Robot Kinematics

— Alexi

Focus of this page

Inverse kinematics means:

end-effector pose  ->  joint angles

You know where you want the robot hand / gripper to be.

The question is:

what joint angles produce that pose?

For this page I’m only using a planar 3-DOF revolute arm.

What makes IK harder than FK

Forward kinematics is direct:

angles -> pose

Inverse kinematics is harder because:

• there may be multiple solutions
• there may be no solution
• singularities can appear
• joint limits can reject an otherwise valid geometric solution

So IK is usually less “just plug and go” than FK.