软体气动驱动器弯曲变形光纤传感与形状重构

Bending deformation of optical fiber sensing and shape reconstruction of soft pneumatic driver

为解决软体气动驱动器弯曲变形的柔性传感测量问题,提出将光纤光栅植入软体气体驱动器应变限制层进行曲率测量与形状重构的方法。建立了软体机构变形光纤传感重构算法模型,理论分析了光纤光栅光谱变化与应变限制层弯曲曲率的关系。搭建了基于光纤光栅特性的软体传感、解调及曲率标定装置,实验分析了不同曲率下光纤光栅反射光谱的特征,得出光纤光栅中心波长漂移量与弯曲变形曲率的关系,计算得出软体气动驱动器在不同弯曲状态下的曲率值,重构出软体气动驱动器的变形形状,验证了形状重构结果的正确性。实验结果表明:将光纤光栅植入软体气体驱动器应变限制层,利用光纤光栅反射光谱变化可实现软体驱动器的曲率测量与形状传感,3种弯曲状态下光纤光栅传感测量值与软体驱动器曲率标定值之间的最大误差为2.1%。该光纤传感方法在软体气动驱动器柔性传感与闭环控制方面具有广阔的应用前景。

To solve the flexible sensing measurement problem of flexural bending of soft pneumatic drivers,a method of curvature measurement and shape reconstruction by embedding fiber grating into a strain limiting layer for a soft pneumatic driver was proposed.First,the relationship between the spectral characteristics of the fiber grating and bending curvature of the strain limiting layer were theoretically analyzed.Then,a device that performs soft sensing,demodulation,and curvature calibration based on the spectral characteristics of fiber grating was developed.The characteristics of the reflection spectrum of fiber grating under different curvatures were experimentally analyzed,and the curve of the center wavelength shift and change in curvature of the fiber grating were calculated.Finally,the curvature values of a soft pneumatic driver under different bending states were calculated,and the deformation shape of the soft pneumatic driver was reconstructed.Results show that the curvature measurement and shape sensing of the soft pneumatic driver can be realized by changing the reflection spectrum of fiber grating embedded in the strain limiting layer.The maximum error between the measured values of the fiber grating sensing and soft pneumatic driver curvature is 2.1%.This fiber sensing method represents a promising application for soft sensing and closed-loop control of soft pneumatic drivers.