Modeling

Conditions for Safe Deceleration of Strings of Vehicles

Lygeros, John
Lynch, Nancy
2000

A simple model for a string of vehicles is constructed. The model explicitly accounts for the possibility of repeated collisions between the vehicles in the string. Based on the model a notion of safety is formulated for the string. Necessary and sufficient conditions are presented that specify when a string of vehicles is safe while performing a simple emergency deceleration maneuver where all vehicles start decelerating at a fixed rate after some delay. The conditions are interpreted in terms of their implications for the safety of platoons of vehicles.

Spatial and Temporal Utility Modeling to Increase Transit Ridership

Church, Richard L.
Noronha, Val
Lei, Ting
Corrigan, Wils
Burbidge, Shaunna
Marston, Jim
2005

The objective of this research project was to develop a better understanding of the possible alternatives that a large employment center, like the University of California at Santa Barbara, can adopt in order to better utilize transit, mitigate traffic, and reduce demand for on-site parking. Although this project was oriented to the UCSB campus, the techniques and approaches developed in this project were designed to be equally applicable elsewhere. There were three major elements of this project: 1) develop an understanding of commuting employees through the use of a survey, 2) identify...

Virtual Weigh Stations in California: A Preliminary Cost-Effectiveness Analysis

Santero, Nicholas
Nokes, William
Harvey, John
2005

A new technology known as Virtual Weigh Stations (VWS) is intended to transform data-collecting weigh-in-motion (WIM) sites to weight enforcement mechanisms. This study investigates the possible benefits to the highway pavements in California from potential use of VWS. The investigation proceeded in two steps: (1) determining the damage currently caused by overweight trucks and (2) modeling the potential pavement life saved with VWS. The data used for analysis is from the California Department of Transportation (Caltrans) WIM database.

Parameter Estimation and Supervisory Techniques for Robust Longitudinal Control of Heavy Vehicles

Druzhinina, Maria
Moklegaard, Lasse
Stefanopoulou, Anna G.
2003

This report describes the development and experimental validation of a coordination scheme between friction and discretely variable compression brakes for a Class 8 Freightliner truck used as a development platform in the California PATH program. The coordination scheme that we developed maintains the speed tracking performance of the nominal PID controller which was originally designed by the UCLA team for the case of friction brakes only. Through the coordination scheme, the command of the nominal PID controller is split into a friction brake command and compression brake command. The...

Simulation Of IVHS On The Smart Corridor Using The Integration Model: Phase 1: Initial Investigations

Gardes, Yonnel
May, Adolf D.
1993

The general objective of this project is to evaluate the potential benefits of Advanced Traveler Information Systems and Advanced Traffic Management Systems on the Smart Corridor. This report describes Phase 1 of the project in which the INTEGRATION traffic simulation model is used to help simulate ATIS and ATMS on a freeway/arterial environment.

Simulation of ITS on the Irvine FOT Area Using "Paramics 1.5" Scalable Microscopic Traffic Simulator: Phase I: Model Calibration and Validation

Abdulhai, Baher
Sheu, Jiuh-Biing
Recker, Will
1999

In this research, a promising ITS-ready microscopic traffic simulator, Paramics1.5, is thoroughlyevaluated both subjectively and objectively in preparation for its use for modeling ITS in SouthernCalifornia. A general and comprehensive list of requirements (evaluation template) for amicroscopic traffic flow simulator to successfully model ITS was first compiled and presented. Theevaluation template covered various aspects of modern transportation network modeling, including:[1] supply/control aspects, [2] demand/behavior aspects, [3] environmental-related aspects, and [4]simulator-...

Modeling And Control Of Articulated Vehicles

Chen, Chieh
Tomizuka, Masayoshi
1997

This report focuses on dynamic modeling and lateral control of commercial heavy-duty vehicles for highway automation. Two types of dynamic models are developed in the study of lateral control of tractor-semitrailer vehicles in an Automated Highway System (AHS): a complex simulation model and two simplified control models. Two control algorithms for lateral guidance are designed. The first is a baseline steering control algorithm and the second is a coordinated steering and independent braking control algorithm.

Models Of Vehicular Collision: Development And Simulation With Emphasis On Safety I: Development of a Model for a Single Vehicle

O'reilly, Oliver M.
Papadopoulos, Panayiotis
Lo, Gwo-jeng
Varadi, Peter C.
1997

This report outlines the development of a novel model for a single vehicle. The model uses a theory of a deformable medium which is known as a Cosserat point to model the deformation of the body of the vehicle. This theory is supplemented with various developments from vehicle system dynamics. The complete set of ordinary differential equations governing the vehicle's motion are presented and numerical simulations of the model under various operating conditions are discussed.

Modeling And Control Design For A Computer Controlled Brake System

Raza, H.
Xu, Z.
Ioannou, P.
Yang, B.
1995

In this paper, the problem of modeling and control design of a computer controlled brake system is addressed. A nonlinear model for the brake system is developed by analyzing the input-output data obtained from the test bench. A controller for the brake system is designed by applying feedback linearization techniques along with intuitive modifications to meet the closed loop specifications.

A Combined Traveler Behavior And System Performance Model With ATIS

Khattak, Asad
Al-deek, Haitham
Thananjeyan, Paramsothy
1994

The specific objective of this study is to assess traveler behavior impacts of Advanced Traveler Information Systems (ATIS) technologies and the consequent system impacts at highway bottlenecks caused by incidents and recurring congestion. This research is based on earlier work regarding impacts of congestion on traveler behavior and system performance in the presence of information. In this paper, the authors enhance the previous work and develop a richer and more comprehensive approach for evaluating ATIS technologies. The unique features of this study are: 1) integration of traveler...