A low-cost attitude determination algorithm based on MEMS IMU/dual-antenna GNSS receiver for UAVs

This paper addresses the problem of attitude determination of small lightweight unmanned aerial vehicles (UAVs) under complex flight environments and motion profiles. To achieve a robust attitude solution, the dual-antenna GNSS attitude determination technique is introduced and enhanced. The short baseline attitude solution requires reliable carrier phase ambiguity resolution to achieve sufficient accuracy. Therefore, a new extension to the LAMBDA algorithm is proposed, which takes the baseline length constraints and pitch/yaw estimation from the MEMS IMU into account. On the one hand, the constraints help resolve float solution. On the other hand, they reduce the volume of ambiguity space. Thus the rapidness and robustness of the algorithm is improved. As a result, a robust attitude solution can be performed in a highly efficient manner. In order to verify the effectiveness of the presented algorithm, a set of experiments are carried out, which shows that both the search efficiency and success rate of carrier phase ambiguity resolution are improved. And thus the stability and reliability of attitude determination are enhanced.