Cloud oriented Additive Technology use for Fast Prototype Development

Digitalization has already affected every segment of the industry and especially manufacturing. Based on market requires that are more specific and faster than ever, there is a need to use some of the online platform packages called Cloud Manufacturing (CM). CM operate through the digital data then here comes the expression CAD models or in particular STL files that are currently adequate for Additive Technologies (AT). On the other hand, there is a rapid increase in the measurement aspects via non-contact forms (3D scanners) where their data are stored in various digital formats: IGES, OBJ, PLY, etc.). Those formats can be processed step by step and follow the full path to Reverse Engineering (RE). In this paper will be discussed the possibility of implementing Cloud Additive Technology (CAT) for Fast Prototype Development (FPD) by analyzing the current situation, barriers during incorporation RE and AT, security and technical-economical aspects

Defect formation in automated fiber placement technology

In the frame of this work, a robotic Automated fiber placement - AFP in situ process was applied to obtain high quality thermoplastic composite structures. Automated fiber placement (AFP) with laser assisted heating (LAFP) is an attractive manufacturing technology for the development of lightweight and high performance components, primarily for the aerospace, automotive, military and many other dominant industries worldwide. For the samples laminate plates produced with the AFP procedure, the flexural strength was investigated, and optical images were analyzed for irregularities such as pore content and weaker interlaminar bonding between the layers. Keywords: automated fiber placement, thermoplastic, laser, flexural strength, irregularitie

Истражување на можностите и точноста на отсликување на геометриската структура на површината од површинскиот слој со контактни профилометри

Во рамките на изведените продлабочени аналитлчки и експериментални истражувања кои се презентирани во научно-истражувачкнот проект со наслов: Истражување на можностите и точноста на отсликување на геометрнската структура на површината од површинскиот слој со контактни профилометри создадена е база со ннформации од научен и апликативен карактер, систематизирана, a се однесува на: Местото и значењето на метрологијата на површините во инженерската метрологија; Методите и техниките за мерење на профилот на рапавоста; Контактни и Безконтактни мерни методи: Споредба на разните видови мерни техники: Структура на контактните мерни системи со надворешна, придодадена референца и со внатрешна, сопствена референца; Видови на читачи кои се користат кај контактните мернн системи; Карактеристики на дигиталниот дел од контактните мерни системи за мерење на нерамнините на површините; Типови. намена и метролошки карактеристики на еталоните за калибрација на системите за мерсњс на топографијата на површините (Тип Al, А2, B1, В2, ВЗ. CI, С2, СЗ, С4, D1, D2, B1, Е2); Препораки при користењето и калибрацијата на системите за мерење на топографијата на површините; Анализа на можностите на компјутерските програми за определување, истражување и пресметка на параметрите на профилот на рапавост: Дефинирање, пресметка н значење на параметрите на профилот на рапавост; Осреднети, Височински, Хоризонтални и Хибриднн параметри; Криви на носењс и Rk параметри на кривите; Можности на софтверот Talyprofile за определување, графичка интерпретација и анализа на профилот на рапавост; Профил филтри (Гаусов. 2RC-ISО и 2RC-PC профил филтер); Примена на програмот Microsoft office Excel за определување на филтер-средна линија на примарниот профилот со користењс на Гаусовиот профил филтер; Анализа на влијанието иа различните мерни услови во процесот на мерењето на топографијата на површините; Поставување на мерниот примерок; Поставување на мерен координатон систем и определување правци за изведување на мерењата; Дефинирање на основните мерни услови при 2Д мерењата; Позиционирање на читачот врз мерната површина; Влијание на лизгачот и на геометријата на мерната игла при копирањето на топографијата на површините; Контрола на состојбата на радиусот на мернатаа игла. Деформација на мерената површина (Статички и Динамички модел); Влијание на семплирачката брзина, семплирачкото растојание и на вкупната мерна должина; Влијание на големината на радиусот на заоблување на врвот од мерната игла и на соодносот помеѓу мерната сила и брзината на мерење; Влијание на карактеристиките иа применетиот трансформатор и па фреквенцијата на сниусоиднниот сигнал врз карактеристиките на диференцијалниот трансформатор и Влијание на квантизацијата на аналогниот сигнал; Статистички параметри на рапавост во ЗД домен. За дијагностицирање на условите при кои се создава обработената површина создаден е мониторинг систем за следење на условите при кои се изведуваат експерименталните истражувања на процесот на обработка со стружење. Отпорите и температурата во процесот на режење се одбрани како индикатори за следење на појавата на вибрации и влијанијата за појава на геометриските отстапувања. Посебно место е посветено на методиката за определување на мерната неодреедност на резултатите од мерењето на рапавоста со примена иа контактни мерни уреди. Во анализата е вклучена продлабочсна систематизација на можните извори на грешките при мерење на рапавоста, кои би требало да се земаат во предвид при определувањето на неодреденоста на резултатите, претставени со дијаграмот па Ишикава

Avoiding heavy computations in inverse calibration procedure for 7 DOF robot manipulator

Procedure for determining commanded coordinates in machine space if desired coordinates are given is inverse calibration. A large amount of data is considered after measurement procedure and it is essential to locate desired point in the real space which is skewed due to measured geometric errors. The machine workspace is divided to cells using measurement points. It is depicted the importance of finding the proper cell in skewed 3D lat- tice, for calibration of translational axes of ATL machine with large workspace. To calibrate 7 DOF robot manipula- tor, this algorithm is extended. The problem of finding the proper cell in 7D skewed grid needs heavy computations and takes significant amount of computational time. Few ideas for avoiding these computations are described and the influence on the final precision of the calibration procedure is explored

Volumetric calibration for improving accuracy of AFP/ATL machines

Automated Fiber Placement (AFP) and Automated Tape Laying (ATL) technologies are mostly used in aerospace industry. Deviations from predefined position and orientation of the AFP/ATL machine’s end-effector may cause defects of the final product like gaps and laps of the laminate ply, tow end placement errors, pressure and temperature variations, etc. That makes clear the importance of accuracy of AFP/ATL machines. Calibration is needed to enhance accuracy. Development and implementation of a comprehensive procedure for volumetric calibration of three linear axes is described in this paper. According to ISO 230-1:2012 and ISO 230-2:2014 standards, 18 position dependent and 3 position independent (in total 21) errors of the 3 linear axes are considered. Measurements are performed using laser interferometer on ATL machine produced by company Mikrosam. Obtained data are used for calibration of that machine and validity of the results is verified by comparison with the calibration results obtained by TRAC-CAL software developed by ETALON AG

Some Experimental Investigation of Products from Thermoplastic Composite Materials Manufactured with Robot and LAFP

For successful avoiding of the irregularities and errors in the products from composite materials, it is important to manage the whole production process in real time. This applies to detecting certain irregularities (positioning defects, bonding defects), controlling the robot and process parameters. This paper presents results from an experimental study of the influence of embedded defects created during in - situ laser automated fiber tape placement (LAFP), on the mechanical properties of carbon/PEEK composites. Three rings have been examined with different designs [(0/±45˚)n], [(0/±30˚)n] and [(0/±90˚)n], in which gaps and overlaps have been introduced during fiber placement. The microstructures were characterized by optic microscopy. ILSS tests were performed on samples from rings and showed that the presence of a gap/overlap and voids more than 3% affect mechanical behavior of pipes but does not affect degree of crystallinity

Application of decision making method (AHP) in Reverse Engineering and Additive Manufacturing Technologies

Continuous market demand shows a fast transition of Additive Manufacturing (AM) from prototype to regular production. The different complex parts are easier to manage using 3D scanners and applying Reverse Engineering (RE) to convert them into digital data that can be reproduced again. Through this paper we intend to explain the relationship between RE and AM with decision making methodology by applying AHP hierarchy, including: goals, criteria, sub-criteria and alternatives. Case study presented confirm the efficiency of the proposed methodology for decision making in production technology

Algorithmic approach to geometric solution of generalized Paden–Kahan subproblem and its extension

Kinematics as a science of geometry of motion describes motion by means of position, orientation, and their time derivatives. The focus of this article aims screw theory approach for the solution of inverse kinematics problem. The kinematic elements are mathematically assembled through screw theory by using only the base, tool, and workpiece coordinate systems—opposite to conventional Denavit–Hartenberg approach, where at least n þ 1 coordinate frames are needed for a robot manipulator with n joints. The inverse kinematics solution in Denavit–Hartenberg convention is implicit. Instead, explicit solutions to inverse kinematics using the Paden–Kahan subproblems could be expressed. This article gives step-by-step application of geometric algorithm for the solution of all the cases of Paden–Kahan subproblem 2 and some extension of that subproblem based on subproblem 2. The algorithm described here covers all of the cases that can appear in the generalized subproblem 2 definition, which makes it applicable for multiple movement configurations. The extended subproblem is used to solve inverse kinematics of a manipulator that cannot be solved using only three basic Paden–Kahan subproblems, as they are originally formulated. Instead, here is provided solution for the case of three subsequent rotations, where last two axes are parallel and the first one does not lie in the same plane with neither of the other axes. Since the inverse kinematics problem may have no solution, unique solution, or many solutions, this article gives a thorough discussion about the necessary conditions for the existence and number of solutions. Keywords Screw motion, Paden–Kahan subproblem, geometric algorithm, inverse kinematics, mathematical foundation

Influence of the Process Parameters on Laser - Assisted Automated Tape Placement Process

Thermoplastic part manufacture by laser-assisted automated tape placement (LATP) process has a high potential for the cost-effective production. Within the frames of this paper it was applied a designing of the industrial LATP process, i.e. planning of the experiments and on the basis of the plan matrix, the specimens were manufactured. Namely, two different thermoplastic prepreg materials were used based on polyphenylene sulfide (PPS) and polyether ether ketone (PEEK) and carbon fibers. The planning of experiments was made separately for processing of these prepreg materials and as the most influenced factors were taken: laser temperature, compact pressure of roller and laser placement angle. For all manufactured specimens the flexural strength was tested and on the basis of the received experimental data it was created the regression equitations which the best describes the processes. This research present and discuss some of laser control system variables and final properties of composite panel specimens

Influence Of Each Of The Geometric Errors On The Total Displacement Error Of The Machine

An algorithm for volumetric calibration is developed and verified practically by measuring of all geometric errors after numerical compensation. In this paper, analysis of the contribution of each of 9 translational and 9 rotational position dependent errors and each of 3 position independent errors in total displacement error vector is presented. Changing only one of the errors, and keeping all the others unchanged, the final total error is examined using the simulation based on forward calibration part of the calibration algorithm. The measurement of all 21 volumetric errors is expensive and time consuming. Instead of numerical compensation in the controller, this analysis yields opportunity to enhance accuracy of the machine, measuring and making correction of only few of the geometric errors. Results from the simulation showed that position independent errors have most significant influence on total displacement error. Decreasing of the squareness error S XY improves the mean of norms of total displacement vectors about 25%, and percentage of improvement for squareness error S ZX is about 20%. If all squareness errors are reduced by factor 0.04, then total improvement is more than 51%