My robot idea is essentially a

My robot idea is essentially a highly automated display for a portion of a lego train display.

I have built most of the mechanical parts of my display but am seeking a way to automate it. The Lego robot controller is too limited and too expensive.

My vision is a series of missile launchers that will be concealed underground. Doors will open and the missiles will rise and rotate and elevate. There will be an air raid siren and also warning lights. This could be triggered manually, based on some time for inactivity or respond to new activity (a person approaching) or a lego train passing. Some logical combination of these triggers could be used.

We have found that the best displays have the most activity in terms of trains and animated functions. Animated functions for most of us (in my club) have been limited to simple motors. This would really amp up the coolness factor....

Thanks for reading.