Towards FBG-Based Shape Sensing for Micro-Scale and Meso-Scale Continuum Robots With Large Deflection
Towards FBG-Based Shape Sensing for Micro-Scale and Meso-Scale Continuum Robots With Large Deflection
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DOI：
10.1109/lra.2020.2969934
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发表时间：
2020-04-01
影响因子：
5.2
通讯作者：
Desai, Jaydev P.
中科院分区：
文献类型：
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作者：
Chitalia, Yash;Deaton, Nancy Joanna;Desai, Jaydev P.
血管内和内窥镜外科手术需要微尺度和中尺度连续体机器人工具来导航复杂的解剖结构。在许多研究中，基于光纤布拉格光栅（FBG）的形状传感已被用于测量较大尺度上的连续体机器人的挠度，但已被证明是一个挑战，为微尺度和中尺度的机器人与大挠度。在这封信中，我们已经开发了一种传感器，通过安装在微机械加工的镍钛合金管的中性轴移动到一侧，由于加工的光纤光栅光纤。中性轴的这种偏移允许FBG芯在管弯曲时经历压缩应变。的传感器的制造方法已明确详细说明，传感器已被测试与肌腱驱动的微尺度和中尺度的连续体机器人外径分别为0.41毫米和1.93毫米。紧凑的传感器允许重复和可靠的估计的形状的两个规模的机器人与最小的滞后。我们提出了一个分析模型，推导出的曲率的机器人关节从光纤光栅光纤应变和静态模型，关节曲率的肌腱力。最后，作为概念验证，我们证明了我们的传感器组件的可行性相结合的肌腱力反馈和FBG应变反馈，以产生可靠的估计关节角度的中尺度机器人。
Endovascular and endoscopic surgical procedures require micro-scale and meso-scale continuum robotic tools to navigate complex anatomical structures. In numerous studies, fiber Bragg grating (FBG) based shape sensing has been used for measuring the deflection of continuum robots on larger scales, but has proved to be a challenge for micro-scale and meso-scale robots with large deflections. In this letter, we have developed a sensor by mounting an FBG fiber within a micromachined nitinol tube whose neutral axis is shifted to one side due to the machining. This shifting of the neutral axis allows the FBG core to experience compressive strain when the tube bends. The fabrication method of the sensor has been explicitly detailed and the sensor has been tested with two tendon-driven micro-scale and meso-scale continuum robots with outer diameters of 0.41 mm and 1.93 mm respectively. The compact sensor allows repeatable and reliable estimates of the shape of both scales of robots with minimal hysteresis. We propose an analytical model to derive the curvature of the robot joints from FBG fiber strain and a static model that relates joint curvature to the tendon force. Finally, as proof-of-concept, we demonstrate the feasibility of our sensor assembly by combining tendon force feedback and the FBG strain feedback to generate reliable estimates of joint angles for the meso-scale robot.