A novel pose sensing model for soft manipulator based on helical FBG

Abstract

Abstract Pose sensing is the key to realizing the closed-loop control for the soft manipulator with large deformation. However, few detection models of the flexible sensors based on fiber Bragg grating (FBG) consider the effect of the soft material on the actual deformation. In this paper, the FBG-based sensing principle suitable for the soft manipulator whose axial elongation/compression cannot be ignored is proposed. Besides, the improved kinematics model including the following deflection angle explains the influence of the nonlinear soft material on the modeling based on conventional piecewise constant curvature (CPCC). The experiments show that the maximum error of the end coordinates detected by the improved piecewise constant curvature (IPCC) is no more than 0.76 mm. The maximum error of the Euler angle β is less than 1 %. The study reveals that IPCC has higher accuracy in pose detection of the soft manipulator and potential to provide the reliable feedback data to realize the feedback control.