Complete Stability Analysis Of Autonomous Vehicle Platoon With Communication Delays

Autonomous vehicles,whose state information can be shared by wireless communication,are moving under the desired spacing policy,providing an effective way of relieving traffic congestion and improving energy efficiency and reducing traffic accidents.Considering the limitation of communication bandwidth and channel obstruction in the communication of V2 V and V2 X,the time delay of communication must exist,which may result in the instability of the vehicle platoon and even cause traffic accidents.It is essential to analyze the stability of vehicle platoon with communication delays and obtain the time delay boundaries,and these works are very important for designing targeted control systems.Most of the existing stability analysis methods for vehicle platoon can only obtain sufficient stability conditions,rather than necessary and sufficient stability conditions,as well as the calculation results of the time delay boundaries are very conservative.Therefore,to access the communication delay boundary of the vehicle platoon,the complete stability of the vehicle platoon with communication delay is studied.The main research work and contributions are summarized as follows:(1)The closed-loop control systems for homogeneous vehicle platoon with single time delay and multiple time delays are constructed,respectively.Meanwhile,the time-delaydependence is proven and the Hurwitz stability criterion with arbitrary information flow topology is proposed for the platoon control system.Furthermore,by using the cluster treatment of characteristic roots(CTCR)paradigm to assess complete stability,the time-delay boundary of the homogeneous platoon control system is obtained.The simulation results support the proposed complete stability analysis method.(2)Considering the different dynamics characteristics and controller gains of the heterogeneous vehicle platoon,the closed-loop control systems and its characteristic equation for homogeneous vehicle platoon with single and multiple time delays are constructed.The state-space form of the subsystems,whose stability is equivalent to the original system,is represented.The time-delay boundary of the heterogeneous platoon control system is obtained using the CTCR paradigm.The simulation results demonstrate the validity of the proposed theoretical method.(3)Based on the PLEXE software platform,the real-time simulation environment of autonomous vehicle platoon is built to make the simulation experiments of homogeneous/heterogeneous vehicle platoon.Besides,the simulation experiments of vehicle platoon with communication delay are represented by modifying the relevant code module under the “four-component” framework.The results are consistent with the numerical simulation results,and further verify the validity of the proposed complete stability analysis method.