Admittance control without Type II Singularity evader

A raw compliant-admittance controller implemented on a 4-DOF parallel robot. The video shows how the user drives the robot to a Type II singularity and loses control with a final fall of the robot. The proximity to a singularity is measured by the determinant of the forward Jacobian (‖J_D ‖) and the minimum angle Ω. The robot's location on z_m, measured by a 3D tracking system, verifies the robot's fall. In the figures, the subindex “a” represents the admittance reference, the subindex “c” stands for measurements, and the “lim” represents the experimental limits.