Lateral Control in Precision Docking Using RTK-GNSS/INS and LiDAR for Localization

Abstract

This article describes the design of a lateral control method for precision docking using GNSS/INS and LiDAR for localization. The aim of this study is to verify whether an automated driving bus can achieve the requirement of standard deviation of the lateral error (1.25 cm) using onboard sensors without additional infrastructure. To design the controller and decide the conditions of pilot tests on public roads, the vehicle dynamics, steering system, sensor dynamics, and disturbances are modelled. The steering system of the vehicle can be approximated as a second-order system, and the measuring time of the sensors are considered, which cause reduction of damping ratio in lateral dynamics. The numerical analysis revealed that the vehicle speed should be reduced to under 4.2 m/s (15 km/h) before precision docking starts, to make the lateral motion of the vehicle more stable. Experimental results show that the standard deviation of lateral error in precision docking using LiDAR for localization is 1.2 cm, which is slightly under the criterion threshold. The results also verify that the vehicle and sensor model describes the vehicle lateral motion appropriately.