Electric drives and motors are used to actuate/move certain parts in the robot, these parts can be arms, fingers, wheels and many other things. They are an essential component of any robot, without them we can not build robots.
Electric Drives are readily adaptable to computer control, the predominant technology used today for robot controllers. Electric drive robots are relatively accurate compared to hydraulically powered robots.
Examples of electric drive systems include: dc servomotors, stepper motors; ac servomotors;
Advantages of Electric drives:
less floor space,
electric power readily available,
clean-air environments, and,
Disadvantages of electric drives:
conventional gear-driven create backlash,friction,
compliance and wear problems causing inaccuracies,
poor dynamic response,
output power relative to weight is low; and,
to increase torque, a larger and heavier motor must be used which is costly.