This research is aimed at the identification of all types of accidents that have occurred on freeways which may affect the vehicle movement in the assumed automated left lane. The emphasis was on six-lane or more urban freeways. The accident data was obtained from the California TASAS ( Traffic...

This report addresses the problem of designing safe controllers for the hybrid system composed by the interaction of the regulation and coordination layers in the hierarchical California PATH Automated Highway System (AHS) architecture. Conditions to achieve safe platooning under normal mode of...

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...

In this paper, a fuzzy traffic density homogenizer is proposed to alleviate or avoid congestion by smoothing the traffic density distribution profile over freeway lanes. The proposed fuzzy homogenizer consists of two parts: the fuzzy mean speed controller and the fuzzy on- ramp controller....

This report focuses on the safety analysis techniques and tools as they are applied to Automated Highway Systems (AHS). The report begins with a description of the AHS model. This is followed by a discussion of the basic features of Requirements State Machine Language (RSML) relevant to the...

In this paper, the authors propose a hierarchical control architecture for dealing with faults an adverse environmental conditions on an Automated Highway System (AHS). The design builds on a previously designed control architecture that works under normal conditions of operation. The faults...

This report presents SHIFT, a programming language for describing dynamic networks of hybrid automata. The SHIFT model offers the proper level of abstraction for describing complex applications such as automated highway systems, etc. The report first describes a simplified version of the SHIFT...

The purpose of this report is to document the development of a platoon collision model which can be used to study platoon collision dynamics under emergency situations. Based on previous studies, the vehicle model within the platoon is implemented with two bumpers which are developed to meet the...

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...

This work focuses on vehicle fault detection and identification. It also describes a vehicle health management approach based on analytic redundancy. It describes a point design of fault detection filters and parity equations that are developed for the vehicle longitudinal mode. A preliminary...