An overview on 3D printing technology: Technological, materials, and applications

The Role of Additive Manufacturing in the Era of Industry 4.0

https://spiral.imperial.ac.uk/bitstream/10044/1/73026/9/1-s2.0-S0264127519306021-main.pdf

Review on design and structural optimisation in additive manufacturing: Towards next-generation lightweight structures

Connecting circular economy and industry 4.0

Assessing challenges for implementing Industry 4.0: Implications for process safety and environmental protection

Topology optimization of 2.5D parts using the SIMP method with a variable thickness approach

For the purpose of generating 2D curve offsets used in 2.5D machining, four new methods based on morphological operations on different mathematical entities are presented in this paper. All of the methods, which lend themselves for parallel processing, exploit the idea that the boundaries formed by a circular structuring element whose center sweeps across the points on a generator/base curve comprise the entire offsets of the progenitor. The first approach, which is a carry-over from image processing, makes good use of morphological operations on binary images to produce 2D offsets via contour tracing algorithms. The second method, which is to rectify the high memory cost associated with the former technique, utilizes morphological operations on (boundary data) sets. The implementation of this basic technique is illustrated by two Matlab functions given in the paper. Despite its simplicity, the time complexity of this paradigm is found to be high. Consequently, the third method, which is evolved from the preceding one, reduces the time complexity significantly with the utilization of a geometric range search method. This technique, which has a considerable margin for improvement, is found to be suitable to be used as a part of the real-time motion command generator for CNC applications. Unlike the previous schemes, the final approach uses polygon operations to generate such curves. The run-time of this technique is highly governed by the complexity of the polygon overlay algorithm selected. The paper analyzes the complexity of each technique. Finally, the presented methods are evaluated (in terms of run-time and geometric accuracy) via two test cases where most CAD/CAM packages fail to yield acceptable results.

New morphological methods to generate two-dimensional curve offsets

This article describes the control of a rotary inverted pendulum utilizing on–off-type cold gas thrusters as the actuators, which have high similarities with thruster actuated spacecrafts with slosh dynamics. The study is completed in three phases. Firstly, a Pulse Width Modulator (PWM) design method is utilized to obtain quasi-linear thrust output from the on–off-type thrusters. Then, a single axis angle controller is designed and tested on the setup along with the PWM scheme. Finally, a pendulum is connected to the other end of the platform and a rotary inverted pendulum (Furuta Pendulum) is constructed. In this way, an inherently unstable, under-actuated, on–off driven system is obtained. For the swing-up motion of the pendulum, an energy-based method is employed. Balancing of the pendulum is achieved by an observer-based state feedback controller under small angle assumption and quasi-linear outputs from the PWM driven thrusters. All of these control methodologies are realized on a real-time target machine. The pendulum is stabilized in seven seconds after five swings, which is comparable to the systems with electric motors.

https://www.mdpi.com/2076-0825/9/4/95/pdf

Control of Rotary Inverted Pendulum by Using On-Off Type of Cold Gas Thrusters

As a part of a “lab-at-home” education paradigm for control engineering courses, this paper proposes (and elaborates) a novel hardware-in-the-loop simulator with 3D animation capabilities. The developed software, which can be tailored to simulate any dynamic systems in non-real-time, is designed to work in conjunction with a control hardware. In the paper, the specific application of the software to a graduate-level course is presented within the framework of a final term project involving the control of a satellite tracking antenna. The success of the software (along with the methodology) is rigorously evaluated through the information collected in three academic semesters including the course instructor's feedback and the questionnaires filled out by the students.

A new hardware-in-the-loop simulator for control engineering education

Additive manufacturing (AM), in other words 3D printing, is becoming more common because of its crucial advantages such as geometric complexity, functional interior structures, etc. over traditional manufacturing methods. Especially, Fused Filament Fabrication (FFF) 3D printing technology is frequently used because of the fact that desktop variants of these types of printers are highly appropriate for different fields and are improving rapidly. In spite of the fact that there are significant advantages of AM, the strength of the parts fabricated with AM is still a major problem especially when plastic materials, such as Acrylonitrile butadiene styrene (ABS), Polylactic acid (PLA), Nylon, etc., are utilized. In this study, an alternative method is proposed in which the strength of AM fabricated parts is improved employing direct slicing approach. Traditional Computer Aided Manufacturing (CAM) software of 3D printers takes only the geometry as an input in triangular mesh form (stereolithography, STL file) g...

Ulas Yaman

Papers

Topology optimization of 2.5D parts using the SIMP method with a variable thickness approach

New morphological methods to generate two-dimensional curve offsets

Control of Rotary Inverted Pendulum by Using On-Off Type of Cold Gas Thrusters

A new hardware-in-the-loop simulator for control engineering education

Improving the strength of additively manufactured objects via modified interior structure