4DOF parallel robot: vision-based hybrid controller to release from a Type II singularity. Trajectory 5.

4DOF parallel robot: vision-based hybrid controller to release from a Type II singularity. Trajectory 5.

This study has addressed the novel task of releasing a 4-DOF PR from Type II singular positions by combining an algebraic controller
with an external computational loop that defines a path for the joint references, only for the limbs that are causing the singularity.
This mechanism can be activated whenever the robot gets into a singular configuration, which is measured by the Forward Jacobian and minΩc.
The embedded sensorization includes a set of encoders attached to the motors to ascertain the joint positions and, in the real experimental
setup, a vision system that provides the cartesian pose of the mobile platform of the PR.