The dead reckoning localization system of the wheeled mobile robot ROMANE

This paper describes the dead reckoning localization system of the wheeled mobile robot ROMANE (Robot Mobile Autonome de Navigation de Exterieur). We are interested in quantifying the vehicle position estimation in an outdoor environment. The accuracy of position estimation by incremental shaft encoders on the wheels is very limited due to the poor quality of the rotational vehicle speed measurements. This paper shows how dead reckoning localization can be improved by the additional use of a gyroscope and a magnetic compass which are both also low cost sensors giving real-time information. We have developed a technique for compensation of magnetic field influences due to the robot itself under consideration of the vehicle dynamics the robot state is estimated by an extended Kalman filter which is developed for sequential data processing in order to reduce the computation time and to make the algorithm more flexible. Experimental results show the efficiency of our low cost dead reckoning localization system.