Connected and Automated Vehicles

Analysis, Design and Evaluation of AVCS for Heavy-Duty Vehicles

Yanakiev, Diana
Kanellakopoulos, Ioannis
1996

In this report, the authors develop two new nonlinear spacing policies, variable time headway and variable separation error gain, designed to all but eliminate the undesirable side effect of large steady-state intervehicle spacings. This disadvantage is pronounced in heavy-duty vehicles, which require larger time headways due to their low actuation-to- weight ratio. The first policy significantly reduces the transient errors and allows for the use of much smaller spacings in autonomous platoon operation, while the second one results in smoother and more robust longitudinal control.

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 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.

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).

A Verified Hybrid Controller for Automated Vehicles

Lygeros, J.
Godbole, D. N.
Sastry, S.
1997

In this report the authors present a unified framework for carrying out safety calculations for the automated highway problem and obtain sufficient conditions for a set of continuous controllers to be safe and use these conditions to design a discrete scheme that switches between them. Guarantees of safety for the closed loop hybrid system follow by design/

A Theory of Traffic Flow in Automated Highway Systems

Broucke, M.
Varaiya, P.
1995

This paper presents a theory for automated traffic flow, based on abstraction of vehicle activities such as entry, exit and cruising, derived from a vehicle's automatic control laws. The theory formulates TMC traffic plans as the specification of the activities and speed of vehicles, and the entry and exit flows for each highway section. The theory permits the study of transient phenomena such as congestion, and TMC feed back traffic rules designed to deal with transients.

A Fuzzy Rule-Based Controller for Automotive Vehicle Guidance

Hessburg, Thomas
Tomizuka, Masayoshi
1991

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.

A Functional Architecture for Automated Highway Traffic Planning

Tsao, H. S. Jacob
1994

This report defines an architecture for Automated Highway System (AHS) capacity-optimizing traffic planning functions. It identifies major traffic planning functions useful for optimizing the capacity of one or more major AHS operating scenarios and organizes them in a robust architecture that is modular, hierarchical, complete, expandable and integratable.

A First Example Specification of an Automated Freeway

Hitchcock, Anthony
1991

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.

A Dynamic Visualization Environment for The Design and Evaluation Of Automatic Vehicle Control Systems

Xu, Z.
1995

This document presents Dynamic Visualization, a project associated with the California PATH Program. The objective of the project is to develop a software which can animate automated highways, visualize the dynamics of automatic vehicles, and help the design and evaluation of automatic vehicle systems. This report summarizes the accomplishments of the project, describes the functions of the developed software, and provides an explanation of how to use the software.