||||
| <h4 id="org3a97e8d"><span class="section-number-4">4.1.2</span> Low rotation speed and High rotation speed</h4> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orgbb666ab" class="outline-4"> | ||||
| <h4 id="orgbb666ab"><span class="section-number-4">4.1.2</span> Low rotation speed and High rotation speed</h4> | ||||
| <div class="outline-text-4" id="text-4-1-2"> | ||||
| <div class="org-src-container"> | ||||
| <pre class="src src-matlab">rot_speed = <span style="color: #D0372D;">2</span><span style="color: #6434A3;">*</span><span style="color: #D0372D;">pi</span><span style="color: #6434A3;">/</span><span style="color: #D0372D;">60</span>; angle_e = <span style="color: #D0372D;">0</span>; | ||||
| @@ -1080,8 +1104,8 @@ bode<span style="color: #707183;">(</span>G_low, G_high<span style="color: #7071 | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org2dbda82" class="outline-3"> | ||||
| <h3 id="org2dbda82"><span class="section-number-3">4.2</span> Identification in the fixed frame</h3> | ||||
| <div id="outline-container-org3ecccf8" class="outline-3"> | ||||
| <h3 id="org3ecccf8"><span class="section-number-3">4.2</span> Identification in the fixed frame</h3> | ||||
| <div class="outline-text-3" id="text-4-2"> | ||||
| <p> | ||||
| Let's define some options as well as the inputs and outputs for linearization. | ||||
| @@ -1162,8 +1186,8 @@ bode<span style="color: #707183;">(</span>Ge<span style="color: #707183;">)</spa | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-orgffd87f4" class="outline-3"> | ||||
| <h3 id="orgffd87f4"><span class="section-number-3">4.3</span> Identification from actuator forces to displacement in the fixed frame</h3> | ||||
| <div id="outline-container-orga260738" class="outline-3"> | ||||
| <h3 id="orga260738"><span class="section-number-3">4.3</span> Identification from actuator forces to displacement in the fixed frame</h3> | ||||
| <div class="outline-text-3" id="text-4-3"> | ||||
| <div class="org-src-container"> | ||||
| <pre class="src src-matlab"><span style="color: #8D8D84; font-weight: bold; font-style: italic; text-decoration: overline;">%% Options for Linearized</span> | ||||
| @@ -1221,48 +1245,48 @@ exportFig<span style="color: #707183;">(</span><span style="color: #008000;">'G_ | ||||
| </div> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org19541fc" class="outline-3"> | ||||
| <h3 id="org19541fc"><span class="section-number-3">4.4</span> Effect of the rotating Speed</h3> | ||||
| <div id="outline-container-orge0b7f4f" class="outline-3"> | ||||
| <h3 id="orge0b7f4f"><span class="section-number-3">4.4</span> Effect of the rotating Speed</h3> | ||||
| <div class="outline-text-3" id="text-4-4"> | ||||
| <p> | ||||
| <a id="orgb8b6174"></a> | ||||
| <a id="orgd1e3b9e"></a> | ||||
| </p> | ||||
| </div> | ||||
| 
 | ||||
| <div id="outline-container-org1a2f75c" class="outline-4"> | ||||
| <h4 id="org1a2f75c"><span class="section-number-4">4.4.1</span> <span class="todo TODO">TODO</span> Use realistic parameters for the mass of the sample and stiffness of the X-Y stage</h4> | ||||
| <div id="outline-container-orgd25182f" class="outline-4"> | ||||
| <h4 id="orgd25182f"><span class="section-number-4">4.4.1</span> <span class="todo TODO">TODO</span> Use realistic parameters for the mass of the sample and stiffness of the X-Y stage</h4> | ||||
| </div> | ||||
| <div id="outline-container-orgf132002" class="outline-4"> | ||||
| <h4 id="orgf132002"><span class="section-number-4">4.4.2</span> <span class="todo TODO">TODO</span> Check if the plant is changing a lot when we are not turning to when we are turning at the maximum speed (60rpm)</h4> | ||||
| <div id="outline-container-org0368be9" class="outline-4"> | ||||
| <h4 id="org0368be9"><span class="section-number-4">4.4.2</span> <span class="todo TODO">TODO</span> Check if the plant is changing a lot when we are not turning to when we are turning at the maximum speed (60rpm)</h4> | ||||
| </div> | ||||
| </div> | ||||
| <div id="outline-container-org5693368" class="outline-3"> | ||||
| <h3 id="org5693368"><span class="section-number-3">4.5</span> Effect of the X-Y stage stiffness</h3> | ||||
| <div id="outline-container-org8ddc330" class="outline-3"> | ||||
| <h3 id="org8ddc330"><span class="section-number-3">4.5</span> Effect of the X-Y stage stiffness</h3> | ||||
| <div class="outline-text-3" id="text-4-5"> | ||||
| <p> | ||||
| <a id="org1d9d05a"></a> | ||||
| <a id="org072e1f4"></a> | ||||
| </p> | ||||
| </div> | ||||
| <div id="outline-container-org542840b" class="outline-4"> | ||||
| <h4 id="org542840b"><span class="section-number-4">4.5.1</span> <span class="todo TODO">TODO</span> At full speed, check how the coupling changes with the stiffness of the actuators</h4> | ||||
| <div id="outline-container-orgd282a96" class="outline-4"> | ||||
| <h4 id="orgd282a96"><span class="section-number-4">4.5.1</span> <span class="todo TODO">TODO</span> At full speed, check how the coupling changes with the stiffness of the actuators</h4> | ||||
| </div> | ||||
| </div> | ||||
| </div> | ||||
| <div id="outline-container-org6384d1d" class="outline-2"> | ||||
| <h2 id="org6384d1d"><span class="section-number-2">5</span> Control Implementation</h2> | ||||
| <div id="outline-container-orgdfc37fb" class="outline-2"> | ||||
| <h2 id="orgdfc37fb"><span class="section-number-2">5</span> Control Implementation</h2> | ||||
| <div class="outline-text-2" id="text-5"> | ||||
| <p> | ||||
| <a id="org5ea3930"></a> | ||||
| <a id="orgaa1e82e"></a> | ||||
| </p> | ||||
| </div> | ||||
| <div id="outline-container-org2123335" class="outline-3"> | ||||
| <h3 id="org2123335"><span class="section-number-3">5.1</span> Measurement in the fixed reference frame</h3> | ||||
| <div id="outline-container-org5ed4967" class="outline-3"> | ||||
| <h3 id="org5ed4967"><span class="section-number-3">5.1</span> Measurement in the fixed reference frame</h3> | ||||
| </div> | ||||
| </div> | ||||
| </div> | ||||
| <div id="postamble" class="status"> | ||||
| <p class="author">Author: Thomas Dehaeze</p> | ||||
| <p class="date">Created: 2019-01-21 lun. 23:32</p> | ||||
| <p class="date">Created: 2019-01-21 lun. 23:44</p> | ||||
| <p class="validation"><a href="http://validator.w3.org/check?uri=referer">Validate</a></p> | ||||
| </div> | ||||
| </body> | ||||
|   | ||||
		Reference in New Issue
	
	Block a user