Call for info: On board servo control?

[GyroGearloose]

We're all familiar with gyro's aiding the stability of servos, but has anyone seen a more basic version of that idea, where an analog input can be added to or directly drive a servo's position signal?

What I'm imagining is other guidance/stability systems, like:

1) a Cadmium (CdS) light sensor that automatically rolls the plane to keep the bright sun "up" compared to the dark ground.
2) Gravity sensors/mercury switches, for similar to #1
3) a laser sensor (or several) that could auto-home the plane -- point a laser towards the plane, and it flies it home following the beam (smart bomb style, sorta).

You get the idea... I just want to turn an input into a servo signal without sending it to the ground and back first.

I know "servo testers" are basically exactly what I'm describing, but I think they are fairly large packages for most planes (even stripped of the normal metal box, I'd imagine it COULD be smaller).

I'd imagine head-tracker interfaces must be similar to this (although they encode PPM for the trainer port, which I suspect is different (???) than what would go to the servos?).

What's say ye wise and knowledgeable folks?

-Gyro

[cre8tiveleo]

So... like Co-pilot 2? (horizon/sky sensor)

Interesting ideas. The laser guidance scheme might raise some flags with certain institutions though.

One of the RTF manufacturers have the sensors already, their 'anti crash' system. One sensor points down (dark, earth) one points up, sky, light) and if you start to loose it, the anti crash system kicks in and levels your flight.