| 1. |
- Deng, Qichen, 1987-
(författare)
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A Constant Spacing Policy for Heavy-Duty VehiclePlatoon Disaggregation at Highway Off-Ramp
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Platooning heavy-duty vehicles (HDVs) on highways using cooperative adaptive cruise control (CACC) can significantly reduce fuel consumption and improve traffic throughput.HDVs operating with small inter-vehicle distances reduce aerodynamic resistance considerably. However, HDV platoons can also have negative impacts on traffic flow when they hinder lane changing at highway off-ramps. This study investigates whether disaggregation of HDV platoons benefits traffic flow at highway off-ramps. A modified constant spacing policy is applied forHDV platoon disaggregation. The feasible region of the CACCparameters is derived based on an analysis of asymptotic stability, driving safety, and HDV acceleration and braking capabilities.The proposed HDV platoon disaggregation strategy at highway off-ramps is implemented and simulated in a microscopic traffic simulation package. According to the simulation outcomes, a disaggregation of HDV platoons at off-ramps leads to significant average speed improvements at high traffic flow rates.
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| 2. |
- Deng, Qichen, et al.
(författare)
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A fast algorithm for planning optimal platoon speeds on highway
- 2014
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Ingår i: Elsevier IFAC Publications / IFAC Proceedings series. - : IFAC Papers Online. - 1474-6670. - 9783902823625 ; 19, s. 8073-8078
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Tidskriftsartikel (refereegranskat)abstract
- To meet policy requirements on increased transport energy efficiency and reduced emissions, smart control and management of vehicles and fleets have become important for the development of eco-friendly intelligent transportation systems (ITS). The emergence of new information and communication technologies and their applications, particularly vehicle-to-vehicle and vehicle-to-infrastructure communication, facilitates the implementation of autonomous vehicle concepts, and meanwhile serves as an effective means for control of vehicle fleet by continuously providing support and guidance to drivers. While convoy driving of trucks by longitudinal automation could save 5-15% of fuel consumption due to the reduction of airdrag resistance, this study attempts to investigate the energy saving potential of truck platoons by intelligent speed planning. Assuming that real-time traffic information is available because of communication, an efficient speed control algorithm is proposed based on optimal control theory. The method is faster than the conventional dynamic programming approach and hence applied in the study to analyze energy saving potential of simple platoon operations including acceleration and deceleration. The numerical result shows significant improvement on energy saving due to speed planning during platooning. It can be further applied for more complex platooning operations.
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| 3. |
- Deng, Qichen
(författare)
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A General Simulation Framework for Modeling and Analysis of Heavy-Duty Vehicle Platooning
- 2016
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Ingår i: IEEE transactions on intelligent transportation systems (Print). - : Institute of Electrical and Electronics Engineers (IEEE). - 1524-9050 .- 1558-0016. ; 17:11, s. 3252-3262
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Tidskriftsartikel (refereegranskat)abstract
- Platooning heavy-duty vehicles (HDVs) on a highway is a method for improving energy and transport efficiency. On one hand, HDV platoon driving in small intervehicle distances could increase highway capacity; on the other hand, HDVs traveling in small intervehicle distances experience significant air-drag reduction and, therefore, improve fuel efficiency. However, although the majority of research has been conducted on the development of platoon systems, very few studies have focused on quantification of the impacts of HDV platooning on traffic flow. This paper initializes a simulation framework to facilitate the study of HDV platooning and establishes the corresponding concept and operations. The longitudinal driving behaviors of HDV platoons are modeled in detail, considering the acceleration capability of an HDV. The proposed framework is applied on three experimental cases: the first case is to study the impacts of HDV platooning on traffic flow and the second and third cases are about the influence of traffic on HDV platoon formation. In the first case, simulation outcomes show that the increasing percentage of HDV platooning in traffic flow generally results in more dramatic improvements on traffic efficiency, while preserving traffic safety for passenger vehicles. In the second and third cases, for the HDV platoon formation, deceleration of the first HDV to a low speed during platoon formation will increase the formation time to a large extent in medium and heavy traffic.
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| 4. |
- Deng, Qichen, 1987-
(författare)
-
A General Simulation Framework for Modeling andAnalysis of Heavy-Duty Vehicle Platooning
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Platooning heavy-duty vehicles (HDVs) on highway is a method of improving energy and transport efficiency. On the one hand, HDV platoon driving in small inter-vehicle distances could increase highway capacity; on the other hand, HDVs traveling in small inter-vehicle distances experience significant air -drag reduction and therefore, improve fuel efficiency. However, the majority of research has been conducted on the development of platoon system, very few studies have focused on quantification of the impacts of HDV platooning on traffic flow. This paper initializes a simulation framework to facilitate the study of HDVplatooning and establishes corresponding concept and operations.The longitudinal driving behaviors of HDV platoons is modeled in detail considering the acceleration capability of HDV. The proposed framework is applied in three experimental cases, the first case is to study the impacts of HDV platoons on traffic flow, and the second and third cases are about the influence of traffic on HDV platoon formation. In the first case, simulation outcomes show that increasing percentage of HDV platooning in traffic flow generally results in more dramatic improvements in traffic efficiency while preserving traffic safety for passenger vehicles; in the second and third cases, for the HDV platoon formation, deceleration of the first HDV in low speed during platoon formation will increase the formation time to a large extent in medium and heavy traffic.
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| 5. |
- Deng, Qichen, 1987-
(författare)
-
Heavy-Duty Vehicle Platooning : Modeling and Analysis
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Coupled with the growth of world economy, the demand for freight transport has escalated and will continue to do so. As the traffic intensity increases, the pressure on infrastructure, energy usage and environment becomes higher than ever. Meanwhile, the number of traffic accidents is also increasing year by year as a result. Heavy-duty vehicle (HDV) platooning makes a group of HDVs driving closely after each other.It is one potential solution to improve transport efficiency, traffic safety and fuel economy. Even though there have been extensive studies on the platooning system and corresponding fuel saving, some of the research areas, such as coordination strategies of platooning, platoon operations and the impacts of HDV platooning on trafficflow are still left open. Under a futuristic scenario where a large number of HDVswill be operating in one or several platoons on highway, how to group HDVs intoa platoon and how to select spacing policies for HDV platooning are essential forautomobile manufacturers, fleet operators and transport planners. Therefore, theformation strategies and operations of HDV platoons, as well as the impacts of HDVplatooning on traffic flow have to be carefully investigated.This thesis presents contributions to the modeling of HDV platooning and simulationof HDV platoon operations. The focus lies mainly on analytical formulation ofspeed-density relation of mixed traffic flow and development of simulation frameworkfor study of HDV platooning. On the one hand, a three-regime speed-density relationis proposed to describe the mixed traffic flow consisting of HDVs and passengercars. The proposed speed-density relation incorporates percentage of HDVs, trafficdensity and spacing policy of HDV platoons as input variables and delivers aggregatehighway velocity as output. By comparing the traffic throughput of no HDV platooningscenario, grouping HDVs into platoon using constant vehicle spacing policy orconstant time gap policy results in significant improvement in highway capacity. On the other hand, a simulation framework is developed for implementation of differentHDV platoon operations. The platoon formation of two HDVs and disaggregation ofa five-HDV platoon at off-ramp are simulated on a two-lane highway. The simulationoutcomes show that HDV platoon formation is more favorable in light and mediumtraffic; disaggregation of a long HDV platoon at off-ramp improves the averagespeed of passenger vehicles considerably at high traffic flow rate.
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| 6. |
- Deng, Qichen, 1987-, et al.
(författare)
-
The Impacts of Heavy-Duty Vehicle Platoon Spacing Policy on Traffic Flow
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Spacing policy of heavy-duty vehicle (HDV) platoons determines the inter-vehicle distance between HDVs in steady state. It plays an important role in traffic throughput. For example, an HDV platoon with small spacing policies saves space on the highway so that it can accommodate more vehicles. Therefore, the traffic efficiency and highway capacity may be improved by applying small spacing policies on HDV platoons. Conversely, an HDVplatoon with larger spacing policies requires more space on highways and thus has a negative impact on capacity.This paper specifically focuses on two commonly used spacing policies in HDV platooning, constant vehicle spacing (CVS) and constant time gap (CTG) and investigates respective impacts on traffic flow. The speed-density relation of mixed traffic flow is formulated as a function of traffic density, the percentage of HDVs on highway and spacing policy of HDV platoon. In order to investigate the effects of HDV platooning to vehicle interaction, the speed-density relation is derived from car-following model. Numerical results show that HDV platooning with CVSpolicy yields the most significant improvement in highway capacity, compared with no HDV platooning scenario and HDV platooning with CTG policy. However, it has worse performance in heavily congested traffic flows thanCTG policy. A mixed CVS-CTG policy is therefore proposed in this study, in order to combine the benefits fromCVS and CTG policies to traffic flow. This mixed spacing policy could be a promising alternative to the single spacing policy.
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| 7. |
- Liang, Kuo-Yun, et al.
(författare)
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The Influence of Traffic on Heavy-Duty Vehicle Platoon Formation
- 2015
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Konferensbidrag (refereegranskat)abstract
- Heavy-duty vehicle (HDV) platooning is a mean to significantly reduce the fuel consumption for the trailing vehicle. By driving close to the vehicle in front, the air drag is reduced tremendously. Due to each HDV being assigned with different transport missions, platoons will need to be frequently formed, merged, and split. Driving on the road requires interaction with surrounding traffic and road users, which will influence how well a platoon can be formed. In this paper, we study how traffic may affect a merging maneuver of two HDVs trying to form a platoon. We simulate this for different traffic densities and for different HDV speeds. Even on moderate traffic density, a platoon merge could be delayed with 20% compared to the ideal case with no traffic.
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| 8. |
- Lyamin, Nikita, 1989-, et al.
(författare)
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Study of the Platooning Fuel Efficiency under ETSI ITS-G5 Communications
- 2016
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Ingår i: 2016 IEEE 19th International Conference on Intelligent Transportation Systems (ITSC). - Piscataway, NJ : IEEE. - 9781509018895 - 9781509018888 - 9781509018901 ; , s. 551-556
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Konferensbidrag (refereegranskat)abstract
- In this paper we evaluate the performance of platoon enabled by contemporary ITS-G5 vehicular communications through a number of simulation experiments. We assess platooning fuel consumption performance under two communication setups and estimate the potential influence of the communication system on the efficiency of the platooning. We also make an attempt to transform our results on platoon fuel efficiency into potential cost reduction gain. Our study shows that platooning fuel-efficiency may vary depending on the communication setup.
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