以高精度重力测量为目标,研究基于静电悬浮的卫星重力探测技术。首先给出了静电加速度计的硬件电路,包括高精度位移测量电路、数字化控制电路以及静电力发生器。然后在分析了静电支承特性的基础上,将其工作状态分为起支和支承两种状态,并设计了相应的数字控制器,保证系统可靠悬浮。仿真和实验结果表明,转子支承中心的重复性优于0.01μm,支承电压的重复性优于0.5‰,48h稳定性优于2‰,满足星载静电加速度计的需求。
Aiming at high accuracy gravity measurement, the satellite gravity surveying technique based on electrostatic suspension is studied in this paper. First, the hardware circuit of the electrostatic accelerometer is given, including the high accuracy displacement measurement circuit, the digital control circuit and the electrostatic force generation circuit. Then, based on analyzing the characteristics of electrostatic suspension, the suspension states are divided into initial levitation state and suspension state, and corresponding digital controllers are designed to suspend the rotor reliably. Simulation and experimental results show that the repeatability of the suspension center of the rotor is less than 0.01 μm, the repeatability of the suspension voltages is less than 0.5 ‰, and the 48 h stability of the suspension voltages is less than 2 ‰, which satisfies the requirements of the space electrostatic accelerometer.