Pan, Tilt and Roll

[Maximus Rumpas]

Hi All,

This is my design for a Pan, Tilt and Roll camera system. The camera is a GoPro Hero HD 2 (the model shows an earlier version of the camera) The 3 servos are standard HiTec 5485 supported by servo blocks from ServoCity. From the base to the center of the lens is 100mm. I intend to fit this within a 225mm dome.

Regards
Maximus

[thamlin]

any idea were your gonna get your dome?? ive been looking and cant find anything in my local area

[Maximus Rumpas]

Hi thamlin,

I found a company that molds plastic for exhibitions and point of sale display, they also make custom replacement windows for boats. I havn't placed an order yet as I still need to finish the design of the pressure chamber but they have said that they can form an optically clear 225mm dome from 8mm acrylic. Hopefully this will cope with a planed dive depth of 100 meters. I would suggest, perhaps, a similar company in your local area.

Regards
Max

[derelicte]

not exactly compact, but I guess it will work. why do you need roll, though. experience with my rov and in most videos I've seen of rovs in operation they are mostly horizontal if balanced correctly. seems like extra work and cost for not much gain.

unfortunately removing the roll axis doesn't look like it will make the assembly much smaller.

good luck!

[Maximus Rumpas]

Hi derelicte,

Size is dictated by my preference of camera and the degree of movement required.

I choose the GoPro Hero 2 because it is used by divers as an underwater camera, with high-quality wide angle HD 1080 video, and 11 megapixel photographs which it can capture at 10 frames per second.

The camera moves around a fixed point on all three axis’s so it is always the same distance from the dome. I have restricted the servos to 170/170/45. The control program will turn the camera to 9 different viewing positions and the camera will be stabilised (optional) using a 3-axis gyroscope. There has to be sufficient clearance between the components to allow the camera to revolve.

You have the advantage over me through having practical experience of using an ROV and I would agree that if properly balanced the vehicle should be stable. However, there may be occasions when the balance changes dynamically for example, through the use of a manipulator arm and the weight of the object. I think this might effect the lateral balance if the arm is not positioned in the front/centre of the vehicle.

I also intend to take video/photographs close to, or on the surface where I suspect wave action will cause problems without roll and the system being stabilised.

Kind regards
Max

[thegadgetguy]

225 mm seems pretty large for a dome; especially since smaller domes have the advantage of being stronger. I also think you might be able to make it smaller/simpler by taking out the roll function; if that is you're navigational camera, you'll probably want fixed(more or less) to the ROV, just so you can tell the ROV's orientation underwater, at least from what I've experienced. How big will your ROV be overall?

BTW, That's a real nice drawing - what program did you use?

Good luck on your ROV

[Maximus Rumpas]

Hi GadgetGuy,

Sorry about delay in replying, broadband has been out!

I use Google’s free SketchUp program for 3D drawing. http://sketchup.google.com/intl/en/download/

There are a good collection of ‘How To’ video/articles and shared user models available from the 3D warehouse, including ROVs.

I take your point about a fixed camera if used for navigation, in my case I would like to use a HUD or aircraft flight instruments to display Heading, Attitude, etc.

I am planning a large ROV around 1000mm x 750mm x 750mm. I will post further details in the Project section soon.

Following comments from yourself and Derelicte, I am rethinking the use of a roll function. Generally I am still in the early planning stage so nothing is set in stone.

Attached is a picture of the GUI for the Camera Servo Control program.

Regards
Max

[Maximus Rumpas]

Hi All,

Modified Pan and Tilt system.

Max

[derelicte]

that dome is huge!

good luck!

[Maximus Rumpas]

And thats a problem why?