  Tracking and controlling the shape of continuum dexterous manipulators (CDM)
in constraint environments is a challenging task. The imposed constraints and
interaction with unknown obstacles may conform the CDM's shape and therefore
demands for shape sensing methods which do not rely on direct line of sight. To
address these issues, we integrate a novel Fiber Bragg Grating (FBG) shape
sensing unit into a CDM, reconstruct the shape in real-time, and develop an
optimization-based control algorithm using FBG tip position feedback. The CDM
is designed for less-invasive treatment of osteolysis (bone degradation). To
evaluate the performance of the feedback control algorithm when the CDM
interacts with obstacles, we perform a set of experiments similar to the real
scenario of the CDM interaction with soft and hard lesions during the treatment
of osteolysis. In addition, we propose methods for identification of the CDM
collisions with soft or hard obstacles using the jacobian information. Results
demonstrate successful control of the CDM tip based on the FBG feedback and
indicate repeatability and robustness of the proposed method when interacting
with unknown obstacles.
