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Refine Spring #102

Merged
merged 7 commits into from
Oct 28, 2022
Merged

Refine Spring #102

merged 7 commits into from
Oct 28, 2022

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andermi
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@andermi andermi commented Oct 28, 2022

The spring model was causing some jitter in the piston position, spring pressures, as well as the force-torque sensor. This was due to a discontinuity in pressures in the implementation of hysteresis in the spring. This agitation in forces occurred for very small velocities (based on changes of sign). A dead-band was added to checking velocity to fix this. Also, pressure now evolves continuously across the hysteresis rather than a step change.

Additionally, to better model the thermal decay of pressure at low speeds, a cooling law has been implemented within the velocity dead-band.

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Signed-off-by: Michael Anderson <anderson@mbari.org>
Signed-off-by: Michael Anderson <anderson@mbari.org>
Signed-off-by: Michael Anderson <anderson@mbari.org>
Signed-off-by: Michael Anderson <anderson@mbari.org>
Signed-off-by: Michael Anderson <anderson@mbari.org>
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@hamilton8415 hamilton8415 left a comment

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You're showing off a little with those sick graphs, nice job! Shortly here I'll provide some test data from an at-sea deployment, it may be worth tuning to that at some point as the larger heat-sink of the ocean could be relevant. Also the usual behaviors at sea have a lower frequency content than the friction moves in the lab. Approved in any event.

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andermi commented Oct 28, 2022

Hah! plotjuggler deserves most of the credit ;-p

Signed-off-by: Michael Anderson <anderson@mbari.org>
Signed-off-by: Michael Anderson <anderson@mbari.org>
@andermi andermi merged commit a51b8ec into main Oct 28, 2022
@andermi andermi deleted the andermi/refine_spring branch October 28, 2022 18:47
@andermi andermi linked an issue Oct 31, 2022 that may be closed by this pull request
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Jitter in ForceTorque & SCRecord upper/lower_psi
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