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

29 KiB

#+TITLE:Effect on the control system of each stages on the vibration of the station

This file is organized as follow:

  • Section sec:effect_control_all:

    • One geophone on the marble and one at the sample location
    • Each stage is turned on one by one
  • Section sec:effect_control_one:

    • One geophone on the marble and one at the sample location
    • Each stage is turned on one at a time
  • Section sec:effect_symetrie_driver:

    • We check if the Symetrie driver induces some vibrations when placed on the marble

Effect of all the control systems on the Sample vibrations

<<sec:effect_control_all>>

ZIP file containing the data and matlab files   ignore

All the files (data and Matlab scripts) are accessible here.

Experimental Setup

We here measure the signals of two L22 geophones:

  • One is located on top of the Sample platform
  • One is located on the marble

The signals are amplified with voltage amplifiers with the following settings:

  • gain of 60dB
  • AC/DC option set on AC
  • Low pass filter set at 1kHz

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.

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
Summary of the measurements and the states of the control systems

Each of the mat file contains one array data with 3 columns:

Column number Description
1 Geophone - Marble
2 Geophone - Sample
3 Time

Load data

We load the data of the z axis of two geophones.

  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;

Analysis - Time Domain

First, we can look at the time domain data and compare all the measurements:

  figure;
  hold on;
  plot(d3(:, 3), d3(:, 2), 'DisplayName', 'Hexa, Rz, SR, Ry, Ty');
  plot(d4(:, 3), d4(:, 2), 'DisplayName', 'Hexa, Rz, SR, Ry');
  plot(d5(:, 3), d5(:, 2), 'DisplayName', 'Hexa, Rz, SR');
  plot(d6(:, 3), d6(:, 2), 'DisplayName', 'Hexa, Rz');
  plot(d7(:, 3), d7(:, 2), 'DisplayName', 'Hexa');
  plot(d8(:, 3), d8(:, 2), 'DisplayName', 'All OFF');
  hold off;
  xlabel('Time [s]'); ylabel('Voltage [V]');
  xlim([0, 50]);
  legend('Location', 'bestoutside');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/time_domain_sample.png

Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location
  figure;
  hold on;
  plot(d3(:, 3), d3(:, 1), 'DisplayName', 'Hexa, Rz, SR, Ry, Ty');
  plot(d4(:, 3), d4(:, 1), 'DisplayName', 'Hexa, Rz, SR, Ry');
  plot(d5(:, 3), d5(:, 1), 'DisplayName', 'Hexa, Rz, SR');
  plot(d6(:, 3), d6(:, 1), 'DisplayName', 'Hexa, Rz');
  plot(d7(:, 3), d7(:, 1), 'DisplayName', 'Hexa');
  plot(d8(:, 3), d8(:, 1), 'DisplayName', 'All OFF');
  hold off;
  xlabel('Time [s]'); ylabel('Voltage [V]');
  xlim([0, 50]);
  legend('Location', 'bestoutside');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/time_domain_marble.png

Comparison of the time domain data when turning off the control system of the stages - Geophone on the marble

Analysis - Frequency Domain

  dt = d3(2, 3) - d3(1, 3);

  Fs = 1/dt;
  win = hanning(ceil(10*Fs));

Vibrations at the sample location

First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.

  [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);

And we compare all the signals (figures fig:psd_sample_comp and fig:psd_sample_comp_high_freq).

  figure;
  hold on;
  plot(f, sqrt(px3), 'DisplayName', 'Hexa, Rz, SR, Ry, Ty');
  plot(f, sqrt(px4), 'DisplayName', 'Hexa, Rz, SR, Ry');
  plot(f, sqrt(px5), 'DisplayName', 'Hexa, Rz, SR');
  plot(f, sqrt(px6), 'DisplayName', 'Hexa, Rz');
  plot(f, sqrt(px7), 'DisplayName', 'Hexa');
  plot(f, sqrt(px8), 'DisplayName', 'All OFF');
  plot(fgm, sqrt(pxxgm), '-k', 'DisplayName', 'Ground Velocity');
  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_sample_comp.png

Amplitude Spectral Density of the signal coming from the top geophone
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_sample_comp_high_freq.png

Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)

Vibrations on the marble

Now we plot the same curves for the geophone located on the marble.

  [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);

And we compare the Amplitude Spectral Densities (figures fig:psd_marble_comp and fig:psd_marble_comp_high_freq)

  figure;
  hold on;
  plot(f, sqrt(px3), 'DisplayName', 'Hexa, Rz, SR, Ry, Ty');
  plot(f, sqrt(px4), 'DisplayName', 'Hexa, Rz, SR, Ry');
  plot(f, sqrt(px5), 'DisplayName', 'Hexa, Rz, SR');
  plot(f, sqrt(px6), 'DisplayName', 'Hexa, Rz');
  plot(f, sqrt(px7), 'DisplayName', 'Hexa');
  plot(f, sqrt(px8), 'DisplayName', 'All OFF');
  plot(fgm, sqrt(pxxgm), '-k', 'DisplayName', 'Ground Velocity');
  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_marble_comp.png

Amplitude Spectral Density of the signal coming from the top geophone
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_marble_comp_high_freq.png

Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)

Conclusion

  • The control system of the Ty stage induces a lot of vibrations of the marble above 100Hz
  • The hexapod control system add vibrations of the sample only above 200Hz
  • When the Slip-Ring is ON, white noise appears at high frequencies. This is studied here

Effect of all the control systems on the Sample vibrations - One stage at a time

<<sec:effect_control_one>>

ZIP file containing the data and matlab files   ignore

All the files (data and Matlab scripts) are accessible here.

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.

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
Summary of the measurements and the states of the control systems

Each of the mat file contains one array data with 3 columns:

Column number Description
1 Geophone - Marble
2 Geophone - Sample
3 Time
/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/img/IMG_20190507_101459.jpg
Voltage amplifier settings for the measurement

Load data

We load the data of the z axis of two geophones.

  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;

Voltage to Velocity

We convert the measured voltage to velocity using the function voltageToVelocityL22 (accessible here).

  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);

Analysis - Time Domain

First, we can look at the time domain data and compare all the measurements:

  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/time_domain_sample_lpf.png

Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location
  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/time_domain_marble_lpf.png

Comparison of the time domain data when turning off the control system of the stages - Geophone on the marble
  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/time_domain_relative_disp.png

Relative displacement of the sample with respect to the marble

Analysis - Frequency Domain

  dt = d_of(2, 3) - d_of(1, 3);

  Fs = 1/dt;
  win = hanning(ceil(10*Fs));

Vibrations at the sample location

First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.

  [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);

And we compare all the signals (figures fig:psd_sample_comp_lpf and fig:psd_sample_comp_high_freq_lpf).

  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_sample_comp_lpf.png

Amplitude Spectral Density of the sample velocity
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_sample_comp_high_freq_lpf.png

Amplitude Spectral Density of the sample velocity (zoom at high frequencies)

Vibrations on the marble

Now we plot the same curves for the geophone located on the marble.

  [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);

And we compare the Amplitude Spectral Densities (figures fig:psd_marble_comp_lpf and fig:psd_marble_comp_lpf_high_freq)

  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_marble_comp_lpf.png

Amplitude Spectral Density of the marble velocity
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_marble_comp_lpf_high_freq.png

Amplitude Spectral Density of the marble velocity (zoom at high frequencies)

Conclusion

  • 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

Effect of the Symetrie Driver

<<sec:effect_symetrie_driver>>

ZIP file containing the data and matlab files   ignore

All the files (data and Matlab scripts) are accessible here.

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:

  • 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.

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

Load data

We load the data of the z axis of two geophones.

  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;

Analysis - Time Domain

  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/time_domain_hexa_driver.png

Comparison of the time domain data when turning off the control system of the stages - Geophone at the sample location

Analysis - Frequency Domain

  dt = d_18(2, 3) - d_18(1, 3);

  Fs = 1/dt;
  win = hanning(ceil(10*Fs));

Vibrations at the sample location

First, we compute the Power Spectral Density of the signals coming from the Geophone located at the sample location.

  [px_18, f] = pwelch(d_18(:, 1), win, [], [], Fs);
  [px_19, ~] = pwelch(d_19(:, 1), win, [], [], Fs);
  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');
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_hexa_driver.png

Amplitude Spectral Density of the signal coming from the top geophone
  <<plt-matlab>>

/tdehaeze/nass-micro-station-measurements/media/commit/7b5c8455a21085f291f369359e54e01d7fc50009/disturbance-control-system/figs/psd_hexa_driver_high_freq.png

Amplitude Spectral Density of the signal coming from the top geophone (zoom at high frequencies)

Conclusion

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.