PATH

An Object-Oriented Database for IVHS

Varaiya, Pravin
1998

The objective of this proposal was to develop a database that integrates various elements-traffic simulation packages, data sets, and computational tools. The difficulty in integration was felt to be the incompatibility of data structures, formats, and software.It was proposed to design, build and test a software environment with an open architecture that would facilitate a synergistic use of these software elements. The core of this environment was to be an object-oriented commercial database system that would be sufficiently general to support many software elements, and which would...

An Investigation of the Costs of Roadway Traffic Congestion: A Preparatory Step for IVHS Benefit's Evaluation

Miller, Mark A.
Li, Kayin
1994

This report focuses on traffic congestion under current road conditions with the objective of developing a quantitative understanding of their costs. The work is intended to provide a foundation upon which to build later estimates of the benefits that could be attributable to the use of Intelligent Vehicle Highway Systems (IVHS) technologies. The report gives an overview of traffic congestion and summarizes the principal sources of research in the areas of quantifying the costs of congestion. It reviews this past work relative to the usage of data, methodological approaches used in the...

An Interface Between Continuous and Discrete-Event Controllers for Vehicle Automation

Lygeros, John
Godbole, Datta N.
1994

Automation of highways and in particular platooning of vehicles raises a number of control issues. A hierarchical structure is used to address these issues. The work presented here is an attempt at constructing a consistent interface between discrete event and continuous time controllers. The design proposed is a finite state machine that communicates with the discrete controllers by issuing commands that get translated to "jerk" input for the vehicle engine. The operation of the proposed design is tested using COSPAN. By virtue of the fact that the interface touches on both the discrete...

An Integrated Physical/Link-Access Layer Model of Packet Radio Architectures

Polydoros, Andreas
1994

The goal of this effort is to devise and analyze an integrated Physical/ Link-Access Layer Model of packet Radio Architectures, with application to the PATH/IVHS (Intelligent Vehicle Highway Systems) communication sub- system design between vehicles and infrastructure, as well as between vehicles on the move. The present report contributes to a generic conceptual model for system evaluation which can be used for quantification of the interaction between network layers. The research tasks that have been performed for achieving the project objectives include collection of data requirements...

An Exploration of the Market for Traffic Information

Chan, Shirley
Malchow, Matthew
Kanafani, Adib
1997

This report attempts to derive a more accurate economic model to describe the supply and cost mechanisms that influence the market for traffic information. It first gives a history of the traffic information market, its economies-of-scale, and its potential for future development.e history of current The report discusses recent developments of value-added-resellers, the differences that exist in the marketing of their products, and factors influencing their success . Suggestions are presented for commercial broadcast stations and public agencies in terms of maximizing the total benefits of...

An Experimental Study on Lateral Control of a Vehicle

Hessburg, Thomas
Peng, Huei
Tomizuka, Masayoshi
Zhang, Wei-bin
1991

Addresses issues regarding the implementation of an integration of several specific technologies involved in achieving lateral guidance of an experimental automotive vehicle on an automated highway. Results demonstrate the feasibility of the proposed discrete magnetic marker reference/sensing system. In addition, the performance and limitations of a PID/feedforward controller is investigated with respect to tracking accuracy of straight and curved sections as well as robustness to changes in load, longitudinal velocity, and cornering stiffness.

An Information and Institutional Inventory of California Transit Agencies

Hickman, Mark
Day, Theodore
1996

This research identifies and investigates the current technical and institutional framework for information systems and technologies at public transit agencies in California. The study examines the current state-of- the-art practice for the collection, use and sharing of data for operations monitoring, service planning, performance measurement and customer information. A survey of transit agencies and site visits were conducted. This paper presents these survey results and generates some conclusions for improving agencies.

Adaptive Throttle Control for Speed Tracking

Xu, Z.
Ioannou, P.
1994

In this paper, the authors design an adaptive control scheme for electronic throttle that achieves good tracking of arbitrary constant speed commands in the presence of unknown disturbances. The design is based on a simplified linear vehicle model which is derived from a validated nonlinear one. The designed control scheme is simulated using the validated full order nonlinear vehicle model and tested on an actual vehicle. The simulation and vehicle test results are included in this paper to show the performance of the controller. Due to the learning capability of the adaptive control...

Adaptive Signal Control System with On-line Performance Measure for Single Intersection

Liu, Henry X.
Oh, Jun-Seok
Recker, Will
2002

This paper introduces an adaptive signal control system utilizing an on-line signal performance measure. Unlike conventional signal control systems, the proposed method employs real-time delay estimation and an on-line signal timing update algorithm. As a signal performance measure, intersection delay for each phase is measured in real-time via an advanced surveillance system that re-identifies individual vehicles both at upstream and downstream stations using vehicle waveforms obtained from advanced inductive loop detectors. In each cycle, the signal timing plan is optimized based on the...

Adaptive Baud Protocol for Wireless Communication

Eskafi, F. H.
Nassiri-toussi, K.
Liu, G.
1998

In this paper, the authors propose an algorithm that increases and decreases the transmission speed according to a user-specified function. The design objective is to regulate baud as efficiently as possible and ensure that in each transmission interval, transmitter and receiver bauds are equal for some period of time during data transmission. An equivalent discrete-time version of the protocol is verified by using the COSPAN software. Application for this adaptive baud protocol for wireless communication is seen in a platoon setting within an Automated Highway System (AHS).