Replies

  • Dear All,

    i want use apm 2.5 for a AUV .Can anybody help me with underwater calibration setup. 

    thanking you

    Regards 

    Ajith

  • Hi,

    Im an ROV Submersible Engineer with over 15 years experience with ROVs working in the UK Oil and gas Industry.

    I have built 3 semi professional vehicles and keep working to see if i can find a cheaper and more basic, feature rich ROV.

    im new to the site but fully intend to post information and help where ever i can.

    With regards the APM control

    i have a question, i wish to use a minimosd to display rov attitude and sensors on the operator screen

    im not quite getting my head around Mavlink or even if that's the correct thing to use at all.

    my intention is to feed the minimosd with values via a serial link from a PC not from an APM

    any help in this direction would be much appreciated.

    Chris

    ROV using APM

    fantastic idea although you would need to consider using LAN or RS485 via a cable connection to the vehicle.

    in all my years in the industry i have not seen a successful wireless vehicle yet.

    the power to weight ratio is always an issue. In order to drive the thrusters for any amount of time requires plenty of batteries and they can become quite heavy - so id use a tethered cable to supply comms and power

    just like the real ones, it funny after years of development the vast majority of industry ROVs are attached by a cable.

    there is approximately 104 manned ROVs like Nautile which was used on the Titanic expedition, these are obviously un tethered.  As for a building kit your local DIY Plumbing section is never a bad place to start.

    if you have access to a machine shop then even better.  i mill and turn all my own pressure vessels and components, design and build electronics, programming bla bla bla.

    i like the simplicity of the Arduino and the fact its 5v tolerant inputs/outputs.  we use microchip pics at work for downhole drilling tools and they are just pants 3.3v not 5v tolerant and a royal bitch to program.

    im working on a few ROV instruments based on the Arduino, A bathy used to get data for calculating proper altimeter measurements, an altimeter (its like a second depth sensor) and a sonar. My depth is from a Druck pressure sensor and the vehicles attitude is measured using an IMU6050.  it seems a bit of a waste for me to incorporate an APM but i ma still open to suggestions and still considering it.

    the video is passed up the umbilical cable over twisted pair via video baluns which convert the video phono/BNC to twisted pair driven balanced lines.

    hence the reason why i wish to add the information to the video on the surface.

    then GUI is written in Visual Basic 6 but i am now working on a C# GUI for the topside control of my vehicles

    thanks to Arduinos i now know a little C# programming.

    You just would not get a Raspberry Pie to do this sort of stuff

    The Intel Galileo however, now thats an animal for running ROVs

    The built in LAN is a God send. Arduino footprint and Arduino programming make the opportunities endless.

    Im not convinced that an APM will have the ability to interface additional sensors to any vehicle

    some additional circuitry will be needed for switching relays to isolate power to external instruments and circuitry for signal conditioning of measured instrument values.

    for example if you purchased a Airmar P75 smart depth sensor to add to your vehicle how would you get the serial nema data from it and pass the via the APM to the surface controller.

    There are a few big Joes out there at this moment saying how do you plan to use a boat depth sensor at depths greater than 2m. please take a step back and just accept the point and concept not the detail.

    cheers

    Jason

    • You can interface additional sensors, here is video of modified Arducopter running alt hold mode and stabilizing a bluerobotics bluerov.

      https://www.youtube.com/watch?v=czE8RpwtPUg

      https://www.youtube.com/watch?v=czORYhbhzOw

      I also plan on adding support for depth sounding and sbl positioning.

      • Developer

        Jacob, do you have your code in github anyplace?  I have been wanting somebody to take on the task of doing an ROV control with Copter for a few years now.  I would love to see some pull requests to bring something into the main code.

        • The version I have running is a hacked version of the ArduCopter-3.2.1 branch. That can be found at https://github.com/jaxxzer/ardupilot-rov.git

          I will not be making any pull requests, because I just hacked apart the hexacopter code for proof of concept. TCIII, is correct. Rusty and I are working on the master branch and going about it proper, so it will hopefully be pulled in.

          • Developer

            Fantastic. I did not realize you were working with Rusty. I will talk to him about it and make sure it gets pulled in

        • Admin

          @Craig,

          Both Jacob and Rusty have been working on ArduSub code here.

          Regards,

          TCIII AVD 

  • Admin

    @All,

    Since I have gotten all of my rovers built for the Sparkfun 2014 AVC and am in the process of tuning them, I have been investigating building a ROV to use in the small lake in the middle of my town home development. So I have been investigating a number of homebrew ROV websites (Homebuiltrovs ) and came across this post: ROV Control-V3

    It being produced in Germany and uses an Atmega 2560 and an Atmega 8.

    Communicates over RS-485.

    Projected price is $225 USD.

    Looks interesting.

    @Grips,

    I am presently evaluating using either brushed or brushless motors. The popular brushed motors are the Johnson Mayfair 750 bilge pump replacement cartridge motors which run around $26 USD on eBay. I have one for evaluation.

    I am also looking into using brushless motors like the HK DT-750 outrunner. Most home brewers run them unenclosed in the water though some of them have epoxy coated them, but I wonder if that screws up the motor balance? I have ordered a couple from HK USA along with a couple of car 30A brushless ESCs to see how they perform.

    The home brewers in the know seem to use Robbe plastic props of around 50mm so I have ordered two CW and one CCW props. Some use ducted fans, but the efficiency is not the best. Also, the use of Kort nozzles does not seem to do much for efficiency.

    The shaft seals on the bilge pump motor cartridges are probably only good down to 100 ft at best. If I do end up using them, I will stay above 50 ft which means a surface pressure of a little above atmospheric. When using the unenclosed brushless motors, you are generally limited by your hull fittings. I believe that the OpenROV ROV is good down to ~200 ft if built properly:-). I served on a USN FBM sub that was built on the Thresher hull design and was not subsafe as the hull fittings had not been changed out:-)

    Regards,

    TCIII ArduRover2 Developer 

     

    Homebuilt Rov Forum • Index page
    • Getting in on this one late...but it is freaking COOL!!!

      My undergrad degree is in Marine Science and Field Biology. I can see LOTS of applications for this in that field. Looks like the Arduino board is controlling the OpenROV. Color me a dumb @SS, but I seriously doubt that the ROV is receiving a GPS signal underwater. I guess you could attach a GPS to it using a rigid tether of some kind. Any thoughts? This would be REALLY cool for marine science researchers.

      • Admin

        @Ken,

        No, GPSs do not work well underwater:-)

        The APM could be used to provide dead reckoning using the compass and the IMU. Also, it could help stabilize the ROV as it moved through the water much like stabilizers on a plane keeping the aircraft level.

        Regards,

        TCIII ArduRover2 Developer

This reply was deleted.

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