Monthly Archives: October 2011

Ejection Seats

I struck a deal with an otoneurologist in San Diego who had two Martin Baker Mk. 7 seats from the F-4 Phantom.  He used them in pioneering diagnosis BPPV.

He replaced this home-built contraption with Epley machines (FDA approved) and no longer had use for these seats.  They are in transit and should arrive on Friday.  One can only imagine he will have an easier time billing insurance!

Motion Control

So the last piece of the puzzle was acquired this week – a two-axis USB inclinometer.  The USB port runs in serial so with a little help from CodeProject I was able to create a method that reads and converts the 8-bit outputs for X and Y and stores them in the equivalent of a DirectX Vector2 struct.

Serial Inclinometer Source Code (C++)

I also have a functional demo app for the joystick using DirectInput (in the SDK) so now I have to make the main set of algorithms that take an X and Y angle from the joystick and adjust the platform as quickly as possible to match what is set in the joystick.  We don’t want to hit the cushions on the actuators so there will be some playing around with the ramps and algorithms which will be further modulated in the future based on increased weight/decreased reaction time.

The inclinometer is more intuitive feedback (IMHO) than 4 position sensors on the actuators which, in the end, actually costs more than this little inclinometer because you need another A/D converter and calibrations anyway.