Source-linked AI summary
Hardware-in-the-Loop Demo of a Cooperative Intersection where Cars don't Stop
Lorenzo Farina, Matteo Piccoli, Salvatore Iandolo, Antonio Solida, Carlo Augusto Grazia, Marco Rapelli, Francesco Raviglione, Claudio Casetti, Alessandro Bazzi
TL;DR
Connected vehicles coordinating intersection movements could optimize crossings and reduce energy use and travel time. This demo implements that coordination in a HiL setup, using SUMO to simulate positions and real hardware and software to connect vehicles with a remote controller. It reports that vehicles can optimize approach speed and cross without stopping.
Problem
The paper addresses how connected autonomous vehicles can coordinate intersection movements to optimize crossings and reduce energy use and travel time.
Source: §I · p. 1Method
A HiL intersection demo uses SUMO to simulate vehicle positions while vehicle and roadside hardware exchange proposals with a controller that validates crossing profiles.
Source: §I · p. 1, §II · p. 2Results
The demo reports that its algorithm and communication protocol effectively optimize approach speed so vehicles can cross without stopping.
Source: §II · p. 3Takeaways & Limitations
The solution is reported to significantly reduce travel times and emissions compared with traffic lights or right-of-way rules.
Source: §I · p. 1The HiL is a preliminary step toward a planned field trial with 1:10 mini-cars on a track.
Source: §III · p. 3
Abstract
from arXiv · showhide
The road transportation sector is undergoing a radical transformation, working for a future where all vehicles will be autonomous and connected. A key challenge in this vision concerns intersections, which will no longer rely on traffic lights or traditional right-of-way rules. Instead, algorithms and communication protocols will be employed to optimize traffic flow. In this context, we are developing a testbed where cars equipped with wireless connectivity exchange information with a remote controller and coordinate their maneuvers. As the vehicles navigate through different types of intersections with various routes, they communicate with the controller, adjusting their speed to pass through intersections without stopping. This demo specifically showcases a hardware-in-the-loop (HiL) implementation of such intelligent intersection, using the SUMO traffic simulator to emulate vehicle positions. Real hardware and software components, which are designed for use in vehicles and roadside infrastructure, are employed to enable real-time data exchange of contextual and control information, running the cooperative coordination algorithm.
I. Introduction and motivations
Connected autonomous vehicles can coordinate intersection movements to optimize crossings, with the prospect of reducing energy use and travel time. The demo moves intersection coordination from theoretical study toward real protocols and hardware, using a HiL implementation in which SUMO simulates vehicle positions and a controller adjusts speeds so vehicles need not stop.
I. Introduction and motivations
- Intersection coordination is presented as a way to optimize crossings and reduce energy consumption and travel time.The paper identifies intersections as a critical scenario for connected autonomous vehicles.Source: §I · p. 1
- The project implements algorithms for vehicles to cross intersections without stopping, extending work previously studied from a theoretical perspective into real protocols and hardware.The authors describe this implementation effort as part of the Italian national project Restart MoVeOver.Source: §I · p. 1
- The controller's algorithm optimizes approaching vehicles' speeds so they can cross without stopping, and the solution is reported to reduce travel times and emissions versus traffic lights or right-of-way rules.The demo uses SUMO to simulate vehicle positions while other components use hardware and software intended for real cars.Source: §I · p. 1
II. Demo description
The demo combines simulated vehicle positions with vehicle and roadside hardware connected to a remote controller. Its coordination protocol validates proposed crossing profiles, while the demonstration reports that vehicles can optimize their approach speed and cross without stopping.
Demo setup
- The example uses an eight-shaped circuit where four vehicles choose directions randomly and approach the intersection without stopping.The setup links vehicles wirelessly to a remote controller; Fig. 1 depicts the SUMO scenario and OBUs alongside the RSU and controller.Source: §II · p. 1, Figure 1 · p. 2
Software and hardware
- OScar is an open-source ETSI C-ITS network stack spanning Transport and Networking through Facilities, with a modular C++ implementation usable on Linux systems including Raspberry Pi.The demo uses Raspberry Pi hardware for the OBU and RSU.Source: §II · p. 1
- The demo's hardware includes a Raspberry Pi 5 Model B with a PCIe HAT installed to host a Wi-Fi card.The figure caption identifies a 1:10 mini-car equipped with a low-cost OBU.Source: §II · p. 2, Figure 2 · p. 3
Communications
- The OBU and RSU exchange proprietary IP-based messages over IEEE 802.11p, with standardized ETSI maneuver coordination messages planned as a future shift.The paper describes the 802.11p network and OCB mode as enabling immediate, very-low-latency data exchange for V2X.Source: §II · p. 2
Coordination protocol
- Vehicles submit position, speed, and acceleration profiles; the controller accepts non-conflicting proposals or rejects them with timing constraints for resubmission.The vehicle must secure an agreed profile before reaching a distance that allows safe and comfortable braking; otherwise, it enters sensor-reliant backup mode without an agreed speed profile.Source: §II · pp. 2–3
Demo results
- The demo reports that its algorithm and communication protocol effectively optimize approach speed so vehicles can cross without stopping.The paper also reports reduced travel times and emissions for the solution compared with traditional intersection management methods.Source: §II · p. 3
III. Future work
The HiL is a preliminary step toward a field trial in which 1:10 mini-cars will approach a real intersection on a track without stopping. Raspberry Pi and OScar are used instead of larger, energy-hungry commercial V2X devices so the OBUs can be mounted on the mini-cars.
III. Future work
- Using Raspberry Pi and OScar rather than larger, energy-hungry commercial V2X devices allows OBUs to be mounted on 1:10 mini-cars for a planned track-based field trial.The authors characterize the current HiL as a preliminary step toward that trial.Source: §III · p. 3