What causes singularities in multi-joint robotic manipulators?

Example Concept: In robotic kinematics, a singularity is a configuration where the manipulator's Jacobian matrix loses rank, resulting in a loss of one or more degrees of freedom. This can occur in various forms, such as wrist singularities in articulated arms where the wrist aligns with the elbow, or in parallel robots where certain links become collinear. Singularities can cause control issues, such as infinite joint velocities or reduced force transmission, and are often handled by avoiding these configurations through careful path planning or using redundancy resolution techniques.