数字闭环石英挠性加速度计信号检测技术

数字闭环石英挠性加速度计可以有效地解决传统模拟式加速度计在模数转换中引起的精度损失问题,而数字式加速度计的精度主要取决于差动电容检测环节。阐述了数字式加速度计的工作原理,重点设计了差动电容检测方法,利用单载波调制与数字自相关解调技术构建完整的数字式加速度计信号检测方案。搭建数字式加速度计原理样机,对其进行0 g/1 g稳定性测试,得到数字式加速度计0 g/1 g零偏稳定性分别为17.595 0 g、19.363 7 g、20.715 3 g。测试结果表明,当前的数字式加速度计精度达到了模拟式加速度计精度量级,有效验证了该方案的可行性及正确性。

Signal detection technology of digital closed-loop quartz flex accelerometer

The digital closed-loop quartz flex accelerometer (DCLA) can effectively solve the precision loss which exists in the output current to the digital conversion of the traditional analog quartz flex accelerometer, and the accuracy of the DCLA mainly depends on the differential capacitance detection circuit. The working principle of DCLA was introduced, and the signal detection scheme was studied. According to the signal characteristics, with the method of single carrier modulation and demodulation technology, triangle wave modulation technique was applied to implement the capacitance detection, and the digital correlative demodulation scheme was proposed to extract the amplitude signal. To build the DCLA experimental prototype, under the 0 g/1 g stability test, the bias stability of 0 g/1 g was 17.595 0 g, 19.363 7 g and 20.715 3 g, respectively. Currently, the result shows that the precision of the DCLA is basically equal to the traditional analog accelerometer, which verifies the correctness of the signal detection method.