静电力平衡式石英挠性加速度计闭环控制系统的设计与分析#br#

针对一种静电力平衡式石英挠性加速度计，建立其表头系统模型并设计一种静电力平衡式闭环控制系统.建立表头摆片的刚度模型和挠度模型，摆片转动引起的电容间隙变化不均匀影响驱动、检测参数;建立驱动电容的静电力方程并分析了静电力负刚度对表头系统刚度的影响.表头的高真空度导致表头阻尼近似为0，因此在闭环控制系统中引入阻尼补偿环节，避免系统在表头谐振频率处振荡，并且在闭环控制系统中设计积分环节和校正环节来提高系统的快速性和稳定性.仿真分析结果表明：在闭环控制系统中引入阻尼补偿环节后可以有效减小系统振荡，静电力平衡式石英挠性加速度计闭环控制系统带宽为2 380 Hz，阶跃响应的超调量为3%，调节时间为0.5 ms，当系统静电力负刚度增大时，闭环系统也可以稳定工作.

Design and Analysis of Close Loop Control System of Electrostatic#br# Force Balance Quartz Flexure Accelerometer#br#

Based on an electrostatic force balance quartz acceleraometer, the dynamic model is established and a close loop control system based on electrostatic force is designed. The stiffness model and deflection model of the pendulous reed are established, indicating that the non uniform of the capacitor gap variable quantity affects the drive and sense parameters. Besides, the electrostatic force model of drive capacitor is established, and the effect of negative stiffness on the dynamic model is analyzed. To decrease the mechanical thermal noise, the accelerometer is evacuated, which causes the system damping decreasing to zero. To avoid oscillation near the system resonant frequency, a damping compesator is added into the close loop system. Besides, an integal element and a correction element are designed to increase the rapidity and atablility of the whole system. The simulation results show that, the bandwidth is 2 380 Hz, and the overshoot abd response time are 3% and 0.5 ms respectively. Besides, the close loop system can work stably with the increasing of negative stiffness.