Denavit-Hartenberg Reference Frame Layout

This video demonstrates use of the Denavit-Hartenberg convention for defining the reference frames of a kinematic chain. In short, the z-axis for each joint is placed along its axis of motion, and then the x-axes are placed along the common normals between these z-axes. Then four parameters are used to specify the transformation between each of these frames: • d - the "depth" along the previous joint&z axis • θ (theta) - the rotation about the previous z (the angle between the common normal and the previous x axis) • r - the radius of the new origin about the previous z (the length of the common normal) • α (alpha) - the rotation about the new x axis (the common normal) to align the old z to the new z.