I posit that a mailing list like this is also an archive. Judging by the traffic that this thread has already generated in one day I wouldn't assume that it's not an interesting topic to other listers or that those with little technical know-how either have nothing to contribute or nothing to learn. Nevermind the people that might be googling for this topic a year or two from now. I for one would like to see how this goes so my vote is keep the discussion here as long as it's practical. I understand that there might be a need to share files etc. Maybe you guys want to consider an open project. Just putting it out there.
Steve Suhana, C&C 32 Toronto On Tue, Jan 21, 2014 at 3:56 PM, Colomba <[email protected]> wrote: > Hi Eric > > of cause I`m interested. > > I think a platform like a forum incl. possibility to upload drw and > files, would be great. I have one in spare, but unfortunately something is > going wrong, because permanent new users are generated, think by a bot, and > for time being, I closed the doors. Perhaps on the WE I will find some time > to try to update this forum, but if you have an other idea, pleased to hear > ;-) > > Peter > > > Am 21.01.2014 19:31, schrieb Eric Frank: > > Hi Peter and David, >> >> This is very interesting for me. Ultimately, my project with these >> things is for building a model sailboat that is semi-autonmous. Give it a >> list of waypoints, and it will navigate to them. This is already >> implemented commercially for model planes, and there are various attempts >> at trans-atlantic crossings with model sailboats (so far unsuccessful). >> To begin the learning process, I am using arduino and a wind direction >> instrument to automatically adjust the sheet for the apparent wind. And to >> get more realtime practice with the arduino, I am adding to the NEMA-based >> system on Cats Paw to derive tilt-compensated true heading info. A >> tilt-compensated Hall effect compass module from Sparkfun generates the >> NEMA code for magnetic heading, and the RMC sentence from a little GPS unit >> provides the local magnetic variation. So that allows construction of HDG >> (magnetic heading + deviation and variation), which standard nav programs >> like MacENC or iNavX can use to get true headings. >> I have not even started putting together an autopilot for the model >> (on Cats Paw I use a Raymarine wheel pilot), but would love to learn more >> about how you implement the "learning" steps in having the autopilot make >> the appropriate rudder corrections for a certain course error. >> My guess is these projects will not be of interest to lots of the >> Stus-list, so perhaps we should start communicating offline. Interested? >> >> Eric Frank >> Cat's Paw >> C&C 35 Mk II >> Mattapoisett, MA >> >> From: David Paine <[email protected]> >>> To: [email protected] >>> Subject: Re: Stus-List Homebrew autopilot >>> Message-ID: >>> <CANtME359m12GxToRtu3JrNd7qGBJh+5G03wYp-aMz1TxfoVNLA@mail. >>> gmail.com> >>> Content-Type: text/plain; charset="windows-1252" >>> >>> Hi Peter, >>> >>> I built a homebrew below deck autopilot for my C&C33 a couple of years >>> ago >>> using a linear actuator, a mechanical clutch, a H-bridge-like serial >>> power >>> controller from Pololu, an arduino, a transreflective serial LCD display, >>> four buttons, and most important of all, a digital compass with serial >>> communication (NMEA 0183) operating at 10Hz which, along with a sparkfun >>> gyro (15 degrees/sec) provides heading information. I bout everything >>> from >>> ebay and probably have $250 and untold hours invested) The programming >>> is >>> fairly easy with arduino since there is a PID controller library >>> available >>> (use two, one for the positioning of the actuator, the other for >>> correcting >>> for the course error (the difference between the intended course and the >>> present heading. >>> >>> I've used my autopilot on many long solo trips including one 80 m mile >>> offshore run with 20 kn wind directly astern and a large swell off the >>> quarter (during which I was able to sleep for four hours as the system >>> was >>> so stable. >>> >>> Hints: Forget using GPS (or wind) alone to set the course you need much >>> faster response time and that is why you need a 10 Hz heading signal. I >>> thought about using a Kalman filter but soon learned that Kalman filter >>> math is serious juju and was very glad to have stuck with PID control -- >>> we >>> only have two degrees of freedom its not like it's a quadracopter! The >>> worst part of my system as it stands now is the mechanical clutch to >>> engage >>> and disengage the actuator -- one day I will find a hydraulic actuator >>> which will allow a solenoid to disengage the actuator. Raymarine >>> actuators >>> have an electromechanical clutch which is also nice but consumes more >>> current than I like. Also, try to use components with serial >>> communications protocols -- these will have on board filtering and make >>> the >>> whole exercise much easier. >>> >>> >>> Best, >>> >>> David >>> >>> >>> >>> >>> On Tue, Jan 21, 2014 at 2:24 AM, Colomba <[email protected]> >>> wrote: >>> >>> 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 >>>> >>> >> >> _______________________________________________ >> This List is provided by the C&C Photo Album >> http://www.cncphotoalbum.com >> [email protected] >> >> > > _______________________________________________ > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > [email protected] >
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