A federated simulation method for multi-modal transportation systems: combining a discrete event-based logistics simulator and a discrete time-step-based traffic microsimulator

Abstract

The primary focus of computer simulation in transportation engineering has been to model individual systems using modeling software packages designed for the specific system under investigation. However, this limits the ability to explore interactions between multiple disparate transportation systems in a dynamic modeling environment. To address this gap, this study develops and tests a technique to federate two transportation models, each constructed using different simulation software packages: (1) a discrete event-based simulation model of a freight trucking terminal and (2) a discrete time-step-based traffic microscopic simulation model of the network serving the terminal. The federation technique is tested to consider potential feedback loops that may arise between the models during a single simulation run. It is then applied in a notional case study of the Port of Savannah to further assess its capabilities. The findings suggest that this federated simulation technique captures the dynamic interaction of the two systems being modeled. A comparison of the observed versus expected time-based characteristics of the interactions are shown to yield statistically significant correlation.

Equipoising multi-modal traffic environments using vehicular ad-hoc networks

“…In these papers the concepts of traffic simulation are well explained according to their purpose and simulation type. The research works of Rakkesh et al [41], Suzumura et al [42] and Wall et al [43] were useful resources to understand the ideas of multi-modal traffic simulation. In these papers, the authors consider the multi-modality of an urban traffic environment when modelling their use-case scenarios.…”

A Federated Simulation Framework for Cross-organisational Processes

“…Federated Simulation enables the combination of more than one simulation model and incorporates the feedback loops of simultaneously executed simulations [5]. It also enables the communication of operational characteristics and functions of one model with another where there is a probability of any dependency, making the overall simulation more accurate.…”

“…Federated simulation has been used in various contexts, and, in particular, it has been explored by the US armed forces in a military context [4]. A later example can be found [5] in the context of multi-modal transportation. While this clearly shows that federated simulation is feasible and valuable, the work is limited in genericity.…”

Dynamic Systems for Individual Tracking via Heterogeneous Information Integration and Crowd Source Distributed Simulation

“…The Karush-Kuhn-Tucker (KKT) optimality condition for Eq. 5 is as follows The KKT condition (6) states that at optimality, the support sets (i.e., the non-zero elements) of x and y are complementary to each other. Therefore, Eq.…”

“…The remainder of this report discusses each of these research activities and accomplishments in detail. Specifically, the following chapters present (1) an overview of the software architecture used by an envisioned DDDAS system for vehicle tracking as well as a testbed implemented in the midtown area of Atlanta, Georgia in the United States, (2) the distributed simulation approach, termed ad hoc distributed simulations, and methods to accurately model system dynamics using queueing networks as a sample application, (3) methods to calibrate online traffic simulation models, (4) an approach and data structure to store historical vehicle trajectories in order to predict the forward trajectory of observed vehicles, (5) an algorithm to speed up replicated microscopic traffic simulations, (6) analysis of data distribution management approaches for the envisioned DDDAS system, (7) energy consumption of distributed simulation algorithms, and (8) fast algorithms for nonnegative matrix factorization (NMF).…”