A Simulation Framework with Guaranteed Error Bounds for Safety and Fuel-Efficiency Analysis of Vehicle Platoons

Abstract

Vehicle platooning is an important technology in modern transportation systems, offering significant improvements in highway traffic efficiency and fuel economy. Achieving coordinated behavior among vehicles in a platoon depends on wireless communication. However, packet losses in wireless communication can create critical safety issues when they occur together with sudden braking. In this paper, we propose a rigorous simulation-based method for studying such safety issues by analyzing the minimum inter-vehicle distance over time across control parameters that guarantee string stability. In particular, our method computes the exact distance at simulation time instants and guarantees that the change in distance between consecutive simulation time instants remains bounded. Therefore, the distances obtained at simulation times are representative of the continuous-time behavior, and the distances between those times can be accurately approximated. Our derivation relies on a lifted state representation and differential inequalities. For the proposed simulation method, we provide two approaches for selecting simulation times to ensure that the error in distance approximation remains within a given bound. We then extend our method to fuel-efficiency analysis, with guaranteed error bounds for calculating the average fuel savings of vehicles. Through an example involving a highway scenario with a merging lane, we demonstrate that among string-stable control parameter settings for a vehicle platoon, some perform better in terms of safety under simultaneous packet losses and sudden braking. We also identify control parameters that result in tradeoffs between safety and average fuel savings in a vehicle platoon.