  Autonomous vehicular platoons will play an important role in improving
on-road safety in tomorrow's smart cities. Vehicles in an autonomous platoon
can exploit vehicle-to-vehicle (V2V) communications to collect information,
such as velocity and acceleration, from surrounding vehicles so as to maintain
the target velocity and inter-vehicle distance. However, due to the dynamic
on-vehicle data processing rate and the uncertainty of the wireless channel,
V2V communications within a platoon will experience a delay. Such delay can
impair the vehicles' ability to stabilize the operation of the platoon. In this
paper, a novel framework is proposed to optimize a platoon's operation while
jointly consider the delay of the wireless network and the stability of the
vehicle's control system. First, stability analysis for the control system is
performed and the maximum wireless system delay requirements which can prevent
the instability of the control system are derived. Then, delay analysis is
conducted to determine the end-to-end delay, including queuing, processing, and
transmission delay for the V2V link in the wireless network. Subsequently,
using the derived delay, a lower bound and an approximated expression of the
reliability for the wireless system, defined as the probability that the
wireless system meets the control system's delay needs, are derived. Then, the
control parameters are optimized to maximize the derived wireless system
reliability. Simulation results corroborate the analytical derivations and
study the impact of parameters, such as the platoon size, on the reliability
performance of the vehicular platoon. More importantly, the simulation results
disclose the benefits of integrating control system and wireless network design
while providing guidelines for designing autonomous platoons so as to realize
the required wireless network reliability and control system stability.
