A Dynamic Measurement Method of Gravity Gradient Based on Torsion Balance
YE Ziwei1,WANG Fei2,BAO Fu2,HUANG Anyi1,YU Ye3,HU Hongbo2,WANG Ruolin1
1. School of Mechanical and Electronic Engineering,Wuhan University of Technology,Wuhan,Hubei 430070,China
2. Hubei Institute of Measurement and Testing Technology,Wuhan,Hubei 430223,China
3. Wuhan Optics Valley Aerospace Sanjiang Laser Industry Technology Research Institute Co. Ltd,Wuhan,Hubei 430073,China
Abstract:To study the problem that the traditional torsion balance gravity gradiometer has high accuracy but poor stability and low measurement efficiency,introducing the dynamic modulation method and applying the Z-type torsion balance structure to the dynamic measurement mode to realize the simultaneous measurement of gravity horizontal gradient and gravity curvature. Using rotating filter and genetic algorithm in the process of signal processing can effectively eliminate the influence of free oscillation of torsion pendulum on target peak value and extract the amplitude and phase of target frequency. The simulation results show that the uncertainty component introduced by the genetic algorithm to extract the target gravity gradient value from the dynamic measurement mode signal does not exceed 0.0077E(1E=10-9/s2). When genetic algorithm is used for data post-processing,the measurement uncertainty of the system is evaluated as 0.0582E.
DIFRANCESCO D. Advances and Challenges in the Development and Deployment of Gravity Gradiometer Systems[C]//EGM 2007 International Workshop, 2007.
[6]
SZAB Z. The history of the 125 year old Etvs torsion balance[J]. Acta Geodaetica Et Geophysica, 2016, 51(2): 273-293.
[9]
ZHANG T X, BAI Y Z, HONG W, et al. A torque type full tensor gravity gradiometer based on a flexure-strip suspension[J]. Review of Scientific Instruments, 2020, 91(6): 064501. 1-064501. 8.
PENG Y W, ZHAO L Z, QU S B, et al. The research and development of a two-dimensional flexure hinge gradiometer[J]. Geophysical and Geochemical Exploration, 2006, 30(5): 401-405, 409.
[11]
QUINN B G. Estimating frequency by interpolation using Fourier coefficients[J]. IEEE Transactions on Signal Processing: A publication of the IEEE Signal Processing Society, 1994, 42(5): 1264-1268.
[15]
YU Y, HU X, SHI W, et al. Measuring and adjusting the distance between the center of mass and optical center of a free-falling body in an absolute gravimeter[J]. Metrologia, 2022, 59(4): 045001.
SUN M T, LIU B. DBN structure adaptive learning algorithm based on improved genetic algorithms[J]. Acta Metrologica Sinica, 2021, 42(1): 91-99.
XU J Y, SU D W, WANG Q Y, et al. Design of host system for miniature absolute gravimeter[J]. Acta Metrologica Sinica, 2022, 43(4): 489-493.
WANG X J, DAN D H, YAN X F, et al. Estimation of fluctuating wind amplitude and phase spectrum using APES algorithm based on field monitored data[J]. Journal of Vibration, Measurement & Diagnosis, 2019, 39(2): 431-437, 452.
[18]
余烨. 扭秤重力梯度仪的设计与误差分析[D]. 武汉: 华中科技大学, 2017.
MOU L S, FENG J Y, WU S Q, et al. Accuracy evaluation of gravity continuous observation at key comparison site of absolute gravimeter[J]. Acta Metrologica Sinica, 2022, 43(12): 1639-1644.
HU P H, ZHAO M, HUANG H, et al. Review on the Development of Airborn/Marine Gravimetry Instruments[J]. Navigation Positioning and Timing, 2017, 4 (4): 10-19.
STOICA P, LI H, LI J. A new derivation of the APES filter[J]. IEEE Signal Processing Letters, 1999, 6(8): 205-206.
GU W. Overview of genetic algorithms[J]. Office Automation, 2016(7): 34-35.
ZHANG X F, ZHANG F Y, LI K, et al. Optimization of leaf-spring-type recovery mechanism for low-frequency standard vibrator based on genetic algorithm[J]. Acta Metrologica Sinica, 2021, 42(11): 1459-1465.
[19]
李刚. 基于静电悬浮的扭秤式重力梯度仪关键技术研究[D]. 北京: 清华大学, 2016.
PAN X Q, LIU C F, ZHU Y. Discussion on experimental data processing and error in rotational inertia measurement by method of torsion pendulum[J]. Physics and Engineering, 2016, 26(1): 46-50.
TIAN X, ZHU J J, LI W, et al. Research on the development direction of gravity measurement field and high resolution measurement methods of gravity sensors[J]. New Technology & New Process, 2022, 414(6): 1-7.
WU Q, TENG Y T, ZHANG B, et al. The research situation of the gradiometer in the world[J]. Geophysical and Geochemical Exploration, 2013, 37(5): 761-768.
[3]
DIFRANCESCO D, GRIERSON A, KAPUTA D, et al. Gravity gradiometer systems-advances and challenges[J]. Geophysical Prospecting, 2009, 57(4): 615-623.
[8]
彭益武. 基于电容传感的扭矩型簧片重力梯度仪的实验研究[D]. 武汉: 华中科技大学, 2006.
[10]
LUO J, XU J H, LIU Q, et al. An improved torque type gravity gradiometer with dynamic modulation[J]. Acta Geodaetica et Geophysica, 2017, 53(2): 171-187.