02/3mar06 td12 encoder trouble


       On 02mar06 about 23:36, tiedown 12 released. The plots show what the tiedowns did (.ps) (.pdf):

    The tiedown position was reported incorrectly starting at 23.6 hours (23:36). The jump from 14 inches to 24 inches took 1 second so it was an error in the encoders, not an actual movement of the tiedowns. The feedback loop tried to bring the tiedown back down but the encoder reading was not changing. You can see occasional position values where the encoder reading was correct. Eventually the tiedown got to 2 inches (fully extended) where it hit a limit switch and was stopped (23.65).  Eventually the encoder reading corrected itself (about 23.66). It sat there till  23.72 (23:42) when it started to move back to the default position (this is when the operator commanded the tiedown to move back).
    The platform was tilted from 23:36 thru 23:45.

    On 03mar06 around 12:34 pm td12 again jumped to 24 inches (.ps) (.pdf):

processing: x101/060302/td12.pro