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Research Report

Unsettled Issues in Commercial Vehicle Platooning

2021-11-15
EPR2021027
While platooning has the potential to reduce energy consumption of commercial vehicles while improving safety, both advantages are currently difficult to quantify due to insufficient data and the wide range of variables affecting models. Platooning will significantly reduce the use of energy when compared to trucks driven alone, or at a safe distance for a driver without any automated assistance. However, drivers typically drive closer to each other than recommended to achieve drafting efficiencies, which may shift the benefit of automated platooning to safety gains. More data will be needed to conclusively demonstrate these gains. Unsettled Issues in Commercial Vehicle Platooning discusses the technologies needed to enable close platooning, including brake system condition monitoring, vehicle-to-vehicle communication, and concrete infrastructure assessment. The report also looks at driver acceptance of platooning technology from a safety and job security perspective.
Journal Article

A Nonlinear Model Predictive Control Design for Autonomous Multivehicle Merging into Platoons

2021-10-25
Abstract Integrated control for automated vehicles in platoons with nonlinear coupled dynamics is developed in this article. A nonlinear MPC approach is used to address the multi-input multi-output (MIMO) nature of the problem, the nonlinear vehicle dynamics, and the platoon constraints. The control actions are determined by using model-based prediction in conjunction with constrained optimization. Two distinct scenarios are then simulated. The first scenario consists of the multivehicle merging into an existing platoon in a controlled environment in the absence of noise, whereas the effects of external disturbances, modeling errors, and measurement noise are simulated in the second scenario. An extended Kalman filter (EKF) is utilized to estimate the system states under the sensor and process noise effectively.
Journal Article

Trajectory Planning for Connected and Automated Vehicles: Cruising, Lane Changing, and Platooning

2021-10-22
Abstract Autonomy and connectivity are considered among the most promising technologies to improve safety and mobility and reduce fuel consumption and travel delay in transportation systems. In this paper, we devise an optimal control-based trajectory planning model that can provide safe and efficient trajectories for the subject vehicle while incorporating platoon formation and lane-changing decisions. We embed this trajectory planning model in a simulation framework to quantify its fuel efficiency and travel time reduction benefits for the subject vehicle in a dynamic traffic environment. Specifically, we compare and analyze the statistical performance of different controller designs in which lane changing or platooning may be enabled, under different values of time (VoTs) for travelers.
Journal Article

Optimizing Transportation Efficiency: From Exploiting Environmental Conditions to Urban Platooning

2021-10-04
Abstract This article explores a wide variety of energy-saving transportation concepts that exploit the unique characteristics of electric vehicles. The confluence of three emerging concepts in transportation, namely electric vehicles, autonomous navigation, and networked vehicles, is shown to present unprecedented opportunities for the optimization of transportation efficiency, especially for passenger and commercial road vehicles. The article addresses both urban and highway driving situations and some of the associated optimization problems. After the introduction of a suitable powertrain model, several optimization problems of practical importance are formulated. It is shown that if the only term in the cost function is transportation energy, and all other conditions are formulated as constraints, substantial energy cost reductions are possible.
Technical Paper

A Modular Approach to Vehicle Management in a Platoon Group

2021-09-22
2021-26-0125
Platooning is a key research area where increased focus and interest is shown in order to maximize the transport efficiency of road vehicles. Although the key benefits are projected as increased fuel efficiency especially when it comes to commercial vehicles, allied benefits such as convoy pack efficiency, traffic throughput rate, increased life cycle of components and a source of monetary benefit when using a subscription model are areas which need to be explored. Existing literature points to control strategies predominantly focused on longitudinal control and traffic management in bottlenecks.
Technical Paper

Application of Electric Cam Phaser System (ECP) for Smooth Engine Starting Behavior in Hybrid Vehicles

2021-09-22
2021-26-0057
In the current situation and upcoming government regulations, hybrid vehicles are very promising in terms of meeting fuel economy and stringent requirements of emission norms. Herein, hybridization will be mostly done with gasoline and CNG vehicles. As a normal practice, engine is switched off at the signal and again restart with engine start-stop technology. So, instances of engine start/stop are increased in hybrid vehicle in comparison with standard IC engine vehicle. In order to achieve smooth engine start, engine starting torque can be optimized by adjusting engine valve timing. As Electric Cam Phaser (ECP) meets valve timing target even before first engine combustion start, this is one of the critical technologies in reducing engine starting torque and time reaching to idle speed. This engine starting strategy also gives benefits in terms of reducing engine start emissions and improving fuel economy.
Journal Article

A Reinforcement Learning Algorithm for Speed Optimization and Optimal Energy Management of Advanced Driver Assistance Systems and Connected Vehicles

2021-08-25
Abstract This article describes the application of Reinforcement Learning (RL) with an embedded heuristic algorithm to a multi-objective hybrid vehicle optimization. A multi-objective optimization problem (MOP) is defined as a minimization of total energy consumption and trip time resulting from optimal control of vehicle speed over a known route. First, a computationally efficient heuristic optimization algorithm is formulated to solve the MOP for multiple traffic scenarios. Then, the off-line integration of RL is applied to the heuristic optimization algorithm process and utilized to solve the MOP. Finally, the online optimization capability of the machine learning algorithm is discussed, as well as its extension to the vehicle routing problem and the hybrid electric vehicle. The specific scenario investigated is where a generic vehicle begins a trip on a one-lane highway. The length of the highway and the number of vehicles and traffic signals on the road are generic as well.
Standard

Taxonomy and Definitions for Terms Related to Cooperative Driving Automation for On-Road Motor Vehicles

2021-07-16
CURRENT
J3216_202107
This document describes machine-to-machine (M2M) communication to enable cooperation between two or more participating entities or communication devices possessed or controlled by those entities. The cooperation supports or enables performance of the dynamic driving task (DDT) for a subject vehicle with driving automation feature(s) engaged. Other participants may include other vehicles with driving automation feature(s) engaged, shared road users (e.g., drivers of manually operated vehicles or pedestrians or cyclists carrying personal devices), or road operators (e.g., those who maintain or operate traffic signals or workzones). Cooperative driving automation (CDA) aims to improve the safety and flow of traffic and/or facilitate road operations by supporting the movement of multiple vehicles in proximity to one another. This is accomplished, for example, by sharing information that can be used to influence (directly or indirectly) DDT performance by one or more nearby road users.
Standard

Taxonomy and Definition of Safety Principles for Automated Driving System (ADS)

2021-07-07
CURRENT
J3206_202107
This SAE Information Report classifies and defines a harmonized set of safety principles intended to be considered by ADS and ADS-equipped vehicle development stakeholders. The set of safety principles herein is based on the collection and analysis of existing information from multiple entities, reflecting the content and spirit of their efforts, including: SAE ITC AVSC Best Practices CAMP Automated Vehicle Research for Enhanced Safety - Final Report RAND Report - Measuring Automated Vehicle Safety: Forging a Framework U.S. DOT: Automated Driving Systems 2.0 - A Vision for Safety Safety First for Automated Driving (SaFAD) UNECE WP29 amendment proposal UNECE/TRANS/WP.29/GRVA/2019/13 On a Formal Model of Safe and Scalable Self-Driving Cars (Intel RSS model) SAE J3018 This SAE Information Report provides guidance for the consideration and application of the safety principles for the development and deployment of ADS and ADS-equipped vehicles.
Technical Paper

Design and Implementation of an Intelligent Expressway Based on Intelligent Network

2021-06-21
2021-01-5063
With the rapid development of emerging technologies, such as cloud computing, big data, Internet of Things, artificial intelligence, fifth-generation mobile network (5G) technology, the construction of intelligent expressway systems has become a trend. Through the analysis of the intelligent expressway business and function, the overall architecture, technical architecture, and data architecture of this system are designed and presented in this paper. The design of the overall architecture describes the basis of intelligent expressway design and implementation. The technical architecture is the foundation of the overall architecture, making it with more complete functions, high security, and high feasibility. The data architecture helps to achieve effective data coordination through data standard management, resource monitoring, catalog management, metadata management, quality management, and security management.
Technical Paper

Roadside Lidar Helping to Build Smart and Safe Transportation Infrastructure

2021-06-16
2021-01-1013
As part of its research in transportation infrastructure, the University of Nevada, Reno’s Nevada Center for Applied Research, in conjunction with the Regional Transportation Commission of Washoe County and the Nevada DOT, used lidar sensors to collect data aimed at making transportation more efficient, sustainable and safe. This paper summarizes the research results and data obtained by UNR’s Nevada Center for Applied Research. The program integrated lidar sensors with traffic signals to detect, count and track pedestrians, cyclists and traffic. It leveraged the data captured with the sensors to help improve traffic analytics, congestion management and pedestrian safety. The initial lidar sensor was placed at a Reno intersection in 2017. A review of studies and data indicates this may have been the first-ever application of lidar on a traffic signal.
Technical Paper

Safe Operations at Roadway Junctions - Design Principles from Automated Guideway Transit

2021-06-16
2021-01-1004
This paper describes a system-level view of a fully automated transit system comprising a fleet of automated vehicles (AVs) in driverless operation, each with an SAE level 4 Automated Driving System, along with its related safety infrastructure and other system equipment. This AV system-level control is compared to the automatic train control system used in automated guideway transit technology, particularly that of communications-based train control (CBTC). Drawing from the safety principles, analysis methods, and risk assessments of CBTC systems, comparable functional subsystem definitions are proposed for AV fleets in driverless operation. With the prospect of multiple AV fleets operating within a single automated mobility district, the criticality of protecting roadway junctions requires an approach like that of automated fixed-guideway transit systems, in which a guideway switch zone “interlocking” at each junction location deconflicts railway traffic, affirming safe passage.
Magazine

SAE Truck & Off-Highway Engineering: June 2021

2021-06-01
No shortage of challenges Supply chain struggles join perennial challenges for Cummins' off-highway business, namely meeting shifting global emissions standards and satisfying emerging technology trends. Batteries not the only route to EV efficiency Allison CTO stresses efficiency and safety of propulsion units also are critical to reducing cost, improving performance and ultimately winning over customers. Batteries go underground A Saft expert evaluates various Li-ion chemistries and strategies - battery swapping vs. fast charging - for electric mining vehicles. Platooning: an evolving pathway to full autonomy Human-guided convoys can provide real-world benefits sooner than individual driverless trucks, but safety and operational issues still need to be resolved to optimize platoon configurations. Supplier Directory Complete listing of industry suppliers categorized by technology area.
Journal Article

Route-VPlat: Survey and Analysis of Routing Protocols for Communication in Multi-hop Vehicular Platooning

2021-04-13
Abstract Over the years, vehicular communication has become a significant and emerging research area. However, the vehicular platooning concept has gained importance only in the last couple of years or so. Typically, a platoon is a group of vehicles governed by the front vehicle, where all other vehicles follow the instruction of the lead vehicle. The vehicles in a platoon have the flexibility to leave the connected path when their destination has arrived. However, maintaining a continuous communication mechanism is a major challenge that still needs to be solved. In a high-speed dynamic setting of platooning, vehicles need not only to exactly follow the pattern of movement of the lead vehicle but also have seamless communication between the vehicles, even while entering and exiting the platoon. Particularly, multi-hop communication is a critical component for vehicular platooning wherein the lead vehicle could communicate with all vehicles in the platoon.
Technical Paper

Infrastructure Camera Video Data Processing of Traffic at Roundabouts

2021-04-06
2021-01-0165
Roundabout is a unique approach of managing traffic at intersections because it relies on driver’s instincts of safety. Roundabouts are considered safer than other ways of intersection traffic management due to low speed limits, smoother merging, and reduced fatal accidents. Despite their benefits and increasing usage, there is lack of clear understanding of the roundabouts, particularly due to scarcity of data and simulation models and the complexity of the structure. Real-time and offline traffic data recorded at a roundabout provides a basis for 1) identification of the safety issues, 2) understanding unexpected and risky driver behavior, 3) proposing potential mobility solutions, and 4) developing simulation models. The processed data may be used in controlling metered roundabouts, communicating with connected and automated vehicles (CAVs) etc. In this paper an approach to obtain useful traffic information from video feed data at a roundabout is presented.
Technical Paper

Assessing the Impacts of Dedicated CAV Lanes in a Connected Environment: An Application of Intelligent Transport Systems in Corktown, Michigan

2021-04-06
2021-01-0177
The interaction of Connect and Automated vehicles (CAV) with regular vehicles in the traffic stream has been extensively researched. Most studies, however, focus on calibrating driver behavior models for CAVs based on various levels of automation and driver aggressiveness. Other related studies largely focus on the coordination of CAVs and infrastructure like traffic signals to optimize traffic. However, the effects of different strategic flow management of CAVs in the traffic stream in the comparative scenario-based analysis is understudied. Thus, this study develops a framework and simulations for integrating CAVs in a corridor section. We developed a calibrated model with CAVs for a corridor section in Corktown, Michigan, and simulate how dedicated CAV lane operations can be implemented without significant change in existing infrastructure.
Technical Paper

Impact of Lateral Alignment for Cooling Airflow during Heavy-Truck Platooning

2021-04-06
2021-01-0231
A truck platooning system was tested using two heavy-duty tractor-trailer trucks on a closed test track to investigate the thermal control/heat rejection system sensitivity to intentional lateral offsets over a range of intervehicle spacings. Previous studies have shown the following vehicle can experience elevated temperatures and reduced airflow through the cooling package as a result of close-formation platooning. Four anemometers positioned across the grille of the following trucks as well as aligned and multiple offset positions are used to evaluate the sensitivity of the impact. Straight sections of the track are isolated for the most accurate airflow impact measurements and to be most representative of on-highway driving. An intentional lateral offset in truck platooning is considered as a controls approach to mitigate reduced cooling efficacy at close following scenarios where the highest platoon savings are achieved.
Technical Paper

Arrangement and Control Method of Cooperative Vehicle Platoon

2021-04-06
2021-01-0113
With the development of cellular communication technology and for the sake of reducing drag resistance, the multi-lane platoon technology will be more prosperous in the future. In this article, the cooperative vehicle platoon method on the public road is represented. The method’s architecture is mainly composed of the following parts: decision-making, path planning and control command generation. The decision-making uses the finite state machine to make decision and judgment on the cooperative lane change of vehicles, and starts to execute the lane change step when the lane change requirements are met. In terms of path planning, with the goal of ensuring comfort, the continuity of the vehicle state and no collision between vehicles, a fifth-order polynomial is used to fit every vehicle trajectory. In terms of control command generation module, a model predictive control algorithm is used to solve the multi-vehicle centralized optimization control problem.
Technical Paper

Correlation between Sensor Performance, Autonomy Performance and Fuel-Efficiency in Semi-Truck Platoons

2021-04-06
2021-01-0064
Semi-trucks, specifically class-8 trucks, have recently become a platform of interest for autonomy systems. Platooning involves multiple trucks following each other in close proximity, with only the lead truck being manually driven and the rest being controlled autonomously. This approach to semi-truck autonomy is easily integrated on existing platforms, reduces delivery times, and reduces greenhouse gas emissions via fuel economy benefits. Level 1 SAE fuel studies were performed on class-8 trucks operating with the Auburn Cooperative Adaptive Cruise Control (CACC) system, and fuel savings up to 10-12% were seen. Enabling platooning autonomy required the use of radar, global positioning systems (GPS), and wireless vehicle-to-vehicle (V2V) communication. Poor measurements and state estimates can lead to incorrect or missing positioning data, which can lead to unnecessary dynamics and finally wasted fuel.
Technical Paper

Experimental Fuel Consumption Results from a Heterogeneous Four-Truck Platoon

2021-04-06
2021-01-0071
Platooning has the potential to reduce greenhouse gas emissions of heavy-duty vehicles. Prior platooning studies have chiefly focused on the fuel economy characteristics of two- and three-truck platoons, and most have investigated aerodynamically homogeneous platoons with trucks of the same trim. For real world application and accurate return on investment for potential adopters, non-uniform platoons and the impacts of grade and disturbances on a platoon’s fuel economy must also be characterized. This study investigates the fuel economy of a heterogeneous four-truck platoon on a closed test track. Tests were run for one hour at a speed of 45 mph. The trucks used for this study are two 2015 Peterbilt 579’s with a Cummins ISX15 and a Paccar MX-13, and two 2009 Freightliner M915A5’s, one armored and the other unarmored. Many analysis methodologies were leveraged to describe and compare the fuel data, including lap-wise and track-segment analysis.
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