Browse Topic: Platooning

Items (163)
ABSTRACT This work presents the development of an algorithm to incorporate measurements from multiple antennas to improve the relative position solution between convoying vehicles provided by Global Positioning System (GPS) measurements. The technique presented, incorporates measurements from multiple antennas with a known fixed-baseline between a base antenna and auxiliary antenna on a base vehicle, and a rover antenna on a rover vehicle. The additional information provided by the fixed-baseline distance is used to provide an additional measurement with low uncertainty for improved integer ambiguity resolution between the base and auxiliary receiver, which in turn, provides additional measurements for determining the integer ambiguity difference between the base and rover receivers for the computation of a high-precision relative position vector (HPRPV
Tabb, Thomas T.Bevly, DavidMartin, ScottRatowski, Jeff
ABSTRACT Military personnel involved in convoy operations are often required to complete multiple tasks within tightly constrained timeframes, based on limited or time-sensitive information. Current simulations are often lacking in fidelity with regard to team interaction and automated agent behavior; particularly problematic areas include responses to obstacles, threats, and other changes in conditions. More flexible simulations are needed to support decision making and train military personnel to adapt to the dynamic environments in which convoys regularly operate. A hierarchical task analysis approach is currently being used to identify and describe the many tasks required for effective convoy operations. The task decomposition resulting from the task analysis provides greater opportunity for determining decision points and potential errors. The results of the task analysis will provide guidance for the development of more targeted simulations for training and model evaluation from
Garrison, Teena M.Thomas, Mark D.Carruth, Daniel W.
ABSTRACT Occupant safety is a top priority of military vehicle designers. Recent trends have shifted safety emphasis from the threats of ballistics and missiles toward those of underbody explosives. For example, the MRAP vehicle is increasingly replacing the HMMWV, but it is much heavier and consumes twice as much fuel as its predecessor. Recent reports have shown that fuel consumption directly impacts personnel safety; a significant percentage of fuel convoys that supply current field operations experience casualties en route. While heavier vehicles tend to fare better for safety in blast situations, they contribute to casualties elsewhere by requiring more fuel convoys. This study develops an optimization framework that uses physics-based simulations of vehicle blast events and empirical fuel consumption data to calculate and minimize combined total expected injuries from blast events and fuel convoys. Results are presented by means of two parametric studies, and the utility of the
Hoffenson, StevenKokkolaras, MichaelPapalambros, PanosArepally, Sudhakar
ABSTRACT To improve robustness of autonomous vehicles, deployments have evolved from a single intelligent system to a combination of several within a platoon. Platooning vehicles move together as a unit, communicating with each other to navigate the changing environment safely. While the technology is robust, there is a large dependence on data collection and communication. Issues with sensors or communication systems can cause significant problems for the system. There are several uncertainties that impact a system’s fidelity. Small errors in data accuracy can lead to system failure under certain circumstances. We define stale data as a perturbation within a system that causes it to repetitively rely on old data from external data sources (e.g. other cars in the platoon). This paper conducts a fault injection campaign to analyze the impact of stale data in a platooning model, where stale data occurs in the car’s communication and/or perception system. The fault injection campaign
Louis, August St.Calhoun, Jon C.
ABSTRACT Leader-follower autonomous vehicle systems have a vast range of applications which can increase efficiency, reliability, and safety by only requiring one manned-vehicle to lead a fleet of unmanned followers. The proper estimation and duplication of a manned-vehicle’s path is a critical component of the ongoing development of convoying systems. Auburn University’s GAVLAB has developed a UWB-ranging based leader-follower GNC system which does not require an external GPS reference or communication between the vehicles in the convoy. Experimental results have shown path-duplication accuracy between 1-5 meters for following distances of 10 to 50 meters. Citation: K. Thompson, B. Jones, S. Martin, and D. Bevly, “GPS-Independent Autonomous Vehicle Convoying with UWB Ranging and Vehicle Models,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022
Thompson, KyleJones, BenMartin, ScottBevly, David
ABSTRACT This paper will document the development of the Convoy Active Safety Technology (CAST) program, which was created to design a low cost, optionally manned vehicle (OMV) solution for tactical wheeled vehicle (TWV) fleet. This paper will describe the approach taken to integrate low cost sensors for understanding the environment sufficiently to accomplish convoy missions. This paper will also discuss the approach taken to develop the low cost guidance and navigation solution used in the CAST program
Simon, DavidTheisen, Bernard
ABSTRACT As unmanned ground vehicle technology matures and autonomous platforms become more common, such platforms will invariably be in close proximity to one another both in formation and independently. With an increasingly crowded field, the risk of collisions between these platforms grows, and with it the need for path deconfliction. This paper presents two complementary technological developments to this end: a pipeline for affirmatively identifying and classifying dynamic objects, e.g., vehicles or pedestrians; and a pipeline for preventing collisions with such objects. The efficacy of these techniques is demonstrated in simulation, and validation on robotic platforms will be undertaken in the near future. Citation: Matthew Grogan, “Dynamic Object Collision Avoidance for Autonomous Multi-Vehicle Systems in the Robotic Technology Kernel”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 13-15, 2019
Grogan, Matthew
ABSTRACT The application of advanced FEV Automotive Smart Vehicle© methods and technologies while maintaining functional safety compliance and how it applies to similar features, requirements and capabilities across the fleet of DoD combat and tactical vehicles will be discussed. The requirement of technologies for DoD autonomous ground vehicle including leader follower, automated convoy operations, and intelligent applique kit’ are common to those specified in the automotive industries. Intelligent vehicles can be advanced and implemented in an expeditious manner through FEV Smart Vehicle technologies, techniques and methodologies while maintain compliance to required functional safety. The application and impact of ISO 26262 (2011) as well as Mil-Std. 882(E) to the implementation of the advanced technologies and techniques in support of full operational vehicle autonomy can hinder development. Leveraging the FEV Automotive Smart Vehicle reduces the time and cost for safety compliant
LaRue, David A.Tasky, TomTarnutzer, StephanLane, Jerry
ABSTRACT The automotive and defense industries are going through a period of disruption with the advent of Connected and Automated Vehicles (CAV) driven primarily by innovations in affordable sensor technologies, drive-by-wire systems, and Artificial Intelligence-based decision support systems. One of the primary tools in the testing and validation of these systems is a comparison between virtual and physical-based simulations, which provides a low-cost, systems-approach testing of frequently occurring driving scenarios such as vehicle platooning and edge cases and sensor-spoofing in congested areas. Consequently, the project team developed a robotic vehicle platform—Scaled Testbed for Automated and Robotic Systems (STARS)—to be used for accelerated testing elements of Automated Driving Systems (ADS) including data acquisition through sensor-fusion practices typically observed in the field of robotics. This paper will highlight the implementation of STARS as a scaled testbed for rapid
Lodato, DiegoKamalanathsharma, RajFarber, Maurice
ABSTRACT Sharing information among vehicles in an unmanned ground vehicle (UGV) convoy allows for improved vehicle performance and reduces the need for each vehicle to be equipped with a full-suite of sensors. Information such as obstacle data, surface properties, and terrain maps are particularly useful for vehicle control and high-level behaviors. This paper describes a system architecture for sharing semantic information among vehicles in a convoy operation. This architecture is demonstrated by sharing terrain information between vehicles in a two-vehicle convoy in both simulation and on actual autonomous vehicles. Update rules fuse information from different sources in a statistical manner and allow for an onboard algorithm to make high-level decisions about the incoming data whether it be from its own sensors or semantic information from other vehicles
Ferrin, Jeffrey L.Bybee, Taylor C.
ABSTRACT This paper presents Neya’s efforts in developing autonomous depot assembly and parking behaviors for the Ground Vehicle Systems Center’s (GVSC) Autonomous Ground Re-supply (AGR) program. Convoys are a prime target for the enemy, and therefore GVSC is making efforts to remove the human operators and make them autonomous. However, humans still have to manually drive multiple convoy vehicles to and from their depot parking locations before and after autonomous convoy operations – a time-consuming and laborious process. Neya systems was responsible for the design, development, and testing of the autonomous depot assembly and disassembly behaviors, enabling end-to-end autonomy for convoy operations. Our solution to the problem, including the concept of operations, design, as well as approaches towards testing and validation are described in detail
Mattes, RichBruck, KurtCascone, AnthonyMartin, Dave
ABSTRACT In this paper, we present CLICS, a program that optimizes convoy vehicle tracks by intelligently combining sensor updates of all vehicles in the convoy in a distributed, cooperative localization system. Currently, follower vehicles in the convoy rely either on GPS breadcrumbs from the lead vehicle, or rely on sensing the location of its predecessor and following its path. However, GPS availability and accuracy oftentimes cause the former solution to fail, and accumulated errors in tracking and control in long convoys can cause the latter solution to fail. Robotic Research’s CLICS system attempts to overcome these problems by (1) integrating multiple heterogeneous sensor outputs from multiple vehicles (2) developing a distributed, real-time non-linear estimation of inter-vehicle pose using spring network providing coordinated localization for members of a vehicle convoy, and (3) real-time robust synchronization of information amongst the convoy, and local convoy and mission
Wilhelm, RayBalas, CristianSchneider, AnneKlarquist, WilliamLacaze, AlbertoMurphy, Karl
ABSTRACT In this paper, we will present the results of our efforts developing the Autonomy Kit for the Tank Automotive Research Development and Engineering Center’s (TARDEC) Autonomous Ground Resupply (AGR) Sustainment Operations (SO) program. Robotic Research, LLC was responsible for the design, build, and implementation of the “Autonomy Kit” for the AGR SO. The Autonomy Kit is designed to be a fault-tolerant, vehicle-agnostic applique kit that provides the hardware and software needed to perform higher-level autonomous driving and planning functions. In the first Increment, the main focus was developing a “Leader/Follower” capability, where a manned “Leader” vehicle could perform a mission with a number of unmanned “Followers” reproducing its trajectory, maintaining convoy constraints, and avoiding obstacles in the path
Schneider, AnneBecker, WilliamHoward, JohnCichosz, AlanTheisen, BernardConger, David
ABSTRACT Many significant advances have been made in autonomous vehicle technology over the recent decades. This includes platooning of heavy trucks. As such, many institutions have created their own version of the basic platooning platform. This includes the California PATH program [1], Japan’s “Energy ITS” project [2], and Auburn University’sCACC Platform [3]. One thing these platforms have in common is a strong dependence on GPS based localization solutions. Issues arise when the platoon navigates into challenging environments, including rural areas with foliage which might block receptions, or more populated areas which might present urban canyon effects. Recent research focus has shifted to handling these situations through the use of alternative sensors, including cameras. The perception method proposed in this paper utilizes the You Only Look Once (YOLO) real-time object detection algorithm in order to bound the lead vehicle using both RGB and IR cameras. Range and bearing are
Flegel, TylerChen, HowardBevly, David
ABSTRACT We describe a simulation environment that enables the design and testing of control policies for off-road mobility of autonomous agents. The environment is demonstrated in conjunction with the design and assessment of a reinforcement learning policy that uses sensor fusion and inter-agent communication to enable the movement of mixed convoys of conventional and autonomous vehicles. Policies learned on rigid terrain are shown to transfer to hard (silt-like) and soft (snow-like) deformable terrains. The enabling simulation environment, which is Chrono-centric, is used as follows: the training occurs in the GymChrono learning environment using PyChrono, the Python interface to Chrono. The GymChrono-generated policy is subsequently deployed for testing in SynChrono, a scalable, cluster-deployable multi-agent testing infrastructure that uses MPI. The Chrono::Sensor module simulates sensing channels used in the learning and inference processes. The software stack described is open
Negrut, D.Serban, R.Elmquist, A.Taves, J.Young, A.Tasora, A.Benatti, S.
ABSTRACT This paper presents two techniques for autonomous convoy operations, one based on the Ranger localization system and the other a path planning technique within the Robotic Technology Kernel called Vaquerito. The first solution, Ranger, is a high-precision localization system developed by Southwest Research Institute® (SwRI®) that uses an inexpensive downward-facing camera and a simple lighting and electronics package. It is easily integrated onto vehicle platforms of almost any size, making it ideal for heterogeneous convoys. The second solution, Vaquerito, is a human-centered path planning technique that takes a hand-drawn map of a route and matches it to the perceived environment in real time to follow a route known to the operator, but not to the vehicle. Citation: N. Alton, M. Bries, J. Hernandez, “Autonomous Convoy Operations in the Robotic Technology Kernel (RTK)”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI
Alton, NicholasBries, MatthewHernandez, Joseph
Traditional live testing of autonomous ground vehicles can be augmented through use of digital twins of the test environment, the vehicle mobility models, and the vehicle sensors. These digital twins combined with the autonomous software under test allow testers to inject faults, weather, obstacles, find edge case scenarios, and collect information to understand the decision making of the autonomous software under test. With this new capability, autonomous ground vehicles can now be tested in four stages. The first stage is testing the autonomous software using digital twins. In this stage with the help of a High-Performance Computer thousands of scenarios can be run. Once issues are communicated and addressed, stage two, hardware in the loop testing can begin. Hardware in the loop uses simulators that already exist to test systems such as autonomous convoys with a virtual leader and a live follower. Stage three employs a live virtual constructive approach by using one vehicle to test
Whitt, John M.Bounker, Paul J.
The deployment of autonomous urban buses brings with it the hope of addressing concerns associated with safety and aging drivers. However, issues related autonomous vehicle (AV) positioning and interactions with road users pose challenges to realizing these benefits. This report covers unsettled issues and potential solutions related to the operation of autonomous urban buses, including the crucial need for all-weather localization capabilities to ensure reliable navigation in diverse environmental conditions. Additionally, minimizing the gap between AVs and platforms during designated parking requires precise localization. Next-gen Urban Buses: Autonomy and Connectivity addresses the challenge of predicting the intentions of pedestrians, vehicles, and obstacles for appropriate responses, the detection of traffic police gestures to ensure compliance with traffic signals, and the optimization of traffic performance through urban platooning—including the need for advanced communication
Hsu, Tsung-Ming
This article offers an algorithmic solution for moving a homogeneous platoon of position-controlled vehicles on a curved path with varying speeds and in the presence of communication losses and delays. This article considers a trajectory-based platooning with the leader–following communication topology, where the lead vehicle communicates its reference position and orientation to each autonomous follower vehicle. A follower vehicle stores this communicated information for a specific period as a virtual trail of the lead vehicle starting from the lead vehicle’s initial position and orientation. An algorithm uses this trail to find the follower vehicle’s reference position and orientation on that trail, such that the follower vehicle maintains a constant distance from the lead vehicle. The proposed algorithm helps form a platoon where each vehicle can traverse a curve with varying speeds. In contrast, in the existing literature, most of the solutions for vehicle platooning on a curved
Bhaskar, RintuWahi, PankajPotluri, Ramprasad
There have been numerous studies on stable platooning, but almost all of them have been on the longitudinal stability problem, wherein, without sufficient longitudinal stability, traffic congestion might occur more frequently than in traffic consisting of manually driven vehicles. Failure to solve this problem would reduce the value of autonomous driving. Recently, some researchers have begun to tackle the lateral stability problem, anticipating shortened intervehicle distances in the future. Here, the intervehicle distance in a platoon should be shortened to improve transportation efficiency. However, if an obstacle to be avoided exists, the following vehicles might have difficulty finding it quickly enough if the preceding vehicle occludes it from their sensors. Also, longer platoons improve transportation efficiency because the number of gaps between platoons is reduced. Hence, in this study, the lateral stability of platoons consisting of autonomous vehicles was analyzed for not
Kurishige, Masahiko
This research investigates platoon dispersion characteristics in mixed-traffic flow of autonomous and human-driven vehicles. It presents a cellular automata-based platoon dispersion model. The study’s key findings are as follows: platoon dispersion initially increases and then decreases with the rise in autonomous vehicle proportions. When the autonomous vehicle proportion is approaching 100%, platoon dispersion descends rapidly and is completely eliminated while the proportion is 100%. Compared to platoon consisting entirely of human-driven vehicles, the peak value of standard deviation of vehicle speed is 1.71 times and the travel time drops by 38.19% when the proportion is 1. Moreover, the lane-changing behavior enhances platoon speed, acceleration, and space utilization at micro- and macrolevels by optimizing space resource allocation within the platoon. The study employs a two-lane mixed-flow platoon dispersion model that assumes uniform vehicle characteristics and prioritizes
Lu, TingLiu, ChenghaoLin, SitongSong, Wenjing
Truck platooning facilitates the operation of trucks in close proximity to one another, resulting in decreased air resistance and improved fuel efficiency. While previous research has mostly focused on the effects of intra-distance on fuel savings, this study aims to develop fuel savings performance functions considering various truck platooning configurations. This article comprehensively investigates the influence of different truck platoon configurations on fuel savings. This analysis focuses on examining the impacts of several variables including inter-vehicle distance, platoon speed, truck weight, number of trucks in the platoon, and the truck’s distinctive design characteristics. Data used in the analysis were collected from 10 different field experiments. Three machine learning techniques—artificial neural networks (ANN), extreme gradient boosting (XGBoost), and K-nearest neighbors (KNN)—alongside the negative binomial regression model were employed. Upon evaluation, the
Mohamed, MohamedHassan, Hany M.
Truck platooning is an emerging technology that exploits the drag reduction experienced by bluff bodies moving together in close longitudinal proximity. The drag-reduction phenomenon is produced via two mechanisms: wake-effect drag reduction from leading vehicles, whereby a following vehicle operates in a region of lower apparent wind speed, thus reducing its drag; and base-drag reduction from following vehicles, whereby the high-pressure field forward of a closely-following vehicle will increase the base pressure of a leading vehicle, thus reducing its drag. This paper presents a physics-guided empirical model for calculating the drag-reduction benefits from truck platooning. The model provides a general framework from which the drag reduction of any vehicle in a heterogeneous truck platoon can be calculated, based on its isolated-vehicle drag-coefficient performance and limited geometric considerations. The model is adapted from others that predict the influence of inter-vehicle
McAuliffe, Brian
Platooning is a coordinated driving strategy by which following trucks are placed into the wake of leading vehicles. Doing this leads to two primary benefits. First, the vehicles following are shielded from aerodynamic drag by a “pulling” effect. Secondly, by placing vehicles behind the leading truck, the leading vehicles experience a “pushing” effect. The reduction in aerodynamic drag leads to reduced fuel usage and, consequently, reduced greenhouse gas emissions. To maximize these effects, the inter-vehicle distance, or headway, needs to be minimized. In current platooning strategy iterations, Coordinated Adaptive Cruise Control (CACC) is used to maintain close following distances. Many of these strategies utilize the fuel rate signal as a controller cost function parameter. By using fuel rate, current control strategies have limited applicability to non-conventional powertrains. Vehicle Specific Power (VSP) has shown promise as a metric by which the performance of such controllers
Bentley, JohnStegner, EvanBevly, David M.Hoffman, Mark
With the rapid development of intelligent driving technology, there has been a growing interest in the driving comfort of automated vehicles. As vehicles become more automated, the role of the driver shifts from actively engaging in driving tasks to that of a passenger. Consequently, the study of the passenger experience in automated driving vehicles has emerged as a significant research area. In order to examine the impact of automatic driving on passengers' riding experience in vehicle platooning scenarios, this study conducted real vehicle experiments involving six participants. The study assessed the subjective perception scores, eye movement, and electrocardiogram (ECG) signals of passengers seated in the front passenger seat under various vehicle speeds, distances, and driving modes. The results of the statistical analysis indicate that vehicle speed has the most substantial influence on passenger perception. The driving mode has a minor effect on the passenger riding experience
Hu, HongyuZhang, GuojuanCheng, MingLi, ZhengyiHe, LeiSu, Lili
The main objective of platoon control is coordinated motion of autonomous vehicle platooning with small intervehicle spacing while maintaining the same speed and acceleration as the leading vehicle, which can save energy consumption and improve traffic throughput. The conventional platoon control methods are confronted with the problem of manual parameter tuning. In order to addres this isue, a novel bifold platoon control approach leveraging a deep reinforcement learning-based model is proposed, which enables the platoon adapt to the complex traffic environment, and guarantees the safety of platoon. The upper layer controller based on the TD3 tuned PID algorithm outputs the desired acceleration. This integration mitigates the inconvenience of frequent manual parameter tuning asociated with the conventional PID algorithm. The lower layer controller tracks the desired acceleration based on the inverse vehicle dynamics model and feedback control. Through this dynamic inverse model, the
Chen, XinhaiWang, RukangCui, YananJin, XiaoxinFeng, ChengjunXie, BoDeng, ZejianChu, Duanfeng
With the extension of intelligent vehicles from individual intelligence to group intelligence, intelligent vehicle platoons on intercity highways are important for saving transportation costs, improving transportation efficiency and road utilization, ensuring traffic safety, and utilizing local traffic intelligence [1]. However, there are several problems associated with vehicle platoons including complicated vehicle driving conditions in or between platoon columns, a high degree of mutual influence, dynamic optimization of the platoon, and difficulty in the cooperative control of lane change. Aiming at the dual-column intelligent vehicle platoon control (where “dual-column” refers to the vehicle platoon driving mode formed by multiple vehicles traveling in parallel on two adjacent lanes), a multi-agent model as well as a cooperative control method for lane change based on null space behavior (NSB) for unmanned platoon vehicles are established in this paper. Specifically, a multi-agent
Yan, DanshuZhao, ZhiguoLiang, KaichongYu, Qin
The cooperative platoon of multiple trucks with definite proximity has the potential to enhance traffic safety, improve roadway capacity, and reduce fuel consumption of the platoon. To investigate the truck platooning performance in a real-world environment, two Peterbilt class-8 trucks equipped with cooperative truck platooning systems (CTPS) were deployed to conduct the first-of-its-kind on-road commercial trial in Canada. A total of 41 CTPS trips were carried out on Alberta Highway 2 between Calgary and Edmonton during the winter season in 2022, 25 of which were platooning trips with 3 to 5 sec time gaps. The platooning trips were performed at ambient temperatures from −24 to 8°C, and the total truck weights ranged from 16 to 39 tons. The experimental results show that the average time gap error was 0.8 sec for all the platooning trips, and the trips with the commanded time gap of 5 sec generally had the highest variations. The average number of disengagements increased when the
Jiang, LuoKheyrollahi, JavadKoch, Charles RobertShahbakhti, Mahdi
Vehicular automation in the form of a connected and automated vehicle platoon is demanding as it aims to increase traffic flow and driver safety. Controlling a vehicle platoon on a curved path is challenging, and most solutions in the existing literature demonstrate platooning on a straight path or curved paths at constant speeds. This article proposes an algorithmic solution with leader-following (LF) communication topology and constant distance (CD) spacing for platooning homogeneous position-controlled vehicles (PCVs) on a curved path, with each vehicle capable of cornering at variable speeds. The lead vehicle communicates its reference position and orientation to all the follower vehicles. A follower vehicle stores this information as a virtual trail of the lead vehicle for a specific period. An algorithm uses this trail to find the follower vehicle’s reference path by solving an optimization problem. This algorithm is feasible and maintains a constant inter-vehicle distance. The
Bhaskar, RintuPotluri, RamprasadWahi, Pankaj
In order to promote the actual application of the vehicular platoon, this study investigates the effect of the specific platoon configurations including predecessor following (PF), predecessor–leader following (PLF), and bidirectional following (BD), on the anti-disturbing performance from the linear to nonlinear perspective. First, based on the method of sensitivity of error propagation to the disturbance, a linear platoon model is established by considering an individual vehicle as a lumped-mass point. Then, the transfer function matrix from disturbance to spacing error is derived for sensitivity analysis. Finally, especially considering the inherent vehicle dynamics, the Burckhardt tire force model is adopted to construct a nonlinear platoon dynamics model for the nonlinear dynamics analysis. The results reveal the characteristics of each platoon configuration, as well as the design of control gains in terms of the anti-disturbing performance. The nonlinear dynamics property in high
Wu, XiangjiYang, XiujianZhang, ShengbinWang, Shenyi
Different platoon controls of connected automated vehicles have been studied to improve the entire fleet’s overall energy efficiency and driving safety. The platoons can be used during highway cruising to reduce unnecessary braking, shorten required headway, and thus improve traffic capacity and fuel economy. They can also be used in urban driving to improve traffic efficiency at intersections. However, there remain two problems that prevent the technology from achieving maximum benefit. First, the presence of human-driven vehicles will change the behavior of the fleet and platoon control of connected mixed traffic. Second, the communication uncertainties impose negative impacts on the dynamics of the platoon. A high-performance state predictor for surrounding vehicles can reduce the human-driven vehicle’s influence and help handle communication uncertainties better. This article proposes a novel inverse model predictive control (IMPC)-based approach to capture and predict longitudinal
Guo, LongxiangJia, Yunyi
Platooning vehicles present novel pathways to saving fuel during transportation. With the rise of autonomous solutions, platooning becomes an increasingly apparent sector requiring the application of this new technology. Platooning vehicles travel together intending to reduce aerodynamic resistance during operation. Drafting allows following vehicles to increase fuel economy and save money on refueling, whether that be at the pump or at a charging station. However, autonomous solutions are still in infancy, and controller evaluation is an exciting challenge proposed to researchers. This work brings forth a new application of an emissions quantification metric called vehicle-specific power (VSP). Rather than utilize its emissions investigative benefits, the present work applies VSP to heterogeneous Class 8 Heavy-Duty truck platoons as a means of evaluating the efficacy of Cooperative Adaptive Cruise Control (CACC). VSP creates a bridge between types of passenger vehicles to compare
Snitzer, PhilipStegner, EvanBentley, JohnBevly, David M.Hoffman, Mark
Road-vehicle platooning is known to reduced aerodynamic drag. Recent aerodynamic-platooning investigations have suggested that follower-vehicle drag-reduction benefits persist to large, safe inter-vehicle driving distances experienced in everyday traffic. To investigate these traffic-wake effects, a wind-tunnel wake-generator system was designed and used for aerodynamic-performance testing with light-duty-vehicle (LDV) and heavy-duty-vehicle (HDV) models. This paper summarizes the development of this Road Traffic and Turbulence System (RT2S), including the identification of typical traffic-spacing conditions, and documents initial results from its use with road-vehicle models. Analysis of highway-traffic-volume data revealed that, in an uncongested urban-highway environment, the most-likely condition is a speed of 105 km/h with an inter-vehicle spacing of about 50 m. Probability distributions for spacing and road speed were used to identify a range of suitable inter-vehicle spacings to
McAuliffe, BrianBarber, Hali
Platooning has produced significant energy savings for vehicles in a controlled environment. However, the impact of real-world disturbances, such as grade and interactions with passenger vehicles, has not been sufficiently characterized. Follower vehicles in a platoon operate with both different aerodynamic drag and different velocity traces than while driving alone. While aerodynamic drag reduction usually dominates the change in energy consumption for platooning vehicles, the dynamics imposed on the follow vehicle by the lead vehicle and exogenous disturbances impacting the platoon can negate aerodynamic energy savings. In this paper, a methodology is proposed to link the change in longitudinal platooning dynamics with the energy consumption of a platoon follower in real time. This is accomplished by subtracting a predicted acceleration from measured longitudinal acceleration. The real-time consumption calculation methodology is evaluated using data from simulated and experimental
Stegner, EvanSnitzer, PhilipBentley, JohnBevly, David M.Hoffman, Mark
The platoon of intelligent vehicles can significantly reduce the aerodynamic drag, which has broad development prospects. This research numerically studies the effect of Reynolds number (Re = 3.32×105 to 19.94×105), the vehicle numbers (3-, 5-, 8-vehicle), and vehicle types (fastback, notchback, and squareback) on the platoon drag reduction with three different front-edge radius (R*=R/W×100 = 9.36, 4.68 and 2.34). The results show that when the Reynolds number is greater than 9.97×105, the drag coefficient ratio CD/CDi (CDi is the drag coefficient of the isolated vehicle) of each vehicle in the platoon is less affected by the Reynolds number. When R*=9.36, the averaged CD/CDi of the fastback platoon (even above 1) is higher than that of both the notchback platoon and the squareback platoon without front-edge separation at the leading vehicle due to the weakest shielding effect on the following car resulting from the prominent downwash wake. Compared with R*=9.36, when the flow
Wang, DehuaXia, ChaoJia, QingYang, Zhigang
Platooning is a promising technology which can mitigate greenhouse gas impacts and reduce transportation energy consumption. Platooning is a coordinated driving strategy where trucks align themselves in order to realize aerodynamic benefits to reduce required motive force. The aerodynamic benefit is seen as either a “pull” effect experienced by the following vehicles or a “push” effect experienced by the leader. The energy savings magnitude increases nonlinearly as headway (following distance) is reduced [1]. In efforts to maximize energy savings, cooperative adaptive cruise control (CACC) is utilized to maintain relatively short headways. However, when platooning is attempted in the real world, small transient accelerations caused by imperfect control result in observed energy savings being less than expected values. This study analyzes the performance of a recently developed nonlinear model predictive control (NMPC) platooning strategy over challenging terrain. The NMPC strategy is
Bentley, John WilliamSnitzer, PhilipStegner, EvanBevly, David M.Hoffman, Mark
Platoon is a system that connects vehicles through vehicle-to-vehicle (V2V) communication technology to maintain a short distance between vehicles while driving on the road. To improve fuel efficiency, many automotive original equipment manufacturers (OEMs) are interested in developing and demonstrating real-world platoon system. However, it is hard for heavy duty trucks to develop this system due to the difficulty of maintaining the targeted intervehicle distance not only for fuel efficiency but also for safety in case of emergency braking. Because of this critical safety issue in the emergency situation, the platoon system for heavy duty trucks can be hardly demonstrated or tested in real vehicle environment. The relatively complex system and the slow response characteristic of commercial vehicles makes this even more difficult. In this paper, focusing on the emergency braking function implemented through the V2V communication interface, we introduce the platoon system developed by
Hong, Jeong-KiKim, SangjunLim, Jong SuNam, JoohanMin, ByeonghyeokLee, Chanhwa
An intelligent connected vehicle (ICV) swarm system that includes N vehicles is considered. Based on the special properties of potential functions, a kinematic model describing the swarm performances is proposed, which allows all vehicles to enclose the tracking target and show both tracking and formation characteristics. Treating the performances as the desired constraints, the analytical form of constraint forces can be obtained inspired by the Udwadia-Kalaba approaches. A special approach of uncertainty decomposition to deal with uncertain interferences is proposed, and a switching-type robust control method is addressed for each vehicle agent in the swarm system. The features and validity of the addressed control are demonstrated in the numerical simulations
Cui, ZhengrongZhao, XiaominHuang, JinChen, Ye-hwa
In the context of global warming and energy shortage crisis, how to deal with vehicle speed planning and energy management strategies using intelligent connected information is one of the most significant ways to improve traffic efficiency and vehicle fuel economy. In this paper, a hierarchical model predictive control algorithm based on the connected environment is designed for the study of series hybrid electric vehicles (HEVs). The higher level and the lower level controller share information with each other and solve two different problems aiming at improving its fuel efficiency. V2X (Vehicle to Everything) information is used as an input for the high-level controller to establish a model predictive framework to plan the future speed and improve its stability of the whole vehicle platoon. The low-level MPC provides a real-time HEV energy management strategy. The result shows that our hierarchical algorithm can achieve the vehicle platoon follow-up control while maintaining the fuel
Tan, SenlinLin, YuqiangHu, BoChen, Jiahui
Vehicle platooning reduces fuel consumption, improves traffic throughput, and achieves smaller intervehicle spacing which increases the probability of danger during platoon braking. This article presents a sliding mode control based on the safety spacing policy for longitudinal control of a connected truck platoon with a focus on the predecessor following interactions. In particular, the modified safety spacing policy considering the intervehicle braking information communication delay, the sluggish nature of the brake actuator, the road conditions on each vehicle as well as the vehicle motion state is proposed. On this basis, an acceleration sliding mode controller is proposed, which takes into consideration the spacing error and speed error of the intervehicle, and the control error is zero, so as to obtain the expected acceleration of each vehicle in the platoon. Simulation results of truck platooning with six trucks using TurckSim have demonstrated the effectiveness of the proposed
Zhao, QianZheng, HongyuKaku, ChuyoCheng, FeihaoZong, Changfu
Governmental regulations and customer demand for more energy-efficient vehicles are driving the development of new solutions in the automotive sector. One way of improving energy efficiency is by reducing the aerodynamic drag. A possible solution to achieve this is the concept of vehicles driving in close proximity, which is now becoming feasible considering the advances in vehicle automation and communication. This study focuses on the behavior of aerodynamic forces and flow effects in a two-truck platoon when more realistic road conditions, such as lateral offset and yaw, are present. The study is primarily numerical, but the results are validated against an experimental campaign conducted earlier by the authors. The main findings are that the drag of the leading truck is mostly governed by the base pressure of its trailer and that the truck sees only minor changes when a lateral offset is added, except at very short intervehicle distances. For larger yaw angles, the leading truck
Törnell, JohannesSebben, SimoneElofsson, Per
There is “no business case” for platooning, or the electronic coupling of two or more trucks in close formation. That was the assessment of Daimler Trucks in 2019 when it decided to pause its years-long platooning development activities. The OEM determined that for U.S. long-distance applications, where conditions were expected to be ideal, the fuel savings were less than stellar and diminished further when the platoon got “disconnected” and trucks had to accelerate to reconnect. Instead, the company turned its full attention to developing highly automated (SAE Level 4) trucks. The fate of Peloton Technology, a company all-in on platooning but that ceased operations in 2021, is another indicator that perhaps platooning's promise has faded
Gehm, Ryan
This article investigates the headway and optimal velocity tracking of autonomous vehicles (AVs), considering their predictive driving for the stability and integrity of spatial vehicle formation in the platoon. First, the human-like anticipation car-following model is used for modeling the autonomous system. Second, an adaptive radial basis function neural network (ARBF-NN)-based sliding mode control (SMC) is proposed for the control purpose. The control objective is to regulate traffic perturbation during entire road operations. To enable the controller to experience less computational burden and adaptation complexity, a minimum parameter learning (MPL) has also been integrated with ARBF-NN-based SMC. Third, an illustrative simulation example has been performed for two scenarios, i.e., constant headway and time-varying headway of vehicles. A performance comparison between the proposed controller and the conventional SMC was conducted, and controller parameter sensitivity was also
Negash, Natnael M.Yang, James
The aerodynamic effects of bodies in close proximity continues to be an interest for those involved in aeronautical, automotive and civil engineering together with those involved in sports such as cycling, motor racing and sailing. For passenger cars, research in the USA published in the 1980s had considered travelling in close proximity, termed “platooning”, as a means for reducing congestion. But the aerodynamic drag reduction and fuel-savings found in associated wind tunnel tests and road-trials became the focus of further investigations. Although practical applications were not originally pursued, the recent development of control systems for connected and autonomous vehicles has provided the opportunity for platooning to be considered again within future traffic management systems. Thus while the focus of automotive work to date has been the potential for the reduction in total aerodynamic drag, the associated changes in aerodynamic lift which might influence the characteristics
Le Good, GeoffreyBoardman, PeterSelf, MatthewResnick, MaxCirstea, Remus
With an increasing focus on the reduction of greenhouse gases by the transport industries and continued development of connected and autonomous vehicle systems, the potential for aerodynamic drag reduction by means of managed systems of vehicles travelling in close-proximity, termed “platooning”, has continued as topic for research. Early-work in passenger-car platooning was conducted by varying the spacing between vehicles in homogeneous platoons. More recently the use of systematic changes in upper-body geometry has provided data for another variable in the assessment of platooning characteristics. The results of the investigation described in this paper adds to previously published platooning results using the Windsor reference model. For this investigation a new add-on geometry to the standard nose was designed to provide a simplified bonnet feature. This was chosen in order to vary the on-set flow approaching the platoon and also to influence the flow in the gap between test
MacAskill, JamesLe Good, GeoffreyCirstea, Remus
Platooning heavy-duty trucks decreases aerodynamic drag for following trucks, reducing energy consumption, and increasing both range and mileage. Previous platooning experimentation has demonstrated fuel economy benefits in two-, three-, and four-truck configurations. However, exogenous variables disturb the ability of these platoons to maintain the desired formation, causing an accordion effect within the platoon and reducing energy benefits via acceleration/deceleration events. This phenomenon is increasingly exacerbated as platoon size and road grade variations increase. The current work assesses how platoon size, road curvature, and road grade influence platoon energy efficiency. Fuel consumption rate is experimentally quantified for four heterogeneous Class 8 vehicles operating in standalone (baseline), two-, and four-truck platooning configurations to assess fuel consumption changes while driving through diverse road conditions. Platooning was accomplished via PID-based
Snitzer, PhilipStegner, EvanSiefert, JanBevly, David M.Hoffman, Mark
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