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UNH-OE / wave-tow-tank

Configuration files and issue tracking for the UNH wave & tow tank.
MIT License
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Refine tow axis homing routine to set soft limits #19

Open petebachant opened 9 years ago

petebachant commented 9 years ago

Need to fix https://github.com/UNH-OE/tow-tank-issues/issues/4 first, so we can find the positive hard limit. Positive soft limit should be calculated such that the carriage will not hit the mechanical limit upon kill deceleration from max speed.

petebachant commented 9 years ago

Negative soft limit will be zero, but we can create an offset in the S700 homing routine to allow safe emergency deceleration on that side.

Distance 

dx = v0**2/(2*decel)

For maximum deceleration (KDEC) (2 m/s2), we have

v0 (m/s) dx (m)
0.2 0.01
0.3 0.022
0.5 0.063

We don't really expect fast towing towards the beach--more jogging with the pendant, so maybe 0.3 m/s is a good speed to use for calculating the deceleration distance. This would only cut off 2 cm of travel, which is not bad.