Constructing Artificial Traffic Fluids by Designing Cruise Controllers

TL;DR

This paper develops control strategies for autonomous vehicles to create artificial traffic fluids with customizable properties, using Lyapunov-based controllers and macroscopic fluid models.

Contribution

It introduces a novel control Lyapunov function approach for decentralized cruise controllers and derives macroscopic fluid-like models of traffic flow.

Findings

Artificial traffic fluids can be designed with adjustable physical properties.

Decentralized controllers ensure vehicle safety and flow consistency.

Fluid models accurately represent the emergent traffic dynamics.

Abstract

In this paper, we apply a Control Lyapunov Function methodology to design two families of cruise controllers for the two-dimensional movement of autonomous vehicles on lane-free roads using the bicycle kinematic model. The control Lyapunov functions are based on measures of the energy of the system with the kinetic energy expressed in ways similar to Newtonian or relativistic mechanics. The derived feedback laws (cruise controllers) are decentralized, as each vehicle determines its control input based on its own speed and on the relative speeds and distances from adjacent vehicles and from the boundary of the road. Moreover, the corresponding macroscopic models are derived, obtaining fluid-like models that consist of a conservation equation and a momentum equation with pressure and viscous terms. Finally, we show that, by selecting appropriately the parameters of the feedback laws, we can determine the physical properties of the "traffic fluid", i.e. we get free hand to create an artificial fluid that approximates the emerging traffic flow.