Temperature compensation system and method for capacitance type micro-mechanical accelerometer

Abstract

The invention discloses a temperature compensation system and a temperature compensation method for a capacitance type micro-mechanical accelerometer. The temperature compensation system for the capacitance type micro-mechanical accelerometer comprises a capacitance type micro-mechanical acceleration sensor, a driving signal generating circuit, a capacitance / voltage switching circuit, an analog band-pass filter, a first digital / analog (D / A) converter, an analog / digital (A / D) converter, a second D / A converter, a third D / A converter and a field programmable gate array chip. The temperature compensation method for the capacitance type micro-mechanical accelerometer comprises three steps of: carrier wave generating / synchronously demodulating, resonance frequency locking and zero offset temperature compensating. According to the invention, the temperature change of a capacitance type micro-mechanical acceleration sensor is detected by the means that the resonance frequency of the capacitance type micro-mechanical acceleration sensor changes along with the change of the temperature, and the temperature compensation system is used for compensating the temperature by the means that the resonance frequency is taken as a compensation reference signal of an output signal of a capacitance type micro-mechanical accelerometer system. Therefore, the temperature compensation cost is reduced, the influence of temperature measurement errors on compensation precision is eliminated, and the temperature compensation precision is improved.

Description

technical field [0001] The invention relates to a temperature compensation system, in particular to a capacitive micromachine accelerometer temperature compensation system and a method thereof. Background technique [0002] Due to its advantages of small size, low power consumption, and mass production, micromachined accelerometers have gradually gained attention in civilian and even military fields. Compared with other types of accelerometers, capacitive micromachined accelerometers also have the advantages of simple detection, high detection sensitivity, and relatively insensitivity to temperature changes. Even so, temperature is still an important factor affecting the detection accuracy of capacitive micromachined accelerometers. Temperature compensation is important to improve the accuracy of capacitive micromachined accelerometers. [0003] The capacitive micromachined accelerometer temperature compensation device in the prior art fixes the temperature sensor on the ca...

AI Technical Summary

Problems solved by technology

The temperature sensor increases the complexity of the system hardware, and the thermistor and the integrated temperature sensor will introduce a certain measurement error when measuring the temperature. At the same time, because the size of the capacitive micro-machined acceleration sensor is on the order of millimeters, it is packaged The size of the metal shell is on the order of centimeters, so there is a certain temperature gradient inside the package, and the temperature sensor in the temperature compensation device is placed on the outer surface of the metal shell of the acceleration sensor, so the temperature measured by the temperature sensor cannot be obtained. Accurately reflect the real temperature of the capacitive micromachined acceleration sensor, that is, there is a certain error in the measured value of the temperature

Therefore, the existing temperature compensation device cannot achieve high compensation accuracy

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