Effect of External and Internal Loads on Tension Loss of Tendon-Driven Continuum Manipulators

We present a novel analytical modeling approach to investigate the combined effects of external loads (i.e., contact and gravitational loads) and internal distributed friction forces on tension loss of a generic variable-curvature tendon-driven continuum manipulator (TD-CM). Unlike previous studies, in our proposed approach, we do not assume the deformation behavior (e.g., bending shape/curvature) and friction distribution profile are known a priori and/or can be experimentally obtained/tuned before or during the experiments. Instead, we only assume the tendons’ tensions at the base of manipulator and magnitudes and locations of external forces are available while both deformation behavior and internal distributed forces are unknown and correlated. To evaluate the efficacy of the proposed approach, we performed different sets of simulation and experimental studies in the presence of both concentrated point and distributed surface contact loads. We compared the results of the performed studies with the results obtained by a friction-less modeling technique. This comparison clearly demonstrates the phenomenal performance of the proposed modeling approach in modeling tendon tension loss of a TD-CM experiencing both internal and external loads.