Stability and Safety of Cooperative Adaptive Cruise Control Vehicular Platoon under Diverse Information Flow Topologies

Abstract

For the cooperative adaptive cruise control (CACC) vehicular platoon, apart from decentralized controllers, the dynamics of a platoon can be affected substantially by the information flow among connected and automated vehicles (CAVs). Existing research studies mainly focus on the stability analysis of platoons where CAVs only adopt the predecessor-following (PF) communication scheme; however, when CAVs “look” further ahead or behind than one vehicle, the stability of platoons might change. To this end, this study seeks to explore the stability and investigate the rear-end collision risk of CACC vehicular platoon under diverse information flow topologies. The research first comprehensively reviews typical information flow topologies for CAV platoons and platoon stability criteria for analyzing local and string stability of platoons. Moreover, the CACC longitudinal dynamic model is derived using the exact feedback linearization technique, which accommodates the inertial delay of powertrain dynamics. Accordingly, sufficient conditions of stability are mathematically derived to guarantee distributed frequency-domain-based control parameters. Simulation experiments are conducted to verify the correctness of derived sufficient stability conditions. The results show that platoons could better maintain stability with more vehicle information taken into consideration. However, when assessing the safety, it is found that the bidirectional type information flow topology would increase rear-end collision risk for CAV platoon. Further, the information flow topology of two-predecessor-leader following is the most recommended to enhance fully CAV platoon stability.

A Two-Stage Cooperative Adaptive Cruise Control for Connected Automated Vehicles in Multislope Roads considering Communication Delay and Actuator Delay

“…Platoon Communication Topology. According to the papers [38][39][40][41], it is mentioned that platoons could better maintain stability with more vehicle information taken into consideration, and the bidirectional topology would increase rear-end collision risk. Considering the platoon stability and the amount of data that need to be processed, the predecessor-leader following topology is used in this paper and is shown in Figure 1.…”

“…For communication topology, they could classically be categorized into six types [38]: (1) predecessor-following (PF) topology; (2) bidirectional (BD) topology; (3) predecessor-leader-following (PLF) topology; (4) two-predecessor-following (TPF) topology; (5) bidirectional-leader-following (BDLF) topology; and (6) twopredecessor-leader-following (TPLF) topology. Te abovementioned six communication topologies are studied in the literature [39]. Te platoon tends to be more stable as more information is received by the vehicles, but BD will increase the risk of tailgating.…”

Research on a Cooperative Adaptive Cruise Control (CACC) Algorithm Based on Frenet Frame with Lateral and Longitudinal Directions

“…In recent years, the research on CACC mainly focuses on longitudinal single-lane control, including stability analysis [ 30 , 31 , 32 , 33 , 34 ], communication problem analysis [ 35 , 36 , 37 , 38 ], heterogeneous problem analysis [ 39 , 40 , 41 , 42 ], etc. The control algorithm is mainly aimed at improving the original single-vehicle control algorithm, such as PID control, sliding mode control, and distributed model predictive control.…”