【作者】 王磊；

【导师】 屈少波；

【作者基本信息】 华中科技大学 ， 无线电物理， 2019， 硕士

【摘要】 空间静电加速度计/空间惯性传感器主要用于地球重力场测量、空间引力波探测、空间等效原理实验检验等高精度应用场合。高精度电容位移传感电路作为空间惯性传感器中的核心关键技术,其测量精度对惯性传感器的分辨率具有直接影响。本文针对空间引力波探测等深空探测计划的应用需求,对结构简单、低功耗、高精度的充放电式电容位移传感电路进行研究,对该电路的原理和噪声模型进行了分析,针对方波幅值电压与二极管开关电路所引起的主要噪声源进行了分析,采取了相关噪声抑制方法,显著降低了该传感电路的主要噪声项。首先,本文对充放电式电容位移传感电路的基本原理进行了介绍,同时对传感电路中每个部分分别进行了噪声建模和分析,其中二极管是传感电路中的最大噪声源,并且通过实验验证了二极管的噪声模型。同时提出应用并联基准源方案到方波发生电路中,理论分析该方案能降低方波幅值的相对电压噪声,从而最终改善了传感电路的电容分辨率。其次,对并联基准源方案和传感电路的相关性能进行了实际的测量。实验数据表明,并联基准源方案达到了降低相对电压噪声的目的。传感电路灵敏度系数的标定结果在误差范围内与理论预期保持一致;在0.1Hz处的电容分辨率达到2.2?10^-7pF/Hz^1/2,在1Hz处达到1.5?10^-7pF/Hz^1/2;传感电路的总功耗为341mW,基本都达到了预期的需求。最后,对充放电式电容位移传感电路多路同时工作的状态进行理论分析和电路仿真,验证了多路同时工作的可行性,仿真结果同理论分析保持一致。同时对传感电路的小型化方案进行了初步设计,包含电路板布局以及元器件封装的选择。更多还原

【Abstract】 Space electrostatic accelerometers/space inertial sensors are mainly used for high-precision applications including earth gravity field measurement,space gravitational wave detection,and space experimental test of equivalent principle.The ultra-sensitive capacitive position sensor circuit is the key technology in space inertial sensor,and its measurement accuracy has direct impact on the resolution of inertial sensor.In this thesis,on the application demand of space gravitational wave detection and other deep space detection missions,a simple structured,low power,high precision charging-discharging capacitive position sensor circuit is studied.The principle and noise model of the circuit are analyzed.The main noise sources caused by the voltage of square wave amplitude and the diodes switching circuit are analyzed.Related noise suppression methods are adopted,which reduced significantly the main noise items of the capacitance sensor circuit.Firstly,the fundamental principle of the charging-discharging capacitive displacement sensor is introduced.In the meantime,the noise modeling and analysis are carried out for each part of the sensing circuit,in which the diodes are found to be the largest noise source in the sensing circuit.The noise model from the diode is verified by experiments.At the same time,the paralleled scheme of voltage reference sources is applied to the square wave generating circuit.Theoretical analysis shows that the scheme can reduce the relative voltage noise of the square wave amplitude,and finally improve the capacitance resolution of the sensing circuit.Secondly,the performance of the paralleled reference source and the sensing circuit are measured.Experimental data shows that the parallel reference source scheme achieves the goal of reducing the relative voltage noise.The calibration results of the sensitivity coefficient of the sensing circuit are consistent with the theoretical expectation within the error range.The capacitance resolution of 2.2?10^-7pF/Hz^1/2 at 0.1 Hz,and1.5?10^-7pF/Hz¹/2/2 at 1Hz are achieved.The total power consumption of the sensing circuit is 341mW.All these results basically meet the expected level.Finally,a theoretical analysis and circuit simulation on the multichannel simultaneous operation of the charging-discharging capacitance sensor circuit are carried out,which verified the feasibility of multichannel simultaneous operation and the simulation results are consistent with the theoretical analysis.At the same time,the miniaturization scheme of the sensing circuit is designed preliminarily,including the layout of the circuit board and the choice of electronic component packaging.更多还原