Add analysis on the new measurements
BIN
slip-ring-test/figs/Glpf_bode_bis.png
Normal file
After Width: | Height: | Size: 75 KiB |
Before Width: | Height: | Size: 4.1 KiB After Width: | Height: | Size: 2.5 KiB |
BIN
slip-ring-test/img/IMG_20190507_101453.jpg
Normal file
After Width: | Height: | Size: 4.0 MiB |
BIN
slip-ring-test/img/IMG_20190507_102756.jpg
Normal file
After Width: | Height: | Size: 3.1 MiB |
@ -166,12 +166,14 @@ We now look at the difference between the signal directly measured by the ADC an
|
|||||||
:END:
|
:END:
|
||||||
|
|
||||||
#+begin_src bash :exports none :results none
|
#+begin_src bash :exports none :results none
|
||||||
|
if [ meas_volt_amp.m -nt data/meas_volt_amp.zip ]; then
|
||||||
zip data/meas_volt_amp \
|
zip data/meas_volt_amp \
|
||||||
mat/data_003.mat \
|
mat/data_003.mat \
|
||||||
mat/data_004.mat \
|
mat/data_004.mat \
|
||||||
mat/data_005.mat \
|
mat/data_005.mat \
|
||||||
mat/data_006.mat \
|
mat/data_006.mat \
|
||||||
meas_volt_amp.m
|
meas_volt_amp.m
|
||||||
|
fi
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
The data and matlab files are accessible [[file:data/meas_volt_amp.zip][here]].
|
The data and matlab files are accessible [[file:data/meas_volt_amp.zip][here]].
|
||||||
@ -286,7 +288,10 @@ Finally, the ASD is shown on figure [[fig:ampli_noise_psd]].
|
|||||||
|
|
||||||
** Conclusion
|
** Conclusion
|
||||||
#+begin_important
|
#+begin_important
|
||||||
Noise induced by the voltage amplifiers is not a limiting factor.
|
*Questions*:
|
||||||
|
- Where does those sharp peaks comes from? Can this be due to aliasing?
|
||||||
|
|
||||||
|
Noise induced by the voltage amplifiers seems not to be a limiting factor as we have the same noise when they are OFF and ON.
|
||||||
#+end_important
|
#+end_important
|
||||||
|
|
||||||
* Measure of the noise induced by the Slip-Ring
|
* Measure of the noise induced by the Slip-Ring
|
||||||
@ -296,12 +301,14 @@ Finally, the ASD is shown on figure [[fig:ampli_noise_psd]].
|
|||||||
:END:
|
:END:
|
||||||
|
|
||||||
#+begin_src bash :exports none :results none
|
#+begin_src bash :exports none :results none
|
||||||
|
if [ meas_slip_ring.m -nt data/meas_slip_ring.zip ]; then
|
||||||
zip data/meas_slip_ring \
|
zip data/meas_slip_ring \
|
||||||
mat/data_008.mat \
|
mat/data_008.mat \
|
||||||
mat/data_009.mat \
|
mat/data_009.mat \
|
||||||
mat/data_010.mat \
|
mat/data_010.mat \
|
||||||
mat/data_011.mat \
|
mat/data_011.mat \
|
||||||
meas_slip_ring.m
|
meas_slip_ring.m
|
||||||
|
fi
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
The data and matlab files are accessible [[file:data/meas_slip_ring.zip][here]].
|
The data and matlab files are accessible [[file:data/meas_slip_ring.zip][here]].
|
||||||
@ -449,7 +456,9 @@ And we plot the ASD of the measured signals (figure [[fig:sr_psd_compare]]);
|
|||||||
|
|
||||||
** Conclusion
|
** Conclusion
|
||||||
#+begin_important
|
#+begin_important
|
||||||
|
*Questions:*
|
||||||
|
- Why is there some sharp peaks? Can this be due to aliasing?
|
||||||
|
- It is possible that the amplifiers were saturating during the measurements => should redo the measurements with a low pass filter before the voltage amplifier
|
||||||
#+end_important
|
#+end_important
|
||||||
|
|
||||||
* Measure of the noise induced by the slip ring when using a geophone
|
* Measure of the noise induced by the slip ring when using a geophone
|
||||||
@ -459,12 +468,14 @@ And we plot the ASD of the measured signals (figure [[fig:sr_psd_compare]]);
|
|||||||
:END:
|
:END:
|
||||||
|
|
||||||
#+begin_src bash :exports none :results none
|
#+begin_src bash :exports none :results none
|
||||||
|
if [ meas_sr_geophone.m -nt data/meas_sr_geophone.zip ]; then
|
||||||
zip data/meas_sr_geophone \
|
zip data/meas_sr_geophone \
|
||||||
mat/data_012.mat \
|
mat/data_012.mat \
|
||||||
mat/data_013.mat \
|
mat/data_013.mat \
|
||||||
mat/data_016.mat \
|
mat/data_016.mat \
|
||||||
mat/data_017.mat \
|
mat/data_017.mat \
|
||||||
meas_sr_geophone.m
|
meas_sr_geophone.m
|
||||||
|
fi
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
The data and matlab files are accessible [[file:data/meas_sr_geophone.zip][here]].
|
The data and matlab files are accessible [[file:data/meas_sr_geophone.zip][here]].
|
||||||
@ -647,7 +658,7 @@ Then the Slip-Ring is OFF, we don't observe this 40kHz anymore (figure [[fig:osc
|
|||||||
#+begin_important
|
#+begin_important
|
||||||
- By looking at the signals using an oscilloscope, there is a lot of high frequency noise when turning on the Slip-Ring
|
- By looking at the signals using an oscilloscope, there is a lot of high frequency noise when turning on the Slip-Ring
|
||||||
- This can eventually saturate the voltage amplifiers (seen by a led indicating saturation)
|
- This can eventually saturate the voltage amplifiers (seen by a led indicating saturation)
|
||||||
- The choice is to add a Low pass filter before the voltage amplifiers to not saturate them and filter the noise.
|
- The choice is to *add a Low pass filter before the voltage amplifiers* to not saturate them and filter the noise.
|
||||||
#+end_important
|
#+end_important
|
||||||
|
|
||||||
** New measurements with a LPF before the Voltage Amplifiers
|
** New measurements with a LPF before the Voltage Amplifiers
|
||||||
@ -812,7 +823,7 @@ Finally, we compare the Amplitude Spectral Density of the signals (figure [[fig:
|
|||||||
*** Conclusion
|
*** Conclusion
|
||||||
#+begin_important
|
#+begin_important
|
||||||
- Using the LPF, we don't have any perturbation coming from the slip-ring when it is on.
|
- Using the LPF, we don't have any perturbation coming from the slip-ring when it is on.
|
||||||
- However, we will use a smaller value of the capacitor to have a cut-off frequency at $1kHz$.
|
- However, we should use a smaller value of the capacitor to have a cut-off frequency at $1kHz$.
|
||||||
#+end_important
|
#+end_important
|
||||||
|
|
||||||
* Measure of the influence of the AC/DC option on the voltage amplifiers
|
* Measure of the influence of the AC/DC option on the voltage amplifiers
|
||||||
@ -822,10 +833,12 @@ Finally, we compare the Amplitude Spectral Density of the signals (figure [[fig:
|
|||||||
:END:
|
:END:
|
||||||
|
|
||||||
#+begin_src bash :exports none :results none
|
#+begin_src bash :exports none :results none
|
||||||
|
if [ meas_noise_ac_dc.m -nt data/meas_noise_ac_dc.zip ]; then
|
||||||
zip data/meas_noise_ac_dc \
|
zip data/meas_noise_ac_dc \
|
||||||
mat/data_012.mat \
|
mat/data_012.mat \
|
||||||
mat/data_013.mat \
|
mat/data_013.mat \
|
||||||
meas_noise_ac_dc.m
|
meas_noise_ac_dc.m
|
||||||
|
fi
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
The data and matlab files are accessible [[file:data/meas_noise_ac_dc.zip][here]].
|
The data and matlab files are accessible [[file:data/meas_noise_ac_dc.zip][here]].
|
||||||
@ -948,13 +961,27 @@ The ASD of the signals are compare on figure [[fig:ac_dc_option_asd]].
|
|||||||
#+begin_important
|
#+begin_important
|
||||||
- The voltage amplifiers include some very sharp high pass filters at 1.5Hz (maybe 4th order)
|
- The voltage amplifiers include some very sharp high pass filters at 1.5Hz (maybe 4th order)
|
||||||
- There is a DC offset on the time domain signal because the DC-offset knob was not set to zero
|
- There is a DC offset on the time domain signal because the DC-offset knob was not set to zero
|
||||||
|
|
||||||
*Questions*:
|
|
||||||
- What option should be used for the measurements?
|
|
||||||
#+end_important
|
#+end_important
|
||||||
|
|
||||||
* Measure of the Low Pass Filter
|
* Transfer function of the Low Pass Filter
|
||||||
** Measurement Description
|
:PROPERTIES:
|
||||||
|
:header-args:matlab+: :tangle low_pass_filter_measurements.m
|
||||||
|
:header-args:matlab+: :comments org :mkdirp yes
|
||||||
|
:END:
|
||||||
|
|
||||||
|
#+begin_src bash :exports none :results none
|
||||||
|
if [ low_pass_filter_measurements.m -nt data/low_pass_filter_measurements.zip ]; then
|
||||||
|
zip data/low_pass_filter_measurements \
|
||||||
|
mat/data_018.mat \
|
||||||
|
mat/data_019.mat \
|
||||||
|
low_pass_filter_measurements.m
|
||||||
|
fi
|
||||||
|
#+end_src
|
||||||
|
|
||||||
|
The computation files for this section are accessible [[file:data/low_pass_filter_measurements.zip][here]].
|
||||||
|
|
||||||
|
** First LPF with a Cut-off frequency of 160Hz
|
||||||
|
*** Measurement Description
|
||||||
*Goal*:
|
*Goal*:
|
||||||
- Measure the Low Pass Filter Transfer Function
|
- Measure the Low Pass Filter Transfer Function
|
||||||
|
|
||||||
@ -972,14 +999,14 @@ Which makes a cut-off frequency of $f_c = \frac{1}{RC} = 1000 rad/s = 160Hz$.
|
|||||||
#+HEADER: :output-dir figs
|
#+HEADER: :output-dir figs
|
||||||
#+begin_src latex :file lpf.pdf :post pdf2svg(file=*this*, ext="png") :exports both
|
#+begin_src latex :file lpf.pdf :post pdf2svg(file=*this*, ext="png") :exports both
|
||||||
\begin{tikzpicture}
|
\begin{tikzpicture}
|
||||||
\draw (0,2) node[circ]
|
\draw (0,2)
|
||||||
to [R=\(R\)] ++(2,0)
|
to [R=\(R\)] ++(2,0) node[circ]
|
||||||
to ++(2,0) node[circ]
|
to ++(2,0)
|
||||||
++(-2,0) node[circ]
|
++(-2,0)
|
||||||
to [C=\(C\)] ++(0,-2)
|
to [C=\(C\)] ++(0,-2) node[circ]
|
||||||
++(-2,0) node[circ]
|
++(-2,0)
|
||||||
to ++(2,0) node[circ]
|
to ++(2,0)
|
||||||
to ++(2,0) node[circ];
|
to ++(2,0)
|
||||||
\end{tikzpicture}
|
\end{tikzpicture}
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
@ -1002,18 +1029,23 @@ Which makes a cut-off frequency of $f_c = \frac{1}{RC} = 1000 rad/s = 160Hz$.
|
|||||||
| 2 | Amplifier 2 |
|
| 2 | Amplifier 2 |
|
||||||
| 3 | Time |
|
| 3 | Time |
|
||||||
|
|
||||||
** Matlab Init :noexport:ignore:
|
#+name: fig:lpf_picture
|
||||||
|
#+caption: Picture of the low pass filter used
|
||||||
|
#+attr_html: :width 500px
|
||||||
|
[[file:./img/IMG_20190507_102756.jpg]]
|
||||||
|
|
||||||
|
*** Matlab Init :noexport:ignore:
|
||||||
#+begin_src matlab :exports none :results silent :noweb yes
|
#+begin_src matlab :exports none :results silent :noweb yes
|
||||||
<<matlab-init>>
|
<<matlab-init>>
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
** Load data
|
*** Load data
|
||||||
We load the data of the z axis of two geophones.
|
We load the data of the z axis of two geophones.
|
||||||
#+begin_src matlab :results none
|
#+begin_src matlab :results none
|
||||||
data = load('mat/data_018.mat', 'data'); data = data.data;
|
data = load('mat/data_018.mat', 'data'); data = data.data;
|
||||||
#+end_src
|
#+end_src
|
||||||
|
|
||||||
** Transfer function of the LPF
|
*** Transfer function of the LPF
|
||||||
We compute the transfer function from the signal without the LPF to the signal measured with the LPF.
|
We compute the transfer function from the signal without the LPF to the signal measured with the LPF.
|
||||||
#+begin_src matlab :results none
|
#+begin_src matlab :results none
|
||||||
dt = data(2, 3)-data(1, 3);
|
dt = data(2, 3)-data(1, 3);
|
||||||
@ -1068,16 +1100,82 @@ We obtain the result on figure [[fig:Glpf_bode]].
|
|||||||
#+CAPTION: Bode Diagram of the measured Low Pass filter and the theoritical one
|
#+CAPTION: Bode Diagram of the measured Low Pass filter and the theoritical one
|
||||||
#+RESULTS: fig:Glpf_bode
|
#+RESULTS: fig:Glpf_bode
|
||||||
[[file:figs/Glpf_bode.png]]
|
[[file:figs/Glpf_bode.png]]
|
||||||
** Conclusion
|
*** Conclusion
|
||||||
#+begin_important
|
#+begin_important
|
||||||
As we want to measure things up to $500Hz$, we chose to change the value of the capacitor to obtain a cut-off frequency of $1kHz$.
|
As we want to measure things up to $500Hz$, we chose to change the value of the capacitor to obtain a cut-off frequency of $1kHz$.
|
||||||
#+end_important
|
#+end_important
|
||||||
|
|
||||||
** TODO Low Pass Filter with a cut-off frequency of 1kHz
|
** Second LPF with a Cut-off frequency of 1000Hz
|
||||||
|
*** Measurement description
|
||||||
This time, the value are
|
This time, the value are
|
||||||
\begin{aligned}
|
\begin{aligned}
|
||||||
R &= 1k\Omega \\
|
R &= 1k\Omega \\
|
||||||
C &= 150nF
|
C &= 150nF
|
||||||
\end{aligned}
|
\end{aligned}
|
||||||
|
|
||||||
Which makes a low pass filter with a cut-off frequency of $f_c = 1060Hz$.
|
Which makes a low pass filter with a cut-off frequency of $f_c = 1060Hz$.
|
||||||
|
|
||||||
|
*** Load data
|
||||||
|
We load the data of the z axis of two geophones.
|
||||||
|
#+begin_src matlab :results none
|
||||||
|
data = load('mat/data_019.mat', 'data'); data = data.data;
|
||||||
|
#+end_src
|
||||||
|
|
||||||
|
*** Transfer function of the LPF
|
||||||
|
We compute the transfer function from the signal without the LPF to the signal measured with the LPF.
|
||||||
|
#+begin_src matlab :results none
|
||||||
|
dt = data(2, 3)-data(1, 3);
|
||||||
|
|
||||||
|
Fs = 1/dt; % [Hz]
|
||||||
|
|
||||||
|
win = hanning(ceil(10*Fs));
|
||||||
|
#+end_src
|
||||||
|
|
||||||
|
#+begin_src matlab :results none
|
||||||
|
[Glpf, f] = tfestimate(data(:, 2), data(:, 1), win, [], [], Fs);
|
||||||
|
#+end_src
|
||||||
|
|
||||||
|
We compare this transfer function with a transfer function corresponding to an ideal first order LPF with a cut-off frequency of $1060Hz$.
|
||||||
|
We obtain the result on figure [[fig:Glpf_bode_bis]].
|
||||||
|
#+begin_src matlab :results none
|
||||||
|
Gth = 1/(1+s/1060/2/pi);
|
||||||
|
#+end_src
|
||||||
|
|
||||||
|
#+begin_src matlab :results none
|
||||||
|
figure;
|
||||||
|
ax1 = subplot(2, 1, 1);
|
||||||
|
hold on;
|
||||||
|
plot(f, abs(Glpf));
|
||||||
|
plot(f, abs(squeeze(freqresp(Gth, f, 'Hz'))));
|
||||||
|
hold off;
|
||||||
|
set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
|
||||||
|
set(gca, 'XTickLabel',[]);
|
||||||
|
ylabel('Magnitude');
|
||||||
|
|
||||||
|
ax2 = subplot(2, 1, 2);
|
||||||
|
hold on;
|
||||||
|
plot(f, mod(180+180/pi*phase(Glpf), 360)-180);
|
||||||
|
plot(f, 180/pi*unwrap(angle(squeeze(freqresp(Gth, f, 'Hz')))));
|
||||||
|
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:Glpf_bode_bis
|
||||||
|
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||||
|
#+begin_src matlab :var filepath="figs/Glpf_bode_bis.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
|
||||||
|
<<plt-matlab>>
|
||||||
|
#+end_src
|
||||||
|
|
||||||
|
#+NAME: fig:Glpf_bode_bis
|
||||||
|
#+CAPTION: Bode Diagram of the measured Low Pass filter and the theoritical one
|
||||||
|
#+RESULTS: fig:Glpf_bode_bis
|
||||||
|
[[file:figs/Glpf_bode_bis.png]]
|
||||||
|
*** Conclusion
|
||||||
|
#+begin_important
|
||||||
|
The added LPF has the expected behavior.
|
||||||
|
#+end_important
|
||||||
|
101
slip-ring-test/low_pass_filter_measurements.m
Normal file
@ -0,0 +1,101 @@
|
|||||||
|
% Matlab Init :noexport:ignore:
|
||||||
|
|
||||||
|
clear; close all; clc;
|
||||||
|
|
||||||
|
%% Intialize Laplace variable
|
||||||
|
s = zpk('s');
|
||||||
|
|
||||||
|
%% Initialize ans with org-babel
|
||||||
|
ans = 0;
|
||||||
|
|
||||||
|
% Load data
|
||||||
|
% We load the data of the z axis of two geophones.
|
||||||
|
|
||||||
|
data = load('mat/data_018.mat', 'data'); data = data.data;
|
||||||
|
|
||||||
|
% Transfer function of the LPF
|
||||||
|
% We compute the transfer function from the signal without the LPF to the signal measured with the LPF.
|
||||||
|
|
||||||
|
dt = data(2, 3)-data(1, 3);
|
||||||
|
|
||||||
|
Fs = 1/dt; % [Hz]
|
||||||
|
|
||||||
|
win = hanning(ceil(10*Fs));
|
||||||
|
|
||||||
|
[Glpf, f] = tfestimate(data(:, 2), data(:, 1), win, [], [], Fs);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
% We compare this transfer function with a transfer function corresponding to an ideal first order LPF with a cut-off frequency of $1000rad/s$.
|
||||||
|
% We obtain the result on figure [[fig:Glpf_bode]].
|
||||||
|
|
||||||
|
Gth = 1/(1+s/1000)
|
||||||
|
|
||||||
|
figure;
|
||||||
|
ax1 = subplot(2, 1, 1);
|
||||||
|
hold on;
|
||||||
|
plot(f, abs(Glpf));
|
||||||
|
plot(f, abs(squeeze(freqresp(Gth, f, 'Hz'))));
|
||||||
|
hold off;
|
||||||
|
set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
|
||||||
|
set(gca, 'XTickLabel',[]);
|
||||||
|
ylabel('Magnitude');
|
||||||
|
|
||||||
|
ax2 = subplot(2, 1, 2);
|
||||||
|
hold on;
|
||||||
|
plot(f, mod(180+180/pi*phase(Glpf), 360)-180);
|
||||||
|
plot(f, 180/pi*unwrap(angle(squeeze(freqresp(Gth, f, 'Hz')))));
|
||||||
|
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]);
|
||||||
|
|
||||||
|
% Load data
|
||||||
|
% We load the data of the z axis of two geophones.
|
||||||
|
|
||||||
|
data = load('mat/data_019.mat', 'data'); data = data.data;
|
||||||
|
|
||||||
|
% Transfer function of the LPF
|
||||||
|
% We compute the transfer function from the signal without the LPF to the signal measured with the LPF.
|
||||||
|
|
||||||
|
dt = data(2, 3)-data(1, 3);
|
||||||
|
|
||||||
|
Fs = 1/dt; % [Hz]
|
||||||
|
|
||||||
|
win = hanning(ceil(10*Fs));
|
||||||
|
|
||||||
|
[Glpf, f] = tfestimate(data(:, 2), data(:, 1), win, [], [], Fs);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
% We compare this transfer function with a transfer function corresponding to an ideal first order LPF with a cut-off frequency of $1060Hz$.
|
||||||
|
% We obtain the result on figure [[fig:Glpf_bode_bis]].
|
||||||
|
|
||||||
|
Gth = 1/(1+s/1060/2/pi);
|
||||||
|
|
||||||
|
figure;
|
||||||
|
ax1 = subplot(2, 1, 1);
|
||||||
|
hold on;
|
||||||
|
plot(f, abs(Glpf));
|
||||||
|
plot(f, abs(squeeze(freqresp(Gth, f, 'Hz'))));
|
||||||
|
hold off;
|
||||||
|
set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
|
||||||
|
set(gca, 'XTickLabel',[]);
|
||||||
|
ylabel('Magnitude');
|
||||||
|
|
||||||
|
ax2 = subplot(2, 1, 2);
|
||||||
|
hold on;
|
||||||
|
plot(f, mod(180+180/pi*phase(Glpf), 360)-180);
|
||||||
|
plot(f, 180/pi*unwrap(angle(squeeze(freqresp(Gth, f, 'Hz')))));
|
||||||
|
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]);
|
BIN
static-measurements/figs/psd_marble_comp_lpf.png
Normal file
After Width: | Height: | Size: 152 KiB |
BIN
static-measurements/figs/psd_marble_comp_lpf_high_freq.png
Normal file
After Width: | Height: | Size: 186 KiB |
BIN
static-measurements/figs/psd_sample_comp_high_freq_lpf.png
Normal file
After Width: | Height: | Size: 190 KiB |
BIN
static-measurements/figs/psd_sample_comp_lpf.png
Normal file
After Width: | Height: | Size: 150 KiB |
BIN
static-measurements/figs/time_domain_marble_lpf.png
Normal file
After Width: | Height: | Size: 103 KiB |
BIN
static-measurements/figs/time_domain_sample_lpf.png
Normal file
After Width: | Height: | Size: 78 KiB |
BIN
static-measurements/img/IMG_20190507_101459.jpg
Normal file
After Width: | Height: | Size: 3.3 MiB |
BIN
static-measurements/img/IMG_20190507_101502.jpg
Normal file
After Width: | Height: | Size: 3.3 MiB |
BIN
static-measurements/img/IMG_20190507_101506.jpg
Normal file
After Width: | Height: | Size: 3.6 MiB |
@ -432,6 +432,243 @@ First, we compute the Power Spectral Density of the signals coming from the Geop
|
|||||||
- 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?
|
- 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
|
#+end_note
|
||||||
|
|
||||||
|
* Effect of all the control systems on the Sample vibrations - One stage at a time
|
||||||
|
** 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]].
|
||||||
|
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 :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
|
||||||
|
|
||||||
|
** 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]])
|
||||||
|
|
||||||
|
#+begin_src matlab :results none
|
||||||
|
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('Voltage [V]');
|
||||||
|
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 :results none
|
||||||
|
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('Voltage [V]');
|
||||||
|
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]]
|
||||||
|
|
||||||
|
** 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('ASD [V/sqrt(Hz)]')
|
||||||
|
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: PSD of the signal coming from the top geophone
|
||||||
|
#+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: PSD of the signal coming from the top geophone (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 ASD (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('ASD [V/sqrt(Hz)]')
|
||||||
|
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: PSD of the signal coming from the top geophone
|
||||||
|
#+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: PSD of the signal coming from the top geophone (zoom at high frequencies)
|
||||||
|
#+RESULTS: fig:psd_marble_comp_lpf_high_freq
|
||||||
|
[[file:figs/psd_marble_comp_lpf_high_freq.png]]
|
||||||
|
|
||||||
|
** TODO Conclusion
|
||||||
|
#+begin_important
|
||||||
|
#+end_note
|
||||||
|
|
||||||
* Transfer function from one stage to the other
|
* Transfer function from one stage to the other
|
||||||
** Experimental Setup
|
** Experimental Setup
|
||||||
For all the measurements in this section:
|
For all the measurements in this section:
|
||||||
|
@ -58,12 +58,12 @@ The voltage amplifiers are: 60db, DC(!) and 1kHz
|
|||||||
Channel 1: marble motion
|
Channel 1: marble motion
|
||||||
Channel 2: Sample motion
|
Channel 2: Sample motion
|
||||||
|
|
||||||
- All OFF meas_013.mat
|
- All OFF =meas_013.mat=
|
||||||
- Ty ON meas_014.mat
|
- Ty ON =meas_014.mat=
|
||||||
- Ry ON meas_015.mat
|
- Ry ON =meas_015.mat=
|
||||||
- SR ON meas_016.mat
|
- SR ON =meas_016.mat=
|
||||||
- Rz ON meas_017.mat
|
- Rz ON =meas_017.mat=
|
||||||
- Hexa ON meas_018.mat
|
- Hexa ON =meas_018.mat=
|
||||||
|
|
||||||
* Test without the Hexapod Driver on the granite
|
* Test without the Hexapod Driver on the granite
|
||||||
|
|
||||||
|