Modeling

Two Proposals To Improve Freeway Traffic Flow

Karaaslan, Ufuk
Varaiya, Pravin
Walrand, Jean
1990

The following two proposals are presented: (1) Vehicles are organized in platoons in which the lead car is manually driven and the other cars are under automatic spacing (headway) control. A plausible model of the resulting flow of traffic indicates that, for an average platoon size of 20, the capacity of the freeway increases by a factor of four. (2) A macroscopic model of freeway traffic congestion along with a control law for reducing congestion is presented. Simulation of the resulting closed loop model indicates a dramatic reduction in congestion.

The Naturalistic Driver Model: Development, Integration, and Verification of Lane Change Maneuver, Driver Emergency and Impairment Modules

Cody, Delphine
Tan, Swekuang
Caird, Jeff K.
Lees, M.
Edwards, C.
2005

The need for a drivers’ model that integrates a wider range of natural driver activities is important to the traffic engineering and human factors communities. Integration of real traffic behaviors into micro-simulations increases the accuracy and explanatory power of these models. For human factors engineers, improvements to driver modeling efforts provide a useful framework by which Intelligent Transportation Systems (ITS) can be evaluated for safety and mobility. This project includes a means to consider normal lane changing maneuver, driver support for emergency management and impaired...

Command Modification Using Input Shaping for Automated Highway Systems with Heavy Trucks

Bae, Hong S.
Gerdes, J. Christian
2004

Automated vehicles require sufficiently accurate system models in order to achieve a desired level of closed-loop performance in, for example, automated highways systems or smart cruise control systems. Parameters of the models are one of the important factors that determine the accuracy of system modeling and, eventually, the overall performance of the closed-loop system. Current GPS sensing technology enables estimation of road grade and, consequently, simple treatment of parameter estimation from a static force balance. This work has demonstrated that road grade can be reliably...

Development of an Adaptive Corridor Traffic Control Model

Recker, Will
Zhenhg, Xing
Chu, Lianyu
2010

This research develops and tests, via microscopic simulation, a real-time adaptive control system for corridor management in the form of three real-time adaptive control strategies: intersection control, ramp control and an integrated control that combines both intersection and ramp control. The development of these strategies is based on a mathematical representation that describes the behavior of traffic flow in corridor networks and actuated controller operation. Only those parameters commonly found in modern actuated controllers (e.g., Type 170 and 2070 controllers) are considered in...

A Combined Quantitative and Qualitative Approach to Planning for Improved Intermodal Connectivity at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Ceder, Avi
Tung, Steven
Tso, Kristin
Shladover, Steven
Xiong, Jing
Yoon, Sangwon
2009

This report has been prepared as the final deliverable for a research project developing a combined quantitative and qualitative approach to planning for improved intermodal connectivity at California airports. The quantitative approach involves the development of an Intermodal Airport Ground Access Planning Tool (IAPT) that combines transportation system performance measurement, an air passenger mode choice model, and a model of transportation provider behavior, and is designed to interface with a traffic network analysis model. The qualitative approach is used to enhance the quantitative...

Models, Simulation, And Performance Of Fully Automated Highways

Varaiya, Pravin
1994

The research findings presented in this report deal with the modeling, simulation and performance evaluation of fully automated highway systems ( AHS). The report begins with a brief reconstruction of the history of the AHS concept, and a particular AHS proposal that has been intensely studied in PATH. The next section summarizes the principal findings of AHS performance. This is followed by an overview of the simulation program SmartPath. An outline of the current work on SmartPath and plans for the immediate future are given. This section also proposes an object oriented distributed...

Fault Detection And Identification With Application To Advanced Vehicle Control Systems

Douglas, Randal K.
Speyer, Jason L.
Mingori, D. Lewis
Chen, Robert H.
Malladi, Durga P.
Chung, Walter H.
1995

In this report, a preliminary design of a health monitoring system for automated vehicles is developed and results of tests in a high-fidelity nonlinear simulation are reported. Two car models are described: low- dimensional linear models for fault detection filter design and high fidelity nonlinear model is used for evaluation and to obtain the linear models used for design. The faults and the fault detection filters and system are then described. An evaluation of the performance of the fault detection filters in a nonlinear simulation are presented. A fault detection filter residual...

A Design Framework For Hierarchical, Hybrid Control

Lygeros, John
Godbole, Datta N.
Sastry, Shankar
1997

In this research, the authors focus on the problem of designing hierarchical, hybrid controllers for large scale systems. An overview of the proposed design process is first given. A modeling formalism is then introduced which allows for the modeling of multi-agent systems with hybrid dynamics in a modular fashion. An algorithm that makes use of ideas from game theory to capture the interaction between the agents, derive continuous controllers and quantify the discrete coordination needed to achieve certain performance objectives is presented. The algorithm is then applied to the problem...

Opportunities for Improved Intermodal Connectvitiy at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Xiong, Jing
2006

This working paper has been prepared as part of research to develop a combined quantitative and qualitative approach to planning for improved intermodal connectivity at California airports. The quantitative approach involves the development of an Intermodal Airport Ground Access Planning Tool that combines an air passenger model choice model, a model of transportation provider behavior and a traffic network analysis model. The qualitative approach will be used to enhance the quantitative analysis to account for those factors which are difficult to quantify and to provide recommended policy...

Ad-hoc Medium Access Control Protocol Design and Analysis for Vehicle Safety Communications

Sengupta, Raja
Xu, Qing
Mak, Tony
Ko, Jeff
2004

This paper studies the design of ad-hoc Medium Access Control (MAC) protocols for a vehicle or the roadside to send safety messages to other vehicles. Such a protocol is needed by Advanced Vehicle Safety Systems (AVSS) and the national Dedicated Short Range Communications (DSRC) architecture. The problem is formulated to meet the communication requirements of vehicle safety applications and the DSRC multi-channel operation model. We propose several ah-hoc protocols, all based on the principles of repetition coding. Analytical bounds of the protocols' performance are derived. Simulations...