ABSTRACT
Actuators are devices that produce actions, which typically are forms of motion or forces/torques exerted. The input to the actuator is some form of energy and the output is mechanical motion or force exertion. Actuators are therefore key components in an electromechanical system such as a robotic manipulator. The input to the manipulator is a controlled amount of electrical energy and the result is the manipulator motion corresponding to the robotic task. DC Brushless motors do not make use of commutators to regulate the power or current flowing into the coils. Instead, brushless motors regulate the current flow through semiconductor switches with position feedback of the motor shaft. An inherent characteristic of brushless motors is the requirement of sensors to sense the absolute angular position of the motor shaft. There are two popular types of driver circuits being used for the brushed DC motors: linear drive and the widely used pulse width modulation (PWM) drive.
