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Simulation-Based Optimization of Earthmoving Operations Using Genetic Algorithm
KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
2012 (English)In: Proceedings of the 17th International Conference of Hong Kong Society for Transportation Studies, 2012, 57-64 p.Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
2012. 57-64 p.
National Category
Transport Systems and Logistics
Identifiers
URN: urn:nbn:se:kth:diva-115980Scopus ID: 2-s2.0-84896854386OAI: oai:DiVA.org:kth-115980DiVA: diva2:588561
Conference
the 17th HKSTS International Conference
Note

TSC import 2104 2013-01-15. QC 20130531

Available from: 2013-01-15 Created: 2013-01-15 Last updated: 2017-03-22Bibliographically approved
In thesis
1. Logistics of Earthmoving Operations: Simulation and Optimization
Open this publication in new window or tab >>Logistics of Earthmoving Operations: Simulation and Optimization
2013 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Earthworks are a fundamental part of heavy construction engineering and involve the moving and processing of the soil surface of earth. Normally, earthmoving operations are carried out during the early stages of heavy construction projects. To a large extent, the success of the fundamental earthmoving determines the sequence of the remaining parts of a project. Furthermore, the operations require expensive heavy equipment as well as manpower. Thus, improving the efficiency of earthmoving operations is a primary target from the point of view of the project management.

This thesis develops simulation and optimization methods for logistics of earthmoving operations. Modeling earthmoving operations correctly is essential to ensure the credibility of simulation, and the well-known CYCLONE modeling methodology is employed to represent the earthmoving logistics. Discrete event simulation techniques are used to capture the interaction between resources and the randomness of the earthmoving activities. A prototype has been developed (Paper I) to demonstrate that the capability of the simulation system of evaluating alternative operating strategies and resource utilizations for earthmoving operations at a detailed level, as well as conducting productivity estimation and Total Cost of Ownership (TCO) calculations. The simulation system is then integrated with optimization to solve the optimal fleet selection problem for earthmoving operations (Paper II and III). Two optimization objectives are formulated and solved using the proposed simulation-based optimization framework and a genetic optimization algorithm: TCO minimization and maximization of productivity. The case studies show that the proposed mechanism can effectively allocate an optimal equipment combination for earthmoving operations and hence serve as an efficient tool for construction management. The main aim of the integrated simulation-based optimization platform is to act as a sales tool to help customers optimize their fleet and eventually their sites.

In addition to the simulation-based optimization framework for earthmoving logistics, the thesis examines the possibility of reducing fuel consumption for articulated haulers which are the most fuel consuming machines in earthmoving (Paper IV). Fuel consumption has become one of the main focuses for automobile manufacturers and several studies have been carried out over the last years to evaluate the possibility of using topographical information and positioning systems to aid look-ahead control systems for road vehicles. Based on the assumption of available road slope information and positioning system, an optimal control problem is formulated to determine the optimal gear shift sequence and time of shifting. Model Predictive Control algorithms together with Dynamic Programming techniques are employed to solve the optimal gear shifting problem. Computer simulations show that both fuel consumption and travel time can be reduced simultaneously. In addition, the optimal gear shift sequence resembles the behavior of an experienced driver.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. ix, 35 p.
Series
Trita-TEC-LIC, ISSN 1653-445X ; 13:002
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-122893 (URN)978-91-87353-05-5 (ISBN)
Presentation
2013-06-14, V7, Teknikringen 76, KTH, Stockholm, 14:00 (English)
Opponent
Supervisors
Note

QC 20130531

Available from: 2013-05-31 Created: 2013-05-29 Last updated: 2013-05-31Bibliographically approved
2. Evaluating and Improving the Transport Efficiency of Logistics Operations
Open this publication in new window or tab >>Evaluating and Improving the Transport Efficiency of Logistics Operations
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The thesis focuses on evaluating and improving the transport efficiency of two types of logistics operations in the supply chain.

One research area is the production of raw material in construction operations, specifically earthmoving operations. Methods and tools are developed to provide decision support in improving the transport efficiency of earthmoving at the vehicle and the systems levels. Using known road topography and a GPS unit, an optimal control problem is formulated and solved (Paper III) to determine the optimal gear shift sequence and timing in order to improve the transport efficiency at the vehicle level. For decision support at the systems level, a Fleet Performance Simulation (FPS) model is designed (Paper IV) to evaluate the transport efficiency for a given mix of construction vehicles in earthmoving. The FPS system is integrated with an optimization algorithm to solve the optimal fleet composition problem for earthmoving operations (Paper V & VI). Construction operations are dynamic and the environment is changing constantly, which bring difficulties in decision-making. Using GPS data from construction vehicles, a map inference framework (Papers I & II) is developed to automatically extract relevant input to decision support at the vehicle and the systems levels, which include the locations of various workstations, driving time distributions and road networks.

The second research area is the transport efficiency of urban distribution system, which is in the final phase of the supply chain. An off-peak delivery pilot project in Stockholm is used as the background, designed to evaluate the potential for commercial vehicles to make use of off-peak hours for goods delivery. The thesis (Paper VII) evaluates the transport efficiency impacts of the off-peak pilot. An evaluation framework is defined where transport efficiency is studied in a number of dimensions. GPS data, fleet management data, and logistic information are used to assess the impacts.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2017. 47 p.
Series
TRITA-TSC-PHD, 17-002
Keyword
transport efficiency, earthmoving operations, off-peak urban deliveries, simulation, optimization, GPS data
National Category
Transport Systems and Logistics
Research subject
Transport Science
Identifiers
urn:nbn:se:kth:diva-204030 (URN)978-91-87353-99-4 (ISBN)
Public defence
2017-04-28, Kollegiesalen, Brinellvägen 8, Stockholm, 14:00 (English)
Opponent
Supervisors
Note

QC 20170323

Available from: 2017-03-23 Created: 2017-03-22 Last updated: 2017-03-27Bibliographically approved

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