Dual-capacitance type micro-machine accelerator sensor and temperature self-compensating system based on it

Abstract

The invention discloses a dual-capacitance type micro-machine accelerator sensor and a temperature self-compensating system based on the dual-capacitance type micro-machine accelerator sensor; the dual-capacitance type micro-machine accelerator sensor comprises two grids and two fixing aluminum electrodes which are respectively corresponding to two output ends; the two output ends are respectively connected with input ends of two differential capacitance voltage switching circuits, and output ends of the differential capacitance voltage switching circuits are respectively connected with an output end of a high-frequency carrier wave generator and an input end of a coherent demodulator; the output end of the coherent demodulator is connected with the input end of a low pass filter, and the output end of the low pass filter is connected with the input end of the temperature self-compensating system. The system can measure temperature of the acceleration sensor instead of an additional temperature sensor, expel the influence of the temperature measurement bias caused by temperature gradient on the compensation precision, improve the temperature compensation precision while eliminate the influence of the non-linear characteristics of the temperature coefficient on the temperature compensation result.

Description

technical field [0001] The invention belongs to the field of acceleration measurement, in particular to a dual-capacitance micro-machine acceleration sensor and a temperature self-compensation system based on the sensor, which optimizes and improves the temperature drift performance of the capacitive micro-machine acceleration sensor. Background technique [0002] The capacitive micro-mechanical acceleration sensor is sensitive to the external acceleration signal, and converts the acceleration signal into the change of the differential capacitance. The change of the differential capacitance is converted into a voltage signal through the differential capacitance voltage conversion circuit, and the input acceleration can be obtained through the subsequent processing circuit. The size of the signal, so as to realize the detection of acceleration. [0003] Since the key unit of the capacitive micromachined acceleration sensor is the capacitor, when the temperature changes, the s...

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Problems solved by technology

[0003] Since the key unit of the capacitive micromachined acceleration sensor is the capacitor, when the temperature changes, the structural size of the capacitor, the dielectric constant in the environment, the thermally induced stress and the residual stress in the structure will all change, resulting in the capacitance of the capacitor A change occurs, that is, a change in the output signal of the accelerometer, which affects the detection of the real acceleration signal by the accelerometer

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