Monday, March 1, 2010

Completed Autopilot Boards and Frame

Completed autopilot system on Twitpic
The quadcopter has finally taken shape. All the carbon-fibre struts are now attached and the flight boards are boxed up. We got all the LiPo's and chargers and everything works as expected. The lab power supplies cannot push the requires current to run the motors so for flight testing the LiPo's will be essential. It will also give us an idea on how the lift/weight ratio will be and how much angular momentums we will have to deal with. The motors run PPM pulsed from the signal generator.

Completed quad frame on TwitpicAs discussed before the Arduino will be producing the PPM pulse in-flight. The encoding uses 0-250 in byte to achieve stepped PPM time shift from 1ms to 2ms. This leaves 5 bytes to address separate motors, we have only 4, we might use the additional byte to trigger the camera or a parachute release output.

The current issue is getting a camera to work with a Verdex, we might have gone with an entirely separate camera subsystem, but that makes it difficult to syncronize the clocks. A USB camera attached to the Gumstix will have to do for now, they are cheaper and lighter than a full camera. The lightest option will be a phone style integrated camera but that can wait.

Concepcion, Chile. Mega earthquake (M8.3) hit this city this ... on Twitpic

We can atleast attempt to stream pictures from the Quad to WorldWind, should not be rocket science, since pictures of earthquake in Chile are coming in via twitter. We can even pull the telemetry and locate the quad over the flight area. So I modelled the quad in Blender with some success and plenty of help from the propellor modelling tutorial. WorldWind now has shapefile support as well, making mission planning easier. Only if we had a quad as big as the one I rendered.

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