Helical Routing: Decoupling Segments of Tendon-Driven Continuum Robots

Tendon-driven continuum robots are slender, flexible manipulators, actuated by pulling and releasing tendons routed through their bodies. These tendons are conventionally routed through straight channels to simplify manufacturing, but this design solution couples the actuation of each backbone segment, significantly complicating kinematics and operation. In this article, we exploit helical routing to decouple backbone segments physically. This new continuum robot concept is presented with a general piecewise constant curvature kinematic model and validated experimentally, showing how specific helical paths can reduce the computational weight of kinematic models by orders of magnitude, and improve mechanical performance by decreasing actuation unit weight and power consumption.