PATH

A Parmetric Study of Platoon Dynamics and Robust H[infinity] Controller Design

Oh, Pahngroc
Packard, Andy
Tongue, Benson H.
1999

A comprehensive simulation capability is presented for the analysis of vehicular platoons with or without collisions. A separate collision module (CDM) is integrated within the Platoon Simulation Package (PSP) to allow the recognition and dynamic simulation of intra- platoon collisions. Test simulations are presented and an alternative control strategy, one based on H , optimization, is described. This control approach allows an explicit account to be taken unknown disturbances and system variations, i.e. it produces a robust design.

Field Operational Tests of Adaptive Transit Signal Priority Systems

Li, Meng
2010

An Adaptive Transit Signal Priority (ATSP) system is built upon and integrated with the existing Transit Automated Vehicle Location/Advanced communications system (AVL/ACS) to provide transit buses with needed priority by adaptively determining an optimum signal timing strategy based on status of both the concerned transit bus and the traffic conditions. PATH has conducted a series of studies on ATSP in collaboration with the California Department of Transportation (Caltrans) and San Mateo County Transit District (SamTrans) since 2000, involving the development and implementation of a...

Traffic Control For Automated Highway Systems: A Conceptual Framework

Tsao, Jacob
1995

This paper proposes a conceptual framework for designing a traffic control scheme. It adopts a top-down approach to defining major design steps starting with high-level feature definition. With the desired features defined, the top-down approach then identifies and defines moves and related planning and movement functions that are required for supporting the desired features. The paper takes a systems view and identifies the safety issues regarding the movement coordination of the large number of vehicles on an Automated Highway System (AHS).

A Communication Architecture For IVHS

Streisand, Susan L.
Walrand, Jean
1992

This paper documents the development of a communications architecture for Intelligent Vehicle Highway Systems (IVHS) being studied by the California PATH Program. The authors use a layered architecture based on the OSI 7- layer reference model.

Stage Definition For Ahs Deployment And An Ahs Evolutionary Scenario

Tsao, H. S. Jacob
1996

This paper proposes an approach to defining evolutionary scenarios for the deployment of an Automated Highway System (AHS). Six dimensions of deployment difficulties are identified: technology, infrastructure, human factors, vehicle manufacturing and maintenance, insurance, and public will.

Assessing the Value of TMCs and Methods to Evaluate the Long Term Effects of ITS Implementation: A General Equilibrium Approach

Gillen, David
2004

This research builds on the contributions of MOU 357, 3001 and task Order 4119 all of which focus on methodological and measurement issues in benefit cost assessments of ITS applications. The important contributions of this work are not only providing methods for calculating benefits and costs but also an empirical assessment of the set of projects that have been implemented. In all of this work, as well as most other project evaluation studies, two strong assumptions are made. First, the project is implemented successfully and second the impact of the transportation project is felt wholly...

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...