Showing papers in "PATH research report in 1991"

The Design of Platoon Maneuver Protocols for IVHS

Abstract: This report focuses on the design of controllers for platoons of automatically-controlled automobiles using COSPAN computer language. In order to ensure that it is safe to initiate a maneuver, the platoon layer controller enters into a negotiation with its neighbors and is implemented as a protocol. After a successful protocol termination, the actions of the vehicles involved become coordinated and the maneuver can be initiated.

Communications and Positioning Systems in the Motor Carrier Industry

Abstract: Until recently, truck drivers and their dispatchers have relied on public telephones and voice radio systems to communicate with each other. Today, however, vendors are beginning to offer new technologies for determining the positions of trucks and communications to and from trucks. Eighteen systems and their implications for the industry and intelligent vehicle highway systems (IVHS) activities are reviewed in this paper. Some of the newer communications and/or positioning systems are in the proposal stage. Others are available with not yet fully developed capability or only in limited markets. Some other systems, such as cellular telephones or modern voice radio, represent recent improvements of existing systems. New satellite based systems offer the most comprehensive coverage, but they are relatively expensive and tend to be favored by large, irregular route truckload carriers which have reported significant increases in productivity from system use. Regardless of the technology used, the challenge for truck fleet operators is the full integration of the information provided by the systems with their operations. In the transition to a high degree of information integration, three distinct steps or levels can be identified. First, the dispatcher's work is eased and made more efficient. The communications system plays a key role because the basic source of information is the moving vehicle. Then, information is shared between different departments within the trucking firm. Finally, interorganizational links between the trucking firm and its customers are established. Firms in the industry have always strived for information integration at these levels. What is new is the possibility of a much higher level of information automation and integration. The implications of trucking industry trends for IVHS programs may be summed up in two observations. Managers of trucking firms are interested in improved productivity, service improvements, and cost reductions. Highway agency professionals are interested in improved facility operations. But the mutual interests of firms and IVHS-interested agencies appear to fall through the cracks, so to speak. Trucking firms are achieving higher and higher levels of information-enabled integration. The potential for integration of information from the trucking industry has not yet been considered by the IVHS community.

An Experimental Study On Lateral Control Of A Vehicle

Abstract: 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.

Optimal Preview Control for Vehicle Lateral Guidance

Abstract: This report introduces an optimal preview control algorithm which utilizes preview information pertaining to road curvature as well as superelevation angle for vehicle lateral control purposes. The optimal control law consists of both feedback control action and feedforward preview control action. The feedforward preview control action significantly improves tracking performance while maintaining a small closed loop bandwidth so ride quality is not impaired. Frequency domain analyses and numerical simulation results show improvements obtained in both frequency domain and time domain

A Fuzzy Rule-based Controller For Automotive Vehicle Guidance

Abstract: A fuzzy rule-based controller is applied to lateral guidance of a vehicle for an automated highway system. The fuzzy rules, based on human drivers' experiences, are developed to track the center of a lane in the presence of external disturbances and over a range of vehicle operating conditions.

Platoon Collision Dynamics and Emergency Maneuvering I: Reduced Order Modeling of a Platoon for Dynamical Analysis

Abstract: The purpose of this three-year project is to develop an operational model of vehicle platoon dynamics under emergency conditions and to evaluate the platoon's dynamical behavior under non-nominal, or emergency, conditions New platoon protocols and/or controller modifications will be formulated after analyzing the platoon response data in order to minimize damage to the platoon and the vehicles' occupants This progress report discusses the results of the modeling phase of this work A detailed literature review is included as Appendix B

Restructuring The Automobile/highway System For Lean Vehicles: The Scaled Precedence Activity Network (SPAN) Approach

Abstract: This paper studies relative time savings between vehicles unequipped and equipped with route guidance and navigation systems. In particular, the report investigates to what extent relative travel time savings decrease as the percentage of equipped vehicles increases. In addition, some other potential services that can be provided by navigation systems are identified. The report focuses on benefits for commuters, although some results are applicable for other users.

Expanding Usage Of Cellular Phones: User Profile And Transportation Issues

Abstract: This study presents an initial step toward an understanding of consumer responses to advanced traveler information systems. Specifically, it is aimed at understanding the role that cellular telephones can play in the management of urban traffic systems. To assess the interrelationships between cellular communication and driver behavior, a mail survey of GTE Mobilnet customers in the San Francisco Bay Area was conducted.

Sketch Of An Ivhs Systems Architecture

Abstract: Presents a sketch of a system architecture for the control and management tasks of an intelligent vehicle/highway system (IVHS)

Fault Tree Analysis of a First Example Automated Freeway

Abstract: This paper describes a fault tree analysis of an automated freeway and how conformity to safety criteria can be demonstrated by fault tree analysis. The system is initially explained, followed by a discussion of hazard analysis, fault tree, and an analysis of the results. Readers are advised to consult "Methods for Analysis of IVHS Safety: Final Report of MOU 19" by the author to acquire background information in regard to this report.

Model Selection and Initial Application of CONTRAM Model for Evaluating In-Vehicle Information Systems

Abstract: The objectives of this study were to select a traffic assignment and simulation model, apply that model to an integrated freeway/arterial network such as the Smart Corridor in Los Angeles, California, and using the model, make an initial evaluation of in-vehicle information systems and the applicability of the model.

A First Example Specification of an Automated Freeway

Abstract: This paper presents a specification for an automated freeway in a fully formal manner. A series of safety analyses have been carried out on the specification. The objective of the program is to derive a technique of safety analysis for such systems. Readers are advised to consult " Methods for Analysis of IVHS Safety: Final Report of PATH MOU 19" by the author for background information to this report.

Use of NASS Data for Evaluation of AVCS Devices

Abstract: This report examines the applicability of the 1986 National Accident Sampling System (NASS) in providing sufficient information about a traffic accident to determine if an advanced vehicle control system (AVCS) could have had an impact in preventing that accident. The author states that, in general, NASS raw data are useful for evaluation of AVCS whenever a driver' s choices are limited to keeping a straight course at an appropriate speed

Electronic Toll Collection System (ETC) User Survey

Abstract: This is a summary of several surveys concerning the use of an electronic toll collection system (ETC) among San Francisco Bay Area motorists. The objective of these surveys was to determine the level of interest in subscribing to an electronic toll collection service for Bay Area toll bridges. The issues addressed in the surveys were: (1) interest in the ETC service; (2) preferred types of automated vehicle identification (AVI) tags; (3) preferred location or placement of AVI tags on the vehicle; (4) desired method of payment for the ETC service; and, (5) perceived benefits of ETC.

Evaluation of Highway Bottlenecks

Abstract: This is the final report of the PATH research project Bottleneck Evaluation Model. The goal of the project was to develop a computer tool for evaluating capacity and travel time benefits of PATH improvements. The Bottleneck Traffic Simulator (BTS) is used to investigate the time benefits of changes in highway design and operation. Key issues include the effects of (1) highway reliability, in the form of incident frequency, duration and reliability; and (2) changes in traveler behavior, in the forms of arrival time choice and reneging.

Studies of the Adoption and Use of Location and Communication Technologies by the Trucking Industry

Abstract: Describes current and proposed investigations on the adoption and use of positioning (navigation) and communication technologies by the trucking industry

Evaluation Of Potential Hybrid Electric Vehicle Applications: Vol I

Abstract: Identifies potentially promising market segments for electric and hybrid vehicle technologies; covers topics including energy and power requirements, battery and range extender, propulsion system, and air conditioning

Control Strategies and Route Guidance in Signal Controlled Networks

Abstract: The goal of this study was to provide a better understanding of the impacts of route guidance on urban arterials and networks controlled by traffic signals. Control and timing strategies to handle diverted traffic from the freeways to surface streets were developed and tested through simulation on real-life networks. These strategies showed that for a small number of diverted vehicles, optimal timing plans for favoring the diverted routes improved the performance of diverted traffic without significant adverse impacts to the rest of the network.