The Different Types of Robotic Manipulator Arms

While robotic arms do have a certain amount of range of motion (usually around 3 to 6 degrees), The range of motion is determined by the joints that are connected to various segments of the arm (think shoulder, upper arm, forearm, and wrist). The type of robotic arm used is generally determined by the space in which it operates, and the range of motion that it requires to perform the task. Below are some of the most common types of robotic manipulator arms.  

Articulated Robot – Perhaps the most commonly recognized type of robotic manipulator arms, articulated robots offer the most degrees of freedom possible and can consist of between 3 and 6 revolute joints (a revolute joint connects two segments and offers 1 degree of rotational freedom). As one can imagine, given the relatively high number of joints and segments, the greatest advantage of an articulated robot is the wide range of motion that it can employ.

 

SCARA Robot – These types of robotic manipulator arms consist of one prismatic joint which is responsible for movement on the Z axis and two additional revolute joints. A prismatic joint allows two connected objects to slide along a common axis while prohibiting rotational movement. SCARA robots are commonly used to lift heavy items in industrial settings.

Gantry Robot – These robotic manipulator arms leverage a type of rail system that allows them to move along the X, Y, and Z axis. Like SCARA robots, gantry robots are well equipped to handle incredibly heavy payloads.

 

Spherical Robot – Spherical robots consist of two revolute and one prismatic joint. The former provides rotational range of motion while the latter joint allows the arm to extend its reach. Typically, spherical robots are used for welding.

Parallel Robot – These types of robotic manipulator arms are typically installed using an overhead mounting system and will consist of anywhere from 3 to 6 arms, each with its own revolute or prismatic joint, as required.