Method for improving accuracy of miniature AHRS (Attitude and Heading Reference System) module and miniature AHRS module

Abstract

The invention discloses a miniature AHRS (Attitude and Heading Reference System) module. The miniature AHRS module comprises an AHRS, wherein the AHRS comprises a gyroscope, an accelerometer, an MCU (Micro Control Unit) and a magnetic compass; the output ends of the gyroscope, the accelerometer and the magnetic compass are respectively connected with the MCU; and according to the installation mode, the gyroscope, the accelerometer and the magnetic compass are parallel to a coordinate axis of a carrier coordinate system. The invention also provides a method for improving the accuracy of the miniature AHRS module. According to the miniature AHRS module and the method provided by the invention, the problem of singularity of quaternion covariance is solved, and data fusion is carried out by an extended Kalman filter so as to obtain accurate output of attitude; 360-degree all-directional output of the attitude and the heading in the three-axis direction can be achieved, the static accuracy of the attitude and heading data is less than 0.5 degree, and the dynamic accuracy of the attitude and heading data is less than 2 degree; an internal sensor has an automatic correction function, and can carry out automatic compensation correction on interference of temperature drifts, noises and external magnetic fields of the sensor; and the miniature AHRS module has the characteristics of ultralong-time stability and fast dynamic response.

Description

technical field [0001] The present invention relates to the technical field of AHRS modules, in particular to a method for improving the precision of a micro-AHRS module and a micro-AHRS module, more preferably, to a low-cost and high-precision micro-AHRS module and a method for improving the precision of a micro-AHRS module. Background technique [0002] The attitude and heading reference system (AHRS) is an inertial measurement device used to accurately measure the attitude of the carrier in three axes (pitch, roll, yaw) in the space coordinate system. Fields such as ships, virtual reality, and the automotive industry all play a very important role. With the commercialization of MEMS components, micromachined gyroscopes and accelerometers have begun to be used for attitude measurement. The attitude system consists of 3 micromachined gyroscopes, 3 micromachined accelerometers and a 3-axis geomagnetic sensor. The gravity vector and the geomagnetic vector are selected as re...

AI Technical Summary

Problems solved by technology

In the process of research, the inventor found that traditional inertial navigation systems use gyroscopes and accelerometers to determine the attitude of the carrier relative to a fixed coordinate system, and the bias drift of such gyroscopes is quite stable for a long time, but the volume is large , high power consumption, high cost

In applications that are sensitive to cost, volume, and power consumption, such as micro-unmanned aerial vehicles, robots, and human motion perception, there is an urgent need to develop a low-cost, low-power, and small-volume high-precision AHRS based on cheap sensors; As for the algorithm, many scholars at home and abroad have done a lot of work in this area, and proposed an attitude calculation method based on the direction cosine matrix Kalman filter, but the direction cosine matrix itself has orthogonality, and in the direction cosine matrix update process will lose its orthogonality, and the accuracy of the solution cannot be guaranteed without correction

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