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SWUTC Research Project Description

Assessment of Vehicle Performance in Harsh Environments Using Driving Simulator and Numerical Simulations

University: Louisiana State University

Principal Investigator:
Steve Cai
Gulf Coast Research Center for Evacuation and Transportation Resiliency
(225) 578-8898

Project Monitor:
Dan Magri
Louisiana Department of Transportation and Development
Highway Safety Administrator

Funding Source: USDOT

Total Project Cost: $25,000

Project Number: 600451-00112

Date Started: 5/1/13

Estimated Completion Date: 5/31/14

Project Summary

Project Abstract:
The present study aims to investigate the safety of vehicles during normal operations as well as emergencies through experimentally and numerically replicating the natural environments. An attempt will be made to simulate the complicated weather, road surface, and driver operational process, such as rain, camber, grade, and acceleration/ deceleration as well as steering processes. With the proposed accident assessment framework, the accident-related response is studied and accident risks are assessed for vehicles. The present study may provide a useful basis for traffic designs on highways with complicated topographic and weather conditions and optimization of evacuation routes and strategy that may lead to minimized single-vehicle accident risks.

Project Objectives:
The main goal of this research study is to lay a foundation for modeling the vehicle performance during harsh conditions that can be used as part of assessments to decide when evacuation routes need to be closed during hurricane and tropical storm events.

  1. Investigate how to use the driving simulator to replicate vehicle performance of typical vehicles used by the general public, fire departments, emergency management teams, etc.
  2. Study the driver response to different driving conditions (such as windy, wet conditions) and develop the corresponding mathematical model for drivers’ response, i.e., steering reaction.
  3. Develop an analysis framework and estimate the rollover risk index of vehicles under different combinations of environmental and driver operational conditions;

Task Descriptions:

Task 1: Simulation Using Driving Simulator
The driving simulator provides multi-channel audio/visual systems with 180° display, full-width automobile cab including windshield, driver and passenger seats, center console and dash, full instrumentation, control loaded steering, braking and acceleration, mini-LCD rear-view mirrors plus realtime one degree of freedom motion simulation. This driving simulator has a library of residential, urban, rural, commercial, industrial, highway, intersection and traffic signal control; autonomous, interactive ambient traffic; extensive, interactive scripted vehicle activity; variable roadway friction and weather effects; and data collection definition. Its flexible scenario creation interface and customizable highway system design tools will enable the research team build the various virtual simulation networks that will be used for this study.

The dynamics of the driving simulator can be modified within the SimCreator proprietary software tool which is a graphical simulation and modeling system. At its top level, it represents a graphical user interface that allows placement and connection of various components including extensive, scripted vehicle activity in C/C++ code components. Relevant components will be explored and modified to allow the driving simulator to behave (vehicle component loadings) as a sedan, SUV, minivan, fire truck, mass transportation bus and a commercial truck.

Task 2: Simulation of Vehicle Performance and Data Analysis
This task involves observing the effect of wind forces and other harsh conditions such as wet road surface on test subjects. A selection of sample of students will be used as test subjects to experiment with the driving simulator. The purpose of this is to make a preliminary observation of the effect of the harsh conditions on different driving behaviors/ styles. For each simulation scenario, data will be collected throughout the experiment to measure how each human subject reacted and responded to the different wind forces and vehicle type. Data will be collected in two ways: through the monitoring software tools provided by the proprietary SimObserver and Data Distillery software and secondly by interviewing the test subjects.

Task 3: Assessment of Vehicle Performance
The PI’s group has developed a general truck rollover crash risk estimation model, which can consider the adverse weather, topographic and driver operational conditions [Chen and Cai 2004, Chen et al. 2009]. The driver operational condition is quantified with vehicle speed and reaction time under different vigilant level (e.g. good, average or poor). The information of the drivers’ behavior from Task 2 will be incorporated in the analysis. A rollover risk index (an indicator of rollover risks, from 0-1) will be assigned to each type of vehicles under different combinations of weather conditions (e.g. wind, rain, ice or snow), topographic conditions (e.g. grades, curves and camber) and driver operational condition (e.g. vehicle driving speeds and vigilant level). This information will be useful for evacuation planning and transportation management.

Task 4: Final Report
A final report documenting the entire research effort, including the methodology used in the research, conclusions drawn from the research, and recommendations for future research and implementation plan will be submitted.

Implementation of Research Outcomes:
With the economic booming development of coastal areas, the importance of the traffic planning becomes obvious not only in a hurricane evacuation but also in the daily transportation. Vehicle performance on the freeway during harsh environments is critical to the success of the planning process. This study aimed to study the effect of harsh environments on the driving behavior and vehicle performance. The driving simulator installed in Louisiana State University was used to investigate the driver’s behavior and vehicle performance in different adverse conditions such as strong crosswinds, wet road surface, and curving.

Products produced by this research:

PresentationSimulation of Aerodynamic Forces of Vehicles in Cross Wind, Jiexuan Hu, C.S. Cai and Yan Han, Louisiana State University, presented at the Engineering Mechanics Institute (ASCE), 2015 International Conference, The Hong Kong Polytechnic University, Hong Kong, China, January 7-9, 2015.  Also published in Program and Book of Abstracts.

Presentation:  Driving Simulation of Vehicles in Harsh Environment, Jiexuan Hu and C.S. Cai, presented at the Second International Symposium on Life-Cycle Performance of Bridges and Structures, Changsha, China, December 18-20, 2015.

Journal Article in PressWind Tunnel Tests for Mean Wind Loads on Road Vehicles, Xianzhi Liu, Yan Han, C.S. Cai, Marc Levitan and Dimitris Nikitopoulos, Louisiana State University, published in Journal of Wind Engineering and Industrial Aerodynamics, 2016.

Impacts/Benefits of Implementation:
The accumulated knowledge, related to driver behavior and vehicle performance in harsh environments, produced by this research will help develop safer traffic management plans, which in turn will improve the safety of the driving public.

Web Links:
Final Technical Report