Enhancing Work Zone Capacity by a Cooperative Late Merge System Using Decentralized and Centralized Control Strategies

2022 ◽  
Vol 148 (2) ◽  
Author(s):  
Majeed Algomaiah ◽  
Zhixia Li
Keyword(s):  
Control Strategies ◽  
Work Zone ◽  
Centralized Control

scholarly journals A Decentralized, Flat-Structured Control System for Chiller Plants

2019 ◽  
Vol 9 (22) ◽  
pp. 4811 ◽  
Author(s):  
Dong He ◽  
Qingyu Xiong ◽  
Xuyang Zhang ◽  
Yunchuang Dai ◽  
Ziyan Jiang
Keyword(s):  
Energy Efficiency ◽  
Control System ◽  
Decentralized Control ◽  
Control Method ◽  
Control Strategies ◽  
Measured Data ◽  
Self Organization ◽  
Centralized Control ◽  
Self Recognition

This paper presents a novel control system for chiller plants that is decentralized and flat-structured. Each device in chiller plant system is fitted with a smart node. It is a smart agent, which collects, handles and sends out information to its neighbours. All the smart nodes form a network that can realize self-organization and self-recognition. Different kinds of control strategies can be converted into series of decentralized computing processes carried on by the smart nodes. The principle and mechanism of this decentralized, flat-structured control system for chiller plants are described in detail. Then a case study is presented to show how to build the decentralized, flat-structured control system actually. The measured data shows that the decentralized control method is energy efficiency. Moreover, it is much more flexible and scalable compared with the traditional centralized control method.

Work Zone Safety Performance: Comparison of Alternative Traffic Control Strategies

2017 ◽  
Vol 2617 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Emira Rista ◽  
Timothy Barrette ◽  
Raha Hamzeie ◽  
Peter Savolainen ◽  
Timothy J. Gates
Keyword(s):  
Traffic Safety ◽  
Traffic Control ◽  
Control Strategies ◽  
Safety Performance ◽  
Work Zone ◽  
Segment Length ◽  
Crash Rates ◽  
Study Results ◽  
Significant Difference ◽  
Lane Closures

Work zone temporary traffic control strategies generally affect both traffic safety and operations. However, there is a substantial gap in the knowledge base with respect to the safety impacts of various work zone characteristics. The Highway Safety Manual provides crash modification functions that account for the effects of project length and duration on crash frequency as compared with normal road operations. However, these methods do not allow for explicit comparisons of expected safety performance among different work or closure types. This research examined the safety impacts of various temporary traffic control strategies on freeways, including shoulder closures, lane closures, and lane shifts. Data were collected for the periods during which these treatments were in effect and during similar nonconstruction periods from the preceding year. Safety performance functions were estimated that account for segment length, duration, traffic volume, and closure type. Random parameter count data models were estimated to accommodate segment-specific temporal correlation and unobserved heterogeneity. Crash rates were shown to vary roughly in proportion to traffic volumes. In contrast, segment length and project duration showed inelastic effects; this finding implies that crash rates increase more rapidly in work zones that are shorter in length or duration. Single-lane closures, multilane closures, and lane shifts were associated with an increase in crashes, whereas shoulder closures did not show a significant difference compared with similar, non-work-zone conditions. Ultimately, the study results provide important information that can be used to assess the crash risk for various temporary traffic control strategies.

scholarly journals A review: Smart Distribution Grid Management using Agents

2020 ◽  
Vol 19 ◽  
Keyword(s):  
Control Strategies ◽  
Fault Management ◽  
Management Control ◽  
Centralized Control ◽  
Distribution Grid ◽  
Reliability Modeling ◽  
Modeling And Analysis ◽  
Reliability Indices ◽  
Smart Distribution Grid ◽  
Grid Management

This paper focuses on the main features of the smart distribution grid (grid management using agents). The fault management is consisting of three stages including faulted section identification, faulted section isolation, and restoration. The probable control strategies utilized in the smart grid are either centralized, decentralized, or autonomous control. Multi-Agent System (MAS) based model uses both centralized and decentralized strategies. The fault management process is usually carried out based on MAS. A literature survey on fault management control schemes is investigated. Furthermore, the reliability is estimated for both centralized, decentralized, autonomous, and modified centralized control strategies. This paper presents reliability modeling and analysis of all considered control strategies. In this paper, comprehensive detailed reliability models of considered control strategies are developed. Using this equivalent reliability model, various reliability indices are calculated.

scholarly journals Control Strategy Optimization for Two-Lane Highway Lane-Closure Work Zones

2019 ◽  
Vol 11 (17) ◽  
pp. 4567 ◽  
Author(s):  
Hua ◽  
Wang ◽  
Yu ◽  
Zhu ◽  
Wang
Keyword(s):  
Control Strategy ◽  
Traffic Control ◽  
Queue Length ◽  
Control Strategies ◽  
Good Alternative ◽  
Management Control ◽  
Work Zone ◽  
Delay Model ◽  
Work Zones ◽  
Two Phase

Traffic control is very important for two-lane highway lane-closure work zone traffic management. Control of the open lane’s right of way is very similar to that of a two-phase signalized intersection. Thus, four control strategies including flagger control, pre-timed control proposed by Schonfeld, pre-timed control proposed by Webster, and actuated control are employed for possible use at work zones. Two primary methodologies, the mathematical delay model adopted from signalized intersections, and the simulation model calibrated with field data, are proposed. The simulation and mathematical results show that control strategies for two one-way road intersections could be used for two-lane highway lane-closure work zones. Flagger control after gap-out distance optimization prevails over all the other control strategies in terms of stopped delay, queue length, and throughput, under low or high volumes. Actuated control could be a good alternative for work zone areas due to its small queue length and large vehicle throughput under moderate volume conditions. Our findings may help to optimize the work-zone control strategy and improve operational efficiency at two-lane highway lane-closure work zones.

scholarly journals H 2 and H ∞ Optimal Control Strategies for Energy Harvesting by Regenerative Shock Absorbers in Cars †

Vibration ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 99-115
Author(s):  
Alessandro Casavola ◽  
Francesco Tedesco ◽  
Pasquale Vaglica
Keyword(s):  
Ride Comfort ◽  
Control Strategies ◽  
Suspension System ◽  
Centralized Control ◽  
Design Strategies ◽  
Control Laws ◽  
Car Model ◽  
Shock Absorbers ◽  
Objective Control ◽  
Vehicle Suspension System

Regenerative suspension systems, unlike traditional passive, semi-active or active setups, are able to convert the traditionally wasted kinetic energy into electricity. This paper discusses flexible multi-objective control design strategies based on LMI formulations to suitably trade-off between the usual road handling and ride comfort performance and the amount of energy to be harvested. An electromechanical regenerative vehicle suspension system is considered where the shock absorber of each wheel is replaced by a linear electrical motor which is actively governed. It is shown by simulations that multivariable centralized control laws designed on the basis of a full-car model of the suspension system are able to achieve larger amount of harvested energy under identical ride comfort prescriptions with respect to scalar decentralized control strategies, designed on the basis of a single quarter-car model and implemented independently on each wheel in a decentralized way. Improvements up to 40 % and 20 % of harvested energy are respectively achievable by the centralized multivariable H 2 and H ∞ optimal controllers under the same test conditions.

scholarly journals Distributed Input-Delay Model Predictive Control of Inland Waterways

10.29007/p2cx ◽  
2018 ◽  
Author(s):  
Pau Segovia ◽  
Lala Rajaoarisoa ◽  
Fatiha Nejjari ◽  
Eric Duviella ◽  
Vicenç Puig
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Control Strategies ◽  
Current Control ◽  
Distributed Model ◽  
Centralized Control ◽  
Delay Model ◽  
Inland Waterways ◽  
Control Actions ◽  
System Partitioning

Inland waterways are large, complex systems composed of interconnected navigation reaches dedicated mainly to navigation. These reaches are generally characterized by negligible bottom slopes and large time delays. The latter requires ensuring the coordination of the current control actions and their delayed effects in the network. Centralized control strategies are often impractical to implement due to the size of the system. To overcome this issue, a distributed Model Predictive Control (MPC) approach is proposed. The system partitioning is based on a reordering of the optimality conditions matrix, and the control actions are coordinated by means of the Optimality Condition Decomposition (OCD) methodology. The case study is inspired by a real inland waterways system and shows the performance of the approach.

Simulation and evaluation of speed and lane-changing advisory of CAVS at work zones in heterogeneous traffic flow

2020 ◽  
Vol 34 (21) ◽  
pp. 2050201
Author(s):  
Wenjing Wu ◽  
Renchao Sun ◽  
Anning Ni ◽  
Zhikang Liang ◽  
Hongfei Jia
Keyword(s):  
Traffic Flow ◽  
Control Strategy ◽  
Control Strategies ◽  
Heavy Traffic ◽  
Autonomous Vehicle ◽  
Heterogeneous Traffic ◽  
Work Zone ◽  
Lane Changing ◽  
Advantages And Disadvantages ◽  
Car Following Model

Emerging connected autonomous vehicle (CAV) technologies provide an opportunity to the vehicle motion control to improve the traffic performance. This study simulated and evaluated the CAV-based speed and lane-changing (LC) control strategies at the expressway work zone in heterogeneous traffic flow. The control strategies of CAV are optimized by the multi-layer control structure based on model predictive control. The heterogeneous traffic flow composed of human-driven vehicles and CAVs is constructed based on cellular automata by the proposed Expected Distance-based Symmetric Two-lane Cellular Automate (ED-STCA) LC model and CAV car-following model. The six control strategies composed of variable speed limits (VSL), LC and their coordinated control strategies are experimented. The average travel time and throughput are selected to assess the advantages and disadvantages of each strategy under each combination of vehicles’ arrival rates and CAV mixed ratios. The numerical results show that: (i) the effect of the control strategy on the traffic is not obvious under free flow, and the control strategy may worsen the traffic under medium traffic. (ii) Early lane-changing control (ELC) is better than late lane-changing control (LLC) under medium traffic, and LLC is better under heavy traffic. (iii) [Formula: see text] is the best choice under heavy traffic and the mixed rate of CAVs is high. The simulation results obtained in the paper would provide some practical references for transportation agencies to manage the traffic in work zone under networking environment in the future.

Evaluation of the effectiveness of single-lane two-way traffic control at maintenance and reconstruction zones

2006 ◽  
Vol 33 (9) ◽  
pp. 1217-1226 ◽  
Author(s):  
Ahmed Al-Kaisy ◽  
Eric Kerestes
Keyword(s):  
Adaptive Control ◽  
Traffic Control ◽  
Control Strategies ◽  
Stochastic Approach ◽  
Fixed Time ◽  
Work Zone ◽  
Average Delay ◽  
Zone Length ◽  
Time Control ◽  
Study Results

This paper presents a study on evaluating traffic control at single-lane closures on two-lane two-way highways. Four traffic control strategies were investigated by this study. Those strategies involved fixed-time control, fixed-queue control, "static optimum" or convoy rule, and adaptive control. Traffic control strategies were modeled using two approaches; a deterministic approach in spreadsheet application and a stochastic approach in microscopic traffic simulation. Parametric analyses were performed using several variables that are related to traffic control at this type of lane closure. Those variables involved work zone length, average speed at work zone, lost time, traffic level, directional split, and interruptions to traffic by movement of construction vehicle and (or) equipment into and out of the construction site. Study results suggest that significant savings in average delay can be accrued by using more advanced traffic control strategies. Those savings could be as high as 53% for the range of conditions investigated by this research.Key words: work zone, flaggers, adaptive control, simulation, optimization.

scholarly journals Evaluation of Two Improved Schemes at Non-Aligned Intersections Affected by a Work Zone with an Entropy Method

2020 ◽  
Vol 12 (14) ◽  
pp. 5494
Author(s):  
Yang Shao ◽  
Zhongbin Luo ◽  
Huan Wu ◽  
Xueyan Han ◽  
Binghong Pan ◽  
...  
Keyword(s):  
Traffic Management ◽  
Control Strategies ◽  
Management Strategies ◽  
Entropy Method ◽  
Work Zone ◽  
Work Zones ◽  
Research Results ◽  
The Road ◽  
Traffic Operation ◽  
The Impact

The impact of work zones on traffic is a common problem encountered in traffic management. The reconstruction of roads is inevitable, and it is necessary and urgent to reduce the impact of the work zone on the operation of traffic. There are many existing research results on the influence of highway work zones, including management strategies, traffic flow control strategies, and various corresponding model theories. There are also many research results on the impacts of urban road and subway construction on traffic operation, including construction efficiency, economic impact, and travel matrix. However, there are few studies concerning the choice of work zone location, and most previous studies have assumed that the work zone choice was scientific and reasonable. Therefore, it is reasonable to choose the location of the work zone and to assess whether there is room for improvement in the road form of the work zone, but this remains a research gap. Therefore, we studied a seven-lane main road T-intersection in Xi’an, China, and investigated a work zone located at this intersection that caused a road offset, leading to the non-aligned flow of main traffic. We designed two road improvement schemes and multiple transition schemes, used VISSIM software to evaluate the traffic operation of the two schemes, and used the entropy method to choose the suitability of the two schemes under different conditions. According to the results, in the best case, the driving time, delay, and number of stops are reduced by 44%, 66%, and 92%.

scholarly journals Centralized-Decentralized Control for Regenerative Braking Energy Utilization and Power Quality Improvement in Modified AC-Fed Railways

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2582
Author(s):  
Qiwei Lu ◽  
Zhixuan Gao ◽  
Bangbang He ◽  
Cheng Che ◽  
Cong Wang
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Decentralized Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Energy Utilization ◽  
Regenerative Braking ◽  
Centralized Control ◽  
Power Quality Improvement ◽  
Railway System

This paper proposes a centralized-decentralized control strategy for regenerative braking energy utilization and power quality improvement in the modified AC-fed railway system with energy-storage-based smart electrical infrastructure. The proposal of a centralized-decentralized control strategy can enhance the ability to withstand and rapidly recover from disruptions, thus providing further guarantees for safe and reliable operation and energy conservation for railway systems. First of all, the description and control strategy of the modified railway system are outlined, and then the control principles and implementation process of the centralized control and decentralized control strategies are given. Moreover, a method of load power detection and regulated power reference calculation is proposed. Finally, the effectiveness of the proposed strategy is verified in a case of a modified railway system consisting of four traction substations and eight power supply sections. The results demonstrate that regenerative braking energy can be efficiently utilized in railways and that power quality can be improved using the proposed centralized-decentralized control strategy.

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