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摘要:
机翼柔性动态形变制约分布式位置姿态系统(POS)传递对准精度的提升,光纤光栅传感器可精确测量柔性基线,然而光纤光栅传感器测量的应变转化为基线过程需要时间,这导致测量得到的基线不能实时用于传递对准。针对该问题,在光纤光栅传感器柔性基线测量的基础上,提出基于自回归模型的柔性基线在线预测方法。利用过去一段时间内实测应变值转换的基线数据来超前预测当前时刻的基线值,用于子节点实时传递对准量测匹配误差补偿,其中,模型参数可随输入实测基线数据在线递推更新,使得基线预测更加精确。在模拟机翼平台上进行振动实验,结果表明:所提方法实现了基线的精确预测,预测误差在0.051 mm之内,且具有很强的实时性。
Abstract:The flexible dynamic deformation of the wing restricts the improvement of transfer alignment accuracy for distributed position and orientation system(POS). The fiber grating sensor can accurately measure the flexible baseline. However, the process of transforming the strain measured by the optical fiber grating sensor into the baseline takes extra time, which results in that the measured baseline cannot be used for transfer alignment in real time. This paper proposes an online prediction method of the flexible baseline based on the autoregressive model in order to solve this problem. The method is based on the measurement of the flexible baseline of the fiber grating sensor. By updating the model parameters recursively online with the measured baseline data as input, the model can predict the baseline with greater accuracy. Finally, the vibration experiment is carried out on a simulated wing platform. The experimental results show that the method proposed in this paper achieves accurate baseline prediction, the prediction error is within 0.051 mm and has strong real-time performance.
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Key words:
- array synthetic aperture radar /
- transfer alignment /
- fiber grating /
- autoregressive model /
- baseline
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表 1 机翼模型关键技术参数
Table 1. Key technical parameters of wing model
翼型长度/mm 翼根弦长/mm 翼尖弦长/mm 最大厚度/mm 根梢比 2700 320 240 21 0.75 表 2 机翼抖动的前4阶模态
Table 2. The first fourth modes of wing flutter
阶数 抖动频率/Hz 最大位移/mm 模态类型 1 2.217 432.89 横向弯曲 2 11.641 455.34 横向弯曲 3 30.860 466.91 横向弯曲 4 34.363 28.34 侧向扭曲 表 3 不同模型阶数下模型参数辨识速度
Table 3. Identification speed of model parameter under different model orders
模型阶数 耗时/s 模型阶数 耗时/s 1 0.0060 11 0.0090 3 0.0065 13 0.0108 5 0.0073 15 0.0134 7 0.0081 17 0.0152 9 0.0087 19 0.0201 表 4 不同模型阶数的预测误差
Table 4. Single step prediction errors for model different orders
模型阶数 单步预测误差/mm 3 0.0060 5 0.0056 13 0.0037 19 0.0040 表 5 基线预测误差
Table 5. Baseline prediction errors
柔性基线采样序列 实测基线值/mm 预测基线值/mm 误差/mm 0~200 300.448 300.499 0.051 201~400 300.431 300.479 0.048 401~600 300.424 300.472 0.048 601~800 300.411 300.458 0.047 801~ 1000 300.414 300.462 0.048 -
[1] LIU Y H, YE W, WANG B, et al. A multi-node synchronous baseline calibration system based on vision measurement for DPOS[J]. Measurement Science and Technology, 2020, 31(3): 035005. doi: 10.1088/1361-6501/ab5466 [2] LI J L, JIA L D, LIU G. Multi-sensor time synchronization error modeling and compensation method for distributed POS[J]. IEEE Transactions on Instrumentation and Measurement, 2016, 65(11): 2637-2645. [3] GU B, LI J L, FANG J C, et al. Airborne distributed POS flexible baseline measurement method based on MCLS[J]. IEEE Sensors Journal, 2019, 19(6): 2087-2095. doi: 10.1109/JSEN.2018.2886582 [4] LIU Y H, YE W, WANG B. Application of correntropy-based CDKF in transfer alignment for accuracy enhancement of airborne distributed POS[J]. IEEE Sensors Journal, 2022, 22(1): 685-694. doi: 10.1109/JSEN.2021.3129605 [5] LIU Y H, YE W, WANG B. A flexible baseline measuring system based on optics for airborne DPOS[J]. Sensors, 2021, 21(16): 5333. doi: 10.3390/s21165333 [6] WANG B, YE W, LIU Y H. Variational Bayesian cubature RTS smoothing for transfer alignment of DPOS[J]. IEEE Sensors Journal, 2020, 20(6): 3270-3279. doi: 10.1109/JSEN.2019.2958335 [7] LU Z X, LI J L, FANG J C, et al. Adaptive unscented two-filter smoother applied to transfer alignment for ADPOS[J]. IEEE Sensors Journal, 2018, 18(8): 3410-3418. doi: 10.1109/JSEN.2018.2799211 [8] GONG X L, LIU H J, FANG J C, et al. Multi-node transfer alignment based on mechanics modeling for airborne DPOS[J]. IEEE Sensors Journal, 2018, 18(2): 669-679. doi: 10.1109/JSEN.2017.2771263 [9] LIU Y H, NING X L, LI J L, et al. A promising distributed position and orientation system with flexible baseline for array SAR applications[C]//Proceedings of the European Navigation Conference. Piscataway: IEEE Press, 2020: 1-9. [10] 段振云, 戴现伟, 赵文辉, 等. 机翼颤振模型梁架加工变形研究[J]. 机械工程师, 2014(5): 113-115.DUAN Z Y, DAI X W, ZHAO W H, et al. Research on machining distortion of wing flutter model beams[J]. Mechanical Engineer, 2014(5): 113-115(in Chinese). [11] 周健斌, 章俊杰, 孟光. 计及陀螺效应的翼吊式机翼-发动机系统结构动力学特性研究[J]. 振动与冲击, 2012, 31(6): 145-149.ZHOU J B, ZHANG J J, MENG G. Structural dynamic characteristics of a wing-engine system with gyro effects[J]. Journal of Vibration and Shock, 2012, 31(6): 145-149(in Chinese). [12] 朱庄生, 张萌. 面向InSAR的空气扰动影响机翼挠曲变形建模[J]. 北京航空航天大学学报, 2020, 46(1): 38-50.ZHU Z S, ZHANG M. Air disturbance affecting wing deflection deformation modeling for InSAR[J]. Journal of Beijing University of Aeronautics and Astronautics, 2020, 46(1): 38-50(in Chinese). [13] ZHU Z S, ZHANG M, ZHOU X Y. A new baseline measurement method for multi-node and multi-baseline interferometric SAR systems using fiber Bragg gratings[J]. IEEE Transactions on Aerospace and Electronic Systems, 2022, 58(1): 4-16. doi: 10.1109/TAES.2019.2939606 [14] 王志刚. 自回归模型的定阶方法选择及弱信号探测[D]. 武汉: 武汉理工大学, 2020.WANG Z G. Selection of order determination method[D]. Wuhan: Wuhan University of Technology, 2020(in Chinese). [15] 何璇. 基于MATLAB的AR模型参数估计[J]. 信息与电脑, 2019(7): 5-6.HE X. MATLAB-based parameter estimation of AR model[J]. China Computer & Communication, 2019(7): 5-6(in Chinese).