ARTICOLE PUBLICATE IN CADRUL PROIECTULUI
Abstract: The paper presents a new method for online identification of the dimensional dynamics to be used for the dimensional control of reconfigurable machining systems. The dimensional control is designed as adaptive and predictive.
The dimensional control of the reconfigurable machining system is a key action in order to achieve the quality desired for the finite product. As a diminishing deviation presents the disadvantage that reducing deviations are accompanied by high costs, the deviation compensation implies a better control of the process.
The deviation compensation emerged during the working process requires knowledge of a model which describes the dimensional dynamics of the machine tool, which is the relation between the dimensional changing of the processed part and the parameters of the process. On the other hand the behavior of the machining system evolution changes significantly in time even during the processing of a small number of parts processed. This is the reason that dimensional dynamics must reveal the changing in time of the relation between dimensional variation of the parts and the process parameters.
Key-Words: - reconfigurable machine tools, online identification, dimensional dynamics, dimensional control
Abstract: One of the main research directions in CAD/CAM machining area is the reducing of machining time. The feedrate scheduling is one of the advanced techniques that allows keeping constant the uncut chip area and as sequel to keep constant the main cutting force. They are two main ways for federate optimization. The first consists in the cutting force monitoring, which presumes to use complex equipment for the force measurement and after this, to set the feedrate regarding the cutting force variation. The
second way is to optimize the feedrate by keeping constant the material removal rate regarding the cutting conditions. In this paper there is proposed a new approach using an extended database that replaces the system model. The feedrate scheduling is determined based on the identification of the reconfigurable machine tool, and the feed value determination regarding the uncut chip section area, the contact length between tool and blank and also regarding the geometrical roughness. The first stage consists in the blank and tool monitoring for the determination of actual profiles. The next stage is the determination of programmed tool path that allows obtaining the piece target
profile. The graphic representation environment models the tool and blank regions and, after this, the tool model is positioned regarding the blank model according to the programmed tool path. For each of these positions the geometrical roughness value, the uncut chip area and the contact length between tool and blank are calculated. Each of
these parameters are compared with the admissible values and according to the result the feed value is established. We can consider that this approach has the following advantages: in case of complex cutting processes the prediction of cutting force is possible; there is considered the real cutting profile which has deviations from the theoretical profile; the blank-tool contact length limitation is possible; it is possible to correct the programmed tool path so that the target profile can be obtained. Applying this method, there are obtained data sets which allow the feedrate scheduling so that the uncut chip area is constant and, as a result, the cutting force is constant, which allows to use more efficiently the machine tool and to obtain the reduction of machining
time.
Keywords: —reconfigurable machine tool, system identification,
uncut chip area, cutting conditions scheduling.
3. Epureanu A., Teodor V., Oancea N., Banu M., Marinescu V., Method for On-Line Identification of Reconfigurable Machine-Tool Geometry Based on a Topological Neural Approach, Journal of Manufacturing Science and Engineering (trimisă spre publicare) (indexata ISI)
4. Epureanu, Al., Teodor, V., Dima, M., Oancea, N., A Reconfigurated Rack‑Tool for Generation of Gears, International Journal of Advanced Manufacturing Technology, transmisă spre evaluare; (indexata ISI)
Abstract: We consider that a responsive cost-effective manner to market dynamic changes can be obtained through the development of reconfigurable manufacturing systems (RMS) that quickly and effective react to the demands of the competitive market due to the following set of characteristics: modularity, convertibility, integrability, scalability, diagnosability and customization.
The characteristic set which makes a RMS different is identified in a particular manner in every reconfigurable machine tool (RMT) belonging to the system structure. The typical structure of reconfigurable machine tool includes the following basic components: the assembly of the modules that ensures the needed active and passive degrees of freedom, work piece, tooling and fixturing. The set of these six main characteristics specific to the RMS is presented in a particular form at RMT level and at each of its basic components.
In this paper we present a rack‑gear cutter that satisfies the reconfiguration requirements and a virtual manufacturing based technique for its improved reconfiguration.
It is accepted that the value of the main cutting force depends on the cutting area thickness (the geometrical area of the chip detached by the active cutting edges assembly of this kind of tools at one pass). In this paper it is proposed a model of the cutting schema made through Visual Basic Applications programming environment, for the creation of new constructive forms of the cutting tools that lead to an undeformed chip cross section adjustable to the machined wheel teeth number, in order to reduce the teething cutting force.
It is proposed a criterion for the undeformed chip cross section characterization, which allows the comparison of chip area value variation at modeling of the cylindrical wheel generation. Based on the synthesis of the new calculations of the undeformed chip cross section and considering the teething process and the teeth number of the generated wheel, are presented constructive solutions for reconfigurable rack tools.
Keywords: Virtual Manufacturing, Reconfigurable tool, Rack‑cutter
6. Dima, M., Oancea, N., Teodor, V., Cutting Scheme Modeling at Generation by Rack-gear Tool. Algorithms, Buletinul Institutului Politehnic din Iasi publicat deUniversitatea Tehnica ”Gh.Asachi”, Iasi Tomul LII(LVI), Fasc. 5, A, Sectia Constructii de Masini, p.85-90,2006, ISSN 1582-6392
7. Dima, M., Teodor, V., Oancea, N., Cutting Scheme-Reconfiguration Criteria of the Rack-Gear Tool Reconfigurability. Solutions for Rack Gear Tool, Buletinul Institutului Politehnic din Iasi publicat de Universitatea Tehnica ”Gh. Asachi”, 2006, Iasi Tomul LII(LVI), Fasc. 5, A, Sectia Constructii deMasini, p. 97-104, ISSN 1582-6392
8. Marinescu V., Constantin I. C., Epureanu A., Teodor V., Graphical Programming of Programmable Logic Controllers. Case Study for a Punching Machine, Publicată în revista Enformatika, vol. 15, ISBN 975-00803-4-3, ISSN 1305‑5313, pag. 273-277, (indexata BDI)
9. Oancea, N., Mihăluţă, M., Teodor, V., Aproximation of the Gear Cutter Profile Used in the Generation of Interior Polyform Surfaces, Analele Universităţii „Dunărea de Jos” din Galaţi, Fasc. V, 2006, ISSN 1221‑4566, pag. 40‑44; (indexata BDI)
10. Cuzmin C., Frumusanu G., Marin F.B., Paunoiu V., Cuzmin G., Epureanu A., Adaptive Dimensional Control System for Reconfigurable Machine-Tools., Vol. 1, Universitatea Tehnică a Moldovei, ISBN 978-9975-45-035-1, TCMR International Conference, Chisinau, 2007
Abstract: The paper is presenting a method for online identification of the dimensional dynamics to be used for dimensional control of reconfigurable machining systems. The dimensional control is a key action in order to achieve quality desired for finite product. As diminishing deviation is accompanied with high costs: deviation compensation seem to be a better control of the process.
11. Constantin I., Marinescu V., Epureanu A., Cuzmin C., Marin F. B., A modular manufacturing control system, TCMR International Conference, Chisinau, 2007, ISBN 978-9975-45-035-5, pag. 301-306
Abstract: This paper proposes a modular manufacturing system structure. The key. concept is to modularize the machines. the auxiliary equipment and finally the plant. In architecture, each module had a set of configuration parameters used by the main module of each sub-structure. The multi processor structure allows the production facility to adapt itself to the production task.
12. Marin F. B., Constantin I. C., Marinescu V., Cuzmin C., Epureanu A., Development of reconfigurable software module for CNC machine tools, TCMR International Conference, Chisinau, 2007, ISBN 978-9975-45-035-5, pag. 265-269
Abstract: After reconfiguration process the new hardware architecture implies also software architecture changing. Reconfigurable machine tools performance is determined most by ramp-up-time. O important part of this is the time needed for software reconfiguration. This paper presents a reconfigurable interpreter, developed as new software approach, which provide a fast software reconfiguration to be operated by the user of the machine. The interpreter design methodology and corresponding software presented in the paper was developed at the "Dunarea de Jos" University – Galati. Results achieved confirmed the efficiency of this approach.
Keywords: reconfigurable machine tools, open-architecture, interpreter, condition instructions set
13. George C. BALAN, Alexandru EPUREANU, Ciprian CUZMIN, The monitoring of a lathe using an artificial neural network- 5th part (recordings spectral analysis, use of ANN on monitoring of the tool wear, SISOM 2007 and Homagial Session of the Commission of Acoustics, Bucharest 29-31 May
Abstract: The study of machine-tool dynamic is realized here as “monitoring”, meaning checking and improving the functioning of the machine. The state of processing is followed by certain sensors whose signs are processed inside the computer and then it takes the decision of monitoring, meaning the identification of a class from the set of classes (process conditions). In this part of the paper there are presented recordings spectral analysis and use of ANN on monitoring of the tool wear.
Keywords: monitoring, lathe, spectral analysis, ANN
Abstract: The study of machine-tool dynamic is realized here as “monitoring”, meaning checking and improving the functioning of the machine. The state of processing is followed by certain sensors whose signs are processed inside the computer and then it takes the decision of monitoring, meaning the identification of a class from the set of classes (process conditions). In this part of the paper there are presented statistics, monitoring and fuzzy c-means method.
Keywords: monitoring, lathe, ANN
15. Cuzmin, C., Cuzmin, G., Epureanu, Al., Internal Gear Cutting Generation with Toroidal Hob, International Journal of Advanced Manufacturing Technology, transmisă spre evaluare;(indexata ISI)
16. Identificarea suprafeţelor utilizând metoda „soluţiei de start”, În: Numar tematic special al publicatiei Analele Universitatii “Dunarea de Jos” din Galati, Fascicula V, Anul XIX (XXIV), 57, 2007, ISSN 1221-4566, (indexata BDI);
17. Identificarea seturilor de suprafeţe utilizând algoritmi genetici, În: Numar tematic special al publicatiei Analele Universitatii “Dunarea de Jos” din Galati, Fascicula V, Anul XIX (XXIV), 57, 2007, ISSN 1221-4566, (indexata BDI);
18. Identificarea armonică a geometriei unei maşini‑unelte, În: Numar tematic special al publicatiei Analele Universitatii “Dunarea de Jos” din Galati, Fascicula V, Anul XIX (XXIV), 57, 2007, ISSN 1221-4566, (indexata BDI).