PATH

Estimation of Travel Time Distribution and Detection of Incidents Based on Automatic Vehicle Classification

Anatharam, V.
1998

We study the problem of travel time estimation along a section of a freeway based on data derived from vehicle detectors at multiple locations. We pose the problem as one of pattern recognition. We derive algorithms that aim to recognize patterns which persist between the error-prone upstream detector samples and the error-prone downstream detector samples. We describe how these can allow us to estimate the distribution of the travel time between these detector locations. The most promising algorithm derived in this research is a dynamic programming based algorithm based on sequence...

Estimation of Parameter Probability Distributions for Lithium-Ion Battery String Models Using Bayesian Methods

Couto, Luis D.
Zhang, Dong
Aitio, Antti
Moura, Scott
Howey, David
2021

Abstract. This paper addresses the parameter estimation problem for lithium-ion battery pack models comprising cells in series. This valuable information can be exploited in fault diagnostics to estimate the number of cells that are exhibiting abnormal behaviour, e.g. large resistances or small capacities. In particular, we use a Bayesian approach to estimate the parameters of a two-cell arrangement modelled using equivalent circuits. Although our modeling framework has been extensively reported in the literature, its structural identifiability properties have not been reported yet to the...

Estimating ATIS Benefits for the Smart Corridor

Sengupta, Raja
Hongola, Bruce
1998

This report studies the effects of Advanced Traveler Information Systems (ATIS) on traffic congestion in the Smart Corridor of the Santa Monica Freeway. Simulation modeling is used to estimate the potential travel time savings to divert traffic from the Smart Corridor to arterial roads when incidents occur. The study attempts to establish relationships between traffic management variables, such as incident detection time, incident duration, capacity reduction, percentage of traffic diversion, and duration of traffic diversion.

Enhancements to a Simulation Framework for Analyzing Urban Traffic Networks with ATIS/ATMS

Jayakrishnan, R.
Rathi, U.
Rindt, C.
Vaideeshwaran, G.
1996

This report focuses on the DYNASMART simulation program presents a model that is capable of simulating large urban networks under various Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS) strategies. It includes modules for driver responses to information and for capturing the dynamics of the network paths. The research also included the simulation study of a network in Orange County, California, where the benefits from candidate ATIS and ATMS strategies were evaluated. The DYNASMART model has evolved into a flexible tool that can be applied to...

Enhanced Performance of Li-ion Batteries via Modified Reference Governors and Electrochemical Models

Perez, Hector
Shahmohammadhamedani, Niloofar
Moura, Scott
2015

This paper examines reference governor (RG) methods for satisfying state constraints in Li-ion batteries. Mathematically, these constraints are formulated from a first principles electrochemical model. Consequently, the constraints explicitly model specific degradation mechanisms, such as lithium plating, lithium depletion, and overheating. This contrasts with the present paradigm of limiting measured voltage, current, and/or temperature. The critical challenges, however, are that: 1) the electrochemical states evolve according to a system of nonlinear partial differential equations, and 2...

Ecological Velocity Planning Through Signalized Intersections: A Deep Reinforcement Learning Approach

Pozzi, Andrea
Bae, Sangjae
Choi, Yongkeun
Borrelli, Francesco
Raimondo, Davide M.
Moura, Scott
2020

The use of infrastructure-to-vehicle communication technologies can enable improved energy efficient autonomous driving. Traditional ecological velocity planning methods have high computational burden, particularly when plug-in hybrid electric vehicles are considered. Consequently, in order to retrieve an optimal velocity profile in real time, it is necessary to rely on significant approximations.In this paper, the aforementioned issue is addressed by exploiting deep reinforcement learning in order to "learn" an eco-driving velocity planner for a plug-in hybrid electric vehicle within a...

Development of User Needs And Functional Requirements for A Real-time Ridesharing System

Kowshik, Raghu
Gard, John
Loo, Jason
Jovanis, Paul P.
Kitamura, Ryiuichi
1993

This report documents the results of a user needs assessment conducted to define the concept of real-time ridesharing, and identify the problems that are to be addressed by the proposed Real-Time Rideshare Matching System. The user needs are then utilized to develop functional requirements for the real-time rideshare matching system. The functional requirements identify services that should be provided by the system, and the interfaces to be used to access the system.

Development Testing and Evaluation of Advanced Techniques for Freeway Incident Detection

Ritchie, Stephen G.
Abdulhai, Baher
1997

In this research, the authors introduce and define a universal incident detection framework that is capable of fulfilling all components of a set of recognized needs. An algorithm is presented that has the potential to fulfill the defined universality requirements. It is a modified form of a probabilistic neural network (PNN) that utilizes the concept of statistical distance. The first part of the report presents a definition of the attributes and capabilities that a potentially universal freeway incident detection framework should possess. The second part discusses the training and...

Development of Vehicle Simulation Capability

Stoner, James W.
Evans, Douglas F.
Mcgehee, Daniel
1997

This report summarizes work on developing simulation databasing tools and procedures to support driving human factors experiments. The simulator requirements are specified, and a complete description of the resulting Iowa Driving Simulation facility are provided. The specification and description of the visual features of the ORCHIDS data base illustrate the capabilities generated. Subsystems necessary to support simulation are described. Experimental design procedures are outlined. An example scenario illustrates the potential for applying driving simulation as a research tool to examine...

Development and Experimental Evaluation of Autonomous Vehicles for Roadway/Vehicle Cooperative Driving

Ioannou, Petros
1998

Automatic vehicle following is an important feature of a fully or partially automated highway system (AHS). The on-board vehicle control system should be able to accept and process inputs from the driver, the infrastructure and other vehicles, perform diag- nostics and provide the appropriate commands to actuators so that the resulting motion of the vehicle is safe and compatible with the AHS objectives. The purpose of this paper is to design and test a vehicle control system in order to achieve full vehicle automation in the longitudinal direction for several modes of operation, where the...