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Zero platform degrees of freedom?

Hello David,

I encountered an issue while trying to export the platform’s degree of freedom results. I opened the stored simulation data and selected store output from 20s, with a total running time of 100s. However, in the exported results, I found: X_ G Pressr Platform Trans [m] Y_ G Pressr Platform Trans [m] Z_ G Pressr Platform Trans [m] X_ G Pressr Platform Root. [deg] Y_ G Pressr Platform Root. [deg] Z_ G Pressr Platform Root. [deg].

These results are all zero. How can I handle them to obtain these data?

Best regards
sby

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Hello Sby,

the sensors you are looking at are only showing a prescribed platform motion (see LINK), which is zero by default if no prescribed motion file is used.

The platform motions you are looking for are found in the “Hydrodynamic Time Graph”. The sensor names are “NP Trans. X_g [m]” and “NP Roll X_l [deg]”, “NP Pitch Y_l [deg]” and “NP Yaw Z_l [deg]”, where NP stands for the Neutral Point of the platform.

BR,

David

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sby

Hello David,

Thank you very much for your help. I have found the file in the ASCII results, and I have another question. How can I export a power spectral density image (PSD) like the example in the picture?

 

Best regards
sby

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Hi sby,

you can change the graph type to the “All Data PSD Graph” and export the curves. In the graph options you can also set a moving average filter to smooth the curves or change the axes to log scale.

Alternatively, you can of course also generate the PSD from the time series yourself in Python, Matlab or similar…

BR,

David