Performance comparison of unmanned aircraft system (UAS) flight controller with independent flight test instrumentation (FTI) during flight

To ensure the safety of the flight control law, several development stages shall be passed, starting from the software in the loop simulators, hardware in the loop simulators, and finally the flight tests. During the flight test, the flight test data can be used to improve the aerodynamic parameter inside the flight mechanical model which is used during the hardware in the loop simulators stage. The improved aerodynamic parameters are responsible to guarantee the flight mechanical model generates the aircraft dynamics as close as possible with the real UAV at several trim points. The flight mechanical model with improved aerodynamic parameters normally called the improved flight mechanical model. The flight control law which was developed by using the improved flight mechanical model can ensure the UAV performs the auto flight as closely as possible, between the simulation and the real flight. Considering the importance of the flight test data, there is a need to develop the independent flight test instrumentation (FTI). To date, the UAV flight test data are recorded by using the flight control computer (FCC). However, there is no guarantee that the FCC record the correct data. Therefore, the independent FTI is needed for the comparative device as well as the backup device for recording the flight test data. This paper will discuss the design of a flight test instrument (FTI) system as well as a performance comparison with the FCC during the flight test. The performance comparison will compare the roll, pitch, yaw angle, and altitude (GNSS & barometer) parameters which are acquired by the FTI and the FCC. The comparison shows that the parameters obtained from the FTI have a similar trend to the FCC's. However, there is a slightly different installation location along the X-axis of the UAV, between the FCC and the FTI. That difference makes the value of pitch and yaw angle acquired by the FTI are different from the value from the FCC, while the value of the roll angle stays the same.