Airborne Distributed Position and Orientation System Transfer Alignment Method Based on Fiber Bragg Grating

Abstract

With the demand for high resolution remote sensing, load array technology has gradually become an effective measure to improve imaging resolution. However, the external flow and internal engine vibration disturbance may lead to the flexible deformation of wings. The traditional rigid baseline error compensation method cannot solve the problem of serious coupling movement error caused by flexible deformation. To address the problem, a transfer alignment model based on fiber Bragg grating for distributed position and orientation system is proposed in this paper. Firstly, based on the multidimensional requirements of flexible deformation information, the layout scheme of fiber Bragg grating was designed, then the continuous strain in the wing surface was obtained after the quadratic fitting of strain measured by fiber Bragg gratings, and the deformation displacement and angle are calculated. Thirdly, flexible deformation compensation for distributed position and orientation system based on fiber Bragg grating was studied. The state equation including position error, velocity error, misalignment angle, and inertial device error was established. The position and attitude information compensated by the flexible lever arm was used as the quantitative measurement. The filtering estimation improved the measurement accuracy of the slave inertial navigation systems. At last, the experiment was carried out and showed that the accuracy of the transfer alignment has been improved significantly. the distributed POS (DPOS) [6,7]. DPOS is composed of a high-precision master IMU, a navigation computer, a global positioning system, and a number of low-precision sub-IMUs. IMU is installed at the different nodes of the carrier, and transfer alignment of each sub-IMU is carried out using the high-precision navigation information obtained from the main POS, which can provide accurate position and orientation information for all the phase points of distributed SAR and other kinds of loads, and achieve high-precision imaging [8].The subarray antenna is often installed at different wing nodes, which is limited by volume weight and even cost and conducts distributed motion measurement often using MEMS-IMU, and its precision is far lower than that of the main system. When the array antenna SAR is three-dimensional imaging, not only is the motion compensation required at each node, but also the required precision of the baseline length between nodes is very high [9]. At present, most of the technical means are accomplished by mathematical modeling or filtering, for example, the second-order Markov process is used to describe the deformation process, in which the parameters are often selected through experience, and the aerodynamics model is used to analyze the wing model [10,11]; the process is very complex, and the wing material, vibration frequency and wing length should be considered. The model based on CKF is used, which features poor anti-interference performance [12,13]. Moreover, the mathematical modeling method has strong pertinence ...

Adaptive transfer alignment method based on the observability analysis for airborne pod strapdown inertial navigation system

“…A non-linear relation between the flexural angle and flexural lever arm variation method is to establish a novel 27-state non-linear model of the transfer alignment 10 . The transfer alignment model based on fiber Bragg grating has been performed to solve the problem of the coupling movement error caused by flexible deformation 11 . Three rapid transfer alignment matching methods "velocity plus attitude", "velocity plus rate" and "attitude plus rate" have been compared from different aspects in this paper 12 .…”

Optimization Method of High-Precision Control Device for Photoelectric Detection of Unmanned Aerial Vehicle Based on POS Data

“…Among them, J xx , J yy , J zz is the moment of inertia and J xy , J xz , J yx , J yz , J zx , J zy is the inertia product. Since the rigid body of the UAV is completely symmetrical, formula (10) can be obtained according to the definition of inertia product:…”

“…en, the POS data was quadratically fitted to obtain continuous strain, deformation displacement, and angle. e final experimental results showed that the positioning accuracy of the distributed positioning system based on POS data has been significantly improved [10]. Jianli proposed a second-order adaptive dual-filter smoother for solving nonlinear problems in POS data systems, which could adaptively estimate noise covariance in real time.…”

Application of Fiber Bragg Gratings as a Sensor of Pulsed Mechanical Action

“…The basic principles of FBG operations are summarized, in particular in the reviews [ 1 , 2 , 3 , 4 , 13 ]; possible applications in [ 1 , 2 , 3 , 4 , 5 , 6 , 8 , 15 , 16 , 17 ]; and manufacturing technology in [ 1 , 2 , 3 , 7 , 11 , 13 , 14 , 15 ]. In particular, the use of FBG in medicine is considered in the reviews [ 4 , 6 , 8 , 11 ]; in biochemistry and pharmacy in [ 4 , 5 , 14 ]; for environmental applications in [ 5 , 11 , 14 ]; as well as for other applications [ 16 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. An overview of works on the properties of chirped FBG and their application is given in [ 27 ].…”