(2020-01-25, 07:35 PM)seandepagnier Wrote: The noaa wave data is a model based on wind and other weather to predict what the sea state would have been and the model is updated to match the measurements of the relatively few actual buoy measurements.
I am not sure how this would be useful to an autopilot anyway, and consider that all of the measurements recorded greatly depend on the vessel itself not just the conditions. The predicted waves and forecast is useful for planning where you will sail, but not really useful to the autopilot who is steering in the moment.
Useless, I agree. I meant real time wave or water mouvement data of high sampling rate (>50Hz - in fact, highest rate reliably achieved by Pypilot), to analyze as an exploratory step. Maybe eventually make a training set out of it. Vessel here is essentially a constant, the bulk of variability comes from water movement (and wind, then deployment of sails would also be variables).
[quote pid='12030' dateline='1579977342']
I have performed fourier transforms (pypilot's scope has this built in) of various sensor data, and in certain sea states I can see both the swell period as well as the boat period, but have yet to apply this in a useful way. The future improvements for using rudder feedback as well as all the other sensors I believe is similar to how a human can learn steer better (machine learning)
[/quote]
Since here the amount of data is quite small (compared to typical recent machine learning contexts), the measurement error is also quite small, and all the data, including predicted rudder control values, are numerical and not categorical, machine learning (Tensorflow) could be an overkill or inappropriate. It's more of a black box approach, becoming grey if you incorporate a parametric model, and I personally prefer to use that kind of ML only when everything else fails, or if I'm not interested in understanding.
An afterthought:
About those sails being a variable. If there was a way to get sheet tension through a sensor, this could be used to add an "electronic" sheet-to-tiller component to Pypilot. Wouldn't some type of rudder corrections could then be initiated and continued almost at the same rate as a gust develops, before the other sensors can detect a change significant enough to do it?
"Self-steering for sailing craft" by John S. Letcher has a well thought in depth analysis of sheet to tiller systems that could be drawn upon.
"Overthinking, I try very hard not to do that."