The Key Research Of Acceleration Measurement System Based On Quartz Flexible Accelerometer

Acceleration is a physical quantity representing the speed changing of object,and also one of the important parameters in the field of measurement and control, and acceleration sensor is one of the core devices in inertial navigation technology. High precision acceleration measurement has a very important application value in industrial technology and the research of national defense construction. With the development of the technology in various fields,the measurements of acceleration with more practicability, convenience and accuracy are needed. And the acceleration sensor of the micro, high precision technology has become to the development trend,and also a variety of acceleration sensors have been used in different environments. In this paper the quartz flexible accelerometer is used for high precision measuring.Based on the differential capacitor structure of quartz accelerometer, this paper designs a measurement method for high precision and stability using the amplitude and frequency characteristics of the resonant circuit. This method is based on the principle that the amplitude of the input signal is different from the different resonance frequency. It outputs a DC voltage which is linear with difference of differential capacitance. After the amplification, correction and other processing, the analog DC signal will feed back to the acceleration sensor and force the sensor return to the balance position. At the same time the A/D conversion is used to sample the signal. The data collected is read by the FPGA and transmitted through USB,which is uploaded to the host computer in the form of data flow. Finally, the acceleration measurement system is calibrated with a standard accelerometer, and also the sensitivity,repeatability and stability of this system are tested.This paper introduces the hardware and software design of the acceleration measurement system and data acquisition system, and the feasibility of the method of this design is verified by simulation. The error and noise of the system are analyzed and the corresponding improvement measures are put forward. According to the analysis of the experimental data of the system, the specific performance index of the acceleration measurement system is demarcated. This system has simple structure, high accuracy and high stability, and also a good sensitivity of acceleration measurement. It basically meets the requirements of the design.