Improving the accuracy of dynamic localization systems using RTK GPS by identifying the GPS latency

For precise localization of outdoor mobile robots, real-time kinematic Global Positioning System (RTK GPS) has obvious advantages: position data are given with centimeter-accuracy, and the required infrastructure is reduced to a sole fixed reference station. Yet, the use of this solution arises a number of issues, such as satellite maskings, or the existence of the so-called GPS latency, which delays the output of the localization data. This paper deals with the latter problem, and proposes a method to identify this parameter without using other external sensors. Experimental results carried out with the robot MELODY are presented so as to validate our solution.