I intend to build a ROBOT car as a hobby project.

The car will be controlled by a small on-board computer and (homegrown) artificial intelligence software.
Web cameras (and possibly other sensors) will provide the computer with information by which to navigate.
Think of the rovers used in the Mars expeditions - it's kind of the same principle...


The requirements of the car is that it should be :

- Able to carry a combined bulk of about 25 lbs (12 kg) (frame, motors, batteries, computer, camera, etc)

- Able to move at a stable very slow speeds (maybe as little as 1 inch pr second) for an extended period (30 min+)

- Able to move at normal walking speed

- Able to move in reverse

- Using 4 electro motors for locomotion (1 for each of 4 wheels, providing on-the-spot turning by running motors on one side forward and the other reverse)

- Using electronic speed controller (ECS) (which will be controlled from the computer)

- Using relatively cheap components (I'm a student!)


Unfortunately I am completely new to electronics and motors (being a computer programming student), so I could use some advice from someone more into this field.


I wonder what I should look (out) for when choosing equipment:


Motors:

What should I look for when selecting the 4 motors for this car ?

Should I connect the wheels directly to the motor, or use belts/cogwhees/drivechains?

Suggestion for specific motor make/model?


Electronic speed control:

What specifications should the ECS meet for handling those 4 motors ?

Do I need more than 1 "dual" speed controller for handling 4 motors?
The 2 motors on each side motors will always be moving at the same speed/direction.
Does that have any relevance for the ECS?
Can I somehow combine those, so the ECS sees each side as one motor?
(As hinted at, I'm a complete newbie with electronics...)

The ECS will be connected to a computer interface card which normally accepts servo connector plugs (3 pins).
Do ECS have similar 3-pin connectors attaced?

Suggestion for specific ECS make/model ?


Any help/suggestion/comment would be very much appreciated!


- Keops