FBG-based Shape Sensing Tubes for Continuum Robots

摘要: Fiber Bragg gratings (FBG)-based optical sensors are a promising real-time technique for sensing the 3D curva- ture of continuum robots. Existing implementations, however, have relied on embedding fibers in small-diameter metal wires or needles. This paper proposes polymer tubes as an alternative substrate fibers. approach separates from robot structural components while using minimal amount robot's tool lumen and providing potential inexpensive fabrication. Since stiffer than substrate, design challenges arise modeling strain transfer between tube substrate. To investigate this approach, model is derived validated through simulation experiment. I. INTRODUCTION Continuum robots take shape three dimensional curves able to change their com- bination bending, rotation extension contraction components. Because these capabilities, ideally suited applications such minimally invasive surgery. Their flexibility, leads uncertainty backbone curve well location tip. Approaches that been studied include imaging, electromagnetic (EM) tracking force tendon-based actuation. These techniques all shortcomings, however. For example, drawbacks with imag- ing limited resolution (ultrasound), risk ionizing radiation (x-ray CT), slow speed (MRI). Tendon length-based estimation single bends its accuracy depends highly kinematic model. In contrast approaches, tech- nology could be easily inserted removed preferred because direct measurement, instant adaptability continuous ease replaceability. Curvature fiber (FBG) has received recent attention, due small size, biocompatibility high sensitivity. Compared EM (1), FBG-based smaller, immune noise can contain multiple along length fiber. example designs attached (2) embedded (3), (4) implemented 1mm diameter wires. Both approaches reasonably assumed perfect wire FBG. While had effect stiffness made it possible accommodate large curvatures (gratings