Connected and Automated Vehicles

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.

Development of Binocular Stereopsis for Vehicle Lateral Control, Longitudinal Control and Obstacle Detection

Malik, Jitendra
Kosecka, Jana
Taylor, Camillo J.
McLauchlan, Philip
1999

This nal report describes the application of computer vision techniques to the lateral and longitudinal control of an autonomous highway vehicle. In the part of the project we focused on an analysis of the vehicle's lateral dynamics and the design of an appropriate controller for lateral control and investigated various static feedback strategies where the measurements obtained from vision, namely o set from the centerline and angle between the road tangent and the orientation of the vehicle at some look-ahead distance, are directly used for control. The role of the look-ahead, its...

Highway Electrification and Automation Technologies - Regional Impacts Analysis Project: Phase III Appendices: Mobility Statistics

Scag
Path
1993

This report presents appendices to the third, and final, phase of the Highway Electrification and Automation Technologies Regional Impacts Analysis Project (HE&A). The focus of Phase III report is the assessment of regional impacts associated with application of roadway electrification, and automation technologies to selected freeway sections in the Southern California region.

Trajectory Design and Implementation of Longitudinal Maneuvers on AHS Automated and Transition Lanes

Chen, Pin-yen
Alvarez, Luis
Horowitz, Roberto
1997

In this report, the authors present a modified safe join trajectory for the regulation layer maneuvers of the hierarchical PATH Automated Highway System (AHS) architecture. This new design presents a more conservative behavior for the controlled platoon in a maneuver. The new trajectory reduces the chance of having a collision when the platoon ahead applies and holds maximum braking.

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).

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...

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.

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,...

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.

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...