A system for 3D Localization of Civil-Engineering Machines

This paper presents a localization fusion technique for civil-engineering machines. It is designed for 6 DOF position and attitude determination. The system uses an optical instrument called SIREM, which provides azimuth and elevation angles of known landmarks. The approach is based on dead-reckoning techniques updated by the external measurements of SIREM using the Extended Kalman Filter formalism. As the dynamics and accelerations of the vehicles we consider are small enough, the use of inclinometers is attractive since they directly provide attitude angles. In such a context, we propose a new 3D deadreckoning method which integrates data from two inclinometers and an odometer. A particular contribution of the paper is that the Kalman filter has only four elements in its state vector. A large section of the paper is devoted to real experiments. These are performed with an outdoor tire-type robot moving on a 30x40 square meters non planar lawn. The results are compared with a differential RTK GPS.