p. 125-130

 

CONTROL OF A THERMOPLASTIC TAPE WINDING PROCESS WITH OPTICAL

IN-LINE METROLOGY  

 

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Robert SCHMITT1, Andreas WITTE2,*

 

¹⁾ Prof. Dr.-Ing., Managing Director, Metrology and Quality Management, WZL of RWTH Aachen University, Aachen, Germany

²⁾ Scientific Assistant, Production quality and metrology, Fraunhofer Institute for Production Technology IPT, Aachen, Germany

  

Abstract: The energy-efficient production of fiber reinforced plastics allow the usage of lightweight products for various applications in future. Structures made of carbon fibers convince through 70% lower weights in comparison to products made of steel or aluminum and can achieve better mechanical and chemical properties at the same time. Carbon fibers are therefore very attractive for automotive applications and can be used to reduce the weight of vehicles and consequently their fuel consumption.

The thermoplastic tape winding process is an energy-efficient technique for the production of fiber reinforced plastics. The main disadvantage of this process in comparison to established thermosetting winding processes is the missing quality assurance. Products for safety critical applications like pressure vessels require high process stabilities which are not obtainable without any quality assurance provisions.

The process integration of innovative metrology systems enables the industry to use thermoplastic tape winding for safety critical products. One of the main quality weaknesses of the manufacturing process is the exact positioning of the tapes. To increase the tape positioning accuracy, a metrology based control system has to be implemented. As the manufacturing process is using robots as machine tools the control systems needs to be adapted to robot specific requirements. Within this paper we present a system which has been developed to analyze and evaluate the use of optical metrology to control the robot based tape winding process.

 

Key words: quality assurance, tape winding, optical metrology, robot control, pressure vessel, carbon fiber, energy efficient poduction.

 

p. 131-138 

 

ASPECTS REGARDING THE USE OF GENETIC PROGRAMMING

IN MODELLING THE CUTTING PROCESS  

 

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p. 139-144 

 

MODERN SYSTEMS SUPPORTING MAINTENANCE OF MACHINES  

 

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Stanislaw LEGUTKO*

 

Prof. DSc. PhD. MSc. Eng., Poznan University of Technology, Faculty of Mechanical Engineering and Management

Poznan, Poland

 

Abstract: The paper presents programs of computer aided maintenance of machine operation; an analysis of the changes taking place and assessment of their suitability has also been performed. Computer systems aiding the management of machine operation, selection an adequate system as a way to the enterprise success have been considered, too. General classification of the Computerized Maintenance Management Systems (CMMS) has been presented. Various kinds of computer aided machine operation maintenance systems have been presented. The strategy of developing the machine operation maintenance development, including the utilization of Business Intelligence in the systems of CMMS class, as well as the availability of the CMMS in Poland have been described, too. Most of the CMMS systems available in Poland have been presented. The following applications are discussed: Betacom, Aretics, Comarch, EUROTRONIC 2000, Overhaul and Exploitation Economy, IFS Application, CMMS Machine Program, Golem OEE System, MAXIMO, Operation Maintenance System FBD and Utilization of Machines and Devices in an Enterprise. They help to keep order in all the issues related to overhauls and operation maintenance. It should be pointed out that, when the TPM (Total Productive Maintenance) concept was introduced in enterprises, it has turned out that its efficient functioning requires implementation of a computer system to supervise and control machine operation maintenance.

 

Key words: maintenance of machines, CMMS, MAXIMO system, CMMS machine, Business Intelligence.

 

p. 145-148 

  

DECISION ANALYSIS IN PROJECTS WITH WINQSB SOFTWARE  

 

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Marian Andrei GURAU

 

PhD student, Faculty of Engineering and Technological Systems Management, University “Politehnica” of Bucharest, Romania  

  

Abstract: Starting with an introduction discussion about the decision process and IT systems for decision assist, this paper introduces some aspects about the advantages and disadvantages of the Decision Analysis module and of using it in a project. The case study presents a real situation of a manufacturing company, which wants to launch a new product with more possibilities. The problem was solved using WinQSB software to assist the better economic decision. I wanted the evaluation of economic consequences (both running costs of production and estimated profits) for each possible situation based on data assumptions.

 

Key words: decision system, IT systems to assist decision, decision analysis, WinQSB.

 

p. 149-152 

Drop Test of Electronic Device by Virtual Prototype Simulation

 

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Georgi TODOROV1, Borislav ROMANOV2, Konstantin KAMBEROV3,*, Svetoslav STOEV4

 

¹⁾ Prof. PhD Eng., Dean, Faculty of Industrial Technologies, Technical University, Sofia, Bulgaria

²⁾ Eng., Research Engineer, Laboratory “CAD/CAM/CAE in Industry”, Faculty of Industrial Technologies, Technical University, Sofia, Bulgaria

³⁾ PhD Eng., Research Engineer, Laboratory “CAD/CAM/CAE in Industry”, Faculty of Industrial Technologies, Technical University, Sofia, Bulgaria

⁴⁾ Eng., Research Engineer, Laboratory “CAD/CAM/CAE in Industry”, Faculty of Industrial Technologies, Technical University, Sofia, Bulgaria

 

 

Abstract: Contemporary products are subjected to increased requirements for reliability and safety that reflect as new standards and norms. The development of numerical techniques based on virtual prototyping technology facilitates their application in a wide variety of new designed products. Implementing virtual prototyping in product development process results in reduced time/money spent for this stage as well as increased knowledge about certain failure mechanism. So called “drop test” became nearly a “must” step in development of handheld equipment, which could be very time-consuming task because of its nature. This study aims to present a simplified approach for fast design verification at its early stage – before final verification of the product and its documentation. It uses a quasi-static analysis approach to solve a typical dynamic task, instead of usual explicit dynamic procedure, which is related to time consuming nonlinear analysis. This two-step approach involves initial analysis to calculate dynamic factors for a final steady-state static analysis that results in sufficient like accuracy data. Two major advantages of this approach are the decreased overall simulations time – reaches more than 10 times reduction in some cases – and avoid of nonlinearity that could be a certain error source. Certain example is shown, based on a research study of electronic device, subject of impact loads during drop test.

 

Key words: simulation, drop test, virtual prototype, electronic device, FEA.

 

p. 153-158 

 

MODELING AND PERFORMANCE ANALYSIS OF A SPINDLE ELECTRIC DRIVE

WITH ADAPTIVE SPEED CONTROL  

 

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Mikho MIKHOV1,*, Marin ZHILEVSKI2, Alexander SPIRIDONOV3

 

¹⁾ Assoc. Prof., Eng, PhD, Faculty of Automatics, Technical University of Sofia, Bulgaria

²⁾ MSc, Eng, Faculty of Automatics, Technical University of Sofia, Bulgaria

³⁾ Eng, Faculty of Automatics, Technical University of Sofia, Bulgaria

 

Abstract: The performance of a DC electric drive system with dual-zone speed regulation is discussed in this paper. The controlled object consists of a four-quadrant power converter for armature voltage, a nonreversible power converter for field voltage and a separately excited DC motor. The motor speed is regulated at constant magnetic flux in the first zone, while in the second zone the flux is reduced at constant armature voltage. The speed zone switching is a function of armature voltage of the motor. Controllers have been synthesized for the regulated variables of motor speed, armature current and field current. To improve the electric drive performance an adaptive speed controller with switchable structure is offered. In the second zone the controller parameters adapt to the decreasing magnetic flux. To verify the offered control algorithm functionality appropriate computer simulation models have been developed, using the MATLAB/SIMULINK software package. Detailed study and analysis by means of modelling and computer simulation have been carried out for different loads at the respective transient and steady state regimes. The analysis shows that such a driving system can ensure good performance. The developed models and the results obtained could be used in optimization and final set up of such types of speed control driving systems.

 

Key words: speed control, dual-zone regulation, modelling, computer simulation, performance analysis.

 

p. 159-164 

 

STUDIES ON AUTOMATED NON-DESTRUCTIVE INSPECTION FOR ALUMINIUM CASTING PARTS

MACHINED ON A MILLING CENTER  

 

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Florea Dorel ANANIA1,*, Dumitru Titi CICIC 2 , Cătălin Gheorghe AMZA 3 , Diana POPESCU 4

 

¹⁾ Lecturer, PhD, Machine and Production Systems Department, University Politehnica of Bucharest, Bucharest, Romania

²⁾ Lecturer, PhD, Materials Technology and Welding Department, University Politehnica of Bucharest, Bucharest, Romani

 ³⁾ Assistant Prof, PhD, Materials Technology and Welding Department, University Politehnica of Bucharest, Bucharest, Romania

⁴⁾ Lecturer, PhD, Machine and Production Systems Department, University Politehnica of Bucharest, Bucharest, Romania

  

Abstract: In this paper some aspects concerning the influences of milling process over the surface quality for casting material are presented. A non-destructive technique was used to identify defects over the surface caused by cutting process conditions and different CAD-CAM techniques. The general goal of this paper is to present a way of automatic inspection of products quality in machining process.

A general plan was made for a computer integrated manufacturing which could include a fully-automated liquid penetrant inspection line for increasing productivity. A case study was made for an inspection of milling a casting piece. The piece was casted in aluminium mould using a gravity die casting technique. On this piece a pocket was created by using a 3x milling centre and an advanced CAD-CAM software. Roughing and finishing machining operations were used in order to achieve better surface quality.  

 

Key words: milling, cutting process, CAD CAM, LP non-destructive inspection, optical inspection.

 

p. 165-170 

MATERIALS PROPERTIES OF PARTS PRODUCED BY FUSED DEPOSITION
MODELING RAPID PROTOTYPING TECHNOLOGY  

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 Ludmila NOVAKOVA-MARCINCINOVA

Eng., scientific worker, Faculty of Manufacturing Technologies, Technical University of Kosice, Presov, Slovakia

Abstract: Rapid Prototyping (RP) can be defined as a group of techniques used to quickly fabricate a scale model of a part or assembly using three-dimensional computer aided design (CAD) data. What is commonly considered to be the first RP technique, Stereolithography, was developed by 3D Systems of Valencia, CA, USA. The company was founded in 1986, and since then, a number of different RP techniques have become available. In this contribution are presented basic information about basic and new materials used for realization of products by Fused Deposition Modelling RP technology application. In different Rapid Prototyping technologies the initial state of material can come in either solid, liquid or powder state. In final part of the paper is presented project of experimental part design and production with application of Rapid Prototyping technology realized by students and workers of Faculty of Manufacturing Technologies in Presov, Slovakia. In frame of part design there was model with three holes realized together with its dual part. Production of the parts was connected with realization of produced parts dimensional issues and final product assembly.

Key words: Rapid Prototyping, Fused Deposition Modeling, materials for rapid prototyping.

 

p. 171-176 

 

APPLICATION OF WIRELESS STANDARDS IN DYNAMIC PARAMETERS MONITORING SYSTEM FOR VEHICLES AND INDUSTRIAL MACHINES

 

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Georgi STANCHEV1,*, Nikolay STOYANOV2, Zdravko DOICHEV3, Plamen BALZHIEV²

 

¹⁾ Assist. Prof., Eng, PhD, Faculty of Mechanical Engineering, Technical University – Sofia, Bulgaria

²⁾ MSc, Eng, Faculty of Telecommunications, Technical University – Sofia, Bulgaria

³⁾ Eng, Faculty of Telecommunications, Technical University – Sofia, Bulgaria

Abstract: This paper presents the design of a wireless sensing system based on ZigBee networks and GSM communication standards for measurement and monitoring of dynamic parameters of industrial machines and vehicles. ZigBee standard is particularly suitable for developing a wide network of intelligent sensors. Combined with GSM technology such system can be implemented in various places without depending on power or communication with computer for data transfer and processing. The underlying benefit of combining the two technologies is remote control of multiple systems and their flexible management. In this paper we report a new concept of a multi-point, multi-sensor intelligent system for monitoring and analysis of certain parameters in industrial machines and vehicles. For this particular application data acquisition and measurement modules are designed. Experimental results and functional evaluation of system is reported as well. Various crucial for the industrial machines parameters are measured and analyzed – vibrations, temperature, charging voltage, speed, position tracking etc. The designed wireless sensing system for measurement and monitoring of various dynamic parameters in industrial machines or vehicles is suitable for simultaneous monitoring of desired parameters in particular points and places. The ZigBee standard provides reliable radio communication channel and different network topologies which assure system flexibility and reliable communication link.

 

Key words: wireless standards, intelligent sensors, measurement system, ZigBee network, industrial measurement.

 

 

p. 177-182  

 

A Software system for determining
  the cutting edge profile of disc cutter teeth

 

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Desislava ATANASOVA1*, Yulian MLADENOV2, Ivo ATANASOV3

 

¹⁾ Assoc. Prof., PhD, Lecturer, Department of IIT, Ruse University, Ruse, Bulgaria

²⁾ Prof., PhD, Lecturer, Department of MTM, Ruse University, Ruse, Bulgaria

³⁾ Princ. Assist., Lecturer, Department of MTM, Ruse University, Ruse, Bulgaria

 

Abstract: The article describes the authors’ developed algorithm for profiling the work part of the disc cutter for cutting gears with larger modules. A software system using the algorithm has been designed and the interface is given. The computing capabilities are used, applying the method of coating and its variant - a constructive coating method for determining the profile of cutting teeth - the angle of their slope from the perpendicular to the axis of the disc cutter. The software system allows profiling of involute gears with different number of teeth. The proposed software system is universal and therefore could be applicable from engineers in tool departments in different factories. The software system could be also used in training students in subjects, which study themes in profiling tools for cutting involute gears. In the paper is given a solution for application of the designed from authors software system, for profiling of prefabricated disk cutter for gear with the parameters, as follows: module m = 20 mm; profile angle a = 20⁰; number of teeth z₁ = 50; coefficient of shifting the initial contour х₁ = 0.

 

Key words: disc cutter, profiling, cylindrical gear, software system, time for profiling.