Coupled Longitudinal and Lateral Control for an Autonomous Vehicle Dynamics Modeled Using a Robotics Formalism

摘要

The development of autonomous and intelligent vehicles is increasing continuously in the aim to reach a reliable and secured transportation system. Indeed, autonomous navigation include three main steps: perception and localization, planning and control. This work covers essentially the study of the vehicle modeling and the vehicle control. We present a coupled control algorithm for longitudinal and lateral dynamics of an autonomous vehicle. The control is realized using Lyapunov functions and aims to ensure a robust tracking of the reference trajectory especially in coupled longitudinal and lateral maneuvers such as lane-change maneuvers, obstacle avoidance maneuvers and combined lane-keeping and steering control during critical driving situations. The control is based on the vehicle model that is carried out using the robotics formalism. This modeling approach is considered here for the accuracy it presents, since multi-body models provide more information, which are usually neglected when using a closed-form model. It considers the vehicle as a multi-body poly-articulated system and uses the modified Denavit-Hartenberg geometric description to represent the vehicle. Newton-Euler algorithm is then used to compute the direct dynamical model of the vehicle. The developed model takes into consideration all the vehicle parts and their interconnections, that renders it more representative of the vehicle behavior especially in critical driving scenarios.