PATH

Commercial Vehicle Operations: Government Interfaces And Intelligent Transportation Systems

Hall, Randolph W.
Intihar, Chris
1997

This report documents findings from a series of studies investigating how Intelligent Transportation Systems (ITS) could be used to improve the integration of commercial vehicle operations (CVO) with governmental services and regulations within intermodal transportation management centers. After a summary of prior project research, the report gives a review of ITS/CVO technologies. This is followed by results of interviews and focus groups that reveal that trucking companies are willing to invest and participate in projects that possess four basic characteristics: 1) modest investment, 2)...

Hierarchical, Hybrid Control Of Large Scale Systems

Lygeros, John
1996

This dissertation presents a hierarchical, hybrid point of view to the control of large-scale systems. The analysis is based on a new hybrid dynamical system formulation that allows for the modelling of large scale systems in a modular fashion. Three problems are addressed: controller design, closed loop performance verification and the extension of system autonomy. A control scheme based on semi-autonomous agent operation is first proposed. An algorithm, using ideas from game theory, is presented to produce continuous controllers for hierarchical, hybrid designs. A discussion of design...

Studies Of Collisions In Vehicle Following Operations By Two-dimensional Simulation

Chan, Ching-yao
1998

In Automated Highway Systems (AHS), vehicles are equipped with automatic control systems to govern the accelerating, steering and braking functions in order to maintain an appropriate speed and spacing with respect to the surrounding vehicles. One concept of AHS suggests the implementation of vehicle platoons with small spacing between vehicles. With vehicles moving closely together in platoons, the hazards of "chain-reaction" collisions become a concern. The benefits of small delta-V need to be weighed against the number of collisions in such feared "chain-collision" scenarios. This...

Development Of A Dynamic Equilibrium Assignment Procedure For Network-level Analysis Of New Technology

Sullivan, Edward C.
Wong, Sun
1989

Recognizing that many of the new technologies under consideration in the areas of automation, navigation, and control require a system-wide perspective to evaluate their full impacts, this investigation sought to identify a suitable network analysis procedure which would, with acceptable accuracy, quantify the traffic redistribution effects of deploying new technologies in actual urban settings. The specific focus of the work was to identify a network traffic assignment procedure to be used in the analysis and evaluation of new technologies deployed in selected corridors containing High...

Optimization and Microsimulation of On-ramp Metering for Congested Freeways

Gomes, Gabriel C.
2004

This dissertation investigates various aspect of the design and testing of on-ramp metering control systems, including optimization-based control and microscopic freeway modeling. A new technique for generating optimal metering plans is developed. As with most predictive designs, the ramp metering rates are found as the solution to a nonlinear optimization problem. In contrast to previous designs, the new approach 1) produces a globally optimal solution to the nonlinear problem, 2) requires only to solve a single linear program, and 3) allows the enforcement of hard constraints on the on-...

California Trains Connected

Kanafani, Adib
Benouar, Hamed
Chiou, Bensen
Ygnace, Jean-Luc
Yamada, Kazuhiro
Dankberg, Adam
2006

This project is to assist the Capitol Corridor Joint Power Authority (CCIPA) and the California Department of Transportation (Caltrans) assemble a decision framework for selecting wireless Internet access on behalf of customers riding the three California State sponsored Intercity Rail Services. To accomplish this objective, we researched the state of worldwide deployment of service based on the wireless technologies, such as wireless fidelity (WiFi) and Worldwide Interoperability for Microwave Access(WiMAX), conducted a survey of the WiFi service at San Francisco Airport, and examined the...

A Conceptual Simulation Framework For Mobile Radio Communications: A Flexilevel Approach

Silvester, John A.
1997

Mobile radio communications systems are attracting more and more attention since they provide a means for users on the move to exchange information with other stationary or mobile stations. The capability of communication on the move can support many services and create lots of applications. For example, in the future Intelligent Vehicles Highway Systems (NHS), mobile communication technologies have enabled two important subsystems, namely Advanced Traffic Management and Information Systems (ATMIS) and Automatic Vehicular Control Systems (AVCS). The purpose of this research is to develop a...

Implementation Of The Regulation Layer Using Shift

Gulick, David
Alvarez, Luis
Horowitz, Roberto
1998

In this report, the implementation in the SHIFT programming language of regulation layer control laws for the hierarchical California PATH Automated Highway System (AHS) is presented. The implemented regulation layer control laws are derived after the safe-feedback based maneuvers designed in previous PATH projects. These maneuvers were modified to use the acceleration of vehicles as the control signal. Simulation results and a summary of the code developed are included.

Functional And Interface Requirements For Advanced Public Transportation Systems

Hickman, Mark D.
Tabibnia, Sam
Day, Theodore
1998

This report studies the current development of functional requirements and interface standards for the public transit industry. It begins with a critical review of recent architecture efforts and their functional and interface requirements. It then describes the results of a survey of public transit vendors that was conducted to learn about the technical characteristics of products and vendor attitudes toward interface standards. Four case studies of recent technology applications in the San Francisco Bay Area are then described. These case studies reflect that factors such as market...

Design and Error Analysis of Accelerometer-Based Inertial Navigation Systems

Tan, Chin-Woo
Park, Sungsu
2002

We examine the feasibility of designing an accelerometer-based (or gyroscope-free) inertial navigation system that uses only accelerome-ters to compute the linear and angular motions of a rigid body. The accelerometer output equation is derived to relate the linear and an-gular motions of a rigid body relative to a fixed inertial frame. A suf-ficient condition is given to determine if a configuration of accelerom-eters is feasible. If the condition is satisfied, the angular and linear motions can be computed separately using two decoupled equations of an input-output dynamical system; a...