Steering of Multisegment Continuum Manipulators Using Rigid-Link Modeling and FBG-Based Shape Sensing
Steering of Multisegment Continuum Manipulators Using Rigid-Link Modeling and FBG-Based Shape Sensing
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DOI：
10.1109/tro.2016.2527047
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发表时间：
2016-04-01
影响因子：
7.8
通讯作者：
Misra, Sarthak
中科院分区：
文献类型：
--
作者：
Roesthuis, Roy J.;Misra, Sarthak
连续体机械臂的精确闭环控制需要将描述其运动的模型和评估机械臂形状的方法相结合。这项工作提出了一个模型，该模型通过一系列刚性链接近似连续连续的机械臂形状，由柔性旋转关节连接。该刚性连杆模型可以描述不同载荷条件下机械手的形状。基于所提出的刚性连杆模型的机械臂雅可比矩阵实现运动学控制器，实现轨迹跟踪，同时利用机械臂的运动冗余度完成避障的二次任务。在一个由两个弯曲节段的平面肌腱驱动连续机械臂组成的实验台上对该控制器进行了评估。利用光纤光栅（FBG）传感器重构机械臂的三维形状，并作为反馈对机械臂进行闭环控制。对两种情况进行了评估：第一种情况涉及绕过静态障碍物的转向，第二种情况涉及沿着直线路径避开移动障碍物的转向。平均轨迹跟踪误差分别为0.24和0.09 mm，最大误差分别为1.37和0.52 mm。最后，我们展示了FBG传感器测量相互作用力的可能性，同时使用它们进行形状传感。
Accurate closed-loop control of continuum manipulators requires integration of both models that describe their motion and methods to evaluate manipulator shape. This work presents a model that approximates the continuous shape of a continuum manipulator by a serial chain of rigid links, connected by flexible rotational joints. This rigid-link model permits a description of manipulator shape under different loading conditions. Akinematic controller, based on the manipulator Jacobian of the proposed rigid-link model, is implemented and realizes trajectory tracking, while using the kinematic redundancy of the manipulator to perform a secondary task of avoiding obstacles. The controller is evaluated on an experimental testbed, consisting of a planar tendon-driven continuum manipulator with two bending segments. Fiber Bragg grating (FBG) sensors are used to reconstruct 3-D manipulator shape, and is used as feedback for closed-loop control of the manipulator. Manipulator steering is evaluated for two cases: the first case involving steering around a static obstacle and the second case involving steering along a straight path while avoiding a moving obstacle. Mean trajectory tracking errors are 0.24 and 0.09 mm with maximum errors of 1.37 and 0.52 mm for the first and second cases, respectively. Finally, we demonstrate the possibility of FBG sensors to measure interaction forces, while simultaneously using them for shape sensing.