Modeling

Design Of Fault Tolerant Control Systems For Ahs

Sastry, S.
Horowitz, R.
Hedrick, K.
1998

This report describes research in the area of fault detection and handling designs used in the longitudinal control system of platooned automated vehicles. Results are presented on experimental testing of the designs. The authors also describe a consistent interface between the fault detection and handling modules and how it was implemented in the SHIFT programming language for the specification of hybrid systems. In addition, the report describes part of the modeling formalism required for the formal verification of safety claims.

Model of Human Vehicle Driving - a Predictive Nonlinear Optimization Approach

Prokop, Günther
2000

When driving a vehicle the human acts as a controller in a highly dynamic environment. Thus human behavior in that control loop has to a large extent been described using control theoretical methodology. We develop a driver model, in which driving is seen as a model predictive control task in such a way that the driver accumulates knowledge about his/her vehicle's handling properties. He/she builds a model out of that knowledge and uses it to predict the vehicle's future reactions on his/her control inputs. The human's behavioral optimization is reflected in the driver model by using that...

Model Selection And Initial Application Of CONTRAM Model For Evaluating In-vehicle Information Systems

Gardes, Yonnel
Haldors, Bruce
May, Adolf D.
1991

The objectives of this study were to select a traffic assignment and simulation model, apply that model to an integrated freeway/arterial network such as the Smart Corridor in Los Angeles, California, and, using the model, make an initial evaluation of in-vehicle information systems and the applicability of the model.

Built Environment Profiles for Latin American Urban Settings: The SALURBAL Study

Sarmiento, OL
Useche, A
Rodriguez, DA
Dronova, I
Guaje, O
Montes, F
Stankov, I
Wilches, M
Bilal, U
Wang, X
Guzman, L
Pena, F
Quistberg, D
Guerra-Gomez, J
Roux, AV Diez
2021

The built environment of cities is complex and influences social and environmental determinants of health. In this study we, 1) identified city profiles based on the built landscape and street design characteristics of cities in Latin America and 2) evaluated the associations of city profiles with social determinants of health and air pollution. Landscape and street design profiles of 370 cities were identified using finite mixture modeling. For landscape, we measured fragmentation, isolation, and shape. For street design, we measured street connectivity, street length, and directness. We...

Assessing Public Health Benefits of Replacing Freight Trucks with Cargo Cycles in Last Leg Delivery Trips in Urban Centers

Hartle, J
Elrahman, O
Wang, C
Rodriguez, D
Ding, Y
McGahan, M
2022

Increased urbanization, population growth, and demand for time-sensitive deliveries means increased freight movement in cities, which contributes to emissions, noise, and safety concerns. One innovative mode gaining widespread attention for urban deliveries is cargo cycles—bicycles adapted for freight delivery. Despite the recognized potential and possible success of transporting at least 25% of freight via cycle, research remains limited. This research investigates the potential of cargo cycle delivery for last mile freight in Oakland, California, with a focus on the West Oakland...

Marked Crosswalks in US Transit-oriented Station Areas, 2007–2020: A Computer Vision Approach Using Street View Imagery

Li, M
Sheng, H
Irvin, J
Chung, H
Ying, A
Sun, T
Ng, A
Rodriguez, D
2022
Improving the built environment to support walking is a popular strategy to increase urban sustainability and walkability. In the past decade alone, many US cities have implemented crosswalk visibility enhancement programs as part of road safety improvements and active transportation plans. However, there are no systematic ways of measuring and monitoring the presence of key built environment attributes that influence the safety and walkability of an area, such as marked crosswalks. Furthermore, little is known about how these attributes change over time at a national scale. In this paper, we...

Social Disparities in Flood Exposure and Associations with the Built Environment in 47,187 Urban Neighborhoods in Eight Latin American Countries

Kephart, JL
Bilal, U
Ferreira, A
Gouveia, N
Rodriguez, DA
Barbieri, IS
Miranda, J
Roux, AV Diez
2023
BACKGROUND AND AIM: Climate change is expected to greatly increase population exposure to flooding and related health impacts, particularly in urban areas of the Global South. We aimed to examine within-city social disparities in exposure to flooding within 326 Latin American cities and associated features of the neighborhood environment. METHOD: We used a high spatial resolution dataset of historical flood events from 2000-2018 to describe flood exposure at the neighborhood level for all cities with 100,000+ residents in eight Latin American countries (Argentina, Brazil, Chile, Colombia,...

Greenness and Excess Deaths from Heat in 323 Latin American Cities: Do Associations Vary According to Climate Zone or Green Space Configuration?

Schinasi, LH
Bakhtsiyarava, M
Sánchez, BN
Kephart, JL
Ju, Y
Arunachalam, S
Gouveia, N
Caiaffa, WT
O'Neill, MS
Dronova, I
Roux, AV Diez
Rodriguez, D
2023
Green vegetation may protect against heat-related death by improving thermal comfort. Few studies have investigated associations of green vegetation with heat-related mortality in Latin America or whether associations are modified by the spatial configuration of green vegetation. We used data from 323 Latin American cities and meta-regression models to estimate associations between city-level greenness, quantified using population-weighted normalized difference vegetation index values and modeled as three-level categorical terms, and excess deaths from heat (heat excess death fractions [heat...

Models Of Vehicular Collision: Development And Simulation With Emphasis On Safety IV: An Improved Algorithm For Detecting Contact Between Vehicles

O'Reilly, Oliver M.
Papadopoulos, Panayiotis
Lo, Gwo-jeng
Varadi, Peter C.
1998

This report describes a procedure for detecting the geometry of the contact interface between vehicles. This technique uses a better approximation of the vehicle's shape and also preserves the advantage of the ellipsoidal model. This new model for the low relative velocity vehicular collision is based on a box model for the outer surface of the vehicle and is referred to as BM.

Longitudinal Control of Commercial Heavy Vehicles Equipped with Variable Compression Brake

Moklegaard, Lasse
Druzhinina, Maria
Stefanopoulou, Anna G.
2002

In this report, we extend our previous work within MOU 372 on modeling and longitudinal speed control design for heavy commercial vehicles equipped with variable compression braking mechanisms. Previously, we developed a detailed crankangle based simulation model for a six cylinder, 350 hp diesel engine with a continuously varying compression brake that is capable of describing the intrinsic interactions between individual cylinder intake and exhaust processes, turbocharger dynamics during combustion and braking modes, and the transition between those modes. Moreover, for control design...