Older blog entries for tim.holt (starting at number 2)

Looking at pontoons for prototype vehicle. Have decided to just use larger diameter (8") PVC pipe to create pontoons, as this should provide a lot of strength, plus is easy to work with. With a bit of calculation I figure a 6' pontoon made from 8" diameter PVC will support about 130 lbs. Multiply that by two (two pontoons) and we're talking about 260 lbs buoyancy, which should be more than sufficient for the initial prototype boat.

A bit of web searching gave me this project powerpoint which shows a similar setup to how our prototype vehicle will be layed out.

Starting to create the control software for the project. Implementation is in Perl, and is designed around a client/server (TCP/IP) architecture.

We'd like to have a manual control for the vehicle, for a user to steer it during learning phases and situations where the AI is unable to properly respond. An example might be bringing it into the dock. GPS will get the ASV close to the dock (within the < 15m error range of GPS), but can't deliver it right to someone ready to grab it.

Right now we're using the ActiveState Perl Win32::Multimedia::Joystick module. It is able to work with conventional joysticks such as one from Logitech as well as game controllers such as this one also from Logitech. I'm also implementing a mouse based controller where a user clicks and drags inside a target window to simulate joystick motion, for situations when a joystick is not available.

Acquired a Vantec CDFR23 dual DC motor controller.

Next step is to acquire motor components and pontoon system. Pontoons will either be built (rigid foam with fiberglass skin and embedded Unistrut on top) or purchased (Kelly pontoons).

Image of current prototype design at http://www.nacse.org/~holtt/images/boatpic2.gif

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