PATH

An Adaption Method For Fuzzy Logic Controllers In Lateral Vehicle Guidance

Hessburg, Thomas
Tomizuka, Masayoshi
1995

In this report, a formulation is made for a model reference adaptive fuzzy logic control (MRAFLC) algorithm and applied to automatic steering control of a vehicle. The purpose of the research is to design a fuzzy logic controller such that changes in operating conditions are addressed in the controller. The changes in operating conditions of interest include vehicle speed and road surface conditions.

Towards A Fault Tolerant Ahs Design Part I: Extended Architecture

Lygeros, J.
Godbole, D. N.
Broucke, M.
1996

In this study, the authors propose a hierarchical control architecture for dealing with faults and adverse environmental conditions on an Automated Highway System (AHS). The faults are classified according to the capabilities remaining on the vehicle or roadside after the fault has occurred. Information about these capabilities is used by supervisors in each of the layers to select appropriate control strategies. The extended control strategies that are needed by these supervisors in each layer of the hierarchy are outlined. A companion paper, abstracted in PATH Database record no. 9597,...

Travel Behavior of Immigrant Groups in California

Handy, Susan, PhD
Blumenberg, Evelyn, PhD
Donahue, Moira
Lovejoy, Kristin
Rodier, Caroline, PhD
Shaheen, Susan, PhD
Shiki, Kimiko
Song, Lily
Tal, Gil
2009

California is the destination for over one-quarter of immigrants to the United States, and immigrants now make up over one-quarter of the state’s population, with nearly half of immigrants originating in Mexico. To ensure that transportation systems and services adequately meet the needs of recent immigrants, planners need a firm understanding of the travel behavior of immigrant groups. This paper reports on key findings from a three-phased study: (1) analysis of data on commute travel of California immigrants from the 1980, 1990, and 2000 Censuses; (2) focus groups with recent Mexican...

Diagnosis and Communication in Distributed Systems

Sengupta, Raja
1999

This paper discusses diagnosis problems in distributed systems within the context of a language- theoretic discrete event formalism. A distributed system is seen as a system with multiple spatially separated sites with each site having a diagnoser that observes some of the events generated by the system and diagnoses the faults associated with the site. We allow the diagnosers to share information by sending messages to each other. Distributed systems are classified as being centrally, decentrally, and independently diagnosable. We characterize the class of distributed systems for which...

Lean Machines: Preliminary Investigations

Garrison, William Louis
Pitstick, Mark E.
1990

This report provides information on a study assessing the potential for the transition of the fleet of highway vehicles to lean vehicles (General Motors Lean Machine). The report provides information on the organization of the study and the results of preliminary explorations of parking, ownership and operating, and highway capacity topics. In addition, a discussion paper provides a broad brush treatment of topics bearing on the adoption and use of the lean vehicles in California.

Inter-technology Effects in Intelligent Transportation Systems

Levinson, David M.
Kanchi, Seshasai
Gillen, David
2002

This project examines the expected benefits of varying combinations of ITS applications: Freeway Service Patrol, Changeable Message Signs, and Ramp Metering. The research analyzes the simulated results of a stylized network in a microscopic traffic simulator. The traffic network includes parallel roadways, ramp meters and changeable message signs.We have tested these technologies in various combinations. We measure effectiveness and define a measure of inter-technology economies.In brief, it is found that additional technologies are sub-additive, and more benefits come from each technology...

An Investigation in the Use of Inductive Loop Signatures for Vehicle Classification

Sun, Carlos
2000

This final report describes an advanced traffic surveillance technique based on pattern recognition and the use of current inductive loop technology. The focus of the investigation was a study of the feasibility of using inductive loop signatures for obtaining vehicle classification information on a network-wide level.

Red-Light-Running Collision Avoidance

Grembek, Offer
Zhou, Kun
Zhang, Wei-Bin
2009

Red light running (RLR) problem has been recognized as a significant safety problem in California as well as throughout the United States. This paper follows a two step process to develop enhanced signal timing models for possible reduction of RLR. In the first step, field data are collected with one-second resolution and discrete choice models are estimated to determine the significant influencing factors of RLR; in the second step, based on the findings from the first step, T7F software package as well as custom designed programs is used to find the enhanced signal timing plans that can...

Analysis, Design, And Evaluation Of Avcs For Heavy-duty Vehicles With Actuator Delays

Yanakiev, Diana
Eyre, Jennifer
Kanellakopoulos, Ioannis
1998

This report focuses on the design of longitudinal control algorithms for commercial heavy vehicles (CHVs). The algorithms use nonlinear spacing policies, backstepping control design, and aggressive prediction schemes to deal with the presence of significant delays and saturations in the fuel and brake actuators. The algorithms can also deal with delays both in the presence and in the absence of intervehicle communication. A by-product on this research is the development of two software packages, Platoon-Builder and TruckVis, for simulation and animation of CHV platoons. Additionally,...

Cooperative Collision Warning Systems: Concept Definition and Experimental Implementation

Sengupta, Raja
Rezaei, Shahram
Shladover, Steven E.
Cody, Delphine
Dickey, Susan
Krishnan, Hariharan
2006

The concept of cooperative collision warning (CCW) systems is introduced and explained, followed by presentation of experimental results showing the performance of a first prototype CCW system. The CCW concept provides warnings or situation awareness displays to drivers based on information about the motions of neighboring vehicles obtained by wireless communications from those vehicles, without use of any ranging sensors. This has the advantages of a potentially inexpensive complement of onboard vehicle equipment (compared to ranging sensors that could provide 360 degree coverage), as...