The common engineering robot is the robot arm. A typical robot arm machine has about seven metal segments, joined by six links. This robot arm machine work by using computer controls to rotate the individual motors linked to each joint and some larger robot arm machine make use of pneumatics. The robot arm machine has a shoulder, elbow and wrist that is equivalent to human.
Robot arm machine is a form of a mechanical devices that is programmable, that performs close functions such as human hand human arm, this arm can be the part of a complex robot. The joints of the manipulator are considered to form a kinematic chain which allow the join to either rotate such as in an articulated robot or translational displacement.