A single-device virtual accelerometer based on time measurement and its implementation method

Abstract

The invention discloses a single-device virtual accelerometer based on time measurement and a realization method thereof, and belongs to the field of micro-electro-mechanical systems (MEMS). The virtual accelerometer is merely formed by a single device, and the structure thereof comprises a movable mass block, four support beams, an electrostatic force driving capacitor and a detection capacitor.A single-device sensor operates in a resonance state and outputs voltage signals, and vibration displacement signals of the mass block are represented by the voltage signals. A group of displacement reference points, which are represented by voltage reference points, are defined; and when the physical position of the vibrating mass block passes through the displacement reference points, it is represented that the voltage signals output by the detection capacitor pass through the voltage reference points, a series of triggering events are generated, and an acceleration can be resolved through measurement of the time interval between the corresponding triggering events. The resolved acceleration is insensitive to the position changes of the defined displacement reference points, therefore, Ngroups of displacement reference points are defined, and N accelerations can be resolved and outputted at the same moment; and an acceleration output with high precision can be obtained through a redundant information fusion technology, namely, a virtual accelerometer is realized. According to the virtual accelerometer, the sensor precision is improved.

Description

[0001] Field: [0002] The invention relates to an acceleration sensor, in particular to a single-device virtual accelerometer based on time measurement and its realization method, belonging to the technical field of sensors. Background technique: [0003] The accelerometer is an instrument used to measure the acceleration of the carrier. It is the basic core component of the inertial navigation system. It has important application value in aerospace, automotive industry, consumer electronics, construction machinery and other fields. With its many advantages such as small size, light weight, low cost and easy mass production, MEMS accelerometer has become the main development direction of accelerometer. However, its accuracy is not as high as that of flexible accelerometers, so that micromachined accelerometers can only be used in low-end fields such as the automotive industry and consumer electronics, and are difficult to be applied in high-end fields such as aerospace. At p...

AI Technical Summary

Problems solved by technology

However, in addition to the defects of large size, high power consumption, and high cost, realizing a virtual accelerometer with multiple sensors has two natural defects; The output of each sensor cannot represent the real acceleration value at a certain moment; second, the sensitivity of each sensor in the array is different and the direction of the sensitive axis is not completely coincident with the ideal state, resulting in poor consistency of the output signals of each sensor

These two natural defects will affect the virtual sensor accuracy improvement

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