What does a robot include?

　　Robotics is widely applied across numerous sectors, ranging from industrial processes that manufacture machinery and tools, to the security and defense industries, and even the healthcare sector. Robots have taken over demanding tasks—such as precision, repeatability, and continuous monitoring—that are beyond human capabilities. The latest generation of robots can perform complex operations like welding, lifting, or assembly, significantly reducing risks of bodily injury and toxic contamination.

　　Any industry that involves large-scale manufacturing or the movement of materials may employ industrial robots. In manufacturing, robotics is commonly used for part fabrication, finishing, transfer, and assembly. This article will introduce six major types of industrial robots used in the manufacturing sector.

　　What types of robots are included in industrial robotics?

　　Based on their mechanical structure, industrial robots can be classified into six major types: articulated robots, Cartesian robots, multi‑joint robots, parallel robots, polar robots, and cylindrical‑coordinate robots. In addition to their mechanical configuration, industrial robots can also be categorized according to motion control, power supply, and physical characteristics.

　　Articulated robots: Multi‑joint robots are one of the most widely used types of industrial robots. Their mechanical structure resembles a human arm, with the arm connected to the base via rotary joints. The number of revolute joints in the arm can range from two to ten, with each joint providing an additional degree of freedom. These joints may be arranged parallel to one another or orthogonal. Articulated robots with six degrees of freedom are among the most common industrial robots, as their design offers exceptional flexibility. The primary advantages of articulated robots are their ability to operate at high speeds and their remarkably compact footprint.

　　Cartesian robots, also known as linear robots or gantry robots, feature a rectangular structure. These industrial robots have three prismatic joints that enable linear motion by sliding along three perpendicular axes—X, Y, and Z. They may also be equipped with a wrist to allow rotational movement. Cartesian robots are widely used in most industrial applications due to their configurational flexibility, which makes them well-suited to specific application requirements. They offer high positioning accuracy and can handle heavy payloads.

　　Multi-joint robots: SCARA robots feature a circular work envelope and consist of two parallel joints, enabling flexible motion within a selected plane. The rotary axis is oriented vertically, while the end effector mounted on the arm moves horizontally. SCARA robots excel at lateral motions and are primarily used in assembly applications. Compared with cylindrical-coordinate and Cartesian robots, SCARA robots offer faster positioning and are easier to integrate.

　　Parallel robots are also known as parallel‑link robots because they consist of parallel kinematic chains connected to a common base. By directly controlling each joint at the end effector, the position of the end effector can be precisely managed via its arms, enabling high‑speed operation. Parallel robots feature a dome‑shaped workspace and are commonly used for fast pick-and-place or product‑transfer applications. Their primary functions include gripping, packaging, palletizing, and loading/unloading machine tools.

　　The polar robot features a torsional joint connecting the arm to the base, along with a combination of two rotary joints and one linear joint linking the links. These are also referred to as spherical robots because they have a spherical workspace and their axes form a polar coordinate system. These industrial robots possess a central pivot axis and a telescoping rotary arm. The turret configuration of the polar robot covers a large volume of space, but the arm’s reach is confined within its working envelope.

　　Cylindrical-coordinate robots feature at least one rotary joint and at least one prismatic joint connecting links at the base. These robots have a cylindrical workspace, with a pivot and a telescopic arm that can move vertically and slide. Consequently, cylindrical‑type robots provide vertical and horizontal linear motion as well as rotational motion about a vertical axis. The compact design of the arm’s end effector enables these industrial robots to reach tight workspaces without compromising speed or repeatability. They are primarily used for simple tasks such as picking up, rotating, and placing materials.