Singularities with a six-axis articulated robot kinematic

A distinction is made between three types of singularity:

  1. Wrist singularity
  2. Elbow singularity
  3. Shoulder singularity

Wrist singularity

This occurs when angle A5 (axis B3) is equal to zero.

Elbow singularity

An elbow singularity occurs when the wrist lo located on a straight line running through the axes B1 and B2. When HD12 = 0, this corresponds to an angle A3 (axis B2) equal to zero.

Elbow singularity
Elbow singularity

Shoulder singularity

A shoulder singularity occurs when HD32 = 0 if the wrist is located on the extended C1 axis.

When HD32 ≠ 0, the shoulder singularity occurs if the wrist is located on the cylindrical sleeve of radius HD32 about the C1 axis.