摘要
模数转换环节引入的精度损失是基于模拟伺服方案的石英挠性加速度计的主要缺陷。提出了一种数字闭环检测方法,该方法在实现加速度信号闭环检测的同时,直接提供数字输出,理论上不存在精度损失。建立了数字闭环检测系统的数学模型,通过阻尼修正部分将摆片的模型改善为最佳阻尼状态,利用积分环节和补偿校正消除系统的一阶静态误差,保证足够的相角裕度。依据国军标测试方法对试验样机进行测试,结果表明:系统超调量在20%左右,-3 dB带宽接近300 Hz。实验结果与理论仿真基本一致,验证了数字闭环检测方法的正确性和可行性。
The accuracy loss introduced by analog-digital conversion is the main defect of quartz flex accelerometer based on analog servo scheme. A digital closed-loop measurement method is presented. At the same time when the acceleration signal is measured in close loop ,the method directly provides digital output,so there is no accuracy loss theoretically. The mathematical model of the closed-loop measurement system is established ; damp emendation is used to improve the model of the pendulous reed and make it enter its optimal damp state; and integral unit and compensator are used to eliminate the system first-order static error and ensure enough phase margin. The performance of the quartz flex accelerometer was tested according to the national and military standards; the results show that the system overshoot is approximately 20% ,and the -3 dB bandwidth is close to 300 Hz. The experiment result coincides with that of theoretical simulation ,which verifies the validity and feasibility of the digital close-loop measurement method.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2012年第12期2833-2839,共7页
Chinese Journal of Scientific Instrument
关键词
惯性导航
石英挠性加速度计
数字闭环
模型分析
校正设计
inertial navigation
quartz flex accelerometer
digital close-loop
model analysis
emendation design
