Casas Jonathan, Leal-Junior Arnaldo, Díaz Camilo R, Frizera Anselmo, Múnera Marcela, Cifuentes Carlos A
Biomedical Engineering Department, Colombian School of Engineering Julio Garavito, Bogotá 111166, Colombia.
Graduate Program of Electrical Engineering, Federal University of Espirito Santo, Vitoria 29075-910, Brazil.
Materials (Basel). 2019 May 3;12(9):1443. doi: 10.3390/ma12091443.
This paper presents the development and validation of a polymer optical-fiber strain-gauge sensor based on the light-coupling principle to measure axial deformation of elastic tendons incorporated in soft actuators for wearable assistive robots. An analytical model was proposed and further validated with experiment tests, showing correlation with a coefficient of R = 0.998 between experiment and theoretical data, and reaching a maximum axial displacement range of 15 mm and no significant hysteresis. Furthermore, experiment tests were carried out attaching the validated sensor to the elastic tendon. Results of three experiment tests show the sensor's capability to measure the tendon's response under tensile axial stress, finding 20.45% of hysteresis in the material's response between the stretching and recovery phase. Based on these results, there is evidence of the potential that the fiber-optical strain sensor presents for future applications in the characterization of such tendons and identification of dynamic models that allow the understanding of the material's response to the development of more efficient interaction-control strategies.
本文介绍了一种基于光耦合原理的聚合物光纤应变片传感器的开发与验证，该传感器用于测量可穿戴辅助机器人软驱动器中弹性肌腱的轴向变形。提出了一个分析模型，并通过实验测试进一步验证，实验数据与理论数据的相关系数R = 0.998，最大轴向位移范围达到15 mm，且无明显滞后现象。此外，还进行了将经过验证的传感器附着在弹性肌腱上的实验测试。三项实验测试结果表明，该传感器能够测量肌腱在轴向拉伸应力下的响应，发现在材料的拉伸和恢复阶段之间的响应存在20.45%的滞后现象。基于这些结果，有证据表明光纤应变传感器在未来此类肌腱的表征以及识别动态模型方面具有潜力，这些动态模型有助于理解材料的响应，从而开发更有效的交互控制策略。
