There are six main types of industrial robots: Articulated, Cartesian, Cylindrical, Polar, Scara, and Delta. However, there are several additional types of robot configurations. Each of these types offers a different joint configuration. The joints in the arm are called axes.
Articulated – This robot design features rotary joints and can range from two simple joint structures to 10 or more joints. The arm is connected to the base with a swivel joint. The links on the arm are connected by rotary joints. Each joint is called an axis and provides an additional degree of freedom or range of motion. Industrial robots commonly have four or six axes.
Cartesian: also called rectilinear or gantry robots. Cartesian robots have three linear joints that use the Cartesian coordinate system (X, Y, and Z). They may also have a doll attached to allow rotational movement. The three prismatic joints deliver a linear movement along the axis.
Cylindrical: The robot has at least one rotary joint at the base and at least one prismatic joint to connect the links. The rotary joint uses a rotational movement along the axis of the joint, while the prismatic joint moves in a linear movement. Cylindrical robots operate within a cylindrical-shaped work envelope.
Polar – Also called spherical robots, in this configuration, the arm is connected to the base with a rotary joint and a combination of two rotary joints and a linear joint. The axes form a polar coordinate system and create a spherically shaped work envelope.
Scara – Commonly used in assembly applications, this selectively compliant arm for robotic assembly is primarily cylindrical in design. It features two parallel joints that provide compliance in a selected plane.
Delta: These spider-like robots are built from linked parallelograms connected to a common base. Parallelograms move a single EOAT in a dome-shaped work area. Widely used in the food, pharmaceutical and electronics industries, this robot configuration is capable of delicate and precise movements.