Implementation of Unscented Kalman Filter and Complementary Filter Applied to the ASSE scheme for Synthetic Flow Angles Estimation

This paper presents the results of the implementation of a quaternion-based Unscented Kalman Filter (UKF) and a Complementary Filter (CF), for attitude estimation, along with the Angle of Attack and Sideslip Estimator technology (ASSE), in order to provide an Air Data Synthetic Sensor for aerodynamic angles estimation. The attitude estimation is crucial for the computation of the full rotation matrix from the Inertial Reference Frame to the Body Reference Frame, needed by the ASSE algorithm. The estimation at issue exploits an Inertial Measurement Unit (IMU) equipped with a three-axis accelerometer, a gyroscope, a magnetometer and a Global Positioning System (GPS) receiver. Firstly, the filter algorithm is implemented in MATLAB and Simulink environment and its performance is assessed by using the measurements of a Flight Test Instrumentation (FTI) unit, a technological demonstrator built in Polytechnic University of Turin which encompasses the IMU. The verification is carried out with a series of tests employing a motion table at the National Metrology Institute of Italy (INRiM). Finally, the implementation of the filter with the ASSE technology is successfully demonstrated through a set of flight simulation data.