Static Measurements
Table of Contents
1 Notes
- 5530: Straightness Plot: Yz
- Filename:
r:\home\PDMU\PEL\Measurement_library\ID31\ID31_u_station\TY\12_12_2018\linear deviation _tyz_401_points.txt - Acquisition date: 09/01/2019 13:49:42
- Current date: 08/03/2019 08:46:35
- Measurement Type: STRAIGHTNESS vertical
- Travel Mode: Bidirectional
- Number of Target Positions: 401
- Number of total data pairs: 2406
- Number of total data runs:6
- Position Value Units: millimeters
- Error Value Units: micrometers
| Environmental Data | Min | Max | Avg |
|---|---|---|---|
| Air Temp (C) | 024,57 | 024,61 | 024,59 |
| Air Prs (mm) | 742,56 | 743,29 | 742,83 |
| Air Hmd (%) | 024,00 | 024,00 | 024,00 |
| MT1 Temp (C) | 020,00 | ||
| MT2 Temp (C) | 024,40 | 024,44 | 024,42 |
| MT3 Temp (C) | 024,32 | 024,36 | 024,34 |
2 Data Pre-processing
sed 's/\t/ /g;s/\,/./g' "data/linear deviation _tyz_401_points.txt" > data/data.txt
head "data/data.txt"
| Run | Pos | TargetValue | ErrorValue |
|---|---|---|---|
| 1 | 1 | -4.5E+00 | 7.5377892E+00 |
| 1 | 2 | -4.4775E+00 | 7.5422246E+00 |
| 1 | 3 | -4.455E+00 | 7.5655617E+00 |
| 1 | 4 | -4.4325E+00 | 7.5149518E+00 |
| 1 | 5 | -4.41E+00 | 7.4886377E+00 |
| 1 | 6 | -4.3875E+00 | 7.437007E+00 |
| 1 | 7 | -4.365E+00 | 7.4449354E+00 |
| 1 | 8 | -4.3425E+00 | 7.3937387E+00 |
| 1 | 9 | -4.32E+00 | 7.3287468E+00 |
3 Matlab - Data Import
filename = 'data/data.txt'; fileID = fopen(filename); data = cell2mat(textscan(fileID,'%f %f %f %f', 'collectoutput', 1,'headerlines',1)); fclose(fileID);
4 Data - Plot
figure; hold on; for i=1:data(end, 1) plot(data(data(:, 1) == i, 3), data(data(:, 1) == i, 4), '-k'); end hold off; xlabel('Target Value [mm]'); ylabel('Error Value [um]');
Figure 1: Time domain Data
Compute mean value of each position
mean_pos = zeros(sum(data(:, 1)==1), 1); for i=1:sum(data(:, 1)==1) mean_pos(i) = mean(data(data(:, 2)==i, 4)); end
figure; hold on; for i=1:data(end, 1) filt = data(:, 1) == i; plot(data(filt, 3), data(filt, 4) - mean_pos, '-k'); end hold off; xlabel('Target Value [mm]'); ylabel('Error Value [um]');
Figure 2: caption
5 Translate to time domain
t = linspace(0, 1, length(data(data(:, 1)==1, 4)));
figure; hold on; plot(t, data(data(:, 1) == 1, 4) - mean_pos, '-k'); hold off; xlabel('Time [s]'); ylabel('Error Value [um]');
Figure 3: caption
6 Compute the PSD
n_av = 5; Fs = 1/t(2); x = data(data(:, 1) == 1, 4) - mean_pos; [pxx, f] = pwelch(x, hanning(ceil(length(x)/n_av)), [], [], Fs); pxx_t = zeros(length(pxx), data(end, 1)); for i=1:data(end, 1) x = data(data(:, 1) == i, 4) - mean_pos; [pxx, f] = pwelch(x, hanning(ceil(length(x)/n_av)), [], [], Fs); pxx_t(:, i) = pxx; end
figure; hold on; plot(f, mean(pxx_t, 2)); hold off; xlabel('Frequency (Hz)'); ylabel('PSD ($m^2/Hz$)'); set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log'); legend({'PSD - x', 'PSD - y', 'PSD - z'});
Figure 4: PSD of the Z motion when scanning with Ty at 1Hz