Robot Structure

When selecting an industrial robot there are many factors that must be considered in order to choose the industrial robot that will be best for your application needs. Robot specifications help define the capabilities and limitations of a given robot. One of the main specifications used to define an industrial robot is their structure.

Robot structure references the type of robot one is. There are several different robot structures with each having their own benefits. The type of application you are automating will often determine the robot structure needed as payload capacity, reach, work envelope, etc. depend upon a robot’s structure. The most common robot structures for robotic automation include:

• • Articulated - Articulated robot structures feature a serial link jointed arm that is attached to a rotating base. Articulated structures are the most popular since they closely resemble and function similarly to a human arm. Due to their human arm-like resemblance they are able to take over most production tasks from humans, but with better accuracy. Six-axis robot configurations are the most common for articulated structures since they have a range of motion that is comparable to a human. Four-axis and five axis robots are also fairly common for articulated structures as they are often used to automate tasks requiring simple movements such as robotic palletizing. There is a wide variety of articulated robots from small robots with payloads as little as 0.5 kg to large robots with payloads for heavy lifting applications. Due to the wide-ranging capabilities, articulated robots can automate most industrial applications including welding, material handling, assembly, material removal, and painting. The FANUC R2000ib is ideal for spot welding automation. While the FANUC M10ia is a compact articulated robot that is often used for lightweight material handling.


• • Delta - Delta robots feature a parallel link arm structure. They often consist of three slim arms that extend downward from their body where they are all connected together by the end-effector. Some delta robots may have a fourth arm. Delta robots are often deployed when speed and precision are needed. If you need a heavy payload robot, this robot structure will not be for you as most delta robots have payloads under 10 kg. FANUC’s spider series, which features the M-2ia, are some of the most well-known delta robots.


• • Gantry - Gantry robot structures feature a serial link robotic manipulator that is mounted to a track system. This robot structure can also be referred to as a cartesian robot. The FANUC M20ia/20T is an example of an industrial robot with a gantry structure. This structure is ideal for applications requiring a large work envelope since they can travel great distances quickly. Most gantry style robots are used to automate pick and place applications or for robotic machine tending.


• • SCARA - SCARA robot structures consist of a jointed two-link arm that operates on a single plane. This robot structure is mainly used to automate simple assembly or pick and place applications due to the limited range of motion. What SCARA robots lack in their movement capabilities they make up for with their incredibly fast speeds.