Types of Robot Joints to Know for Robotics

Robot joints are crucial for movement and functionality in robotics. They come in various types, each offering different degrees of freedom and motion capabilities. Understanding these joints helps in designing robots that can perform complex tasks effectively.

1. Revolute joint

   • Allows rotation around a single axis, similar to a hinge.
   • Commonly used in robotic arms to enable bending and twisting motions.
   • Provides one degree of freedom (DOF), making it essential for tasks requiring angular movement.
   • Examples include joints in humanoid robots and robotic grippers.

2. Prismatic joint

   • Enables linear movement along a single axis, akin to a sliding door.
   • Provides one degree of freedom (DOF) for extending or retracting components.
   • Frequently used in applications like linear actuators and robotic legs.
   • Essential for tasks that require precise positioning along a straight path.

3. Cylindrical joint

   • Combines rotational and translational movement, allowing for both rotation and sliding along a cylinder.
   • Provides two degrees of freedom (DOF), facilitating more complex motions.
   • Commonly found in robotic arms that need to reach and rotate simultaneously.
   • Useful in applications requiring both extension and rotation, such as in robotic assembly.

4. Spherical joint

   • Allows rotation around multiple axes, similar to a ball-and-socket joint.
   • Provides three degrees of freedom (DOF), enabling a wide range of motion.
   • Essential for applications requiring flexibility and adaptability, such as in robotic wrists.
   • Commonly used in humanoid robots to mimic natural human movements.

5. Planar joint

   • Facilitates movement in a two-dimensional plane, allowing for sliding and rotation.
   • Provides two degrees of freedom (DOF), useful for planar robotic systems.
   • Often used in applications like robotic arms that operate on a flat surface.
   • Important for tasks that require movement in both horizontal and vertical directions.

6. Helical joint

   • Combines rotational and translational movement along a helical path, similar to a screw.
   • Provides one degree of freedom (DOF) with a complex motion profile.
   • Commonly used in applications requiring precise linear motion with rotation, such as in screw mechanisms.
   • Essential for tasks that involve lifting or lowering components while rotating.