面向生物医学智能装备和软体机器人等领域柔性机构以及高端装备和重大基础设施复杂结构的曲率测量需求, 提出一种高适应性柔性曲率传感器。通过将光纤布拉格光栅封装在硅胶基体中, 并将硅胶基体与聚氯乙烯薄片贴合, 形成基于光纤布拉格光栅的柔性硅胶曲率传感器。采用光纤传感解调系统和标准曲率标定块, 实验测得光纤光栅传感器反射谱特征及其随标定块曲率变化规律, 分析了光栅波长位移与曲率变化的关系以及传感器灵敏度与嵌入硅胶基体深度的关系。实验结果表明: 硅胶-聚氯乙烯基体的曲率传感器可以实现曲率变化实时测量, 最高灵敏度可达0.329 2 nm/m-1。随着光纤光栅嵌入深度的增加, 传感器灵敏度在0.2~0.35 nm/m-1范围内逐渐增大。在多次重复测量中传感器具有较好的一致性, 可用于柔性机构和复杂结构的曲率测量。

In order to solve the curvature measurement problems of flexible mechanism such as biomedical intelligent equipment, software robots and complex structures of high-end equipment, major infrastructure, a highly adaptive curvature sensor was proposed. The fiber Bragg grating was encapsulated in the silicone rubber layer, which was fixed on the polyvinyl chloride matrix to form a flexible silicone rubber curvature sensor based on fiber Bragg grating. The fiber-optic sensor demodulation system and standard curvature calibration blocks were used to measure the characteristics of the FBG sensor′s reflection spectrum and its variation with the calibration block curvature. The relationship between the FBG wavelength shift and the curvature change was analyzed, as well as the sensor sensitivity and the embedded depth of FBG. The experimental results show that the curvature sensor based on silicone-polyvinyl chloride can measure the real-time change of curvature with the highest sensitivity of 0.329 2 nm/m-1. With the increase of the embedded depth of fiber grating, the sensitivity of the sensor gradually increases with the range from 0.2 nm/m-1 to 0.35 nm/m-1. The sensor has good consistency in repeated measurements and can be used for curvature measurement of flexible mechanisms and complex structures.