published journal article

Aircraft Navigation in GNSS-Denied Environments via Radio SLAM With Terrestrial Signals of Opportunity

IEEE Transactions on Intelligent Transportation Systems

Publication Date

October 1, 2024

Author(s)

Zaher Kassas, Nadim Khairallah, Joe Khalife, Chiawei Lee, Juan Jurado, Steven Wachtel, Jacob Duede, Zachary Hoeffner, Thomas Hulsey, Rachel Quirarte, RunXuan Tay

Abstract

A radio simultaneous localization and mapping (radio SLAM) framework enabling aircraft navigation with terrestrial signals of opportunity (SOPs) is presented and experimentally validated. The framework does not assume availability of global navigation satellite system (GNSS) signals. Instead, it assumes the aircraft to have an initial estimate of its own states, after which it navigates by exploiting pseudorange measurements extracted from terrestrial SOPs, while estimating the states of the aircraft simultaneously with the SOPs’ states. Two radio SLAM frameworks are presented: (i) tightly-coupled SOP-aided inertial navigation system (INS) and (ii) utilizing a Wiener process acceleration (WPA) dynamical model for the aircraft’s dynamics instead of the INS. Results from four flight runs on a US Air Force C-12 aircraft, equipped with an altimeter and an industrial-grade inertial measurement unit (IMU), are presented. The flight runs took place over semi-urban (SU), urban (U), and rural (R) regions in California, USA; while exercising different aircraft maneuvers: holding (H), descending (D), and grid (G). Different a priori conditions of the SOPs’ positions were studied: from all unknown, to some known, to all known. In all cases, the SOPs’ clock error states (bias and drift) were unknown and estimated alongside the aircraft’s states. The results consistently demonstrated the promise of real-world aircraft navigation via radio SLAM, yielding bounded errors along trajectories of tens of kilometers. The three-dimensional (3–D) position root-mean squared errors (RMSEs) are summarized next, where N denotes the number of SOPs exploited along the trajectory: (1) SU, H, INS-SOP, N=6
 , 56.7 km in 8.5 minutes, maximum altitude of 5,577 ft: 43.27 m with all unknown and 10.14 m with all known; (2) U, H, INS-SOP, N=6
 , 72.7 km in 12.9 minutes, maximum altitude of 5,906 ft: 89.82 m with all unknown and 16.97 m with all known; (3) SU, D, WPA-SOP, N=18
 , 111.9 km in 20.0 minutes, maximum altitude of 6,234 ft: 36.42 m with all unknown and 18.62 m with all known; and (4) R, G, WPA-SOP, N=32
 , 78.4 km in 13.8 minutes, maximum altitude of 7,546 ft: 67.01 m with all unknown and 25.65 m with all known.

Suggested Citation
Zaher M. Kassas, Nadim Khairallah, Joe J. Khalife, Chiawei Lee, Juan Jurado, Steven Wachtel, Jacob Duede, Zachary Hoeffner, Thomas Hulsey, Rachel Quirarte and RunXuan Tay (2024) “Aircraft Navigation in GNSS-Denied Environments via Radio SLAM With Terrestrial Signals of Opportunity”, IEEE Transactions on Intelligent Transportation Systems, 25(10), pp. 14164–14182. Available at: 10.1109/TITS.2024.3405908.

working paper

Strategic Freight Transportation Contract Procurement

Publication Date

January 1, 2006

Author(s)

Abstract

Auction based market clearing mechanisms are widely accepted for conducting business-to-business transactions. This dissertation focuses on the development of auction mechanism decision tools for freight transportation contract procurement. The dissertation categorizes the problems in freight procurement auctions arising in both sport markets and long term markets. Spot markets are widely employed over the Internet using standard classic auctions. For long-term markets, large shippers (typically manufacturing companies or retailers) have begun to use combinatorial auctions to procure services from trucking companies and logistics services providers. Combinatorial auctions involve very difficult optimization problems both for shippers and carriers. In the US truckload market few carriers have the technical sophistication to develop bids for combinatorial auctions. To address the problem we look at a different auction scheme termed a unit auction, where the shipper can exploit the economies of scope in the network and give the carriers the chance to bid on pre-defined packages similar to ‘lotting’ in supply chain procurement.

The problems in developing contract allocations, called the winner determination problem, are computationally complex and large-scale. Hence the development of good heuristics is of utmost importance. Shippers have non-price business constraints, which must be included in the winner determination problems to closely match shipper business objectives. We develop winner determination problem formulations incorporating the non-price business constraints and develop Lagrangian based optimization methods and greedy approximation algorithms for both unit auctions and combinatorial auctions. Extensive empirical results are provided to test the performance of the heuristics against a standard integer-programming solver.

Bidding in auctions from the carrier’s perspective is complicated as it involves taking into account the competitive behavior of other carriers and a carrier’s difficult network optimization problems. We develop bidding strategies for carriers in spot markets using concepts from economic auction theory. For long-term market bidding, we study the effects of demand uncertainty, competitive behavior, carrier network synergies and strategic pricing, and shipper’s winner determination problems on carrier bidding using optimization-based simulation analysis.

MS Thesis

The Effects of VMT on Travel Demand and Implied Equity Issues

Abstract

The purpose of this thesis was to analyze the California Household Travel Survey to examine any differences in travel behavior and demographics between two of California’s multi-county Metropolitan Planning Organization (MPO) areas, the Southern California Association of Governments (SCAG) and the Metropolitan Transportation Commission (MTC). As these regions continue to grow, they have witnessed significant gentrification affecting marginalized communities that are already struggling against increasing costs of living. There were significant differences in both travel times and distance traveled with the SCAG region having values slightly higher than MTC. However, within each region there were significant differences in income and racial demographics at the county level. In SCAG, Orange County had the highest Average HH level incomes and San Bernardino and Imperial Counties having the lowest average HH level incomes. Within the MTC area African Americans and Native Americans were found to more likely walk and use public transit more than other group due to these groups having the lowest incomes out of other groups. Also, these groups tend to reside in Contra Costa and Alameda Counties which have the lowest housing costs in the MTC region.

Suggested Citation
De'Von Jennings (2019) The Effects of VMT on Travel Demand and Implied Equity Issues. MS Thesis. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991034991568704701.

policy brief

Health impacts of moving freight in and out of the ports of long beach and Los Angeles

Suggested Citation
Gunwoo Lee, Soyoung Iris You, Mana Sangkapichai, Stephen G Ritchie, Jean-Daniel Saphores, Oladele Ogunseitan, Roberto Ayala, R Jayakrishnan and Rodolfo Torres (2010) Health impacts of moving freight in and out of the ports of long beach and Los Angeles. Policy Brief UCTC POLICY BRIEF 2010-04. University of California Transportation Center. Available at: https://escholarship.org/uc/item/2fb6k6s6.

working paper

The Economic Effects of Highway Congestion

Publication Date

October 1, 1995

Associated Project

Author(s)

Working Paper

UCI-ITS-WP-95-16, UCTC 292

Areas of Expertise

Abstract

This paper examines the link between highway congestion, labor productivity, and output in a sample of California counties for the years 1977 through 1987. A county production function is modified to include both the value of each county’s highway capital stock and a measure of the congestion on each county’s highway network. This allows a comparison of two distinct policies — expanding the highway stock versus reducing congestion on the existing stock. The productive effects of congestion reduction are significantly positive in five of six regression specifications. The effects of expanding the highway stock are more suspect, and are insignificant in what are arguably the preferred specifications. Overall, the results provide evidence that efficiently using the existing highway network is more likely to yield economic benefits than expanding the highway stock.

Suggested Citation
Marlon G. Boarnet (1995) The Economic Effects of Highway Congestion. Working Paper UCI-ITS-WP-95-16, UCTC 292. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/6tk2m53k.

conference paper

Capability-Enhanced Paramics simulation with developed API library

Proceedings, ITS World Congress

Publication Date

January 1, 2002
Suggested Citation
Lianyu Chu, X. Liu and W. Recker (2002) “Capability-Enhanced Paramics simulation with developed API library”, in Proceedings, ITS World Congress. Chicago, Illinois.

published journal article

A method for identifying rear-end collision risks using inductive loop detectors

Accident Analysis & Prevention

Publication Date

March 1, 2006
Suggested Citation
Cheol Oh, Seri Park and Stephen G. Ritchie (2006) “A method for identifying rear-end collision risks using inductive loop detectors”, Accident Analysis & Prevention, 38(2), pp. 295–301. Available at: 10.1016/j.aap.2005.09.009.

research report

Exploring new directions for the national household travel survey. Phase one report of activities

Publication Date

January 1, 2013

Author(s)

Jean-Daniel Saphores, Sarah Chesebro, Thera Black, Stacey Bricka

Report Number

E-C178
Suggested Citation
Jean Daniel Saphores, Sarah Chesebro, Thera Black and Stacey Bricka (2013) Exploring new directions for the national household travel survey. Phase one report of activities. E-C178. Available at: https://onlinepubs.trb.org/onlinepubs/circulars/ec178.pdf.

published journal article

Tackling the crowdsourced shared-trip delivery problem at scale with a novel decomposition heuristic

Transportation Research Part E: Logistics and Transportation Review

Abstract

This paper presents a set-partitioning formulation and a novel decomposition heuristic (D-H) solution algorithm to solve large-scale instances of the urban crowdsourced shared-trip delivery (CSD) problem. The CSD problem involves dedicated vehicles (DVs) and shared personal vehicles (SPVs) fulfilling delivery orders, wherein the SPVs have their own trip origins and destinations. The D-H begins by assigning as many package delivery orders (PDOs) to SPVs as possible, where the D-H enumerates the set of routes each SPV can feasibly traverse and then solves a PDO-SPV-route assignment problem. For PDO-DV assignment and DV routing, the D-H solves a multi-vehicle routing problem with time-window, tour duration, and capacity constraints using an insertion heuristic. Finally, the D-H seeks potential solution improvements by switching PDOs between SPV and DV routes through a simulated annealing (SA)-inspired procedure. The D-H outperforms a commercial solver in terms of computational efficiency while obtaining near-optimal solutions for small problem instances. The SA-inspired switching procedure outperforms a large neighborhood search algorithm regarding run time, and the two are comparable regarding solution quality. Finally, the paper uses the D-H to analyze the impact of several relevant factors on city-scale CSD system performance, namely the number of participating SPVs and the maximum willingness to detour of SPVs. Consistent with the existing literature, we find that CSD can substantially reduce delivery costs. However, we find that CSD can increase vehicle miles traveled. Our findings provide meaningful insights for logistics practitioners, while the algorithms illustrate promise for large real-world systems.

Suggested Citation
Dingtong Yang, Michael F. Hyland and R. Jayakrishnan (2024) “Tackling the crowdsourced shared-trip delivery problem at scale with a novel decomposition heuristic”, Transportation Research Part E: Logistics and Transportation Review, 188, p. 103633. Available at: 10.1016/j.tre.2024.103633.

published journal article

Searching for policy priorities in the formulation of a freight transport strategy: A canonical correlation analysis of freight industry attitudes

Transportation Research Part E: Logistics and Transportation Review

Publication Date

December 1, 1999

Author(s)

David A Hensher, Thomas Golob

Abstract

An efficient and effective freight transport strategy can be aided by early professional contributions from key stakeholders. One broad group who have historically been given limited opportunity to influence the drafting of a freight strategy, are commercial road users and shippers who manufacture and distribute goods. Utilising a data set collected in Australia in 1996 from a sample of organisations involved directly and indirectly in road freight transportation, views were sought on road infrastructure changes, new road infrastructure, non-road infrastructure needs and transport policies. An optimal scaling approach using non-linear canonical correlation is implemented to search for structural relationships between the under-lying policy and infrastructure dimensions and the various industry categories. This framework provides a powerful mechanism for identifying differences among stakeholders in terms of their support for or opposition to specific policies. Results reveal the considerable differences in attitudes associated with the component parts of the freight industry. (C) 1999 Elsevier Science Ltd. All rights reserved.

Suggested Citation
David A Hensher and Thomas F Golob (1999) “Searching for policy priorities in the formulation of a freight transport strategy: A canonical correlation analysis of freight industry attitudes”, Transportation Research Part E: Logistics and Transportation Review, 35(4), pp. 241–267. Available at: 10.1016/s1366-5545(99)00013-7.