Cross product calibration method for gyroscope in magneto-inertial navigation system of UAV

The tri-axial MEMS gyroscope in the magneto- inertial navigation system (MINS) of unmanned aerial vehicle (UAV) needs to be calibrated. To solve this problem, a cross calibration method is proposed, which is based on the relationship between the angular velocity and the time derivative of a vector to calibrate errors of gyroscope. The time derivative of a constant vector in the navigation coordination frame can be expressed by the cross product of the vector itself and the angular velocity of the aircraft-body coordinate frame. The cross calibration method is derived from the above principles, which can calibrate the tri-axial gyroscope efficiently without precision equipment. Numerical simulation results show that both the integral form and differential form of the cross product calibration method can effectively identify and compensate the error coefficients of gyroscope. And promising calibration results can be achieved under the influence of various factors. Experimental results on the gyroscope of the MINS module show that the accuracy of the proposed method can reach 0.2279°/s, which is close to the conventional method based on the rate table. The calibrated gyroscope data are combined with the second-order complementary filtering algorithm in the flight control of a rotor UAV. The angle deviation is controlled within 0.8° in the fixed-point hover state, which is conducive to the in-field calibration of UAV and the measurement of the attitude data in real flight. © 2020, Science Press. All right reserved.