What’s a kinematic chain?

A kinematic chain is a series of interconnected rigid bodies (links) and joints that allow relative motion between the bodies. The connections between the links are provided by joints, and the arrangement of links and joints forms a sequence or chain. Kinematic chains are commonly used in robotics, mechanical systems, and biomechanics to model and analyze the motion of interconnected parts.

Key features of a kinematic chain include:

1. Links: These are the rigid bodies in the chain. Links represent the physical components that can move relative to each other.

2. Joints: Joints are the connections between links that allow motion. Joints can have various types of degrees of freedom, determining the types of relative motion allowed between connected links. Common types of joints include revolute (rotational) joints and prismatic (translational) joints.

3. Degrees of Freedom (DOF): The degrees of freedom of a kinematic chain represent the number of independent ways the system can move. It is determined by the types and arrangements of joints in the chain.

4. End Effector: The end effector is the final link in the chain, representing the point where the desired motion or action is achieved. In robotics, the end effector is often a tool or manipulator that interacts with the environment.

Kinematic chains are used to model the motion of various mechanical systems, from simple robotic arms to complex biomechanical systems in the human body. Understanding the kinematics of a chain involves analyzing how the joint motions contribute to the overall motion of the system.

In summary, a kinematic chain is a structural arrangement of links and joints that allows for relative motion between the connected bodies. It serves as a fundamental concept in the analysis and design of mechanical systems and robotic manipulators.