摘要硅微谐振式加速度计可将被测加速度直接转换为稳定性和可靠性都很高的频率信号，因此可以获得优良的性能。当然由此也能够简化应用系统的处理电路而充分的发挥MEMS 传感器体积小的优点。所以做出一个精度高，可靠性高的测频电路是十分关键的。本论文的所做的测频电路要实现的目标为：谐振式加速度计的中心谐振频率为23kHz、量程为±15g、标度因数为 80Hz/g、分辨率为 0.01Hz。 在论文中采用的是锁相环测频法，锁相环是由鉴相器、环路滤波、压控振荡器三部分组成，首先将不同模块的功能进行划分，然后找到理论与方法后将其实现，最后再将各个模块拼接成测频电路。本次设计时，先确定设计方案，再用MATLAB进行仿真，最后用Verilog HDL硬件编程语言对FPGA进行编程来实现测频的功能。 在最后的实验中，本次论文设计的测频电路完全达到要求，并且分辨率达到0.08mHz，所以这种测频方法可以适用于硅微机械加速度计。 59964
毕业论文关键词 频率测量 锁相环 FPGA MATLAB
Title The Frequency Measurement Circuit of Micromechanical Silicon Resonant Accelerometer
Abstract The micromechanical silicon resonant accelerometer can transform the measured acceleration into frequency shift which is stable and reliable，so the accelerometer may get better performance．Of course, this also simplifies processing circuit of the application system . This will take the full advantages of small size for MEMS sensors. So to make a frequency measurement circuit of high precision and high reliability is crucial. So the paper discussed the design of the data acquisition system for the micromechanical silicon resonant accelerometer．The design target is that the system can acquire the differential frequency signals of the resonant accelerometer with the resolution of 0.01 Hz, corresponding to 0.125mg on condition that the resonant accelerometer has a normal frequency of 23 KHz, a scale factor of 80 Hz/g，and a measuring range of±15g. In this paper ,new frequency measurement method based on PLL(Phase-locked loop) is adopted. Phase-locked loop consists of phase discriminator, loop filter and the voltage-controlled oscillator of three parts. Divide the functions of different modules first, and then find the theory and method to implement it, finally, various modules patchwork into frequency measuring circuit. In this design, to determine the design scheme, use MATLAB to do the simulation, finally on the FPGA using Verilog HDL language programming to achieve the function of frequency measurement. At the end of the experiment, the frequency measurement circuit completely meet the requirements, and resolution is 0.08 mHz, so this kind of frequency measurement method can be applied to the micromechanical silicon resonant accelerometer.
Keywords Frequency Measurement Phase-Locked Loop MATLAB FPGA
目 次
1．绪论. 1
1.1 微机电系统与硅微加速度计简介 1
1.1.1微机电系统概述 1
1.1.2硅微加速度计概述 . 2
1.1.3硅微谐振式加速度计工作原理 2
1.3 论文的主要内容.. 4
2．硅微谐振式加速度计数据采集方案.. 5
2.1频率测量的基本方法 . 5 FPGA硅微谐振式加速度计测频电路设计+电路图+程序:http://www.751com.cn/zidonghua/lunwen_65306.html