Travel Behavior

Capacity Analysis of Traffic Flow Over a Single-Lane Automated Highway System

Michael, James B
Godbole, Datta N
Lygeros, John
Sengupta, Raja
1998

We calculate bounds on per-lane Automated Highway System (AHS) capacity as a function of vehicle capabilities and control system information structure. We assume that the AHS lane is dedicated for use by fully automated vehicles. Capacity is constrained by the minimum inter-vehicle separation necessary for safe operation. A methodology for deriving the safe minimum inter-vehicle separation for a particular safety criterion is presented. The inter-vehicle separation, which depends on the vehicle braking capability, control loop delays and operating speed, is then used to compute site-...

Chapter 31 - Innovative Pricing Policies for Commuting: A Field Experiment

Lehner, Stephan
Peer, Stefanie
Gren, Mateusz
Koller, Hannes
Dragaschnig, Melitta
Brändle, Norbert
Sengupta, Raja
2020

Based on an innovative field experiment, this paper analyzes the effect of spatially and temporally differentiated pricing instruments on the travel behavior of commuters. The study aims to understand the underlying preferences, trade-offs, and restrictions faced by participants. The experiment uses a smartphone-based tracking technology performing automatic detection of travel modes. We recruited volunteers commuting by car to Vienna (Austria). A dedicated app recorded the commuting behavior of 95 participants throughout five weeks, including a week of pre- and post-measurement,...

Collaborative High-Accuracy Localization in Mobile Multipath Environments

Ekambaram, Venkatesan N.
Ramchandran, Kannan
Sengupta, Raja
2016

We study the problem of high-accuracy localization of mobile nodes in a multipath-rich environment where submeter accuracy values are required. We employ a peer-to-peer framework where nodes can get pairwise multipath-degraded ranging estimates in local neighborhoods, with the multipath noise correlated across time. The challenge is to enable high-accuracy positioning under severe multipath conditions when the fraction of received signals corrupted by multiple paths is significant. Our contributions are twofold. We provide a practical distributed localization algorithm by invoking an...

Congestion Control Based on Channel Occupancy in Vehicular Broadcast Networks

Fallah, Yaser P.
Huang, ChingLing
Sengupta, Raja
Krishnan, Hariharan
2010

Cooperative vehicle safety (CVS) systems rely on vehicular ad-hoc networks operating in broadcast mode to deliver vehicle tracking and safety information to neighboring cars. This information is used to enable collision avoidance and warning systems. One of the main challenges of the eventual large scale deployment of such systems is network congestion, which could critically degrade the quality of a CVS system. In this paper, we present a method for congestion monitoring and control based on limited feedback from the network. We study the relationship between channel occupancy, as a...

Cooperative and Non-Cooperative UAS Traffic Volumes

Bulusu, Vishwanath
Sengupta, Raja
Polishchuk, Valentin
Sedov, Leonid
2017

We describe an analytical process to determine how much UAS traffic is feasible. The process is a simulator and data processing tools. The two are applied to the US San Francisco Bay Area and Norrkoping, Sweden. The amount of UAS traffic is measured in flights per day and simulated up to 200,000 flights. A UAS traffic volume is feasible if specified metrics meet operational requirements with high probability and are stable, in the sense of being below thresholds observed for monotone properties in random geometric graphs. We focus on conflict cluster size and argue for it as a fundamental...

CSL: A Language to Specify and Re-specify Mobile Sensor Network Behaviors

Love, Joshua
Jariyasunant, Jerry
Pereira, Eloi
Zennaro, Marco
Hedrick, Karl
Kirsch, Christoph
Sengupta, Raja
2009

The Collaborative Sensing Language (CSL) is a high-level feedback control language for mobile sensor networks (MSN). It specifies MSN controllers to accomplish network objectives with a dynamically changing ad-hoc resource pool. Furthermore, CSL is designed to allow the updating of controllers during execution (patching). This enables hierarchical control with simpler controllers at lower levels. The CSL Execution Engine contains the intelligence to allocate resources to tasks dynamically and adjust in real time to resource motion, this enables CSL controllers to be simple, intuitive and...

Cyber-Physical Cloud Computing: The Binding and Migration Problem

Kirsch, C.
Pereira, E.
Sengupta, R.
Chen, H.
Hansen, R.
Huang, J.
Landolt, F.
Lippautz, M.
Rottmann, A.
Swick, R.
Trummer, R.
Vizzini, D.
2012

We take the paradigm of cloud computing developed in the cyber-world and put it into the physical world to create a cyber-physical computing cloud. A server in this cloud moves in space making it a vehicle with physical constraints. Such vehicles also have sensors and actuators elevating mobile sensor networks from a deployment to a service. Possible hosts include cars, planes, people with smartphones, and emerging robots like unmanned aerial vehicles or drifters. We extend the notion of a virtual machine with a virtual speed and call it a virtual vehicle, which travels through space by...

Dependence of Cooperative Vehicle System Performance on Market Penetration

Shladover, Steven E.
Polatkan, Gungor
Sengupta, Raja
VanderWerf, Joel
Ergen, Mustafa
Bougler, Benedicte
2007

Cooperative vehicle systems (CVS) can provide intelligent transportation systems services such as probe vehicle information and hazard warnings by exchanging data among suitably equipped vehicles as they travel. The sensitivity of the performance of CVS to the market penetration of suitably equipped vehicles is explained by using Monte Carlo analyses and simulations of wireless message propagation. The CVS functions are implemented by using wireless vehicle-vehicle data communications, which can be successful only when other equipped vehicles exist within wireless range to receive the...

Diagnosability of Discrete-Event Systems

Sampath, M.
Sengupta, R.
Lafortune, S.
Sinnamohideen, K.
Teneketzis, D.
1995

Fault detection and isolation is a crucial and challenging task in the automatic control of large complex systems. We propose a discrete-event system (DES) approach to the problem of failure diagnosis. We introduce two related notions of diagnosability of DES's in the framework of formal languages and compare diagnosability with the related notions of observability and invertibility. We present a systematic procedure for detection and isolation of failure events using diagnosers and provide necessary and sufficient conditions for a language to be diagnosable. The diagnoser performs...

DRBO - A Simulator Calibration Framework Based on Day-to-Day Dynamic Routing and Bayesian Optimization

Jiang, Xuan
Jiang, Chonghe
Cao, Junzhe
Skabardonis, Alexander
Kurzhanskiy, Alex
Sengupta, Raja
2024

Traffic simulation, a tool for recreating real-life traffic scenarios, acts as an important platform in transportation research. Considering the growing complexity of urban mobility, various large scale simulators are designed and used for research and applications. This paper proposes DRBO, a calibration framework for large scale traffic simulators. This framework combines the travel behavior adjustment with Bayesian Optimization, better exploring the structure of the simulator as well as improving its performance. By the calibration procedure, we decrease the gap between the simulator...