Vosper Mini Fins Stabilisers retrofit on MiToS

  • Thread starter Thread starter vas
  • Start date Start date
hm, summer season over, p1ssing down last few days, boat on it's mooring till next June.
Teaching delayed for a week so starting on Monday, had a few hours over the last week to check and finetune the simplified version of the code.
Two itterations, first shot both video from the dock and the capture of the variables plotted dancing about.
Second just variable dancing (much more meaningful in debuging)
Basically minimised (zeroed!) delay, if rollrate goes off zero value, fins react. Still trying to remember why I wasn't doing that in the first place and was deliberately introducing delays and roll.
Problem is although my code is almost 50-50 code vs comments, it still takes me a good few hours in at least two consecutive days to remember what I've done and why.

Anyway, latest test was on the 7th of Oct (all tests done with the liner enters port in the evening) and was much better than previous ones in consistency and performance.
Analysing the graphs I came up with yet another idea on triggering fin movement as I noticed that on many decent rolls, fin initial movement gets boat rollrate almost zeroed, fins stop moving waiting for next roll, but the remaining of the wake re-acts the rolling and fins still wait for rollrate to zero and then rise before acting... Not quite easy to describe tbh on the last video I'm linking below it's clear at circa 20sec when I first activate the fins, a half flap stabilises (not perfectly) but then fins stop and boat starts rolling again. Fins have more travel they could do and minimise that as well, but are not triggered as they've acted as instructed in the same heel earlier. Hope a dozen of lines of code could sort that we shall see in next test :)

If you're really bored you can have a look at these three videos one and three are the geeky ones, second is the boaty one ?



and last attempt:


my next attempt at videoing the thing will be to sync graphs with outside video in one video, that will make following what's going on much easier!
cheers

V.
 
My suggestion would be to connect that graph to a synthesizer and play it through the boats sound system. Then no matter where you are you would be able to tell what the fins are doing from the music ?
 
My suggestion would be to connect that graph to a synthesizer and play it through the boats sound system. Then no matter where you are you would be able to tell what the fins are doing from the music ?
I will seriously consider it :cool:
All my debugging and testing code was done by staring at the plots from arduino IDE - visualising the boat movement, "listening" to boat movement may not be that different. Will check with MAXMSP when weather turns really foul!

looking very good Vas, when does production start and can you do some for a 38" ?
? K, the reason I'm posting all that is twofold:
A. get feedback from ppl like you (still to implement PID control, hope I'll manage this winter!)
B. keep track of my thoughts so that I can trace back where I was and when.
there's no C. make money by building stab kits!
Having said that, over the w/e I was shocked to hear that a fellow prof that retired in the summer is receiving a pension that is only 1000euro :-( I could possibly live with 1.5X that in 10yrs, but not a grand!
Luckily wife is a proper workaholic and has a p/t job in SWE so hoping she's going to receive a decent pension from there :cool:
Happy to help if you decide to go ahead and source a suitable el.motor and gbox. Not sure it's worth the hydraulics hassle tbh, especially as I have to spent a lot to convert the valves to progressive .

For the record, tried my latest idea this evening, managed to stick to under 1d/s rollrate which is almost half the best I've achieved before. Will drop hydraulic flow/pressure to smoothen up the movement a bit and will test again one of the following days.

cheers

V.
 
very interesting Vas,
in your 3th video,
around 7;15 you can see that the roll rate immediately increases when you switch the system off ?
and around 7;25 it takes quite a a while before you notice a decent reduction of roll rate ?
 
Top