Stability analysis and delayed feedback control for platoon of connected automated vehicles with V2X and V2V infrastructure

The dual processing paradigm is a powerful design structure for an autonomous vehicle, in which the driver can take over the vehicle control from an autonomous driving mode to a personal driving mode when the driver thinks the current environment is too complicated for autonomous driving. However, the perception of the motion of a preceding vehicle often affects a follower driver's decision, which inevitably affects the cruising speed of a concerned platoon. With the advancement of information and communication technologies (ICT), the ability of drivers to perceive information can be significantly improved. This paper addresses the platoon control problem for connected automated vehicles (CAVs) with a car-following model and a reaction-time delay under different inter-vehicle communication environments (such as the vehicle-to-vehicle (V2V) mode with pairwise communications and vehicle-to-everything (V2X) mode with simultaneous broadcast). By modeling the reaction-time delay, a nonlinear integrated parameter model is introduced, in which the vehicles’ behavior is assumed to be affected by the “optimal velocity model” (OVM) and connected environments. To capture our daily experience that a driver typically immediately follows the speed change of the preceding vehicle, a combination of the integrated parameter model and velocity difference models is presented, and the string stability of traffic flow and the platoon dynamics for CAVs with a car-following model and the reaction-time delay under V2V and V2X modes are developed and analyzed, respectively. In addition, a delayed feedback design for platoon tracking is developed to improve the tolerable upper bound of reaction-time delay. Our analysis and simulation results show that when the leader vehicle slows down suddenly, (1) the tolerable upper bound of reaction-time delay of the CAVs in the V2X mode is significantly greater than that in the V2V mode; (2) increasing a small reaction-time delay may improve the traveling speed of some rear follower vehicles; and (3) the delayed feedback control can provide additional benefits in terms of traveling speed adjustment for the last few follower vehicles.