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  • Gps/sonar driven auto pilot

    I mentioned some time ago a plan to connect a 12V linear actuator to my kicker for portable (around the boat) steering control. I have a Humminbird fish finder/GPS with a NMEA output.
    Has anyone built a board to convert NMEA heading change info to drive an autopilot. Maybe using an Arduino?
    I hate reinventing the wheel, just need a board to drive a couple of relays to run the actuator for heading corrections.

    Any thoughts?
    Sea Fever
    First boat home built Mustang - in 1959 with 25 hp Johnson
    first RV 16' Triple - E bought 1961
    current outfit 1996 Chev 1 ton Diesel crew cab 6.5 L Turbo 4X4
    Towing 37 foot Jayco designer fifth wheel
    and 1974 Silverline Antigua 18T
    Overall length is 80 feet yes illegal in some places

    Licensed pilot, HAM operator qualified B Helm sailing instructor

  • #2
    Re: Gps/sonar driven auto pilot

    GPS doesn't have the update rate or accuracy required for an auto-pilot. Auto pilots use a flux gate compass and a gyro to get the accuracy and response times need for a successful auto pilot implementation.
    ....

    Comment


    • #3
      Re: Gps/sonar driven auto pilot

      This won't help, but my Raymarine sport pilot plus works very well running off of my Hummingbird 988i. Of course I have my kicker connected to my main engine and the sport pilot steers both. Great for long trolling sessions for salmon and steelhead. I either just point it where I want to go and it goes there, or, I build a track with several waypoints and it will follow that. It takes a lot of waypoints because I can't have it turning 90 degrees at once with 9 to 12 lines out. Usually I have it turn 15 degrees at a time with 5 min in between course changes. Sometimes I even let it take me home. Just have to remember to look out the bow now and again. It can't see other boats.

      Edit. Just read the above from Dingbat, and My GPS does just fine sending NMEA info to my auto pilot. I can also just use the fluxgate compass when I don't want the auto pilot to follow the GPS. And, There is no gyro in my system. Somehow internal to the sport pilot it also compensates for wind and current and even adjusts how fast it changes course (turns the wheel)based on my speed.
      Last edited by Georgesalmon; January 8th, 2014, 09:52 AM.

      Comment


      • #4
        Re: Gps/sonar driven auto pilot

        Originally posted by Georgesalmon View Post
        Edit. Just read the above from Dingbat, and My GPS does just fine sending NMEA info to my auto pilot. I can also just use the fluxgate compass when I don't want the auto pilot to follow the GPS. And, There is no gyro in my system. Somehow internal to the sport pilot it also compensates for wind and current and even adjusts how fast it changes course (turns the wheel)based on my speed.
        The "track" is coming from the GPS. The "somehow" in the system is your flux gate compass. It compensates for the wind, current and other variables that the 1 second update of GPS is to slow to correct. Disconnect the compass from the system while navigating with GPS. I'll guarantee you will not be very happy with the performance.
        Last edited by dingbat; January 9th, 2014, 06:31 AM.
        ....

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        • #5
          Re: Gps/sonar driven auto pilot

          Wait a minute here - I dont need something that will keep me on course + or - a split puppy hair! When I am steering/fishing with the kicker my wake looks like the track of a drunken sailor going home on Saturday night. I just want something that will make gross corrections every few seconds so I don't have to run to the helm or the tiller. If I read the info right the Arduino will do just that with info from the gps. It even looks like I can incorporate a throttle output to adjust trolling speed for wind, current etc.
          Running at 40 MPH on the V-8 might need more accurate heading changes but fishing at 1.5 - 3 MPH takes a while to get in trouble.
          DINGBAT>>> Please have another think on this with greatly reduced expectations as to response time and accuracy, I dont expect a Cheoy Lee at a Lund price. (My taste would run to a 40' Hatteras when I win POWERBALL!)
          First boat home built Mustang - in 1959 with 25 hp Johnson
          first RV 16' Triple - E bought 1961
          current outfit 1996 Chev 1 ton Diesel crew cab 6.5 L Turbo 4X4
          Towing 37 foot Jayco designer fifth wheel
          and 1974 Silverline Antigua 18T
          Overall length is 80 feet yes illegal in some places

          Licensed pilot, HAM operator qualified B Helm sailing instructor

          Comment


          • #6
            Re: Gps/sonar driven auto pilot

            I just had another thought, if the arduino board is capable of converting GPS information via NMEA to fly model aircraft and helicopters on autopilot, how can it be possible not to run a slow moving boat. A model at 140 MPH covers a helluva lot of territory in a second or two. Like about 4 fps Vs. 200 fps. Methinks we are getting to critical in design parameters for the job at hand. If I can keep my boat position within 10 feet and a course within 5 degrees between waypoints it is probably better than steering by hand while helping 4 great grand kids manage their fishing rods.
            Anything to make it easier on old great grampa -Right?
            First boat home built Mustang - in 1959 with 25 hp Johnson
            first RV 16' Triple - E bought 1961
            current outfit 1996 Chev 1 ton Diesel crew cab 6.5 L Turbo 4X4
            Towing 37 foot Jayco designer fifth wheel
            and 1974 Silverline Antigua 18T
            Overall length is 80 feet yes illegal in some places

            Licensed pilot, HAM operator qualified B Helm sailing instructor

            Comment


            • #7
              Re: Gps/sonar driven auto pilot

              Well, this great grandpa is not all that old.
              Here you are...go for it.

              The Marine Installer's Rant: The Arduino autopilot that Jack built
              ....

              Comment


              • #8
                Re: Gps/sonar driven auto pilot

                Interesting project seafever, I'm working on(along with 12 other things) something sort of similar but, less smart, I'm just using a I2C mems rate gyro and microcontroller I'm coding up to talk to one another and attempt to hold'ish given bearings using electric steering drive(servo) I made up this past year. The electric drive fits to my 9.9hp kicker motor. Not expecting it to walk a tight wire or not skew and such, just messing around mainly. It has to do with more fishing and less anything else, so it must be important?


                I'm too cheap to buy anything off the shelf and have really no idea how well it is going to work +/- not work but, it keeps me out of jail working on it, so it has a working side already!!
                Last edited by sam am I; January 11th, 2014, 02:57 AM.

                Comment


                • #9
                  Re: Gps/sonar driven auto pilot

                  Originally posted by sam am I View Post
                  Interesting project seafever, I'm working on(along with 12 other things) something sort of similar but, less smart, I'm just using a I2C mems rate gyro and microcontroller I'm coding up to talk to one another and attempt to hold'ish given bearings using electric steering drive(servo) I made up this past year. The electric drive fits to my 9.9hp kicker motor. Not expecting it to walk a tight wire or not skew and such, just messing around mainly. It has to do with more fishing and less anything else, so it must be important?
                  Me Too!
                  WELL Sam I Am, look on Ebay for a 12V linear actuator with 12 inch travel. The one I ordered from China was $50 with free shipping, It will lift 100 lbs and hold 400 lbs. I am using an Arduino Mega ($45) and a couple of relays. When the course corrections are made I will use a couple of microswitches on the actuator to return the kicker to amidships.
                  Did you notice this is for slow troll fishing? It will steer a 7.5 Hp mercury kicker. There is no way I want my 188Hp Ford 302 V-8 on auto-pilot while flying across the lake at 40 -50 MPH.
                  I hope to take outputs from my Humminbird Chart plotter to an LCD readout at the stern to show fish size and depth and depth under the keel at a transom location. I cannot see the Humminbird at the helm when I am tending lines. I can also rig up an alarm buzzer for shoaling water, off course, etc. I envision a bridge like the startship Enterprise.

                  I'm too cheap to buy anything off the shelf and have really no idea how well it is going to work +/- not work but, it keeps me out of jail working on it, so it has a working side already!!
                  Ebay is so cheap it is criminal to go elsewhere
                  First boat home built Mustang - in 1959 with 25 hp Johnson
                  first RV 16' Triple - E bought 1961
                  current outfit 1996 Chev 1 ton Diesel crew cab 6.5 L Turbo 4X4
                  Towing 37 foot Jayco designer fifth wheel
                  and 1974 Silverline Antigua 18T
                  Overall length is 80 feet yes illegal in some places

                  Licensed pilot, HAM operator qualified B Helm sailing instructor

                  Comment


                  • #10
                    Re: Gps/sonar driven auto pilot

                    Yes I did notice it was for slow trolling, I'm building mine for that as well. The servo I made is just.... basically a DC motor [12V Dewalt screw gun motor and electronics(speed and direction) I hacked apart] that spins a length of coupled ALUM. all-thread forward or revere, a steel nut pressed inside a length of 1/2 ALUM tube that runs up and down this spinning thread making the tube that's attached to the kicker move in and out of a sealed bushing at the end of a 14" PVC pipe assembly.......It will lift a bus.

                    I have an LVDT that attaches to the output actuator tube for position feedback. The Gyro just picks up on any twisting moments of the boat and a microcontroller that processes the required attack rates and position, controls the speed and direction electronics at a rate such that the actuator moves in or out to compensates the kicker's position relative to the boat to hold a bearing I set it to.....Wheeew, now that's a run-on

                    Works in my head anyway.......lol, I have it half built, the servo works as designed, used it all last summer on manual mode to run the kicker. The gyro works as expected(I don't make them, I make them better), I just need to write/finish some code, wire up a small control panel that has perhaps a gain adj., manual position overrides/set and interface the two worlds still..... GL to you and let the cheapest bastard catch the most fish............ -----~ <*)))))>< <*)))))>< <*)))))>< <*)))))><
                    Last edited by sam am I; January 11th, 2014, 03:27 PM.

                    Comment


                    • #11
                      Re: Gps/sonar driven auto pilot

                      Originally posted by sam am I View Post
                      Yes I did notice it was for slow trolling, I'm building mine for that as well. The servo I made is just.... basically a DC motor [12V Dewalt screw gun motor and electronics(speed and direction) I hacked apart] that spins a length of coupled ALUM. all-thread forward or revere, a steel nut pressed inside a length of 1/2 ALUM tube that runs up and down this spinning thread making the tube that's attached to the kicker move in and out of a sealed bushing at the end of a 14" PVC pipe assembly.......It will lift a bus.

                      I have an LVDT that attaches to the output actuator tube for position feedback. The Gyro just picks up on any twisting moments of the boat and a microcontroller that processes the required attack rates and position, controls the speed and direction electronics at a rate such that the actuator moves in or out to compensates the kicker's position relative to the boat to hold a bearing I set it to.....Wheeew, now that's a run-on

                      Works in my head anyway.......lol, I have it half built, the servo works as designed, used it all last summer on manual mode to run the kicker. The gyro works as expected(I don't make them, I make them better), I just need to write/finish some code, wire up a small control panel that has perhaps a gain adj., manual position overrides/set and interface the two worlds still..... GL to you and let the cheapest bastard catch the most fish............ -----~ <*)))))>< <*)))))>< <*)))))>< <*)))))><
                      Wll hey Sam, it sounds like you are well on the way. My system is still in my head, but parts are on the way. My Humminbird 161 Chartplotter has a $GPAPB output sentence intended to drive autopilots. That includes a cross track error distance, a steer to ( l or r), bearings, waypoints. headings and arrival info. I ordered a Arduino microprocessor for $28 and a seconday compass/magnetometer for $8 and some relays and switches and LEDs. (BTW LEDs on EBay 7 colors, 10 of each, with resistors for 3.3V, 5V and 12V cost $3.00) LED holders 10 for $1.50.
                      The 12VDC actuator will be the steering engine, I havent figured out yet whether to use limit switches or a variometer (potentiometer on an arm) to indicate kicker (read rudder) position. I am thinking the pot will make it easier to return the helm amidships after course correction. I am working on a method to preplot waypoints on a given lake using a map program on the laptop and have them preloaded. Then last night I realized I have several old laptops that died after a lightning strike.
                      If I can get one of the LCD displays working I should be able to feed GPS and fish finder info to a remote screen,

                      Question Sam! If I remember right the LVDT needs an AC voltage across it to give an ouput position signal. Where are you getting AC from?
                      First boat home built Mustang - in 1959 with 25 hp Johnson
                      first RV 16' Triple - E bought 1961
                      current outfit 1996 Chev 1 ton Diesel crew cab 6.5 L Turbo 4X4
                      Towing 37 foot Jayco designer fifth wheel
                      and 1974 Silverline Antigua 18T
                      Overall length is 80 feet yes illegal in some places

                      Licensed pilot, HAM operator qualified B Helm sailing instructor

                      Comment


                      • #12
                        Re: Gps/sonar driven auto pilot

                        Originally posted by seafever View Post
                        Question Sam! If I remember right the LVDT needs an AC voltage across it to give an ouput position signal. Where are you getting AC from?
                        It's takes unregulated DC, something like 8 to 25 volts DC........they put all kinds of smoked filled electronics inside, including a voltage regulator and an oscillator.

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                        • #13
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                          Re: Gps/sonar driven auto pilot

                          Yep they do, I have let the smoke out of a few things in my time and had a helluva time gettinn the smoke back in. The smoke was tough but getting the arcover or light flashh was even worse to capture. That lil bugger is fast.
                          First boat home built Mustang - in 1959 with 25 hp Johnson
                          first RV 16' Triple - E bought 1961
                          current outfit 1996 Chev 1 ton Diesel crew cab 6.5 L Turbo 4X4
                          Towing 37 foot Jayco designer fifth wheel
                          and 1974 Silverline Antigua 18T
                          Overall length is 80 feet yes illegal in some places

                          Licensed pilot, HAM operator qualified B Helm sailing instructor

                          Comment

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