Predictive Time-Based Feedback Control Approach for Managing Freeway Incidents

2000 ◽  
Vol 1710 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Omar B. Sawaya ◽  
Dung L. Doan ◽  
Athanasios K. Ziliaskopoulos
Keyword(s):  
Feedback Control ◽  
Traffic Management ◽  
Control Strategies ◽  
Compliance Rate ◽  
Dynamic Control ◽  
Route Guidance ◽  
Control Approach ◽  
Real Time Traffic ◽  
Freeway Incidents ◽  
Alternate Routes

A feedback control approach is introduced that produces dynamic control strategies in the form of alternate routes around freeway incidents and in response to the prevailing traffic conditions. The approach is based on the equalization of predictive travel times on alternate routes. The methodology is intended to be used as a decision-aid tool for real-time traffic management applications, more specifically for route guidance via variable message signs. The approach is implemented and tested computationally on an example network in a simulated environment under various scenarios of system disturbances. The results indicate that the performance of this approach is fairly robust to uncertainties in demand, compliance rate, and incident severity. It also performs better than an anticipatory approach and an instantaneous time–based feedback control approach.

The Use of Optimally Shaped Piezo-electric Film Sensors in the Active Control of Free Field Structural Radiation, Part 2: Feedback Control

1996 ◽  
Vol 118 (1) ◽  
pp. 112-121 ◽  
Author(s):  
S. D. Snyder ◽  
N. Tanaka ◽  
Y. Kikushima
Keyword(s):  
Feedback Control ◽  
Control Strategies ◽  
Free Field ◽  
Low Frequency ◽  
Acoustic Power ◽  
State Equations ◽  
Subsequent Increase ◽  
Low Frequencies ◽  
Control Approach ◽  
Iir Filters

Feedback control of free field structural radiation is considered. State equations are formulated with a transformation which decouples the acoustic power error criterion. Using the resultant equations, expressed in terms of “transformed mode” states, the order of the state equations can be significantly reduced at low frequencies. Two experimental implementations of feedback control strategies using shaped piezoelectric polymer film sensors to measure the transformed system states are described. The first of these is a simple analog implementation. The second implementation is in discrete time, where an adaptive algorithm for optimizing the weights of IIR filters for practical use is described. It is shown that by using the outlined control approach significant levels of low frequency acoustic power attenuation can be obtained with no control spillover and subsequent increase in higher frequency acoustic power output.

Active Control of a Circular Membrane to Reduce Transient Noise Transmission

1995 ◽  
Vol 117 (3A) ◽  
pp. 252-258 ◽  
Author(s):  
J. L. van Niekerk ◽  
B. H. Tongue
Keyword(s):  
Feedback Control ◽  
Active Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Circular Membrane ◽  
Velocity Feedback ◽  
Circular Duct ◽  
Control Approach ◽  
Noise Transmission

An active control approach that reduces transient noise transmission through a membrane in a circular duct is presented. Discrete sections of piezo-electrical film, PVDF, are used as actuators to adjust the tension of the membrane. Different control strategies, such as optimal, sliding mode and velocity feedback control, are investigated analytically and then implemented experimentally. It is shown that velocity feedback control is the more effective, stable controller for this application.

scholarly journals The Management of Urban Freeway Traffic

1974 ◽  
Vol 1 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Allen R. Cook
Keyword(s):  
Traffic Congestion ◽  
Urban Areas ◽  
Traffic Management ◽  
Control Strategies ◽  
False Alarms ◽  
Freeway Traffic ◽  
Detection Algorithms ◽  
Urban Freeway ◽  
And Control ◽  
Alternate Routes

The advent of computer-controlled electronic freeway surveillance and control systems in the past decade represents a potentially significant new operational tool for traffic engineers in large urban areas. These systems are capable of responding to rapidly changing traffic conditions and in various demonstration projects they have proven useful in maintaining an acceptable level of service for freeway operations, reducing the extent and duration of traffic congestion, minimizing the adverse effects of accidents and other incidents on traffic operations, and reducing accident experience. Surveillance system goals and techniques for achieving these goals are reviewed in this paper with particular emphasis on the problem of managing unexpected capacity-reducing incident situations. Recent research has demonstrated the feasibility of detecting incidents from traffic flow data, which is desirable for surveillance purposes because this information can be used to implement control strategies which attempt in real-time to divert some freeway traffic to alternate routes. Some of the operational problems involved with freeway traffic management are discussed, particularly the generation of false alarms by detection algorithms and driver willingness to be diverted to alternate routes.

Active traffic management on road networks: a macroscopic approach

2010 ◽  
Vol 368 (1928) ◽  
pp. 4607-4626 ◽  
Author(s):  
Alex A. Kurzhanskiy ◽  
Pravin Varaiya
Keyword(s):  
Real Time ◽  
Traffic Management ◽  
Control Strategies ◽  
Continuous Process ◽  
Measurement Data ◽  
Road Networks ◽  
Operations Planning ◽  
Traffic Measurement ◽  
Traffic State ◽  
Real Time Traffic

Active traffic management (ATM) is the ability to dynamically manage recurrent and non-recurrent congestion based on prevailing traffic conditions in order to maximize the effectiveness and efficiency of road networks. It is a continuous process of (i) obtaining and analysing traffic measurement data, (ii) operations planning, i.e. simulating various scenarios and control strategies, (iii) implementing the most promising control strategies in the field, and (iv) maintaining a real-time decision support system that filters current traffic measurements to predict the traffic state in the near future, and to suggest the best available control strategy for the predicted situation. ATM relies on a fast and trusted traffic simulator for the rapid quantitative assessment of a large number of control strategies for the road network under various scenarios, in a matter of minutes. The open-source macrosimulation tool A urora R OAD N ETWORK M ODELER is a good candidate for this purpose. The paper describes the underlying dynamical traffic model and what it takes to prepare the model for simulation; covers the traffic performance measures and evaluation of scenarios as part of operations planning; introduces the framework within which the control strategies are modelled and evaluated; and presents the algorithm for real-time traffic state estimation and short-term prediction.

scholarly journals Developing a Traffic Management Framework for Coastal Expressway Bridges under Adverse Weather Conditions: Case Study of Rain Day in Shenzhen, China

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Chenming Jiang ◽  
Jian John Lu ◽  
Yuming Jiang ◽  
Xiaonan Cai ◽  
Anning Ni
Keyword(s):  
Traffic Management ◽  
Injury Severity ◽  
Control Strategies ◽  
Geographical Location ◽  
Surface Friction ◽  
Weather Conditions ◽  
Negative Influence ◽  
Management Framework ◽  
Adverse Weather ◽  
Alternate Routes

Adverse weather can reduce visibility and road surface friction, lower vehicle maneuverability, and increase crash frequency and injury severity. The impacts of adverse weather and its interactions with drivers and roadway on the operation and management of expressway or expressway bridges have drawn the researchers’ and managers’ attention to develop traffic management frameworks to mitigate the negative influence. Considering the peculiar geographical location and meteorological conditions, the Guangshen Coast Expressway-Shenzhen Segment (GSCE-SS) was selected as a case in this study to illustrate the proposed traffic management framework on rain days. Conditions categorized by rainfall intensity and traffic flow were the main precondition to make the management decisions. CORSIM simulator was used to develop the alternate routes choice schemes, providing reference for other systems in the proposed traffic management framework. Maps of (a) entrance ramp control (ERC) strategies; (b) mainline control strategies; (c) alternate routes choice; (d) information release schemes, under scenarios of different volume and rainstorm warning grades (BLUE to RED), were drawn to present a reference or demonstration for managers of long-span expressway bridges not only in China, but even in the world.

Construction of Urban Traffic Information Service System Based on WebGIS

2013 ◽  
Vol 353-356 ◽  
pp. 3516-3519
Author(s):  
Fei Cai ◽  
Ning Ding ◽  
Xiao Xiao Qu
Keyword(s):  
Traffic Management ◽  
Service System ◽  
Information Service ◽  
Intelligent Transportation ◽  
Remote Sensing Image ◽  
Urban Traffic ◽  
Daily Activities ◽  
Traffic Information ◽  
Route Guidance ◽  
Real Time Traffic

In order to improve utilization of traffic information, this paper introduces the construction of urban traffic information service system based on SuperMap iServer for Java. Overall structure of urban traffic information service system is designed. The system uses the remote sensing image and electronic map of Jinan as basic data and implement functions including route guidance, parking guidance, real-time traffic information and statistical analysis. The system makes advantage of the superiority of Ajax in asynchronous transmission which enhances the user's browsing experience. Efficiency of traffic flow guidance and traffic management decisions increases by the system, which greatly facilitates the daily activities of city residents. Applications show that the system is a beneficial exploration of intelligent transportation with strong practicality and versatility.

Feedback control to delay or advance linear loss of stability in planar Poiseuille flow

1994 ◽  
Vol 447 (1930) ◽  
pp. 299-312 ◽  
Keyword(s):  
Feedback Control ◽  
Poiseuille Flow ◽  
Control Strategies ◽  
Linear Stability Theory ◽  
Flow Instabilities ◽  
Loss Of Stability ◽  
Stress Sensors ◽  
Shear Stress Sensors ◽  
Linear Loss ◽  
Adjacent Wall

By using linear stability theory, we demonstrate theoretically that the critical Reynolds number for the loss of stability of planar Poiseuille flow can be significantly increased or decreased through the use of feedback control strategies which enhance or suppress disturbance dissipating mechanisms in the flow. The controller studied here consists of closely packed, wall mounted, shear stress sensors and thermoelectric actuators. The sensors detect flow instabilities and direct the actuators to alter the fluid’s viscosity by modulating the adjacent wall temperature in such a way as to suppress or enhance flow instabilities. Results are presented for water and air flows.

scholarly journals Assessments of Real-Time Communications over TSN Automotive Networks

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 556
Author(s):  
Lucia Lo Bello ◽  
Gaetano Patti ◽  
Giancarlo Vasta
Keyword(s):  
Performance Evaluation ◽  
Real Time ◽  
Communication System ◽  
Traffic Management ◽  
Mac Layer ◽  
Automated Driving ◽  
Real Time Traffic ◽  
Management Scheme ◽  
Event Driven ◽  
Automotive Networks

The IEEE 802.1Q-2018 standard embeds in Ethernet bridges novel features that are very important for automated driving, such as the support for time-driven communications. However, cars move in a world where unpredictable events may occur and determine unforeseen situations. To properly react to such situations, the in-car communication system has to support event-driven transmissions with very low and bounded delays. This work provides the performance evaluation of EDSched, a traffic management scheme for IEEE 802.1Q bridges and end nodes that introduces explicit support for event-driven real-time traffic. EDSched works at the MAC layer and builds upon the mechanisms defined in the IEEE 802.1Q-2018 standard.

Application of Combined Feedforward and Feedback Controller With Shaped Input to Benchmark Problem

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Young Joo Shin ◽  
Peter H. Meckl
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Control Design ◽  
Single Frequency ◽  
Benchmark Problems ◽  
Control Force ◽  
Benchmark Problem ◽  
Advantages And Disadvantages ◽  
Robust Control Design

Benchmark problems have been used to evaluate the performance of a variety of robust control design methodologies by many control engineers over the past 2 decades. A benchmark is a simple but meaningful problem to highlight the advantages and disadvantages of different control strategies. This paper verifies the performance of a new control strategy, which is called combined feedforward and feedback control with shaped input (CFFS), through a benchmark problem applied to a two-mass-spring system. CFFS, which consists of feedback and feedforward controllers and shaped input, can achieve high performance with a simple controller design. This control strategy has several unique characteristics. First, the shaped input is designed to extract energy from the flexible modes, which means that a simpler feedback control design based on a rigid-body model can be used. In addition, only a single frequency must be attenuated to reduce residual vibration of both masses. Second, only the dynamics between control force and the first mass need to be considered in designing both feedback and feedforward controllers. The proposed control strategy is applied to a benchmark problem and its performance is compared with that obtained using two alternative control strategies.

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