Research On Key Issues Of A Novel Marine Gravity Sensor Based On An Astatic Pendulum

Measuring gravity at sea is extremely significant to the passive gravity navigation system,explore marine resources and build deep blue navy.As a critical component of measuring gravity at sea,high-precision marine gravimeter is used to sensitive the marine gravity anomaly.Its construction principle and overall structure design play a decisive role in the measurement accuracy and dynamic performance of the marine gravimeter.Recently,a mass hung on the zero-length spring is typically used as a gravity sensor.However,a very long spring or very accurate measurement of the mass position is necessary to this typically gravity sensor.Moreover,the manufacturing process of the zero-length spring is very complicated and time-consuming.Therefore,to the straight-line gravimeters based on the zero-length spring,they are costly and unable to achieve mass production.This paper presents a novel marine gravity sensor characterized by a simple structure,high sensitivity and easy processing.This novel gravity sensor makes use of an astatic pendulum way that will make a mass pendulum mounted on an elastic wire and make this gravity pendulum situated in a horizontal position that is an astatic state by twisting elastic wire.The main research contents of this paper are as follows:1.This paper presents a novel marine gravity sensor.Based on the design requirements of the marine gravity sensor,its overall structure is designed.Moreover,its dynamic and static characteristics are analyzed.2.An innovatively support structure based on an elastic twisted wire is proposed.The relationship between the deflection angle of the horizontal twisted wire of the pendulum component and the resolution of the gravity sensor is theoretically analyzed and deduced.The pre-deflection angle of twisted wire satisfying the resolution of gravity sensor is determined.3.The theoretical models of the output characteristic and disturbance torque of the short-circuit turn angle sensor are established.Through the combination of simulation and experiment,the correctness of the theoretical model is verified,and the experimental prototype is developed.Moreover,the optimal parameter configuration of short-circuit-turn sensor is obtained.4.A three-dimensional finite element model of the short-circuit turn angle sensor is established,and the electromagnetic field is analyzed.We obtain the specific distribution of the magnetic flux,induced current on the rotor,and the loss curve of the magnetic flux of the sensor and each component.5.The static magnetic circuit of the moving iron permanent magnet torquer is simulated analysis,and the permanent magnet material is selected reasonably to improve the stability of the torquer.Moreover,the distribution of leakage magnetic field of torquer is obtained.