12 accepted papers
Continuum robots can be slender and flexible to navigate through complex environments, such as passageways in the human body. In order to control the forces that continuum robots apply during navigation and manipulation, we would like to detect the location, direction, and magnitude of contact force
In this letter, we propose a parameterization of the rigid-body inertia tensor that is singularity free, guarantees full physical consistency, and has a straightforward physical interpretation. Based on a version of log-Cholesky decomposition of the pseudo-inertia matrix, we construct a smooth isomo
We propose a new method for improving the stability of concentric tube robots. Prior work sought to improve stability through laser-cut patterns that reduced <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$EI/GJ$</
In this work, the Piecewise Variable-strain (PVS) approach is applied to the case of Concentric Tube Robots (CTRs) and extended to include the tubes' sliding motion. In particular, the currently accepted continuous Cosserat rod model is discretized onto a finite set of strain basis functions. At the
We present a new mechanical bending actuator for soft and continuum robots based on a pair of concentric precurved bellows. Each bellows is rotated axially at its base, allowing independent control of the curvature and bending plane of the concentric bellows pair. Rotation of precurved nested tubes
In this letter, we propose benefiting from load readings at the base of a continuum appendage for real-time forward integration of Cosserat rod model with application in configuration and tip load estimation. The application of this method is successfully tested for stiffness imaging of a soft tissu
Mechanics-based models of thin elastic structures are prevalent in robotics research, both in soft/continuum robot modeling, and in robotic manipulation of strings, sutures, needles, and endoscopes. In all these applications, distributed loads along the device's length can affect its shape in space.…
In this letter, we propose and demonstrate a method for integration of rotations using nonunit quaternions. Unit quaternions are commonly used to represent rotation, in which case the rotation operation involves the conjugate of the unit quaternion. However, a redundant mapping can be defined from a
The large dynamic deflections of continuum robots, soft robots, and slender elastic objects can be accurately modeled with classical rod theories in nonlinear elasticity. In this paper, we propose a real-time computational approach for solving the partial differential equations of a dynamic Kirchhof…
Parallel continuum robots consist of a parallel arrangement of flexible legs and are dexterous, compliant, and easily miniaturized for minimally invasive surgery. By design, parallel continuum robots exhibit large, nonlinear deformations in their legs to achieve multi-DOF end effector articulation,…
In this letter, we present the design, kinematic analysis, model validation, and teleoperation of a miniature eight-degree-of-freedom (8-DOF) parallel continuum manipulator with a cable-driven grasper. Our motivation is to provide increased dexterity and stability in confined-space surgical applicat
Parallel continuum robots have the potential to provide multi-degree-of-freedom articulation using a structure that is simple, compact, compliant, and highly scalable. These characteristics may be useful in micromanipulation, endoscopic robotic-assisted surgery, and human-robot interaction. Our prio…