This invention relates to a sequential filtering method for data fusion in a rotorcraft unmanned aerial vehicle (UAV) attitude reference
system, belonging to the field of UAV attitude
estimation. In this invention, a low-pass filter is used to process the acquired sensor data to obtain the initialized horizontal attitude angle and heading angle, thus initializing the attitude reference
system. During the calculation process, Euler angle differential equations are used to construct the
system's state transition equations, defining relevant state variables and obtaining the
state transition matrix.
Measurement equations are constructed based on the acceleration output and
magnetometer output of the carrier's observations, yielding the corresponding
observation matrix. Following the steps required for Kalman filtering, the state variables required during the
Kalman filter's operation are mapped to the system, and calculations are performed using the
Kalman filter data update method to complete the calculation derivation of the corresponding quantities, thus realizing the sequential
processing method of Kalman filtering. Compared to traditional Kalman filtering algorithms, this
algorithm implements Kalman filtering sequentially, requiring only partial data calculations during attitude updates, and does not involve matrix operations throughout the process, thereby improving the
algorithm's computational efficiency.