Good day
I`m wondering if there is anybody who want to build a DIY autopilot? If
so, it would be interesting to discuss/combine ideas.
In the moment my idea ... and what I`ve done so far is following:
- Controll unit with a raspberry pi
- language Python (because I really do not know C to handle this properly)
The idea in the moment is to use this year the old wheel pilot (Navico)
as steering unit. If the controll unit will work fine, I will change the
steering unit next winter and will mount a linear drive under deck.
What I`ve done up to now ...
I took the code of FishPi autopilot as basic to change to the things
which I think are usefull.
For time being I integrated a compass/magnetrometer/accelerometer
module, called cmps10. It`s cheap and doing it`s job.
For GPS signal I`m using a simple USB GPS mouse to figure out
Lon/Lat/speed/course
... not done yet ... integrate a reader for wind direction. On board I
have the NASA clipper instruments and will read this datas via Atmel
microchip, connected to the controll system via I2Cbus. Atmel Afinity
1327 Chip is programmed and working, but up to now no test if it`s
working with the NASA clipper instrument, due to the fact, mast is down
for winter... so I have to play arround first to test it on board, but
... it`s cold outside, so I`m still waiting.
Rudderangle, just working, with a potentiometer and signals collected by
GPIO pins of raspberry pi.
Route planing .... FishPi provide the idea of integrating routes in gpx
format. I think that idea is ok for an autonomus vehicle, but I do not
like that idea. I`ve tested to run opencpn and FishPi parallel on the
raspberry .... and it works, so I take the signal from opencpn for
heading to next waypoint via UDP and can use opencpn.
For output, Ive integrated a motor controll via SDA network, which
should work with a PA with the wheel unit. Not tested yet.
There are a lot of things to do to get everything working nicely.
- define sailing situation with no go areas (i.e. downwind or app +-38°
head wind)
- define a "learning tool" to define rudder gain vs heeling and
acceleration, my idea is to create a simple database and to store real
life datas.
- implement a kalman filter or a complementary filter (which I prefere
for time being)
- of cause ... to find a nice housing and screen to have the stuff
mounted at wheel also to sea seamap at wheel
One may say, hey, you can by this stuff, exactly what you want ...
correct. But first of all, the hardware will cost me as DIY project
about 100 € instead of min 1000 € ... the other thing is, it makes fun
to create the own platform.
So, if anybody is interesting to join this project, he/she is wellcome ;-)
best regards
Peter
C&C34 Colomba
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