nass-micro-station-measurem.../disturbance-control-system/index.org

834 lines
31 KiB
Org Mode

#+TITLE:Effect on the control system of each stages on the vibration of the station
:DRAWER:
#+STARTUP: overview
#+LANGUAGE: en
#+EMAIL: dehaeze.thomas@gmail.com
#+AUTHOR: Dehaeze Thomas
#+HTML_LINK_HOME: ../index.html
#+HTML_LINK_UP: ../index.html
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../css/htmlize.css"/>
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../css/readtheorg.css"/>
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../css/zenburn.css"/>
#+HTML_HEAD: <script type="text/javascript" src="../js/jquery.min.js"></script>
#+HTML_HEAD: <script type="text/javascript" src="../js/bootstrap.min.js"></script>
#+HTML_HEAD: <script type="text/javascript" src="../js/jquery.stickytableheaders.min.js"></script>
#+HTML_HEAD: <script type="text/javascript" src="../js/readtheorg.js"></script>
#+HTML_MATHJAX: align: center tagside: right font: TeX
#+PROPERTY: header-args:matlab :session *MATLAB*
#+PROPERTY: header-args:matlab+ :comments org
#+PROPERTY: header-args:matlab+ :results none
#+PROPERTY: header-args:matlab+ :exports both
#+PROPERTY: header-args:matlab+ :eval no-export
#+PROPERTY: header-args:matlab+ :output-dir figs
#+PROPERTY: header-args:shell :eval no-export
:END:
For all the measurements shown here:
- geophones used are L22 with a resonance frequency of 1Hz
- the signals are amplified with voltage amplifiers with a gain of 60dB
- the voltage amplifiers include a low pass filter with a cut-off frequency at 1kHz
* Effect of all the control systems on the Sample vibrations
:PROPERTIES:
:header-args:matlab+: :tangle matlab/effect_control_all.m
:header-args:matlab+: :comments org :mkdirp yes
:END:
<<sec:effect_control_all>>
** ZIP file containing the data and matlab files :ignore:
#+begin_src bash :exports none :results none
if [ matlab/effect_control_all.m -nt data/effect_control_all.zip ]; then
cp matlab/effect_control_all.m effect_control_all.m;
zip data/effect_control_all \
mat/data_003.mat \
mat/data_004.mat \
mat/data_005.mat \
mat/data_006.mat \
mat/data_007.mat \
mat/data_008.mat \
effect_control_all.m;
rm effect_control_all.m;
fi
#+end_src
#+begin_note
All the files (data and Matlab scripts) are accessible [[file:data/effect_control_all.zip][here]].
#+end_note
** Experimental Setup
We here measure the signals of two geophones:
- One is located on top of the Sample platform
- One is located on the marble
The signal from the top geophone does not go trought the slip-ring.
First, all the control systems are turned ON, then, they are turned one by one.
Each measurement are done during 50s.
#+name: tab:control_system_on_off
#+caption: Summary of the measurements and the states of the control systems
| Ty | Ry | Slip Ring | Spindle | Hexapod | Meas. file |
|------+------+-----------+---------+---------+----------------|
| *ON* | *ON* | *ON* | *ON* | *ON* | =meas_003.mat= |
| OFF | *ON* | *ON* | *ON* | *ON* | =meas_004.mat= |
| OFF | OFF | *ON* | *ON* | *ON* | =meas_005.mat= |
| OFF | OFF | OFF | *ON* | *ON* | =meas_006.mat= |
| OFF | OFF | OFF | OFF | *ON* | =meas_007.mat= |
| OFF | OFF | OFF | OFF | OFF | =meas_008.mat= |
Each of the =mat= file contains one array =data= with 3 columns:
| Column number | Description |
|---------------+-------------------|
| 1 | Geophone - Marble |
| 2 | Geophone - Sample |
| 3 | Time |
** Matlab Init :noexport:ignore:
#+begin_src matlab :tangle no :exports none :results silent :noweb yes :var current_dir=(file-name-directory buffer-file-name)
<<matlab-dir>>
#+end_src
#+begin_src matlab :exports none :results silent :noweb yes
<<matlab-init>>
#+end_src
** Load data
We load the data of the z axis of two geophones.
#+begin_src matlab :results none
d3 = load('mat/data_003.mat', 'data'); d3 = d3.data;
d4 = load('mat/data_004.mat', 'data'); d4 = d4.data;
d5 = load('mat/data_005.mat', 'data'); d5 = d5.data;
d6 = load('mat/data_006.mat', 'data'); d6 = d6.data;
d7 = load('mat/data_007.mat', 'data'); d7 = d7.data;
d8 = load('mat/data_008.mat', 'data'); d8 = d8.data;
#+end_src
** Analysis - Time Domain
First, we can look at the time domain data and compare all the measurements:
- comparison for the geophone at the sample location (figure [[fig:time_domain_sample]])
- comparison for the geophone on the granite (figure [[fig:time_domain_marble]])
#+begin_src matlab :results none
figure;
hold on;
plot(d3(:, 3), d3(:, 2), 'DisplayName', 'All ON');
plot(d4(:, 3), d4(:, 2), 'DisplayName', 'Ty OFF');
plot(d5(:, 3), d5(:, 2), 'DisplayName', 'Ry OFF');
plot(d6(:, 3), d6(:, 2), 'DisplayName', 'S-R OFF');
plot(d7(:, 3), d7(:, 2), 'DisplayName', 'Rz OFF');
plot(d8(:, 3), d8(:, 2), 'DisplayName', 'Hexa OFF');
hold off;
xlabel('Time [s]'); ylabel('Voltage [V]');
xlim([0, 50]);
legend('Location', 'bestoutside');
#+end_src
#+NAME: fig:time_domain_sample
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/time_domain_sample.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:time_domain_sample
#+CAPTION: Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location
#+RESULTS: fig:time_domain_sample
[[file:figs/time_domain_sample.png]]
#+begin_src matlab :results none
figure;
hold on;
plot(d3(:, 3), d3(:, 1), 'DisplayName', 'All ON');
plot(d4(:, 3), d4(:, 1), 'DisplayName', 'Ty OFF');
plot(d5(:, 3), d5(:, 1), 'DisplayName', 'Ry OFF');
plot(d6(:, 3), d6(:, 1), 'DisplayName', 'S-R OFF');
plot(d7(:, 3), d7(:, 1), 'DisplayName', 'Rz OFF');
plot(d8(:, 3), d8(:, 1), 'DisplayName', 'Hexa OFF');
hold off;
xlabel('Time [s]'); ylabel('Voltage [V]');
xlim([0, 50]);
legend('Location', 'bestoutside');
#+end_src
#+NAME: fig:time_domain_marble
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/time_domain_marble.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:time_domain_marble
#+CAPTION: Comparison of the time domain data when turning off the control system of the stages - Geophone on the marble
#+RESULTS: fig:time_domain_marble
[[file:figs/time_domain_marble.png]]
** Analysis - Frequency Domain
#+begin_src matlab :results none
dt = d3(2, 3) - d3(1, 3);
Fs = 1/dt;
win = hanning(ceil(10*Fs));
#+end_src
*** Vibrations at the sample location
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
#+begin_src matlab :results none
[px3, f] = pwelch(d3(:, 2), win, [], [], Fs);
[px4, ~] = pwelch(d4(:, 2), win, [], [], Fs);
[px5, ~] = pwelch(d5(:, 2), win, [], [], Fs);
[px6, ~] = pwelch(d6(:, 2), win, [], [], Fs);
[px7, ~] = pwelch(d7(:, 2), win, [], [], Fs);
[px8, ~] = pwelch(d8(:, 2), win, [], [], Fs);
#+end_src
And we compare all the signals (figures [[fig:psd_sample_comp]] and [[fig:psd_sample_comp_high_freq]]).
#+begin_src matlab :results none
figure;
hold on;
plot(f, sqrt(px3), 'DisplayName', 'All ON');
plot(f, sqrt(px4), 'DisplayName', 'Ty OFF');
plot(f, sqrt(px5), 'DisplayName', 'Ry OFF');
plot(f, sqrt(px6), 'DisplayName', 'S-R OFF');
plot(f, sqrt(px7), 'DisplayName', 'Rz OFF');
plot(f, sqrt(px8), 'DisplayName', 'Hexa OFF');
hold off;
set(gca, 'xscale', 'log');
set(gca, 'yscale', 'log');
xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$')
xlim([0.1, 500]);
legend('Location', 'southwest');
#+end_src
#+NAME: fig:psd_sample_comp
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_sample_comp.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_sample_comp
#+CAPTION: Amplitude Spectral Density of the signal coming from the top geophone
#+RESULTS: fig:psd_sample_comp
[[file:figs/psd_sample_comp.png]]
#+begin_src matlab :results none :tangle no :exports none
xlim([80, 500]);
#+end_src
#+NAME: fig:psd_sample_comp_high_freq
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_sample_comp_high_freq.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_sample_comp_high_freq
#+CAPTION: Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)
#+RESULTS: fig:psd_sample_comp_high_freq
[[file:figs/psd_sample_comp_high_freq.png]]
*** Vibrations on the marble
Now we plot the same curves for the geophone located on the marble.
#+begin_src matlab :results none
[px3, f] = pwelch(d3(:, 1), win, [], [], Fs);
[px4, ~] = pwelch(d4(:, 1), win, [], [], Fs);
[px5, ~] = pwelch(d5(:, 1), win, [], [], Fs);
[px6, ~] = pwelch(d6(:, 1), win, [], [], Fs);
[px7, ~] = pwelch(d7(:, 1), win, [], [], Fs);
[px8, ~] = pwelch(d8(:, 1), win, [], [], Fs);
#+end_src
And we compare the Amplitude Spectral Densities (figures [[fig:psd_marble_comp]] and [[fig:psd_marble_comp_high_freq]])
#+begin_src matlab :results none
figure;
hold on;
plot(f, sqrt(px3), 'DisplayName', 'All ON');
plot(f, sqrt(px4), 'DisplayName', 'Ty OFF');
plot(f, sqrt(px5), 'DisplayName', 'Ry OFF');
plot(f, sqrt(px6), 'DisplayName', 'S-R OFF');
plot(f, sqrt(px7), 'DisplayName', 'Rz OFF');
plot(f, sqrt(px8), 'DisplayName', 'Hexa OFF');
hold off;
set(gca, 'xscale', 'log');
set(gca, 'yscale', 'log');
xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$')
xlim([0.1, 500]);
legend('Location', 'northeast');
#+end_src
#+NAME: fig:psd_marble_comp
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_marble_comp.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_marble_comp
#+CAPTION: Amplitude Spectral Density of the signal coming from the top geophone
#+RESULTS: fig:psd_marble_comp
[[file:figs/psd_marble_comp.png]]
#+begin_src matlab :results none :tangle no :exports none
legend('Location', 'southwest');
xlim([80, 500]);
#+end_src
#+NAME: fig:psd_marble_comp_high_freq
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_marble_comp_high_freq.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_marble_comp_high_freq
#+CAPTION: Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)
#+RESULTS: fig:psd_marble_comp_high_freq
[[file:figs/psd_marble_comp_high_freq.png]]
** Effect of the control system on the transmissibility from ground to sample
As the feedback loops change the dynamics of the system, we should see differences on the transfer function from marble velocity to sample velocity when turning off the control systems (figure [[fig:trans_comp]]).
#+begin_src matlab :results none
dt = d3(2, 3) - d3(1, 3);
Fs = 1/dt;
win = hanning(ceil(1*Fs));
#+end_src
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
#+begin_src matlab :results none
[T3, f] = tfestimate(d3(:, 1), d3(:, 2), win, [], [], Fs);
[T4, ~] = tfestimate(d4(:, 1), d4(:, 2), win, [], [], Fs);
[T5, ~] = tfestimate(d5(:, 1), d5(:, 2), win, [], [], Fs);
[T6, ~] = tfestimate(d6(:, 1), d6(:, 2), win, [], [], Fs);
[T7, ~] = tfestimate(d7(:, 1), d7(:, 2), win, [], [], Fs);
[T8, ~] = tfestimate(d8(:, 1), d8(:, 2), win, [], [], Fs);
#+end_src
#+begin_src matlab :results none
figure;
ax1 = subplot(2, 1, 1);
hold on;
plot(f, abs(T3), 'DisplayName', 'All ON');
plot(f, abs(T4), 'DisplayName', 'Ty OFF');
plot(f, abs(T5), 'DisplayName', 'Ry OFF');
plot(f, abs(T6), 'DisplayName', 'S-R OFF');
plot(f, abs(T7), 'DisplayName', 'Rz OFF');
plot(f, abs(T8), 'DisplayName', 'Hexa OFF');
hold off;
set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
set(gca, 'XTickLabel',[]);
ylabel('Magnitude');
legend('Location', 'northwest');
ax2 = subplot(2, 1, 2);
hold on;
plot(f, mod(180+180/pi*phase(T3), 360)-180);
plot(f, mod(180+180/pi*phase(T4), 360)-180);
plot(f, mod(180+180/pi*phase(T5), 360)-180);
plot(f, mod(180+180/pi*phase(T6), 360)-180);
plot(f, mod(180+180/pi*phase(T7), 360)-180);
plot(f, mod(180+180/pi*phase(T8), 360)-180);
hold off;
set(gca, 'xscale', 'log');
ylim([-180, 180]);
yticks([-180, -90, 0, 90, 180]);
xlabel('Frequency [Hz]'); ylabel('Phase');
linkaxes([ax1,ax2],'x');
xlim([1, 500]);
#+end_src
#+NAME: fig:trans_comp
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/trans_comp.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:trans_comp
#+CAPTION: Comparison of the transfer function from the geophone on the marble to the geophone at the sample location
#+RESULTS: fig:trans_comp
[[file:figs/trans_comp.png]]
** Conclusion
#+begin_important
- The control system of the Ty stage induces a lot of vibrations of the marble
#+end_important
#+begin_note
- Why it seems that the measurement noise at high frequency is the limiting factor when the slip ring is ON but not when it is OFF?
#+end_note
* Effect of all the control systems on the Sample vibrations - One stage at a time
:PROPERTIES:
:header-args:matlab+: :tangle matlab/effect_control_one.m
:header-args:matlab+: :comments org :mkdirp yes
:END:
<<sec:effect_control_one>>
** ZIP file containing the data and matlab files :ignore:
#+begin_src bash :exports none :results none
if [ matlab/effect_control_one.m -nt data/effect_control_one.zip ]; then
cp matlab/effect_control_one.m effect_control_one.m;
zip data/effect_control_one \
mat/data_013.mat \
mat/data_014.mat \
mat/data_015.mat \
mat/data_016.mat \
mat/data_017.mat \
mat/data_018.mat \
effect_control_one.m
rm effect_control_one.m;
fi
#+end_src
#+begin_note
All the files (data and Matlab scripts) are accessible [[file:data/effect_control_one.zip][here]].
#+end_note
** Experimental Setup
We here measure the signals of two geophones:
- One is located on top of the Sample platform
- One is located on the marble
The signal from the top geophone does go trought the slip-ring.
All the control systems are turned OFF, then, they are turned on one at a time.
Each measurement are done during 100s.
The settings of the voltage amplifier are shown on figure [[fig:amplifier_settings]]:
- gain of 60dB
- AC/DC option set on DC
- Low pass filter set at 1kHz
A first order low pass filter with a cut-off frequency of 1kHz is added before the voltage amplifier.
#+name: tab:control_system_on_off
#+caption: Summary of the measurements and the states of the control systems
| Ty | Ry | Slip Ring | Spindle | Hexapod | Meas. file |
|------+------+-----------+---------+---------+----------------|
| OFF | OFF | OFF | OFF | OFF | =meas_013.mat= |
| *ON* | OFF | OFF | OFF | OFF | =meas_014.mat= |
| OFF | *ON* | OFF | OFF | OFF | =meas_015.mat= |
| OFF | OFF | *ON* | OFF | OFF | =meas_016.mat= |
| OFF | OFF | OFF | *ON* | OFF | =meas_017.mat= |
| OFF | OFF | OFF | OFF | *ON* | =meas_018.mat= |
Each of the =mat= file contains one array =data= with 3 columns:
| Column number | Description |
|---------------+-------------------|
| 1 | Geophone - Marble |
| 2 | Geophone - Sample |
| 3 | Time |
#+name: fig:amplifier_settings
#+caption: Voltage amplifier settings for the measurement
#+attr_html: :width 500px
[[file:./img/IMG_20190507_101459.jpg]]
** Matlab Init :noexport:ignore:
#+begin_src matlab :tangle no :exports none :results silent :noweb yes :var current_dir=(file-name-directory buffer-file-name)
<<matlab-dir>>
#+end_src
#+begin_src matlab :exports none :results silent :noweb yes
<<matlab-init>>
#+end_src
** Load data
We load the data of the z axis of two geophones.
#+begin_src matlab :results none
d_of = load('mat/data_013.mat', 'data'); d_of = d_of.data;
d_ty = load('mat/data_014.mat', 'data'); d_ty = d_ty.data;
d_ry = load('mat/data_015.mat', 'data'); d_ry = d_ry.data;
d_sr = load('mat/data_016.mat', 'data'); d_sr = d_sr.data;
d_rz = load('mat/data_017.mat', 'data'); d_rz = d_rz.data;
d_he = load('mat/data_018.mat', 'data'); d_he = d_he.data;
#+end_src
** Voltage to Velocity
We convert the measured voltage to velocity using the function =voltageToVelocityL22= (accessible [[file:~/MEGA/These/meas/src/index.org][here]]).
#+begin_src matlab
gain = 60; % [dB]
d_of(:, 1) = voltageToVelocityL22(d_of(:, 1), d_of(:, 3), gain);
d_ty(:, 1) = voltageToVelocityL22(d_ty(:, 1), d_ty(:, 3), gain);
d_ry(:, 1) = voltageToVelocityL22(d_ry(:, 1), d_ry(:, 3), gain);
d_sr(:, 1) = voltageToVelocityL22(d_sr(:, 1), d_sr(:, 3), gain);
d_rz(:, 1) = voltageToVelocityL22(d_rz(:, 1), d_rz(:, 3), gain);
d_he(:, 1) = voltageToVelocityL22(d_he(:, 1), d_he(:, 3), gain);
d_of(:, 2) = voltageToVelocityL22(d_of(:, 2), d_of(:, 3), gain);
d_ty(:, 2) = voltageToVelocityL22(d_ty(:, 2), d_ty(:, 3), gain);
d_ry(:, 2) = voltageToVelocityL22(d_ry(:, 2), d_ry(:, 3), gain);
d_sr(:, 2) = voltageToVelocityL22(d_sr(:, 2), d_sr(:, 3), gain);
d_rz(:, 2) = voltageToVelocityL22(d_rz(:, 2), d_rz(:, 3), gain);
d_he(:, 2) = voltageToVelocityL22(d_he(:, 2), d_he(:, 3), gain);
#+end_src
** Analysis - Time Domain
First, we can look at the time domain data and compare all the measurements:
- comparison for the geophone at the sample location (figure [[fig:time_domain_sample_lpf]])
- comparison for the geophone on the granite (figure [[fig:time_domain_marble_lpf]])
- relative displacement of the sample with respect to the marble (figure [[fig:time_domain_marble_lpf]])
#+begin_src matlab
figure;
hold on;
plot(d_of(:, 3), d_of(:, 2), 'DisplayName', 'All OFF');
plot(d_ty(:, 3), d_ty(:, 2), 'DisplayName', 'Ty ON');
plot(d_ry(:, 3), d_ry(:, 2), 'DisplayName', 'Ry ON');
plot(d_sr(:, 3), d_sr(:, 2), 'DisplayName', 'S-R ON');
plot(d_rz(:, 3), d_rz(:, 2), 'DisplayName', 'Rz ON');
plot(d_he(:, 3), d_he(:, 2), 'DisplayName', 'Hexa ON');
hold off;
xlabel('Time [s]'); ylabel('Velocity [m/s]');
xlim([0, 50]);
legend('Location', 'bestoutside');
#+end_src
#+NAME: fig:time_domain_sample_lpf
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/time_domain_sample_lpf.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:time_domain_sample_lpf
#+CAPTION: Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location
#+RESULTS: fig:time_domain_sample_lpf
[[file:figs/time_domain_sample_lpf.png]]
#+begin_src matlab
figure;
hold on;
plot(d_of(:, 3), d_of(:, 1), 'DisplayName', 'All OFF');
plot(d_ty(:, 3), d_ty(:, 1), 'DisplayName', 'Ty ON');
plot(d_ry(:, 3), d_ry(:, 1), 'DisplayName', 'Ry ON');
plot(d_sr(:, 3), d_sr(:, 1), 'DisplayName', 'S-R ON');
plot(d_rz(:, 3), d_rz(:, 1), 'DisplayName', 'Rz ON');
plot(d_he(:, 3), d_he(:, 1), 'DisplayName', 'Hexa ON');
hold off;
xlabel('Time [s]'); ylabel('Velocity [m/s]');
xlim([0, 50]);
legend('Location', 'bestoutside');
#+end_src
#+NAME: fig:time_domain_marble_lpf
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/time_domain_marble_lpf.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:time_domain_marble_lpf
#+CAPTION: Comparison of the time domain data when turning off the control system of the stages - Geophone on the marble
#+RESULTS: fig:time_domain_marble_lpf
[[file:figs/time_domain_marble_lpf.png]]
#+begin_src matlab
figure;
hold on;
plot(d_of(:, 3), 1e6*lsim(1/(1+s/(2*pi*0.5)), d_of(:, 2)-d_of(:, 1), d_of(:, 3)), 'DisplayName', 'All OFF');
plot(d_ty(:, 3), 1e6*lsim(1/(1+s/(2*pi*0.5)), d_ty(:, 2)-d_ty(:, 1), d_ty(:, 3)), 'DisplayName', 'Ty ON');
plot(d_ry(:, 3), 1e6*lsim(1/(1+s/(2*pi*0.5)), d_ry(:, 2)-d_ry(:, 1), d_ry(:, 3)), 'DisplayName', 'Ry ON');
plot(d_sr(:, 3), 1e6*lsim(1/(1+s/(2*pi*0.5)), d_sr(:, 2)-d_sr(:, 1), d_sr(:, 3)), 'DisplayName', 'S-R ON');
plot(d_rz(:, 3), 1e6*lsim(1/(1+s/(2*pi*0.5)), d_rz(:, 2)-d_rz(:, 1), d_rz(:, 3)), 'DisplayName', 'Rz ON');
plot(d_he(:, 3), 1e6*lsim(1/(1+s/(2*pi*0.5)), d_he(:, 2)-d_he(:, 1), d_he(:, 3)), 'DisplayName', 'Hexa ON');
hold off;
xlabel('Time [s]'); ylabel('Relative Displacement [$\mu m$]');
xlim([0, 50]);
legend('Location', 'bestoutside');
#+end_src
#+NAME: fig:time_domain_relative_disp
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/time_domain_relative_disp.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:time_domain_relative_disp
#+CAPTION: Relative displacement of the sample with respect to the marble
#+RESULTS: fig:time_domain_relative_disp
[[file:figs/time_domain_relative_disp.png]]
** Analysis - Frequency Domain
#+begin_src matlab :results none
dt = d_of(2, 3) - d_of(1, 3);
Fs = 1/dt;
win = hanning(ceil(10*Fs));
#+end_src
*** Vibrations at the sample location
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
#+begin_src matlab :results none
[px_of, f] = pwelch(d_of(:, 2), win, [], [], Fs);
[px_ty, ~] = pwelch(d_ty(:, 2), win, [], [], Fs);
[px_ry, ~] = pwelch(d_ry(:, 2), win, [], [], Fs);
[px_sr, ~] = pwelch(d_sr(:, 2), win, [], [], Fs);
[px_rz, ~] = pwelch(d_rz(:, 2), win, [], [], Fs);
[px_he, ~] = pwelch(d_he(:, 2), win, [], [], Fs);
#+end_src
And we compare all the signals (figures [[fig:psd_sample_comp_lpf]] and [[fig:psd_sample_comp_high_freq_lpf]]).
#+begin_src matlab :results none
figure;
hold on;
plot(f, sqrt(px_of), 'DisplayName', 'All OFF');
plot(f, sqrt(px_ty), 'DisplayName', 'Ty ON');
plot(f, sqrt(px_ry), 'DisplayName', 'Ry ON');
plot(f, sqrt(px_sr), 'DisplayName', 'S-R ON');
plot(f, sqrt(px_rz), 'DisplayName', 'Rz ON');
plot(f, sqrt(px_he), 'DisplayName', 'Hexa ON');
hold off;
set(gca, 'xscale', 'log');
set(gca, 'yscale', 'log');
xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{m/s}{\sqrt{Hz}}\right]$')
xlim([0.1, 500]);
legend('Location', 'southwest');
#+end_src
#+NAME: fig:psd_sample_comp_lpf
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_sample_comp_lpf.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_sample_comp_lpf
#+CAPTION: Amplitude Spectral Density of the sample velocity
#+RESULTS: fig:psd_sample_comp_lpf
[[file:figs/psd_sample_comp_lpf.png]]
#+begin_src matlab :results none :tangle no :exports none
xlim([80, 500]);
#+end_src
#+NAME: fig:psd_sample_comp_high_freq_lpf
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_sample_comp_high_freq_lpf.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_sample_comp_high_freq_lpf
#+CAPTION: Amplitude Spectral Density of the sample velocity (zoom at high frequencies)
#+RESULTS: fig:psd_sample_comp_high_freq_lpf
[[file:figs/psd_sample_comp_high_freq_lpf.png]]
*** Vibrations on the marble
Now we plot the same curves for the geophone located on the marble.
#+begin_src matlab :results none
[px_of, f] = pwelch(d_of(:, 1), win, [], [], Fs);
[px_ty, ~] = pwelch(d_ty(:, 1), win, [], [], Fs);
[px_ry, ~] = pwelch(d_ry(:, 1), win, [], [], Fs);
[px_sr, ~] = pwelch(d_sr(:, 1), win, [], [], Fs);
[px_rz, ~] = pwelch(d_rz(:, 1), win, [], [], Fs);
[px_he, ~] = pwelch(d_he(:, 1), win, [], [], Fs);
#+end_src
And we compare the Amplitude Spectral Densities (figures [[fig:psd_marble_comp_lpf]] and [[fig:psd_marble_comp_lpf_high_freq]])
#+begin_src matlab :results none
figure;
hold on;
plot(f, sqrt(px_of), 'DisplayName', 'All OFF');
plot(f, sqrt(px_ty), 'DisplayName', 'Ty ON');
plot(f, sqrt(px_ry), 'DisplayName', 'Ry ON');
plot(f, sqrt(px_sr), 'DisplayName', 'S-R ON');
plot(f, sqrt(px_rz), 'DisplayName', 'Rz ON');
plot(f, sqrt(px_he), 'DisplayName', 'Hexa ON');
hold off;
set(gca, 'xscale', 'log');
set(gca, 'yscale', 'log');
xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{m/s}{\sqrt{Hz}}\right]$')
xlim([0.1, 500]);
legend('Location', 'northeast');
#+end_src
#+NAME: fig:psd_marble_comp_lpf
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_marble_comp_lpf.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_marble_comp_lpf
#+CAPTION: Amplitude Spectral Density of the marble velocity
#+RESULTS: fig:psd_marble_comp_lpf
[[file:figs/psd_marble_comp_lpf.png]]
#+begin_src matlab :results none :tangle no :exports none
legend('Location', 'southwest');
xlim([80, 500]);
#+end_src
#+NAME: fig:psd_marble_comp_lpf_high_freq
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_marble_comp_lpf_high_freq.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_marble_comp_lpf_high_freq
#+CAPTION: Amplitude Spectral Density of the marble velocity (zoom at high frequencies)
#+RESULTS: fig:psd_marble_comp_lpf_high_freq
[[file:figs/psd_marble_comp_lpf_high_freq.png]]
** Conclusion
#+begin_important
- The Ty stage induces vibrations of the marble and at the sample location above 100Hz
- The hexapod stage induces vibrations at the sample position above 220Hz
#+end_important
* Effect of the Symetrie Driver
:PROPERTIES:
:header-args:matlab+: :tangle matlab/effect_symetrie_driver.m
:header-args:matlab+: :comments org :mkdirp yes
:END:
<<sec:effect_symetrie_driver>>
** ZIP file containing the data and matlab files :ignore:
#+begin_src bash :exports none :results none
if [ matlab/effect_symetrie_driver.m -nt data/effect_symetrie_driver.zip ]; then
cp matlab/effect_symetrie_driver.m effect_symetrie_driver.m;
zip data/effect_symetrie_driver \
mat/data_018.mat \
mat/data_019.mat \
effect_symetrie_driver.m
rm effect_symetrie_driver.m;
fi
#+end_src
#+begin_note
All the files (data and Matlab scripts) are accessible [[file:data/effect_symetrie_driver.zip][here]].
#+end_note
** Experimental Setup
We here measure the signals of two geophones:
- One is located on top of the Sample platform
- One is located on the marble
The signal from the top geophone does go trought the slip-ring.
All the control systems are turned OFF except the Hexapod one.
Each measurement are done during 100s.
The settings of the voltage amplifier are:
- DC
- 60dB
- 1kHz
A first order low pass filter with a cut-off frequency of 1kHz is added before the voltage amplifier.
The measurements are:
- =meas_018.mat=: Hexapod's driver on the granite
- =meas_019.mat=: Hexapod's driver on the ground
Each of the =mat= file contains one array =data= with 3 columns:
| Column number | Description |
|---------------+-------------------|
| 1 | Geophone - Marble |
| 2 | Geophone - Sample |
| 3 | Time |
** Matlab Init :noexport:ignore:
#+begin_src matlab :tangle no :exports none :results silent :noweb yes :var current_dir=(file-name-directory buffer-file-name)
<<matlab-dir>>
#+end_src
#+begin_src matlab :exports none :results silent :noweb yes
<<matlab-init>>
#+end_src
** Load data
We load the data of the z axis of two geophones.
#+begin_src matlab :results none
d_18 = load('mat/data_018.mat', 'data'); d_18 = d_18.data;
d_19 = load('mat/data_019.mat', 'data'); d_19 = d_19.data;
#+end_src
** Analysis - Time Domain
#+begin_src matlab :results none
figure;
hold on;
plot(d_19(:, 3), d_19(:, 1), 'DisplayName', 'Driver - Ground');
plot(d_18(:, 3), d_18(:, 1), 'DisplayName', 'Driver - Granite');
hold off;
xlabel('Time [s]'); ylabel('Voltage [V]');
xlim([0, 50]);
legend('Location', 'bestoutside');
#+end_src
#+NAME: fig:time_domain_hexa_driver
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/time_domain_hexa_driver.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:time_domain_hexa_driver
#+CAPTION: Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location
#+RESULTS: fig:time_domain_hexa_driver
[[file:figs/time_domain_hexa_driver.png]]
** Analysis - Frequency Domain
#+begin_src matlab :results none
dt = d_18(2, 3) - d_18(1, 3);
Fs = 1/dt;
win = hanning(ceil(10*Fs));
#+end_src
*** Vibrations at the sample location
First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.
#+begin_src matlab :results none
[px_18, f] = pwelch(d_18(:, 1), win, [], [], Fs);
[px_19, ~] = pwelch(d_19(:, 1), win, [], [], Fs);
#+end_src
#+begin_src matlab :results none
figure;
hold on;
plot(f, sqrt(px_19), 'DisplayName', 'Driver - Ground');
plot(f, sqrt(px_18), 'DisplayName', 'Driver - Granite');
hold off;
set(gca, 'xscale', 'log');
set(gca, 'yscale', 'log');
xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$')
xlim([0.1, 500]);
legend('Location', 'southwest');
#+end_src
#+NAME: fig:psd_hexa_driver
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_hexa_driver.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_hexa_driver
#+CAPTION: Amplitude Spectral Density of the signal coming from the top geophone
#+RESULTS: fig:psd_hexa_driver
[[file:figs/psd_hexa_driver.png]]
#+begin_src matlab :results none :tangle no :exports none
xlim([80, 500]);
#+end_src
#+NAME: fig:psd_hexa_driver_high_freq
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
#+begin_src matlab :var filepath="figs/psd_hexa_driver_high_freq.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
<<plt-matlab>>
#+end_src
#+NAME: fig:psd_hexa_driver_high_freq
#+CAPTION: Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)
#+RESULTS: fig:psd_hexa_driver_high_freq
[[file:figs/psd_hexa_driver_high_freq.png]]
** Conclusion
#+begin_important
Even tough the Hexapod'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.
#+end_important