Modeling

The Aerodynamic Forces On Misaligned Platoons

Marcu, Bogdan
Browand, Fred
1998

This report summarizes wind tunnel experimental measurementson the aerodynamic interaction between members of misaligned platoons. Experiments are conducted at the University of Southern California's Dryden Wind Tunnel Facility. All experiments are made using 1/8 scale models of 1991 Chevy Lumina minivan. Models are placed above a ground plane with a porous surface, through which slight suction is applied to remove the boundary layer. Refurbishing of the ground plane surface, and its repositioning to a 1 degree angle of attack produce significantly improved air flow through the test...

Dynamic Origin/Destination Estimation Using True Section Densities

Sun, Carlos
Porwal, Himanshu
2000

This final report presents a practical approach for dynamic origin/destination demandestimation. The proposed dynamic origin/destination estimation framework addressesmany of the shortcomings of the existing formulations and presents a formulation forgeneral networks and not just corridors. One unique feature of this framework is its useof section density as a variable instead of flow. The framework is built upon thefoundation of static origin/destination matrix estimation by adding the temporal aspect.Two traffic assignment models, namely DYNASMART and DTA are used for assigningdynamic...

Longitudinal Control Of A Platoon Of Vehicles. III, Nonlinear Model

Sheikholeslam, Shahab
Desoer, Charles A.
1990

This paper presents a systematic analysis of a longitudinal control law for a platoon of non-identical vehicles using a non-linear model for the vehicle dynamics.

The Cell Transmission Model. Part I: A Simple Dynamic Representation Of Highway Traffic

Daganzo, Carlos
1993

This paper presents a simple representation of traffic on a highway with a single entrance and exit. The representation can be used to predict traffic's evolution over time and space, including transient phenomena such as the building, propagation and dissipation of queues. The easy-to-solve difference equations used to predict traffic's evolution are shown to be the discrete analog of the differential equations arising from a special case of the hydrodynamic model of traffic flow. The proposed method automatically generates appropriate changes in density at locations where the...

Platoon Collision Dynamics And Emergency Maneuvering I: Reduced Order Modeling Of A Platoon For Dynamical Analysis

Tongue, Benson H.
Yang, Yean-tzong
White, Matthew T.
1991

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.

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams. Microscopic Traffic Modeling

Liu, Hao
2018

This document summarizes the microscopic traffic simulation models used in the project entitled Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams. The major components of the microscopic traffic model include the vehicle dispatching model, human driver model and ACC/CACC model. The vehicle dispatching model determines how a modeled vehicle enters the simulation network and the distribution of different types of vehicles across the multi-lane highway. The human driver model and ACC/CACC model specify the car following and lane changing behaviors of...

National Automated Highway System Consortium: Modeling Stakeholder Preferences Project

Lathrop, John
Chen, Kan
1997

This document is the final report of the Modeling Stakeholder Preferences Project. The results of the project consist of three results: 1) evaluation framework; 2) focus group non-quantitative findings/ recommendations; and, 3) performance/impact measures, their endpoints, rankings and weights, for each stakeholder group.

Brake System Modeling, Control And Integrated Brake/throttle Switching Phase I

Hedrick, Karl
Gerdes, J.C.
Maciuca, D.B.
Swaroop, D.
1997

This report is concerned with the modeling and control issues regarding braking in an Intelligent Transportation Systems (ITS) setting. Specifically, it addresses the issue of vehicle control in an automated highway system, brake actuation and coordinated brake and throttle switching. It first presents a hydraulic model of the brake system. A method for designing stable controllers for uncertain, mismatched nonlinear system is then described. A method to estimate the coefficient between the brake pressure at the wheel and the brake torque is presented. The next section describes a...

Transient Platoon Aerodynamics During Passing Maneuvers and In-line Oscillations

Tsuei, J. L.
Savas, O.
Hedrick, J. K.
2000

The transient aerodynamic effects in a four-vehicle platoon during passing maneuvers and in-line oscillations are investigated. A vehicle model is moved longitudinally parallel to a four-car platoon to simulate passing maneuvers. The drag and side forces experienced by each platoon member are measure using strain gauge balances. The resulting data are presented as dimensionless coefficients. It is show that each car in the platoon experiences a repulsive side force when the passing vehicle is in the neighborhood of its rear half. The side force reverses its direction and becomes an...

Modeling the Santa Monica Freeway Corridor: Simulation Experiments

Skabardonis, Alexander
2002

The report describes the findings of a study to develop a simulation testbed for the Santa Monica freeway corridor. The study created one of the largest freeway corridor networks coded for the CORSIM microscopic simulation model. The coded network consists of about 10 miles of I-10 freeway and a surface street network with 75 signalized intersections. The results from the simulation experiments indicate that several CORSIM model parameters need to be adjusted in order to accurately simulate freeway facilities for California conditions. The calibrated CORSIM model produced reasonable and...