Aditya Wagh

Integrated Traffic-Driving-Networking Simulator for the Design of Connected Vehicle Applications: Eco-Signal Case Study

This article first develops an integrated traffic-driving-networking simulator (ITDNS) intended for the design and evaluation of cyber transportation systems (CTS) and connected vehicle (CV) applications. The ITDNS allows a human driver to control a subject vehicle, in a virtual environment, that is capable of communicating with other vehicles and the infrastructure with CTS messages. The challenges associated with the integration of the three simulators, and how those challenges were overcome, are discussed. As an application example, an eco-signal system, which recommends the approach speed for vehicles approaching the intersection so as to minimize fuel consumption and emissions, was implemented in the ITDNS. Test drivers were then asked to virtually drive through a signalized corridor twice, one time with the eco-signal system in place and another without the system. Thanks to the human-in-the-loop component of ITDNS, the research was able to evaluate the likely benefits of the eco-signal system, while accounting for the response of human drivers to the recommended speed profiles. Moreover, the study compared the energy consumption and emission production rates of human-controlled vehicles’ approach trajectories to the rates associated with “idealistic” trajectories that may be attainable via vehicle automation. With respect to ITDNS, the study demonstrates the unique advantages of the simulator and the broad range of applications it can address. Regarding the eco-signal application example, preliminary results demonstrate the potential of the concept to result in tangible reductions of around 9% for energy consumption, 18% for carbon monoxide, and 25% for nitrogen oxides emissions. Moreover, the application eliminated hard accelerations and decelerations maneuvers, and thus may have an additional positive safety impact.

Human centric data fusion in Vehicular Cyber-Physical Systems

Building effective Vehicular Cyber-Physical Systems (VCPS) to improve road safety is a non-trivial challenge, especially when we examine how the driver benefits from the existing and proposed technologies in the presence of Human Factors (HF) related negative factors such as information overload, confusion, and distraction. In this paper, we address a human-centric data fusion problem in VCPS. To the best of our knowledge, this work is the first to apply HF to the data fusion problem, which has both theoretical value and practical implications. In particular, we present a new architecture by defining a distinct High-Level (HL) data fusion layer with HF considerations, that is placed between the safety applications on the VCPS and the human driver. A data fusion algorithm is proposed to fuse multiple messages (based on reaction time, message type, preferred evasive actions, severity of the hazards, etc) and to maximize the total utility of the messages. The algorithm is tested with real human drivers to demonstrate the potential benefit of incorporating such human-centric fusion in existing warning systems.

Vehicle speed control algorithms for eco-driving

Given the rise in fuel prices and the harmful environmental consequences of excessive fuel consumption, we address a new problem in eco-driving, which examines how the upcoming V2V/V2I technology can be harnessed to improve fuel-efficiency. Unlike most of the existing studies in this area where the focus of control is on infrastructure side (i.e., signal timing plans), we present a new approach to eco-speed control at a microscopic level. We use a concept of platoon of vehicles to reduce fuel consumption in a journey covering multiple intersections in a multiple vehicle setting. Three heuristic algorithms are proposed and numerical results from simulations are also presented.

Data fusion with flexible message composition in Driver-in-the-Loop vehicular CPS

Abstract This work addresses a unique data fusion problem in Vehicular Cyber-Physical Systems (VCPS) arising from Human Factors (HF) considerations. Typically, a VCPS message intended for human drivers is composed of many data elements (DEs), and different messages can be fused by the sender before transmission e.g., by eliminating identical (or redundant) DEs in order to save transmission bandwidth in the wireless network. Still, not all distinct DEs can be received properly due to the limited transmission resources available to the sender and/or transmission errors. Subsequently, some of the messages intended for a driver cannot be delivered. On the other hand, a partially delivered message may still be beneficial (in terms of generating some utility) to a driver. More specifically, when considering HF, the DEs can be grouped into two distinct parts: essential and auxiliary. While a partially reconstructed message missing even a single essential DE fails to produce any benefit (or utility) for a driver, each auxiliary DE can independently produce an additional utility so long as all the essential DEs of the message are also available. In this paper, we deal with a new Driver-in-the-Loop Data Fusion Problem (DDFP) with the primary issue being: given a list of out-going messages and a limit on the number of DEs that can be transmitted, how does the sender choose which DEs (each carrying a different utility) to transmit, in order to maximize the system-wide utility at the receiver. We formulate DDFP mathematically, and prove it to be NP-Complete. We study DDFP in both ideal and lossy communication networks, and propose several efficient algorithms for them. Besides the Single-Sender-Single-Receiver model, we also look into DDFP in Multiple-Sender-Single-Receiver and Single-Sender-Multiple-Receiver models with several practical considerations. Numerical results from large scale simulations are also presented.

A Holistic Approach to Service Delivery in Driver-in-the-Loop Vehicular CPS

Vehicular Cyber-Physical Systems (VCPS) provide human drivers with various services related to road safety, and on-road infotainments. Since a service (message) delivery includes service transmission, service display and driver processing, many challenges arise due to limited network resources, possible pre-emption and contention between services for the display and non-negligible driver processing delay. In this paper, we address a new Driver-centric Service Delivery Problem (DSDP) from a cross-disciplinary resource allocation standpoint. Our goal is to deliver a number of services to a set of intended drivers in a given time period so as to maximize the system-wide performance in terms of total utility income (TUI) to drivers. We show that DSDP differs from all existing problems and is NP-Complete. A number of efficient heuristics are proposed to address several issues, including wireless transmission failure as well as distributed implementation of the multi-sender systems. Utilizing real traces collected from taxis in the city of Shanghai, we also present a case study in a more realistic scenario and conduct comprehensive simulations providing numerical results.

Simulation-Based Testing and Evaluation Tools for Transportation Cyber–Physical Systems

Transportation cyber-physical systems (TCPSs) require simulation-based testing and evaluation due to the prohibitive cost of building realistic test beds. Given the transdisciplinary nature of TCPSs, various simulation models and frameworks have been proposed in civil engineering, computer science, and related fields. Traditionally, researchers in different areas have developed their own set of simulation tools, which provide limited capability for TCPS research. In recent years, we have witnessed a growing interest of combining two or more features of traditional simulators to capture the unique characteristics of TCPSs. In this paper, we describe several mainstream simulation models used in transportation, communication, and human-factor studies in TCPS research. Moreover, we present our unique design and implementation of an integrated traffic-driving-network simulator (ITDNS). Finally, we discuss future enhancements that will promote best simulation practices for TCPS research.

Integrated Traffic-Driving-Networking Simulator: A Unique RaD Tool for Connected Vehicles

This paper describes on-going research aimed at developing a 3-in-1 integrated traffic-driving-networking simulator (ITDNS) for the design and evaluation of Cyber Transportation Systems (CTS) and Connected Vehicle (CV) applications. This unique simulator allows a human driver to control a subject vehicle in a virtual environment, this vehicle is capable of communicating with other vehicles and the infrastructure via CTS messages. The challenges associated with the integration of the three simulators, and how those challenges were overcome, are discussed.

Emerging Applications for Cyber Transportation Systems

Recent advances in connected vehicles and autonomous driving are going to change the face of ground transportation as we know it. This paper describes the design and evaluation of several emerging applications for such a cyber transportation system (CTS). These applications have been designed using holistic approaches, which consider the unique roles played by the human drivers, the transportation system, and the communication network. They can improve driver safety and provide on-road infotainment. They can also improve transportation operations and efficiency, thereby benefiting travelers and attracting investment from both government agencies and private businesses to deploy infrastructures and bootstrap the evolutionary process of CTS.

A Partial Reality Experimental System for Human-in-the-Loop Testing of Connected and Automated Vehicle Applications: Development, Validation and Applications

This chapter describes a trans-disciplinary research initiative currently underway at the University at Buffalo, the State University of New York, which aims at developing next generation testing and evaluation platform for emerging Cyber Transportation Systems (CTS). Specifically, the work is developing an integrated traffic-driving-networking simulator (ITDNS), which allows for human-in-the-loop testing of Connected Vehicle (CV) and Automated Vehicle (AV) applications and their interactions. Following a brief discussion of ITDNS, its design rationale and unique advantages, the chapter proceeds to describe some of the on-going research designed to validate and extend ITDNS. The chapter also briefly describes our recent research which is taking advantage of the human-in-the-loop testing capabilities of ITDNS to evaluate a number of CV and AV applications such as eco-signals, Adaptive Cruise Control (ACC), and Co-operative, Integrated Vehicle Infrastructure Control (CIVIC).