Six-Dimensional Deformation Measurement of Distributed POS Based on FBG Sensors

Distributed Position and Orientation System (POS) is a key equipment which can precisely measure multi-node time-spatial motion information for the high-resolution imaging of novel airborne remote sensing systems. The deformation of the lever-arm with irregular cross-section will seriously affect the transfer alignment accuracy of distributed POS. The existing Ko method can measure the deformation of most lever-arms, but it is not applicable to the lever-arm with irregular cross-section and cannot measure the axial displacement which is an important parameter of distributed POS. In order to solve this problem, a six-dimensional deformation measurement method of distributed POS based on Fiber Bragg grating (FBG) sensors is proposed. Firstly, a strain decoupling approach is presented to improve the strain measurement accuracy of the lever-arm with irregular cross-section. Secondly, an axial displacement model is established to further realize six-dimensional deformation measurement. The high precision six-dimensional deformation can be used for transfer alignment to improve the motion information measurement accuracy of distributed POS. Experimental results show the proposed method can measure the six-dimensional deformation with a higher accuracy compared to the existing Ko method.