A Gravity Field Accelerometer Calibration Method Based on Monocular Vision

Abstract

The invention discloses a monocular vision-based gravitational field method accelerometer calibration method, which mainly comprises the following steps of: proposing a plumb bob method to determine the direction of a gravitational field, and then using a plumb line as an initial reference of a rotation angle of a turntable; using a monocular vision system to shoot a rotary table image, and usinga template matching method to determine a rectangular target feature area in the rotary table image; realizing sub-pixel extraction of the characteristic edge of the rectangular target based on a Zernike moment method; extracting a long edge of the rectangular target by using a cumulative probability Hough Transform (PPHT) algorithm, wherein an included angle between the edge and a plumb line is the rotation angle of the rotary table at the current position; the sensitivity of the accelerometer is calculated by using the measured rotation angle, and the gravitational field method accelerometercalibration at any rotation angle can be realized. According to the method, the defects of limited calibration precision and installation error in multi-axis acceleration timing calibration in the traditional gravitational field method accelerometer calibration are overcome.

Description

technical field [0001] The invention belongs to the field of vibration measurement and testing, and in particular relates to high-precision and stable gravitational field method accelerometer calibration for any rotation angle. Background technique [0002] The validity and reliability of accelerometer measurement data need to be guaranteed by regular calibration, and accelerometer calibration is an important means to ensure accurate measurement of accelerometers. [0003] Commonly used accelerometer calibration methods include laser interferometry, comparison method, reciprocity method, and earth gravity field method. Laser interferometry is divided into fringe counting method and sine approximation method; comparative calibration method is to compare the output of the accelerometer to be calibrated with the output of a known reference standard accelerometer to calculate the sensitivity of the accelerometer to be calibrated; reciprocity method calibration uses reversible ,...

AI Technical Summary

Problems solved by technology

Therefore, in view of the fact that the current gravitational field accelerometer calibration method does not accurately locate the direction of the gravitational field, and there are repeated installation errors when calibrating the sensitivity of the multi-axial accelerometer, the present invention proposes a monocular vision method to measure the rotation angle, which is suitable for low frequency , Gravity field accelerometer calibration at any rotation angle

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