Intelligent Transportation Systems

Arterial Travel Time Forecast with Streaming Data: A Hybrid Approach of Flow Modeling and Machine Learning

Hofleitner, Aude
Herring, Ryan
Bayen, Alexandre
2012

This article presents a hybrid modeling framework for estimating and predicting arterial traffic conditions using streaming GPS probe data. The model is based on a well-established theory of traffic flow through signalized intersections and is combined with a machine learning framework to both learn static parameters of the roadways (such as free flow velocity or traffic signal parameters) as well as to estimate and predict travel times through the arterial network. The machine learning component of the approach uses the significant amount of historical data collected by the Mobile...

Mobile Phone Based Drifting Lagrangian Flow Sensors

Beard, Jonathan
Weekly, Kevin
Oroza, Carlos
Tinka, Andrew
Bayen, Alexandre M.
2012

Mobile phone based drifters offer distinct advantages over those using custom electronic circuit boards. They leverage the inexpensive and modern hardware provided by the mobile phone market to supply water resource scientists with a new solution to sensing water resources. Mobile phone based drifters strategically address in situ sensing applications in order to focus on the large scale use of mobile phones dealing with communications, software, hardware, and system reliability. We have demonstrated that a simple design of a drifter built around an Android phone robustly survives many...

Understanding Road Usage Patterns in Urban Areas

Wang. Pu
Hunter, Timothy
Bayen, Alexandre M.
2012

In this paper, we combine the most complete record of daily mobility, based on large-scale mobile phone data, with detailed Geographic Information System (GIS) data, uncovering previously hidden patterns in urban road usage. We find that the major usage of each road segment can be traced to its own - surprisingly few - driver sources. Based on this finding we propose a network of road usage by defining a bipartite network framework, demonstrating that in contrast to traditional approaches, which define road importance solely by topological measures, the role of a road segment depends on...

Cyber Security of Water SCADA Systems—Part II: Attack Detection Using Enhanced Hydrodynamic Models

Amin, Saurabh
Litrico, Xavier
Bayen, Alexander M.
2013

This paper investigates the problem of detection and isolation of attacks on a water distribution network comprised of cascaded canal pools. The proposed approach employs a bank of delay-differential observer systems. The observers are based on an analytically approximate model of canal hydrodynamics. Each observer is insensitive to one fault/attack mode and sensitive to other modes. The design of the observers is achieved by using a delay-dependent linear matrix inequality method. The performance of our model-based diagnostic scheme is tested on a class of adversarial scenarios based on a...

Cyber Security of Water SCADA Systems—Part I: Analysis and Experimentation of Stealthy Deception Attacks

Amin, Saurabh
Litrico, Xavier
Sastry, S. Shankar
Bayen, Alexandre M.
2013

This brief aims to perform security threat assessment of networked control systems with regulatory and supervisory control layers. We analyze the performance of a proportional-integral controller (regulatory layer) and a model-based diagnostic scheme (supervisory layer) under a class of deception attacks. We adopt a conservative approach by assuming that the attacker has knowledge of: 1) the system dynamics; 2) the parameters of the diagnostic scheme; and 3) the sensor-control signals. The deception attack presented here can enable remote water pilfering from automated canal systems. We...

Design of a Network of Robotic Lagrangian Sensors for Shallow Water Environments with Case Studies for Multiple Applications

Oroza, Carlos
Tinka, Andrew
Wright, Paul K
Bayen, Alexandre M.
2013

This article describes the design methodology for a network of robotic Lagrangian floating sensors designed to perform real-time monitoring of water flow, environmental parameters, and bathymetry of shallow water environments (bays, estuarine, and riverine environments). Unlike previous Lagrangian sensors which passively monitor water velocity, the sensors described in this article can actively control their trajectory on the surface of the water and are capable of inter-sensor communication. The addition of these functionalities enables Lagrangian sensing in obstacle-encumbered...

Autonomous River Navigation Using the Hamilton–Jacobi Framework for Underactuated Vehicles

Weekly, Kevin
Tinka, Andrew
Anderson, Leah
Bayen, Alexandre M.
2014

The feasibility of drifter studies in complex and tidally forced water networks has been greatly expanded by the introduction of motorized floating sensors. This paper presents a method for such motorized sensors to accomplish obstacle avoidance and path selection using the solutions to Hamilton-Jacobi-Bellman-Isaacs (HJBI) equations. The method is then validated experimentally.

Privacy-Preserving Dual Splitting Distributed Optimization with Application to Load Flattening in California

Belletti, Francois
Le Floch, Caroline
Moura, Scott
Bayen, Alexandre M.
2015

This article presents a dual splitting technique for a class of strongly convex optimization problems whose constraints are block-wise independent. The average-based input in the objective is the only binding element. A dual splitting strategy enables the design of distributed and privacy preserving algorithms. Theoretical convergence bounds and numerical experiments show this method successfully applies to the problem of charging electric devices so as to even out the daily energy demand in California. The solution we provide is a privacy enforced algorithm readily implementable in...

Link Density Inference from Cellular Infrastructure

Yadlowsky, Steve
Thai, Jérôme
Wu, Cathy
Pozdnukov, Alexey
Bayen, Alexandre
2015

This work explores the problem of estimating road link densities from cellular tower signals by mobile subscribers in urban areas. The authors pose the estimation problem as a quadratic program, and present a robust framework that produces vehicle density estimates and is suitable for large-scale problems. The authors demonstrate that both simple and sophisticated models of cellular network connections can be handled robustly by the framework, without sacrificing efficiency or scalability. The authors present a numerical experiment on the I-15 corridor in San Diego based on a...

Cellpath: Fusion of Cellular and Traffic Sensor Data for Route Flow Estimation via Convex Optimization

Wu, Cathy
Thai, Jérôme
Yadlowsky, Steve
Pozdnoukhov, Alexei
Bayen, Alexandre
2015

A new convex optimization framework is developed for the route flow estimation problem from the fusion of vehicle count and cellular network data. The issue of highly underdetermined link flow based methods in transportation networks is investigated, then solved using the proposed concept of cellpaths for cellular network data. With this data-driven approach, our proposed approach is versatile: it is compatible with other data sources, and it is model agnostic and thus compatible with user equilibrium, system- optimum, Stackelberg concepts, and other models. Using a dimensionality...