Research And Application Of The Differential Capacitive Accelerometer Measurement System

As an important technical foundation of modern science and technology, sensortechnology is a high-tech with remarkable and rapid development in today’s world, and it isone of the most important symbol of the science and technology development and the overallstrength of a national. As an important branch of the sensor, acceleration sensor receives moreand more attention.The sensitive structure of capacitive accelerometer has been the key design ofaccelerometer because of its high sensitivity, low power consumption, small temperature drift,simple structure, non-intrusive installation, etc. Based on the principle of variable clearancedifferential capacitive acceleration sensor and the sensor output signal characteristics, thispaper designed and produced a modified relaxation oscillation measurement circuit, for themeasurement of small capacitance change. The test result of this circuit shown it has goodperformance in sensitivity, resolution, non-linearity, zero drift,etc. For the output signal of themeasuring circuit, then designed data acquisition and processing system which used DSP asits core, for achieving the function about processing measurement data and uploading data toPC.By designing of LabVIEW virtual instrument software, it realized the serial data reading,the combination display of the text and curve, the storage of measurement data, etc. Finally,the result of calibration and actual experiments for the entire measurement system shown thatthe designed capacitive accelerometer measurement system was running well, acceleration ofthe measured object can be displayed real-time and accurately.This measuring system can be widely used in industrial automation, automotive airbags,medical equipment, and other fields, so it has high application value.