scholarly journals Characteristics of Traffic Flow at Nonsignalized T-Shaped Intersection with U-Turn Movements

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Hong-Qiang Fan ◽  
Bin Jia ◽  
Xin-Gang Li ◽  
Jun-Fang Tian ◽  
Xue-Dong Yan
Keyword(s):  
Traffic Flow ◽  
Performance Measures ◽  
Initial Conditions ◽  
Main Road ◽  
Control Delay ◽  
Traffic Conditions ◽  
Ca Model ◽  
Average Control ◽  
Simulation Results ◽  
High Congestion

Most nonsignalized T-shaped intersections permit U-turn movements, which make the traffic conditions of intersection complex. In this paper, a new cellular automaton (CA) model is proposed to characterize the traffic flow at the intersection of this type. In present CA model, new rules are designed to avoid the conflicts among different directional vehicles and eliminate the gridlock. Two kinds of performance measures (i.e., flux and average control delay) for intersection are compared. The impacts of U-turn movements are analyzed under different initial conditions. Simulation results demonstrate that (i) the average control delay is more practical than flux in measuring the performance of intersection, (ii) U-turn movements increase the range and degree of high congestion, and (iii) U-turn movements on the different direction of main road have asymmetrical influences on the traffic conditions of intersection.

Optimization of traffic intersection using connected vehicles

2019 ◽  
Vol 30 (06) ◽  
pp. 1950042
Author(s):  
R. Marzoug ◽  
B. Castillo Téllez ◽  
M. Castillo Téllez ◽  
G. A. Mejía Pérez ◽  
A. Bassam ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Road Safety ◽  
The Other ◽  
Connected Vehicles ◽  
Traffic Situation ◽  
Traffic Conditions ◽  
Traffic Intersection ◽  
Central Controller ◽  
Simulation Results ◽  
The One

In this paper, we proposed a model based on the connected vehicles to control the traffic flow at the intersection. To evaluate this model, we studied its impact on the flux and the probability of accidents at the intersection. On the one hand, simulation results showed that the increase in the number of connected vehicles decreases the congestion coefficient and enhances the traffic situation in the system. On the other hand, connected vehicles reduce the probability of accidents at the intersection. In this way, the vehicle intersection (central controller) communication can decrease the congestion and enhance road safety, especially in the intermediate and high traffic conditions.

scholarly journals Traffic flow cellular automaton model with bi-directional information in an open boundary condition

2020 ◽  
Author(s):  
Liang Zheng ◽  
Zhengpeng He
Keyword(s):  
Traffic Flow ◽  
Traffic Information ◽  
Open Boundary ◽  
Hysteresis Phenomenon ◽  
Connected Vehicle ◽  
Directional Information ◽  
Congested Traffic ◽  
Traffic Conditions ◽  
Ca Model ◽  
Vehicle Technologies

Abstract With Connected Vehicle Technologies being popular, drivers not only perceive downstream traffic information but also get upstream information by routinely checking backward traffic conditions, and the backward-looking frequency or probability is usually affected by prevailing traffic conditions. Meanwhile, the bi-directional perception range of drivers is expected to significantly increase, which results in more informed and coordinated driving behaviours. So, we propose a traffic flow bi-directional CA model with two perception ranges, and perform the numerical simulations with the field data collected from a one-lane highway in Richmond, California, USA as the benchmark data. Numerical results show that the CA model can effectively reproduce the oscillation of relatively congested traffic and the traffic hysteresis phenomenon. When adjusting the backward-looking probability and the perception range, the CA model can well simulate the travel times of all vehicles, and the generation and dissolution of traffic jams under various scenarios.

CELLULAR AUTOMATA MODEL FOR UNSIGNALIZED T-SHAPED INTERSECTION

2009 ◽  
Vol 20 (04) ◽  
pp. 501-512 ◽  
Author(s):  
XIN-GANG LI ◽  
ZI-YOU GAO ◽  
BIN JIA ◽  
XIAO-MEI ZHAO
Keyword(s):  
Cellular Automata ◽  
Traffic Flow ◽  
Cellular Automata Model ◽  
Traffic Lights ◽  
Traffic Conditions ◽  
Main Street ◽  
Simulation Results

In this paper, the unsignalized T-shaped intersection is modeled by a cellular automata model. The main street and the minor street join at the intersection. As to the traffic flow is not controlled by traffic lights, conflict happens between the vehicles from minor street and that from main street. Two different crash avoiding rules are used to dispose the conflicts. In the first rule, the priorities are given to the driving-ahead vehicle and the vehicle on the main street. In the second rule, the vehicle that reaches the conflicting point earlier enters into the intersection. The flux on each lane depending on the inflow rates is studied in detail. The capacity of the system is also investigated. Our simulation results suggest that the two rules do not take the same effect on the capacity under different traffic conditions.

CONTROLLING THE STATES OF TRAFFIC FLOW AT THE INTERSECTIONS

2004 ◽  
Vol 15 (04) ◽  
pp. 553-562 ◽  
Author(s):  
KEPING LI ◽  
ZIYOU GAO
Keyword(s):  
Traffic Flow ◽  
Control Strategy ◽  
Control Signal ◽  
Traffic Model ◽  
Traffic Light ◽  
Main Road ◽  
Periodic State ◽  
City Network ◽  
Simulation Results ◽  
A New Technique

In city network, the state of the traffic flow which is in front of each intersection is random and disorder. It usually leads to some traffic problems. In this paper, we propose a new technique to control such dynamical state of the traffic flow on a main road. A type of the control signal has been designated at a given site (signal point) in front of each intersection. Under the effect of the control signal, the velocities of the vehicles which pass the signal point will be changed. Our method is tested for the "unified" CA traffic model which is the marriage of the NaSch model and the BML model. The simulation results demonstrate that using this control strategy, when the traffic light is green, the disorder state of the traffic flow which is in front of each intersection can be suppressed, and the periodic state of the traffic flow will occur.

Dynamics of the macromolecular composition of the biomass of microalgae in the morning under natural light. Model

2020 ◽  
pp. 45-52
Author(s):  
Alexander S. Lelekov ◽  
Anton V. Shiryaev
Keyword(s):  
Biochemical Composition ◽  
Initial Conditions ◽  
Natural Light ◽  
Photoautotrophic Growth ◽  
Structural Part ◽  
Basic Model ◽  
Microalgae Culture ◽  
Simulation Results ◽  
Structural Parts ◽  
Macromolecular Composition

The work is devoted to modeling the growth of optically dense microalgae cultures in natural light. The basic model is based on the idea of the two-stage photoautotrophic growth of microalgae. It is shown that the increase in the intensity of sunlight in the first half of the day can be described by a linear equation. Analytical equations for the growth of biomass of microalgae and its macromolecular components are obtained. As the initial conditions, it is assumed that at the time of sunrise, the concentration of reserve biomass compounds is zero. The simulation results show that after sunrise, the growth of the microalgae culture is due only to an increase in the reserve part of the biomass, while the structural part practically does not change over six hours. Changes in the ratio of the reserve and structural parts of the biomass indicate a change in the biochemical composition of cells.

Smart Driving System for Improving Traffic Flow

2017 ◽  
Vol 7 (7) ◽  
pp. 236
Author(s):  
Rajesh Kumar Gupta ◽  
L. N. Padhy ◽  
Sanjay Kumar Padhi
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Urban Areas ◽  
Adaptive Cruise Control ◽  
Human Perception ◽  
Cruise Control ◽  
Driving System ◽  
V2v Communication ◽  
Traffic Conditions ◽  
Cooperative Adaptive Cruise Control

Traffic congestion on road networks is one of the most significant problems that is faced in almost all urban areas. Driving under traffic congestion compels frequent idling, acceleration, and braking, which increase energy consumption and wear and tear on vehicles. By efficiently maneuvering vehicles, traffic flow can be improved. An Adaptive Cruise Control (ACC) system in a car automatically detects its leading vehicle and adjusts the headway by using both the throttle and the brake. Conventional ACC systems are not suitable in congested traffic conditions due to their response delay.  For this purpose, development of smart technologies that contribute to improved traffic flow, throughput and safety is needed. In today’s traffic, to achieve the safe inter-vehicle distance, improve safety, avoid congestion and the limited human perception of traffic conditions and human reaction characteristics constrains should be analyzed. In addition, erroneous human driving conditions may generate shockwaves in addition which causes traffic flow instabilities. In this paper to achieve inter-vehicle distance and improved throughput, we consider Cooperative Adaptive Cruise Control (CACC) system. CACC is then implemented in Smart Driving System. For better Performance, wireless communication is used to exchange Information of individual vehicle. By introducing vehicle to vehicle (V2V) communication and vehicle to roadside infrastructure (V2R) communications, the vehicle gets information not only from its previous and following vehicle but also from the vehicles in front of the previous Vehicle and following vehicle. This enables a vehicle to follow its predecessor at a closer distance under tighter control.

scholarly journals Simulations of Switchback, Fragmentation and Sunspot Pair in δ-Sunspots during Magnetic Flux Emergence

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 586
Author(s):  
Che-Jui Chang ◽  
Jean-Fu Kiang
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Field Strength ◽  
Magnetic Flux ◽  
Initial Conditions ◽  
Observation Data ◽  
Flux Emergence ◽  
Polarity Inversion ◽  
Simulation Results ◽  
Spot Type

Strong flares and coronal mass ejections (CMEs), launched from δ-sunspots, are the most catastrophic energy-releasing events in the solar system. The formations of δ-sunspots and relevant polarity inversion lines (PILs) are crucial for the understanding of flare eruptions and CMEs. In this work, the kink-stable, spot-spot-type δ-sunspots induced by flux emergence are simulated, under different subphotospheric initial conditions of magnetic field strength, radius, twist, and depth. The time evolution of various plasma variables of the δ-sunspots are simulated and compared with the observation data, including magnetic bipolar structures, relevant PILs, and temperature. The simulation results show that magnetic polarities display switchbacks at a certain stage and then split into numerous fragments. The simulated fragmentation phenomenon in some δ-sunspots may provide leads for future observations in the field.

scholarly journals Limits of reproducibility and hydrodynamic noise in atmospheric regional modelling

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Beate Geyer ◽  
Thomas Ludwig ◽  
Hans von Storch
Keyword(s):  
Regional Climate Model ◽  
Computer Architecture ◽  
Climate Model ◽  
Initial Conditions ◽  
Regional Climate ◽  
Quality Criterion ◽  
Dynamic State ◽  
Regional Modelling ◽  
Simulation Results ◽  
Mathematical Operations

AbstractReproducibility of research results is a fundamental quality criterion in science; thus, computer architecture effects on simulation results must be determined. Here, we investigate whether an ensemble of runs of a regional climate model with the same code on different computer platforms generates the same sequences of similar and dissimilar weather streams when noise is seeded using different initial states of the atmosphere. Both ensembles were produced using a regional climate model named COSMO-CLM5.0 model with ERA-Interim forcing. Divergent phase timing was dependent on the dynamic state of the atmosphere and was not affected by noise seeded by changing computers or initial model state variations. Bitwise reproducibility of numerical results is possible with such models only if everything is fixed (i.e., computer, compiler, chosen options, boundary values, and initial conditions) and the order of mathematical operations is unchanged between program runs; otherwise, at best, statistically identical simulation results can be expected.

scholarly journals Extended and Unscented Kalman Filtering Applied to a Flexible-Joint Robot with Jerk Estimation

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Mohammad Ali Badamchizadeh ◽  
Iraj Hassanzadeh ◽  
Mehdi Abedinpour Fallah
Keyword(s):  
Initial Conditions ◽  
Covariance Matrices ◽  
Flexible Joints ◽  
Velocity Measurements ◽  
Lagrange Equations ◽  
Robust Nonlinear Control ◽  
Flexible Joint ◽  
Flexible Joint Robots ◽  
Simulation Results

Robust nonlinear control of flexible-joint robots requires that the link position, velocity, acceleration, and jerk be available. In this paper, we derive the dynamic model of a nonlinear flexible-joint robot based on the governing Euler-Lagrange equations and propose extended and unscented Kalman filters to estimate the link acceleration and jerk from position and velocity measurements. Both observers are designed for the same model and run with the same covariance matrices under the same initial conditions. A five-bar linkage robot with revolute flexible joints is considered as a case study. Simulation results verify the effectiveness of the proposed filters.

Design and Development of Logistics and Transport Route Control System

2011 ◽  
Vol 71-78 ◽  
pp. 4261-4264
Author(s):  
Ru Wang ◽  
San Yuan Tang ◽  
Wei Xin Sun
Keyword(s):  
Control System ◽  
Traffic Flow ◽  
Future Development ◽  
Design And Development ◽  
Urban Road ◽  
Traffic Conditions

According that town plan is mainly drawn with software AutoCAD, this article realizes to automatically select a shortest transport route on urban road and dynamically display traffic flow based on VC++ and ObjectARX and lays a foundation for future development taking traffic limit, traffic conditions and other complex conditions into account.

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