3B yazıcılar için yeni bir tasarım ve üretim akışı: LIPRO.

This study starts with highlighting some disadvantages of the conventional design and fabrication pipelines of Additive Manufacturing (AM) processes. In order to overcome the major drawbacks of the conventional pipeline, a novel design and fabrication pipeline called as LIPRO is proposed and it is implemented on two different AM processes to illuminate its effectiveness on alleviating the disadvantages of the conventional approaches. A single board computer is used to realize the method on AM machines. The structure of the LIPRO based on different types of functions is explained and the developed Python scripts are appended to the thesis. By employing this method, some sample parts are fabricated with two AM processes; namely Fused Deposition Modeling and Digital Light Processing. The details of this implementation are elaborated and the advantages are discussed throughout the thesis.M.S. - Master of Scienc

Control for autonomous all-electric ships: Integrating maneuvering, energy management, and power generation control

In the last few years, autonomous shipping has been under extensive consideration by academic and industrial communities as well as governmental organizations due to several potential advantages that it introduces. Furthermore, due to the drastic environmental consequences of transport overwater, international organizations have enforced the shipping industry to reduce its emissions significantly. As a result, the emergence of sustainable autonomous shipping seems inevitable...Transport Engineering and Logistic

A Cloud Manufacturing Application for Additive Manufacturing Methods

Over the past years, the manufacturing industry has witnessed a great enhancement in the field of Additive Manufacturing that allows forming an inchoate market to produce custom-made products with low unit costs. At the same time, everyone may be a designer as well. However, the required equipment is only accessible for all the people. The Cloud Manufacturing aims to resolve this challenge by connecting the customers to the manufacturers. Therefore, this paper introduces a practical fabrication method for 3D printers which can bring flexibility and benefits to cloud manufacturing scheme. A model of this integration is provided and implemented on two types of 3D printers. Further, by printing sample specimens, the advantages of this approach such as using low memory size for operating each printer and the ability of changing the design during the fabrication process is described in details

A Cloud Manufacturing Application for Additive Manufacturing Methods

Over the past years, the manufacturing industry has witnessed a great enhancement in the field of Additive Manufacturing that allows forming an inchoate market to produce custom-made products with low unit costs. At the same time, everyone may be a designer as well. However, the required equipment is only accessible for all the people. The Cloud Manufacturing aims to resolve this challenge by connecting the customers to the manufacturers. Therefore, this paper introduces a practical fabrication method for 3D printers which can bring flexibility and benefits to cloud manufacturing scheme. A model of this integration is provided and implemented on two types of 3D printers. Further, by printing sample specimens, the advantages of this approach such as using low memory size for operating each printer and the ability of changing the design during the fabrication process is described in details

Utilization of Curve Offsets in Additive Manufacturing

Curve offsets arc utilized in different fields of engineering and science. Additive manufacturing, which lately becomes an explicit requirement in manufacturing industry, utilizes curve offsets widely. One of the necessities of offsetting is for scaling which is required if there is shrinkage after the fabrication or if the surface quality of the resulting part is unacceptable. Therefore, some post-processing is indispensable. But the major application of curve offsets in additive manufacturing processes is for generating head trajectories. In a point-wise AM process, a correct tool-path in each layer can reduce lots of costs and increase the surface quality of the fabricated parts. In this study, different curve offset generation algorithms are analyzed to show their capabilities and disadvantages through some test cases and improvements on their drawbacks are suggested

Adaptive control for autonomous ships with uncertain model and unknown propeller dynamics

Motion control is one of the most critical aspects in the design of autonomous ships. During maneuvering, the dynamics of propellers as well as the craft hydrodynamical specifications experience severe uncertainties. In this paper, an adaptive control approach is proposed to control the motion and trajectory tracking of an autonomous vessel by adopting neural networks that is used for estimating the dynamics of the propellers and handling hydrodynamical uncertainties. Considering that the maneuvering model of a vessel resemble a nonlinear non-affine-in-control system, the proposed neural-based adaptive control algorithm is designed to estimate the nonlinear influence of the input function which in this case is the dynamics of propellers and thrusters. It is also shown that the proposed methodology is capable of handling state dependent uncertainties within the ship maneuvering model. A Lyapunov-based technique and Uniform Ultimate Boundedness are used to prove the correctness of the algorithm. To assess the method's performance, several experiments are considered including trajectory tracking simulations in the port of Rotterdam.Accepted Author ManuscriptTransport Engineering and Logistic

Model predictive maneuvering control and energy management for all-electric autonomous ships

Over the last few years, autonomous shipping has been under extensive investigation by the scientific community where the main focus has been on ship maneuvering control and not on the optimal use of energy sources. In this paper, the purpose is to bridge the gap between maneuvering control, energy management, and the control of the Power and Propulsion System (PPS)to improve fuel efficiency and the performance of the vessel. Maneuvering control, energy management, and the control of the PPS are in the literature typically studied independently from one another, while they are closely connected. A generic control methodology based on receding horizon control techniques is proposed for the ship maneuvering control as well as energy management. In the context of this research, Direct Current (DC)all-electric architectures are considered for the PPS where the relationship between the produced power by energy sources and vessel propellers is established by a DC microgrid. The objective of the proposed approach is to ensure the ship mission objectives by guaranteeing efficient power availability, decreasing the trajectory tracking error, and increasing the fuel efficiency. In this regard, for the ship motion control, a Model Predictive Control (MPC)algorithm is proposed which is based on Input–Output Feedback Linearization (IOFL). Through this algorithm, the required power for the ship mission is predicted and then, transferred to the proposed Predictive Energy Management (PEM)algorithm which decides on the optimal split between different on-board energy sources during the mission. As a result, the fuel efficiency and the power system stability can be increased. Several simulations are carried out for the evaluation of the proposed approach. The results suggest that by adopting the proposed approach, the trajectory tracking error decreases and the Specific Fuel Consumption (SFC)efficiency is significantly improved.Transport Engineering and Logistic

Toward a Simple Design and Manufacturing Pipeline for Additive Manufacturing

A novel design and manufacturing pipeline for Additive Manufacturing is presented. The architecture of the pipeline is motivated by the observation that the conventional pipeline is unnecessarily complex. Most of the time, only a small set of programming steps suffices for 3D design and manufacture. In particular, the proposed method requires no complex hardware or software, and it generates the geometric data on the fly. This is demonstrated using a simplified evaluation of general volumetric sweeps. The method side-steps many of the problems of the conventional Additive Manufacturing pipeline. Several scripts are provided that illustrate the capabilities and the advantages of the proposed approach. These scripts are processed on a single-board computer and the parts are manufactured on a Fused Filament Fabrication type of 3D printer

Eco-VTF: Fuel-efficient vessel train formations for all-electric autonomous ships

In this paper, a distributed control approach is proposed to enable fuel-efficient Vessel Train Formations (VTF) in inland waterways and port areas for addressing the efficiency and environmental issues of transport over water. For path tracking, collision avoidance, and consensus over the VTF speed a distributed Model Predictive Control (MPC) algorithm is adopted which uses the Alternating Direction Method of Multipliers (ADMM) to guarantee path following and consensus between vessels. The all-electric Direct Current (DC) configuration is considered for the Power and Propulsion Systems (PPS) of the autonomous vessels under study. Considering their PPS specification, the vessels negotiate with each other to agree on the most efficient speed for all the vessels in the VTF. Simulation results suggest that a significant amount of fuel saving can be obtained by using the proposed approach.</p

Simulator of an additive and subtractive type of hybrid manufacturing system

Additive Manufacturing (AM) facilitates the production of intricate objects despite its weakness in attainable part quality and fabrication speed compared to the conventional manufacturing methods. To alleviate the problems arising as a natural outcome of AM methods, hybrid technologies become viable options by employing concurrent manufacturing procedures, e.g. synergetic additive and subtractive manufacturing (SM) actions. Hybrid workstations have recently opened up new dimensions to 3D-printing industry, but related research topics remain underexplored in the literature. In this study, a hybrid manufacturing simulator that imitates AM and SM operations is presented. The hybrid simulator reported aims to provide users with a comprehensive interpretation of the G-codes, thereby previews the AM/SM tool paths and the eventual shape of the fabricated object. Consequently, the simulator lets users realize the final form of the artifacts besides enabling them to notice possible problems on the manufacturing trajectories. In addition, a post-processor customized for multi-axis hybrid platforms is built for the generation of G-code files. As a significant feature of the proposed manufacturing simulator, the capability to handle variable bead-width on the additive infill path has also been addressed in the study