Attitude Representation for Precise 3D Terrain Mapping with Autonomous Unmanned Helicopter

Autonomous unmanned helicopters are useful in various disaster prevention activities. 3D terrain mapping system is one of the most promising applications of autonomous unmanned helicopters. To improve the accuracy of the terrain mapping, it is necessary to improve the estimation accuracy of the attitude. In this paper, we focused on minimal representations of the attitude, which do not require unprofitable procedures in filtering, such as normalization. We defined generalized Rodrigues parameters, which are generalizations of Rodrigues and modified Rodrigues parameters. Generalized Rodrigues parameters were compared with Euler angles, which are the most well-known minimal representation of the attitude. Through numerical simulation results, properties of attitude estimation systems using those attitude representations are discussed in this paper. Finally, we concluded that generalized Rodrigues parameters are suitable for 3D terrain mapping.