Circuit help with Arduino and 6v rechargable

I need to design a circuit that can run a motor and take an input from a dc generator all using a micro arduino and a small stack of rechargeable AAs (a standard arduino is also acceptable, but I already have the micro). On the attached photo: Its hard to see whats going on, but the big drum is acting like a motor and theres a small dc motor(#1) in line acting as a generator and theres a smaller dc motor (#2) which is switch on to spin the drum up it its ideal rpm when the other falls below a certain rpm threshold (controlled by arduino or similar) This is actually small, this is only about 12 inches (.3m) long The DC motors produce very little power (6v, 10oz, 1w) 4x rechargeable AA (6v). Think youd be able to help me on my senior design project? I need a layout and simple arduino code