Study The Detect-circuit Of The Capacitive Accelerometer Sensor

Capacitive Micro-accelerometer, a fundamental component of the measurement system, is a kind of important mechanical inertial sensor. With the development of science and technology, especially in the fields of aviation, robot, automobile and military application, micro-accelerometer has been developing with the orientation of multidimensional and integration, which means the sensors and interface circuits are integrated on a single chip. So it is becoming a hotspot to make research on integrated multidimensional micro-accelerometer.Detecting-circuit is the pivotal technology of the multidimensional micro- accelerometer. Consulted a great deal of data on the sensor and interface circuits, aimed at the micro-accelerometer which is designed and fabricated by the Micro-system Research Center of CQU, the paper is devoted to do some research and eventually design a detecting circuit used to the processing of acceleration signal. Based on the previous research and knowledge, it studies the pivotal technology of detecting-circuit. So it can satisfy the experiment demanding of the sensor. The paper focuses on the following aspects:Firstly, the paper studies the structure and working theory of the accelerometer. Especially the paper introduces the structure and working theory of the planar micro-accelerometer designed by the Micro-system Research Center. And it also studies the mechanical and electrical characteristics of the micro-accelerometer.Secondly, the paper mainly studies the closed-loop mode performance of the micro-accelerometer system. The paper proposes a novel design of the whole circuit as a core to detect the signal of the sensor. Based on the fundamental research the theory of every functional part of the circuit, the paper also simulates some parameters via the software ORCAD10.0.Finally, after optimizing the whole circuit, we debug some parts of the circuit and study the noise of the system. The PCB of circuit diagram has been fabricated to make a thorough test. Through detecting the signal of the micro-accelerometer sensor, the paper studies the result of debugging. It has discussed the interference of the multidimensional signal of the micro-accelerometer. Based on the analysis of the multidimensional signal of the sensor, the results indicate that the interference of the multidimensional signal of the sensor is small and under control. After summarizing the work of the paper, problems are put forward for further study and research.