  As technology advances, the barriers between the co-existence of humans and
robots are slowly coming down. The prominence of physical interactions for
collaboration and cooperation between humans and robots will be an undeniable
fact. Rather than exhibiting simple reactive behaviors to human interactions,
it is desirable to endow robots with augmented capabilities of exploiting human
interactions for successful task completion. Towards that goal, in this paper,
we propose a trajectory advancement approach in which we mathematically derive
the conditions that facilitate advancing along a reference trajectory by
leveraging assistance from helpful interaction wrench present during
human-robot collaboration. We validate our approach through experiments
conducted with the iCub humanoid robot both in simulation and on the real
robot.
