Traffic Control Via Platoons of Intelligent Vehicles for Saving Fuel Consumption in Freeway Systems

Abstract

In this paper a coupled PDE-ODE model describing the interaction between the bulk traffic flow and a platoon of connected vehicles is adopted to develop a control action aiming at reducing the fuel consumption of the overall traffic flow. The platoon is modeled as a capacity restriction acting on the surrounding traffic. The trajectory of the initial and final points of the platoon are optimized by means of a model predictive control strategy, acting on the speeds of the front-end and backend of the platoon, thus resulting in controlling both the speed and the length of the platoon. The approach is assessed in simulations.

Centralized Traffic Control via Small Fleets of Connected and Automated Vehicles

“…, u * N ) : [0, T f ] → R N minimizing a chosen performance index (the cost function). Aiming at reducing fuel consumption and the associated pollutant emissions in case of traffic congestion, we concentrate here on the Total Fuel Consumption (TFC) introduced in [8] and later considered in [6], [24], which is defined as T F C(ρ) = ρF C(ρ), where, due to the first order modeling setting not accounting for accelerations, it is assumed that the fuel consumption rate F C(ρ) = K(v(ρ)) is described as a function of the traffic density through its relation to the average traffic speed. This dependence relation is approximated by a sixth order polynomial K(v), that expresses the fuel consumption as a function of the speed: A Model Predictive Control (MPC) approach has been selected, since it can deal with nonlinear systems, multicriteria optimization and constraints [25].…”

Multi-Scale Model-Based Hierarchical Control of Freeway Traffic via Platoons of Connected and Automated Vehicles

“…They are assumed to be immersed in the macroscopic freeway traffic, which is also composed of conventional (i.e., low automation) vehicles, and are controlled so as to produce a regularizing effect on the surrounding traffic flow by acting as "moving bottlenecks". For instance, in [29], a multi-variable MPC is proposed to control the length and the speed of a platoon of CAVs, with the aim of reducing the fuel consumption of the overall vehicular traffic. In [30], macroscopic models accounting for the trajectory of moving bottlenecks have been proposed, as it is also done, in alternative ways, in [31]- [33].…”

“…Inspired by [29] and [37], in this paper a novel hierarchical multi-level control scheme is proposed to reduce traffic congestion and fuel consumption in freeway traffic systems. The proposal consists of four key elements: a high-level MPC relying on the nominal model of the freeway traffic with a platoon of electric CAVs; an event-triggered logic to enable the high-level optimization only when it is actually needed; medium-level distributed MPCs, one for each CAV in the platoon, in order to track the reference values provided by the high-level control in an energy efficient way; finally, low-level integral sliding mode controllers, acting locally at the level of any single CAV, to enhance the control robustness.…”

“…• It is capable of optimizing, via a high level MPC, a performance index related to both traffic congestion and fuel consumption of vehicles in a freeway stretch with a platoon of electric CAVs. The high level MPC is based on the nominal traffic model, but, differently from [29], it is applied to a traffic system where the traffic demand is not a priori known and where the microscopic/mesoscopic dynamics of the CAVs and of the platoon they form is not neglected. • It is based on an event-triggered control logic, which activates the high level optimizer only when necessary.…”

An Adaptive Disturbance Decoupling Perspective to Longitudinal Platooning

“…The topics of longitudinal platoons of automated vehicles (automated vehicles following each other in string formation) have been investigated in different directions, spanning from computer vision, control and impact in the traffic flow [1]. A pioneering result was the one of Peppard [2], which introduced the problem of 'string stability', i.e.…”