Lock Jesse, Dupont Pierre E
Biomedical Engineering, Boston University, Boston, MA 02215 USA (
IEEE Int Conf Robot Autom. 2011:1139-1146. doi: 10.1109/ICRA.2011.5980347.
Concentric tube robots are a novel class of continuum robots that are constructed by combining pre-curved elastic tubes such that the overall shape of the robot is a function of the relative rotations and translations of the constituent tubes. Frictionless kinematic and quasistatic force models for this class of robots have been developed that incorporate bending and twisting of the tubes. Experimental evaluation of these models has revealed, however, a directional dependence of tube rotation on robot shape that is not predicted by these models. To explain this behavior, this paper models the contributions of friction arising from two sources: the distributed forces of contact between the tubes along their length and the concentrated bending moments generated at discontinuities in curvature and at the boundaries. It is shown that while friction due to distributed forces is insufficient to explain the experimentally observed tube twisting, a simple model of frictional torque arising from concentrated moments provides a good match with the experimental data.
同心管机器人是一类新型的连续体机器人，它由预弯曲的弹性管组合而成，使得机器人的整体形状是组成管的相对旋转和平移的函数。已经开发了这类机器人的无摩擦运动学和准静态力模型，其中纳入了管的弯曲和扭转。然而，对这些模型的实验评估揭示了管旋转对机器人形状的方向依赖性，而这些模型并未预测到这一点。为了解释这种行为，本文对来自两个来源的摩擦贡献进行了建模：沿管长度方向的管间接触分布力以及在曲率不连续处和边界处产生的集中弯矩。结果表明，虽然分布力引起的摩擦不足以解释实验观察到的管扭转，但由集中弯矩产生的摩擦扭矩的简单模型与实验数据匹配良好。
