This video is associated with the paper
"Planning Wrench-feasible Motions for Cable-driven Hexapods"
published in the journal "IEEE Transactions on Robotics" by Oriol Bohigas, Montserrat Manubens, and Lluís Ros. The video is also referred to in the book by the same authors:
"Singularities of Robot Mechanisms: Numerical Computation and Avoidance Path Planning". Springer, 2017.
The video shows the results of executing both the interpolated and planned versions of the q1-q2-q3 movement described in the paper. It can be seen how, as expected, the platform moves smoothly from q1 to q2, but some cables become slack and control of the platform is lost along the interpolated path from q2 to q3, because it leaves the wrench-feasible C-space. Other undesirable effects of following this path include shakyness of the platform under small perturbations, collisions with the environment, and cable tanglement at the motors.
In contrast, control of the platform is maintained when following the path q2-q3 returned by the planner proposed in the paper.
A few snapshots of this video can be seen in Figure 14.
