Attitude heading reference system for low-cost small unmanned aerial vehicle

Abstract

The invention relates to an attitude heading reference system for a low-cost small unmanned aerial vehicle. The attitude heading reference system comprises an angular rate gyro, an accelerometer, a global position system (GPS), an angular rate gyro operation module, an aiding module and a Kalman filter, wherein the angular rate gyro is used for measuring a roll angular rate, a pitch angular rate and a yaw angular rate of an aerial vehicle; the accelerometer is used for measuring a weight component of gravity in an aerial vehicle coordinate axis system; the GPS is used for measuring a track azimuth of an aerial vehicle; the angular rate gyro operation module is used for computing a pitch angle q1, a yaw angle y1 and a roll angle f1 with offsets; the aiding module is used for estimating an estimated roll angle f2 and an estimated pitch angle q2 and using the track azimuth measured by the GPS as an estimated yaw angle y2; and the Kalman filter is used for fusion of data produced by the angular rate gyro operation module and the aiding module to acquire a final attitude angle [f q y]<T>. The attitude heading reference system reduces a cost of a small unmanned aerial vehicle system and a complex degree of a heading reference system and improves the precision of attitude estimation.

Description

technical field [0001] The invention relates to an attitude and heading reference system, in particular to an attitude and heading reference system for low-cost small UAVs based on sensor fusion technology. Background technique [0002] Attitude Heading Reference System (AHRS), referred to as the heading system, is used to determine the orientation of the moving vehicle in space. The attitude information provided by the attitude heading reference system can be widely used in navigation, guidance and control. For autonomous flying UAVs, the heading and attitude system is particularly important, which provides the necessary attitude feedback for the inner loop of the control system. Usually, the determination of attitude information relies on high-precision angular rate gyroscopes. However, high-precision gyroscopes have defects such as high cost, heavy weight, and complex structure, which obviously cannot be applied to low-cost small UAV systems. Therefore, under the constr...

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Problems solved by technology

[0006] For low-cost small UAVs, although sensor fusion technology has been widely used in attitude determination, there are still some problems: First, the sensors used for attitude estimation in small UAV systems are generally angular rate gyroscopes, accelerometers, magnetic Heading (used to measure the heading angle), while the magnetic heading is expensive and not suitable for low-cost UAV systems; secondly, although some small UAV attitude estimation systems use GPS instead of magnetic heading, which reduces the cost , but since the GPS output is an angle, the attitude estimation algorithm at this time is based on the Euler angle method. This method needs to solve the trigonometric function in real time during the calculation, and sometimes there will be a singularity, which makes the problem No solution, so not suitable for low-cost flight control computers with poor computing power

At present, there is no solution that can better solve the attitude estimation when the UAV appears to be maneuvering and overloaded.

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