Civil-engineering articulated vehicle localization: solutions to deal with GPS masking phases

In order to equip the compactors dedicated to road construction with an operator aiding system, a localization system using real-time kinematic GPS is considered. The paper presents the solutions we have developed to maintain an acceptable precision of the vehicle positioning even during the satellite masking phases. By combining a gyro with steering angle and speed measurements, we show that it is possible to obtain satisfying performances in dead reckoning navigation with low-cost equipment. A forward-backward Kalman filter is proposed to deal with particularly long maskings, which typically occur when the compactor works under bridges. Experimental results carried out in the framework of a cooperation with the Laboratoire Central des Fonts et Chaussees and the Centre d´Experimentations Routieres are presented to validate the proposed solutions