A Method of Acquiring Heading Angle Based on Inertial Sensor

Abstract

The invention discloses a course angle obtaining method based on an inertial sensor. The course angle obtaining method comprises the following steps: firstly, course angles are independently calculated by using measured values of a gyroscope and a magnetometer, and then weight fusion is carried out on two results. Specifically, when the course angle is calculated by using the gyroscope, integration is performed on a z-direction angular speed under a carrier coordinate system, which is measured by the gyroscope, wherein whether the integration is carried out or not is judged according to a size relation between a total angular speed at the current moment and a threshold value; when the course angle is calculated by using the magnetometer, a horizontal plane of a geographic coordinate system is divided into eight quadrants, magnetic field strength values measured by the magnetometer are projected to the horizontal plane and correspond to the specific quadrants according to a horizontal plane axis and magnetic field strength components in the axial direction, and in each quadrant, an existing course angle calculation formula is corrected by adopting different correction factors; finally, a weighting coefficient is set by using a variance yield of the angular speed and the course angles calculated by the two methods are fused. According to the course angle obtaining method, the accurate course angle value can be obtained so that the positioning precision is high.

Description

technical field [0001] The invention belongs to the technical field of wireless positioning, and in particular relates to a heading angle acquisition method based on an inertial sensor. Background technique [0002] In recent years, the rapid development of data services has increased people's demand for location-based services. At present, the widely used satellite navigation system can almost achieve global coverage. However, due to the weak signal penetration ability of the satellite navigation system, in complex environments such as urban canyons and indoors, its signal energy and receiving signal-to-noise ratio are lower than There is a great degree of deterioration in the general environment, the availability and overall performance of the signal are greatly reduced, and the positioning accuracy of the receiver is very poor, or even impossible to locate. Therefore, how to provide a more accurate positioning method indoors has become one of the more urgent needs at pre...

AI Technical Summary

Problems solved by technology

Among them, the heading angle can generally be calculated through the angular velocity measured by the gyroscope or the magnetic field strength measured by the magnetometer. Using the gyroscope to integrate the angular velocity to calculate the heading angle can obtain relatively accurate results in a short time, but as time goes by There will be a relatively large cumulative error in the passage; using the magnetometer to calculate the heading angle will have problems such as the inherent deviation of the hardware itself, and the instability of the measured magnetic field strength, which will lead to the error of the heading angle, thereby affecting the accuracy of positioning

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