Add data analysis
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Library/figs/coherence_two_geophones.png
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Library/figs/compare_tf_geophones.png
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Library/figs/psd_marble_comp.png
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Library/figs/psd_marble_comp_high_freq.png
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Library/figs/psd_sample_comp.png
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Library/figs/psd_sample_comp_high_freq.png
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Library/figs/time_domain_m_ry.png
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Library/figs/time_domain_m_ty.png
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Library/figs/time_domain_marble.png
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Library/figs/time_domain_sample.png
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Library/figs/time_domain_ty_ry.png
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Library/figs/trans_comp.png
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Library/index.html
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@ -18,34 +18,671 @@
|
||||
#+PROPERTY: header-args:matlab+ :output-dir figs
|
||||
:END:
|
||||
|
||||
For all the measurements here, the geophones are L22.
|
||||
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 the control system of each stage
|
||||
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 the Slip-Ring on the signal
|
||||
** Experimental Setup
|
||||
One geophone is on the marble, the other at the sample location (see figures below).
|
||||
Two measurements are made with the control systems of all the stages turned OFF.
|
||||
|
||||
The signal from the top geophone goes through the slip-ring.
|
||||
One geophone is located on the marble while the other is located at the sample location (figure [[fig:setup_slipring]]).
|
||||
|
||||
The signals from the geophones are amplified by a voltage amplifier with a gain of 60dB.
|
||||
The voltage amplifier also include a low pass filter with a corner frequency of 1kHz.
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||||
|
||||
#+name: fig:setup_ty_1
|
||||
#+caption: Figure caption
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||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_112613.jpg]]
|
||||
|
||||
#+name: fig:setup_ty_2
|
||||
#+caption: Figure caption
|
||||
#+name: fig:setup_slipring
|
||||
#+caption: Experimental Setup
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_112615.jpg]]
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||||
|
||||
#+name: fig:setup_ty_3
|
||||
#+caption: Figure caption
|
||||
The two measurements are:
|
||||
| Measurement File | Description |
|
||||
|------------------+------------------------------------------------------------------|
|
||||
| =meas_008.mat= | Signal from the top geophone does not goes through the Slip-ring |
|
||||
| =meas_009.mat= | Signal goes through the Slip-ring (as shown on the figure above) |
|
||||
|
||||
Each of the measurement =mat= file contains one =data= array with 3 columns:
|
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| Column number | Description |
|
||||
|---------------+-------------------|
|
||||
| 1 | Geophone - Marble |
|
||||
| 2 | Geophone - Sample |
|
||||
| 3 | Time |
|
||||
|
||||
** 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
|
||||
d8 = load('mat/data_008.mat', 'data'); d8 = d8.data;
|
||||
d9 = load('mat/data_009.mat', 'data'); d9 = d9.data;
|
||||
#+end_src
|
||||
|
||||
** Analysis - Time Domain
|
||||
First, we compare the time domain signals for the two experiments (figure [[fig:slipring_time]]).
|
||||
|
||||
|
||||
#+begin_src matlab :results none
|
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figure;
|
||||
hold on;
|
||||
plot(d9(:, 3), d9(:, 2), 'DisplayName', 'Slip-Ring');
|
||||
plot(d8(:, 3), d8(:, 2), 'DisplayName', 'Wire');
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
xlim([0, 50]);
|
||||
legend('location', 'northeast');
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_time
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/slipring_time.pdf" :var figsize="wide-tall" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_time
|
||||
#+CAPTION: Effect of the Slip-Ring on the measured signal - Time domain
|
||||
#+RESULTS: fig:slipring_time
|
||||
[[file:figs/slipring_time.png]]
|
||||
|
||||
** Analysis - Frequency Domain
|
||||
We then compute the Power Spectral Density of the two signals and we compare them (figure [[fig:slipring_asd]]).
|
||||
#+begin_src matlab :results none
|
||||
dt = d8(2, 3) - d8(1, 3);
|
||||
Fs = 1/dt;
|
||||
|
||||
win = hanning(ceil(1*Fs));
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none
|
||||
[pxx8, f] = pwelch(d8(:, 2), win, [], [], Fs);
|
||||
[pxx9, ~] = pwelch(d9(:, 2), win, [], [], Fs);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none
|
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figure;
|
||||
hold on;
|
||||
plot(f, sqrt(pxx9), 'DisplayName', 'Slip-Ring');
|
||||
plot(f, sqrt(pxx8), 'DisplayName', 'Wire');
|
||||
hold off;
|
||||
set(gca, 'xscale', 'log');
|
||||
set(gca, 'yscale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('ASD [V/sqrt(Hz)]')
|
||||
xlim([1, 500]);
|
||||
legend('Location', 'southwest');
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_asd
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/slipring_asd.pdf" :var figsize="wide-tall" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_asd
|
||||
#+CAPTION: Effect of the Slip-Ring on the measured signal - Frequency domain
|
||||
#+RESULTS: fig:slipring_asd
|
||||
[[file:figs/slipring_asd.png]]
|
||||
|
||||
** Conclusion
|
||||
#+begin_important
|
||||
- Connecting the geophone through the Slip-Ring seems to induce a lot of noise.
|
||||
#+end_important
|
||||
|
||||
#+begin_note
|
||||
*Remaining questions to answer*:
|
||||
- Why is there a sharp peak at 300Hz?
|
||||
- Why the use of the Slip-Ring does induce a noise?
|
||||
- Can the capacitive/inductive properties of the wires in the Slip-ring does not play well with the geophone? (resonant RLC circuit)
|
||||
#+end_note
|
||||
|
||||
* Effect of all the control systems on the Sample vibrations
|
||||
** 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 :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('ASD [V/sqrt(Hz)]')
|
||||
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: PSD 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: PSD 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 ASD (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('ASD [V/sqrt(Hz)]')
|
||||
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: PSD 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: PSD 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
|
||||
|
||||
* Transfer function from one stage to the other
|
||||
** Experimental Setup
|
||||
For all the measurements in this section:
|
||||
- all the control stages are OFF.
|
||||
- the measurements are on the $z$ direction
|
||||
|
||||
*** From Marble to Ty - =mat/meas_010.mat=
|
||||
One geophone is on the marble, one is on the Ty stage (see figures [[fig:setup_m_ty]], [[fig:setup_m_ty_zoom]] and [[fig:setup_m_ty_top]]).
|
||||
|
||||
The =data= array contains the following columns:
|
||||
| Column | Description |
|
||||
|--------+-------------|
|
||||
| 1 | Ground |
|
||||
| 2 | Ty |
|
||||
| 3 | Time |
|
||||
|
||||
#+name: fig:setup_m_ty
|
||||
#+caption: Setup with one geophone on the marble and one on top of the translation stage
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_112620.jpg]]
|
||||
[[file:./img/IMG_20190430_155330.jpg]]
|
||||
|
||||
#+name: fig:setup_m_ty_zoom
|
||||
#+caption: Setup with one geophone on the marble and one on top of the translation stage - Close up view
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_155335.jpg]]
|
||||
|
||||
#+name: fig:setup_m_ty_top
|
||||
#+caption: Setup with one geophone on the marble and one on top of the translation stage - Top view
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_155342.jpg]]
|
||||
|
||||
*** From Marble to Ry - =mat/meas_011.mat=
|
||||
One geophone is on the marble, one is on the Ry stage (see figure [[fig:setup_m_ry]])
|
||||
|
||||
The =data= array contains the following columns:
|
||||
| Column | Description |
|
||||
|--------+-------------|
|
||||
| 1 | Ground |
|
||||
| 2 | Ry |
|
||||
| 3 | Time |
|
||||
|
||||
#+name: fig:setup_m_ry
|
||||
#+caption: Setup with one geophone on the marble and one on top of the Tilt Stage
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_163919.jpg]]
|
||||
|
||||
*** From Ty to Ry - =mat/meas_012.mat=
|
||||
One geophone is on the Ty stage, one is on the Ry stage (see figures [[fig:setup_ty_ry]], [[fig:setup_ty_ry_top]] and [[fig:setup_ty_ry_zoom]])
|
||||
One geophone on the Ty stage, one geophone on the Ry stage.
|
||||
|
||||
The =data= array contains the following columns:
|
||||
| Column | Description |
|
||||
|--------+-------------|
|
||||
| 1 | Ty |
|
||||
| 2 | Ry |
|
||||
| 3 | Time |
|
||||
|
||||
#+name: fig:setup_ty_ry
|
||||
#+caption: Setup with one geophone on the translation stage and one on top of the Tilt Stage
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_170405.jpg]]
|
||||
|
||||
#+name: fig:setup_ty_ry_top
|
||||
#+caption: Setup with one geophone on the translation stage and one on top of the Tilt Stage - Top view
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_170418.jpg]]
|
||||
|
||||
#+name: fig:setup_ty_ry_zoom
|
||||
#+caption: Setup with one geophone on the translation stage and one on top of the Tilt Stage - Close up view
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_170425.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
|
||||
m_ty = load('mat/data_010.mat', 'data'); m_ty = m_ty.data;
|
||||
m_ry = load('mat/data_011.mat', 'data'); m_ry = m_ry.data;
|
||||
ty_ry = load('mat/data_012.mat', 'data'); ty_ry = ty_ry.data;
|
||||
#+end_src
|
||||
|
||||
** Analysis - Time Domain
|
||||
First, we can look at the time domain data.
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(m_ty(:, 3), m_ty(:, 1), 'DisplayName', 'Marble');
|
||||
plot(m_ty(:, 3), m_ty(:, 2), 'DisplayName', 'Ty');
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
legend('Location', 'northeast');
|
||||
xlim([0, 500]);
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:time_domain_m_ty
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/time_domain_m_ty.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:time_domain_m_ty
|
||||
#+CAPTION: Time domain - Marble and translation stage
|
||||
#+RESULTS: fig:time_domain_m_ty
|
||||
[[file:figs/time_domain_m_ty.png]]
|
||||
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(m_ry(:, 3), m_ry(:, 1), 'DisplayName', 'Marble');
|
||||
plot(m_ry(:, 3), m_ry(:, 2), 'DisplayName', 'Ty');
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
legend('Location', 'northeast');
|
||||
xlim([0, 500]);
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:time_domain_m_ry
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/time_domain_m_ry.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:time_domain_m_ry
|
||||
#+CAPTION: Time domain - Marble and tilt stage
|
||||
#+RESULTS: fig:time_domain_m_ry
|
||||
[[file:figs/time_domain_m_ry.png]]
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(ty_ry(:, 3), ty_ry(:, 1), 'DisplayName', 'Ty');
|
||||
plot(ty_ry(:, 3), ty_ry(:, 2), 'DisplayName', 'Ry');
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
legend('Location', 'northeast');
|
||||
xlim([0, 500]);
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:time_domain_ty_ry
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/time_domain_ty_ry.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:time_domain_ty_ry
|
||||
#+CAPTION: Time domain - Translation stage and tilt stage
|
||||
#+RESULTS: fig:time_domain_ty_ry
|
||||
[[file:figs/time_domain_ty_ry.png]]
|
||||
|
||||
** Analysis - Frequency Domain
|
||||
#+begin_src matlab :results none
|
||||
dt = m_ty(2, 3) - m_ty(1, 3);
|
||||
|
||||
Fs = 1/dt;
|
||||
win = hanning(ceil(1*Fs));
|
||||
#+end_src
|
||||
|
||||
First, we compute the transfer function estimate between the two geophones for the 3 experiments (figure [[fig:compare_tf_geophones]]). We also plot their coherence (figure [[fig:coherence_two_geophones]]).
|
||||
#+begin_src matlab :results none
|
||||
[T_m_ty, f] = tfestimate(m_ty(:, 1), m_ty(:, 2), win, [], [], Fs);
|
||||
[T_m_ry, ~] = tfestimate(m_ry(:, 1), m_ry(:, 2), win, [], [], Fs);
|
||||
[T_ty_ry, ~] = tfestimate(ty_ry(:, 1), ty_ry(:, 2), win, [], [], Fs);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
ax1 = subplot(2, 1, 1);
|
||||
hold on;
|
||||
plot(f, abs(T_m_ty), 'DisplayName', 'Marble - Ty');
|
||||
plot(f, abs(T_m_ry), 'DisplayName', 'Marble - Ry');
|
||||
plot(f, abs(T_ty_ry), 'DisplayName', 'Ty - Ry');
|
||||
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(T_m_ty), 360)-180);
|
||||
plot(f, mod(180+180/pi*phase(T_m_ry), 360)-180);
|
||||
plot(f, mod(180+180/pi*phase(T_ty_ry), 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([10, 500]);
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:compare_tf_geophones
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/compare_tf_geophones.pdf" :var figsize="full-tall" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:compare_tf_geophones
|
||||
#+CAPTION: Transfer function from the first geophone to the second geophone for the three experiments
|
||||
#+RESULTS: fig:compare_tf_geophones
|
||||
[[file:figs/compare_tf_geophones.png]]
|
||||
|
||||
|
||||
#+begin_src matlab :results none
|
||||
[coh_m_ty, f] = mscohere(m_ty(:, 1), m_ty(:, 2), win, [], [], Fs);
|
||||
[coh_m_ry, ~] = mscohere(m_ry(:, 1), m_ry(:, 2), win, [], [], Fs);
|
||||
[coh_ty_ry, ~] = mscohere(ty_ry(:, 1), ty_ry(:, 2), win, [], [], Fs);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none :exports none
|
||||
figure;
|
||||
hold on;
|
||||
plot(f, coh_m_ty, 'DisplayName', 'Marble - Ty');
|
||||
plot(f, coh_m_ry, 'DisplayName', 'Marble - Ry');
|
||||
plot(f, coh_ty_ry, 'DisplayName', 'Ty - Ry');
|
||||
hold off;
|
||||
set(gca, 'xscale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('Coherence');
|
||||
ylim([0, 1]); xlim([1, 500]);
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:coherence_two_geophones
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/coherence_two_geophones.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:coherence_two_geophones
|
||||
#+CAPTION: Coherence between the two geophones for the three experiments
|
||||
#+RESULTS: fig:coherence_two_geophones
|
||||
[[file:figs/coherence_two_geophones.png]]
|
||||
|
||||
** Conclusion
|
||||
|
||||
* Effect of the Ty Control System on the vibration of the Sample :noexport:ignore:
|
||||
** Experimental Setup
|
||||
One geophone is on the marble, the other at the sample location (see figures [[fig:setup_ty]]).
|
||||
|
||||
The signal from the top geophone goes through the slip-ring.
|
||||
|
||||
#+name: fig:setup_ty
|
||||
#+caption: Experimental Setup
|
||||
#+attr_html: :width 500px
|
||||
[[file:./img/IMG_20190430_112615.jpg]]
|
||||
|
||||
Two measurements are done:
|
||||
| Setup | Data File |
|
||||
@ -53,7 +690,7 @@ Two measurements are done:
|
||||
| Control of Ty is on | =mat/data_001.mat= |
|
||||
| Control of Ty is off | =mat/data_002.mat= |
|
||||
|
||||
For each of the measurements
|
||||
For each of the measurements, the data are:
|
||||
| Variable | Description |
|
||||
|----------+--------------------------------------------------------------------|
|
||||
| =t= | Time Vector |
|
||||
@ -74,7 +711,7 @@ We load the data of the z axis of two geophones.
|
||||
tyOff = load('mat/data_002.mat', 't', 'x1', 'x2');
|
||||
#+end_src
|
||||
|
||||
** Analysis
|
||||
** Analysis - Time Domain
|
||||
#+begin_src matlab :results none
|
||||
dt = tyOn.t(2)-tyOn.t(1);
|
||||
Fs = 1/dt;
|
||||
@ -87,6 +724,7 @@ We load the data of the z axis of two geophones.
|
||||
plot(tyOn.t, tyOn.x2);
|
||||
hold off;
|
||||
legend({'x1 - ON', 'x2 - ON'});
|
||||
xlim([0, 50]);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none
|
||||
@ -98,6 +736,7 @@ We load the data of the z axis of two geophones.
|
||||
legend({'x1 - OFF', 'x2 - OFF'});
|
||||
#+end_src
|
||||
|
||||
** Analysis - Frequency Domain
|
||||
#+begin_src matlab :results none
|
||||
Fs = 1/dt;
|
||||
win = hanning(ceil(10*Fs));
|
||||
@ -190,110 +829,3 @@ We load the data of the z axis of two geophones.
|
||||
linkaxes([ax1,ax2],'x');
|
||||
xlim([1, 500]);
|
||||
#+end_src
|
||||
* Effect of the Slip-Ring on the signal
|
||||
** Experimental Setup
|
||||
Two measurements are made where the control of all the stages are OFF.
|
||||
|
||||
One geophone is located on the marble while the other is located at the sample location.
|
||||
|
||||
The two measurements are:
|
||||
| Measurement File | Description |
|
||||
|------------------+------------------------------------------------------------------|
|
||||
| =meas_008.mat= | Signal from the top geophone does not goes through the Slip-ring |
|
||||
| =meas_009.mat= | Signal goes through the Slip-ring |
|
||||
|
||||
Each of the measurement =mat= file contains one =data= array with 3 columns:
|
||||
| Column number | Description |
|
||||
|---------------+-------------------|
|
||||
| 1 | Geophone - Marble |
|
||||
| 2 | Geophone - Sample |
|
||||
| 3 | Time |
|
||||
|
||||
** 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
|
||||
data8 = load('mat/data_008.mat', 'data');
|
||||
data9 = load('mat/data_009.mat', 'data');
|
||||
#+end_src
|
||||
|
||||
** Analysis - Time Domain
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(data9.data(:, 3), data9.data(:, 2), 'DisplayName', 'Slip-Ring');
|
||||
plot(data8.data(:, 3), data8.data(:, 2), 'DisplayName', 'Wire');
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
xlim([0, 50]);
|
||||
legend();
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_time
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/slipring_time.pdf" :var figsize="wide-tall" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_time
|
||||
#+CAPTION: Effect of the Slip-Ring on the measured signal - Time domain
|
||||
#+RESULTS: fig:slipring_time
|
||||
[[file:figs/slipring_time.png]]
|
||||
|
||||
** Analysis - Frequency Domain
|
||||
#+begin_src matlab :results none
|
||||
dt = data8.data(2, 3) - data8.data(1, 3);
|
||||
|
||||
Fs = 1/dt;
|
||||
win = hanning(ceil(1*Fs));
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none
|
||||
[pxx8, f] = pwelch(data8.data(:, 2), win, [], [], Fs);
|
||||
[pxx9, ~] = pwelch(data9.data(:, 2), win, [], [], Fs);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(f, sqrt(pxx9), 'DisplayName', 'Slip-Ring');
|
||||
plot(f, sqrt(pxx8), 'DisplayName', 'Wire');
|
||||
hold off;
|
||||
set(gca, 'xscale', 'log');
|
||||
set(gca, 'yscale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('ASD [V/sqrt(Hz)]')
|
||||
xlim([1, 500]);
|
||||
legend('Location', 'southwest');
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_asd
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/slipring_asd.pdf" :var figsize="wide-tall" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_asd
|
||||
#+CAPTION: Effect of the Slip-Ring on the measured signal - Frequency domain
|
||||
#+RESULTS: fig:slipring_asd
|
||||
[[file:figs/slipring_asd.png]]
|
||||
|
||||
** Conclusion
|
||||
*Remaining questions to answer*:
|
||||
- Why is there a sharp peak at 300Hz?
|
||||
- Why the use of the Slip-Ring does induce a noise?
|
||||
- Can the capacitive/inductive properties of the wires in the Slip-ring does not play well with the geophone? (resonant RLC circuit)
|
||||
|
||||
* Measurement when signal from top geophone does not go trought the slip-ring
|
||||
|
||||
| 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= |
|
||||
|
@ -25,7 +25,6 @@ Meas009: everything off with signal goes through the slip-ring
|
||||
** From Marble to Ty
|
||||
=meas_010.mat=
|
||||
Everything off, one geophone on the marble, one geophone on the Ty (measure on Z direction)
|
||||
=> Can be used to determine the vertical stiffness between the Granite and the Ty stage
|
||||
|
||||
Channels:
|
||||
| 1 | Ground |
|
||||
@ -35,7 +34,6 @@ Channels:
|
||||
** From Marble to Ry
|
||||
=meas_011.mat=
|
||||
Everything off, one geophone on the marble, one geophone on the Ry (measure on Z direction)
|
||||
=> Can be used to determine the vertical stiffness of the Ry Stage (by taking into account the Ty stiffness)
|
||||
|
||||
Channels:
|
||||
| 1 | Ground |
|
||||
@ -45,7 +43,6 @@ Channels:
|
||||
** From Ty to Ry
|
||||
=meas_012.mat=
|
||||
Everything off, one geophone on the Ty, one geophone on the Ry (measure on Z direction)
|
||||
=> Can be used to determine the vertical stiffness of the Ry stage
|
||||
|
||||
Channels:
|
||||
| 1 | Ty |
|
||||
|
BIN
slip-ring-test/figs/random_signal.pdf
Normal file
BIN
slip-ring-test/figs/random_signal.png
Normal file
After Width: | Height: | Size: 29 KiB |
BIN
slip-ring-test/figs/random_signal.svg
Normal file
After Width: | Height: | Size: 324 KiB |
7095
slip-ring-test/figs/random_signal.tex
Normal file
BIN
slip-ring-test/figs/slipring_comp_signals.pdf
Normal file
BIN
slip-ring-test/figs/slipring_comp_signals.png
Normal file
After Width: | Height: | Size: 33 KiB |
BIN
slip-ring-test/figs/slipring_comp_signals.svg
Normal file
After Width: | Height: | Size: 572 KiB |
16859
slip-ring-test/figs/slipring_comp_signals.tex
Normal file
BIN
slip-ring-test/index.html
Normal file
108
slip-ring-test/index.org
Normal file
@ -0,0 +1,108 @@
|
||||
#+TITLE:Effect of the rotation of the Slip-Ring
|
||||
:DRAWER:
|
||||
#+STARTUP: overview
|
||||
|
||||
#+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>
|
||||
|
||||
#+PROPERTY: header-args:matlab :session *MATLAB*
|
||||
#+PROPERTY: header-args:matlab+ :comments org
|
||||
#+PROPERTY: header-args:matlab+ :results output
|
||||
#+PROPERTY: header-args:matlab+ :exports both
|
||||
#+PROPERTY: header-args:matlab+ :eval no-export
|
||||
#+PROPERTY: header-args:matlab+ :output-dir figs
|
||||
:END:
|
||||
|
||||
* Measurement Description
|
||||
Random Signal is generated by one DAC of the SpeedGoat.
|
||||
|
||||
The signal going out of the DAC is split into two:
|
||||
- one BNC cable is directly connected to one ADC of the SpeedGoat
|
||||
- one BNC cable goes two times in the Slip-Ring (from bottom to top and then from top to bottom) and then is connected to one ADC of the SpeedGoat
|
||||
|
||||
Two measurements are done.
|
||||
| Data File | Description |
|
||||
|--------------------+-----------------------|
|
||||
| =mat/data_001.mat= | Slip-ring not turning |
|
||||
| =mat/data_002.mat= | Slip-ring turning |
|
||||
|
||||
For each measurement, the measured signals are:
|
||||
| Data File | Description |
|
||||
|-----------+------------------------------------|
|
||||
| =t= | Time vector |
|
||||
| =x1= | Direct signal |
|
||||
| =x2= | Signal going through the Slip-Ring |
|
||||
|
||||
The goal is to determine is the signal is altered when the spindle is rotating.
|
||||
|
||||
Here, the rotation speed of the Slip-Ring is set to 1rpm.
|
||||
|
||||
* 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
|
||||
sr_off = load('mat/data_001.mat', 't', 'x1', 'x2');
|
||||
sr_on = load('mat/data_002.mat', 't', 'x1', 'x2');
|
||||
#+end_src
|
||||
|
||||
* Analysis
|
||||
Let's first look at the signal produced by the DAC (figure [[fig:random_signal]]).
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(sr_on.t, sr_on.x1);
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
xlim([0 10]);
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:random_signal
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/random_signal.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:random_signal
|
||||
#+CAPTION: Random signal produced by the DAC
|
||||
#+RESULTS: fig:random_signal
|
||||
[[file:figs/random_signal.png]]
|
||||
|
||||
We now look at the difference between the signal directly measured by the ADC and the signal that goes through the slip-ring (figure [[fig:slipring_comp_signals]]).
|
||||
|
||||
#+begin_src matlab :results none
|
||||
figure;
|
||||
hold on;
|
||||
plot(sr_on.t, sr_on.x1 - sr_on.x2, 'DisplayName', 'Slip-Ring - $\omega = 1rpm$');
|
||||
plot(sr_off.t, sr_off.x1 - sr_off.x2,'DisplayName', 'Slip-Ring off');
|
||||
hold off;
|
||||
xlabel('Time [s]'); ylabel('Voltage [V]');
|
||||
xlim([0 10]);
|
||||
legend('Location', 'northeast');
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_comp_signals
|
||||
#+HEADER: :tangle no :exports results :results value raw replace :noweb yes
|
||||
#+begin_src matlab :var filepath="figs/slipring_comp_signals.pdf" :var figsize="wide-normal" :post pdf2svg(file=*this*, ext="png")
|
||||
<<plt-matlab>>
|
||||
#+end_src
|
||||
|
||||
#+NAME: fig:slipring_comp_signals
|
||||
#+CAPTION: Alteration of the signal when the slip-ring is turning
|
||||
#+RESULTS: fig:slipring_comp_signals
|
||||
[[file:figs/slipring_comp_signals.png]]
|
||||
|
||||
* Conclusion
|
||||
|
||||
*Remaining questions*:
|
||||
- Should the measurement be redone using voltage amplifiers?
|
||||
- Use higher rotation speed and measure for longer periods (to have multiple revolutions) ?
|
@ -1,2 +0,0 @@
|
||||
|data_001|slip-ring not turning|
|
||||
|data_002|slip-ring turning|
|