| 1. |
- Rylander, David, 1981-
(författare)
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Characteristics and Models for Energy Optimization of Cyclic Transport Operations in Mining
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- There is a large potential in automation and optimization of transports within quarry and mining, but operational models and characteristics for this purpose are lacking. This paper aims to provide insight into cyclic transports and the parameters that affect energy consumption and productivity. For this purpose, data from machines in operation has been collected and analyzed. The paper presents and discusses the characteristics of the operation identified, develops models for energy consumption and productivity, and discusses its relation for optimization and automation purposes. A conclusion is that there are stochastic fluctuations in activity times that need continuous real-time control for an optimization system to be effective. The method used in the paper resulted in regression models for cycle energy cost and hauler fuel rate, which provide both correlation and significance, which is promising for future validation and use in optimization control systems.
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| 2. |
- Rylander, David, 1981-, et al.
(författare)
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Design and Evaluation of a System of Systems Architecture for the Optimization of a Cyclic Transport Operation
- 2021
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Konferensbidrag (refereegranskat)abstract
- Cyclic transport missions involving fleets of vehicles are common in quarry and mining operations and have shown to have a significant potential for energy optimization. Vehicles such as articulated haulers and dump trucks utilized in transport missions can be of different brand, type and have different performance characteristics such as engine power, traction and load. Vehicles may also be operated and owned by different organizations as they can be subcontracted to an operation. The transport operation characteristics include stochastic behaviors and activity times that fluctuate over time, and hence real-time control is required for efficient optimization. As the vehicles are mobile, wireless communication also needs to be available. As the constituent systems (vehicles) have managerial and operational independence, a system of systems approach is applicable. This paper provides an overview of the key characteristics and requirements for such a system and discusses the pros and cons of acknowledged and directed system architectures. Further, a case study is presented where an acknowledged system of systems is implemented in a real world mine and evaluated through a qualitative assessment of an operator assistive optimization system. Key findings include the drawbacks and characteristics of the architecture approaches. Further challenges and potential for automation and production control of a larger process system are described.
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| 3. |
- Rylander, David, 1981-, et al.
(författare)
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On the viability of autonomous follower truck convoys
- 2023
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Ingår i: 15th ITS European Congress, Lisbon, Portugal, 22-24 May-2023.
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Konferensbidrag (refereegranskat)abstract
- Autonomous follower truck convoy (AFTC) is a concept that addresses the major shortage of truck drivers and increasing transport costs. The AFTC concept can be described as a vehicle convoy concept consisting of two or more vehicles where the first, lead vehicle has a human driver and where the following vehicles in the convoy are driverless. The argument is made that this technology is less technically complex than single autonomous vehicles and targets higher economic values compared to driver-assisted platooning functions. The contribution of this paper is a viability study of the AFTC concept. The conclusions from the study are that the concept viability depends on the continuous evolvement of three main factors. The emergence of autonomous capabilities, legal frameworks, and logistics actors’ interest in adapting current processes and infrastructure to meet the operational limitations of the concept.
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| 4. |
- Rylander, David, 1981-
(författare)
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Productivity Improvements in Construction Site Operations through Lean Thinking and Wireless Real-Time Control
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of a quarry is to extract rock material to deliver gravels, cement and asphalt to its customers. These products are important input to the construction and maintenance of road infrastructure, buildings and more. The operation of quarry and road work sites is similar to factory production, since it contains sequential production processes, tasks and activities to produce the output product. Compared to the factory, the quarry and road work processes are generally not synchronized and controlled towards the overall throughput in real-time. Some sites control parts of the production but do generally not utilize real-time technologies for the whole site and all its activities. This fact indicates a general improvement potential in increased productivity, but also unsolved challenges for the same reason. This thesis investigate how Lean thinking utilizing real-time control and wireless communication can be used to improve productivity and safety in the operation of quarry and road construction. The main overall contribution is the identified operational improvements, its use cases, the system design constraints and challenges as well as assessed impact in productivity, energy efficiency and safety if introducing wireless real-time control to the site operation. The results include the presentation and demonstration of a developed method based on Lean value stream mapping, for identifying wastes in sequential processes and activities including mobile machines. Further it investigates the performance and evaluates how the latest developments of wireless communication and vehicular ad-hoc networks (VANET) can be utilized within the quarry and road construction operation. The main system requirements and constraints are identified and the tradeoffs and gains in terms of system design, communication coverage, energy consumption and safety for the identified use cases are presented.
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| 5. |
- Rylander, David, 1981-
(författare)
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Productivity Improvements in Construction Transport Operation through Lean Thinking and Systems of Systems
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of a quarry is to extract rock material to deliver gravel and raw material to its customers. The products can be further processed to e.g., extract minerals such as iron or to produce cement and asphalt. These products are an important input to the construction and maintenance of road infrastructure, buildings, and more. The operation of quarry and road work sites is similar to the manufacturing industry since it contains sequential processes to produce the output product. Within the operation, there are cyclic transport activities that in general are not synchronized and controlled in real-time towards the overall throughput. This fact indicates a potential to increase productivity but also points at unsolved challenges.This thesis investigates how Lean and systems thinking combined with real-time control and optimization technologies can be used to improve productivity and safety in the transport operation within quarry and road construction. The main contributions are the identified operational improvements, its use cases, the system design constraints, operational characteristics, and models as well as assessed impact in productivity, energy efficiency, and safety.The results include the development and demonstration of a method based on Lean value stream mapping, for identifying wastes in sequential processes and activities including mobile earthmoving machines. Operational wastes of 33% are presented from real world operations. Related fuel savings of 42% are measured in controlled environments. Further, the thesis presents and assesses a system design for transport optimization purpose. A study of how wireless communication and vehicular ad-hoc networks (VANET) can be utilized and its performance within the quarry and road construction operation is presented. The main system requirements and constraints are identified, and the trade-offs are discussed in terms of system design with a system of systems perspective. Energy consumption models are developed for optimization purposes and the key characteristics of real world operation is identified. Finally, a prototype system has been developed and tested in controlled and operative environments. In controlled trials, a fuel reduction of 20% for individual machines was obtained using the suggested optimization technique.
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