joint

In robotics, a joint is a movable component that allows relative motion between adjacent rigid members, called links. These joints are essential for constructing a robot manipulator, which is defined as a reprogrammable, multifunctional device designed to move materials, parts, tools, or specialized devices through programmed motions for various tasks.1

There are five principal types of mechanical joints used in robot manipulators: two linear joints, where motion is translational, and three rotary joints, where motion involves rotation. These joints, along with the links, form the robot's arm-and-body and wrist sections. The arm-and-body, typically with three joints, positions and moves parts or tools within the robot's workspace. The wrist, with two or three compact joints, precisely orients these items at the work location. The number of independent joints, or degrees of freedom, determines the robot's range of motion and capabilities.12