Kinematic modeling of hybrid parallel serial five-axis machine tool

Paralelne strukture mašina alatki i robota u odnosu na serijske strukture imaju niz prednosti. Za gradnju paralelnih mašina alatki i robota danas se koristi veći broj mehanizama sa paralelnom kinematikom različitih topologija sa 3 do 6 stepeni slobode. Međutim, s obzirom na izvesna ograničenja paralelnih mehanizama intenzivirana su istraživanja na iznalaženju mehanizama hibridnih arhitektura kao kombinacija paralelnih i serijskih struktura. U radu su predstavljeni rezultati kinematičkog modeliranja hibridne paralelno-serijske petoosne mašine alatke na bazi Tricept mehanizma. Kako ovakva mašina uključuje paralelnu strukturu sa tri stepena slobode i serijsku strukturu sa dva stepena slobode, to rešenja problema inverzne i direktne kinematike takođe uključuju paralelni i serijski deo. Inverzni kinematički problem je rešen analitički dok rešenje direktnog kinematičkog problema sadrži analitički i numerički deo. Na osnovu rešenja inverznog kinematičkog problema analiziran je radni prostor u cilju izbora projektnih parametara prototipa.Compared with serial structured machine tools and robots, parallel kinematic machine tools and robots have many advantages. Many different topologies of parallel mechanisms with 3-6 DOF have been used. Considering that some limitations are indeed due to the use of parallel mechanisms, it is appealing to investigate architectures based on hybrid arrangements where serial and parallel concepts are combined. This paper is aimed at presenting a study on the kinematic modeling of the Tricept based five-axis vertical machine tool. Since the machine comprises 3-DOF parallel structure and 2-DOF serial wrist direct and inverse kinematics also comprise serial and parallel part. Inverse kinematics is solved analytically while direct kinematics consists of an analytical and numerical part. Based on machine inverse kinematics, the workspace has been analyzed in order to select machine prototype design parameters

Kinematic modeling of the TRICEPT based 5-Axis machine tool

This paper is aimed in presenting a study on the kinematic modeling of the Tricept based five-axis vertical machine tool. Since the machine comprises 3-DOF parallel structure and 2-DOF serial wrist kinematic modeling also comprises serial and parallel part. As solution of direct and inverse kinematics of 2-DOF serial wrist is well known the study in this paper will focus on the parallel structure only

Configuring A Mini-Laboratory and Desktop 3-Axis Parallel Kinematic Milling Machine

Configuring new machine tools is a complex task that involves the use of a large range of conceptions, methods, models, virtual prototypes and simulations. This paper presents a methodology for configuring a new machine tool to the level of a virtual prototype by using CAD configurator Pro/WEB.Link and a top-down approach. This methodology is explained via an example of the development of a mini-laboratory and desktop 3-axis parallel kinematic milling machine (PKMM). The results are two variants of the virtual prototype and one real world prototype. The configured virtual prototypes are used for the verification of the machining program and programming system using machining simulation in the CAD/CAM environment. The mini-laboratory and desktop 3-axis PKMM has been verified by the successful machining of test workpieces

Configuring A Mini-Laboratory and Desktop 3-Axis Parallel Kinematic Milling Machine

Configuring new machine tools is a complex task that involves the use of a large range of conceptions, methods, models, virtual prototypes and simulations. This paper presents a methodology for configuring a new machine tool to the level of a virtual prototype by using CAD configurator Pro/WEB.Link and a top-down approach. This methodology is explained via an example of the development of a mini-laboratory and desktop 3-axis parallel kinematic milling machine (PKMM). The results are two variants of the virtual prototype and one real world prototype. The configured virtual prototypes are used for the verification of the machining program and programming system using machining simulation in the CAD/CAM environment. The mini-laboratory and desktop 3-axis PKMM has been verified by the successful machining of test workpieces

Compliance analysis of an articulated machining robot

This paper describes analytically and experimentally based compliance modeling and identification of 5-axis vertical articulated machining robot. The conventional method for the calculation of Cartesian space compliance based on joint compliances and Jacobian matrix is expanded and used for experimental 5-axis machining robot. Analytical analysis was conducted for effects of compliances of each joint individually on Cartesian space robot compliance. Experimentally, the Cartesian space compliance is obtained by direct measurement of the absolute displacements evoked by static forces along 3- orthogonal directions at the tool tip in the robot workspace for the case of 3-axis machining

Compliance analysis of an articulated machining robot

This paper describes analytically and experimentally based compliance modeling and identification of 5-axis vertical articulated machining robot. The conventional method for the calculation of Cartesian space compliance based on joint compliances and Jacobian matrix is expanded and used for experimental 5-axis machining robot. Analytical analysis was conducted for effects of compliances of each joint individually on Cartesian space robot compliance. Experimentally, the Cartesian space compliance is obtained by direct measurement of the absolute displacements evoked by static forces along 3- orthogonal directions at the tool tip in the robot workspace for the case of 3-axis machining

Analiza popustljivosti robota za obradu vertikalne zglobne konfiguracije

This paper describes analytically and experimentally based compliance modeling and identification of 5-axis vertical articulated machining robot. The conventional method for the calculation of Cartesian space compliance based on joint compliances and Jacobian matrix is expanded and used for experimental 5-axis machining robot. Analytical analysis was conducted for effects of compliances of each joint individually on Cartesian space robot compliance. Experimentally, the Cartesian space compliance is obtained by direct measurement of the absolute displacements evoked by static forces along 3- orthogonal directions at the tool tip in the robot workspace for the case of 3-axis machining.U radu su predstavljeni analitičko i eksperimentalno modeliranje i identifikacija popustljivosti 5-osnog robota za obradu vertikalne zglobne konfiguracije. Konvencionalni pristup za određivanje popustljivosti robota u Kartezijevom prostoru, zasnovan na popustljivosti zglobova i Jakobijan matrici je proširen i upotrebljen za određivanje popustljivosti eksperimentalnog 5-osnog robota. Analitička analiza je provedena s ciljem definiranja utjecaja popustljivosti svakog zgloba pojedinačno na popustljivost robota u Kartezijevom prostoru. Popustljivost robota u Kartezijevom prostoru je eksperimentalno određena direktnim mjerenjem apsolutnih pomicanja vrha robota izazvanih statičkom silom u sva tri ortogonalna pravca u radnom prostoru za slučaj 3-osne obrade

Odnos funkcionalne sposobnosti polena i stepena zametanja plodova u vinove loze (Vitis sp.)

In this paper, pollen functional ability of the cultivars Chardonnay Smederevka and SV 12-375, used as the male parent, for pollination of the cultivar Bagrina, as the female parent, was investigated. Free pollination of the cultivar Bagrina was observed as well as controlled pollination. Satisfactory pollen germination in vitro was established for the cultivars SV 12-375 (76.65%) and Smederevka (66.08%), while the cultivar Chardonnay had low pollen germination (20.88%). An association between pollen functional ability of the pollinizers and fruit set degree was determined for the cultivar Bagrina. Cultivars SV 12-375 and Smederevka were suitable pollinizers for the cultivar Bagrina.U ovom radu proučavana je funkcionalna sposobnost polena sorti Šardone Smederevka i SV 12-375 koje su korišćene u svojstvu oca za oprašivanje sorte Bagrina koja je korišćena u svojstvu majke. Pored kontrolisanog oprašivanja praćeno je i slobodno oprašivanje sorte Bagrina. Funkcionalna sposobnost polena utvrđena je metodom bojenja acetokarminom i metodom in vitro naklijavanja. Stepen oplodnje ustanovljen je na osnovu broja zametnutih plodova i broja ubranih plodova. Sve ispitivane sorte pokazale su visok procenat obojenih polenovih zrna (preko 75,00%). Zadovoljavajuća klijavost polena in vitro utvrđena je kod sorti SV 12-375 (76,65%) i Smederevka (66,08%), dok je kod sorte Šardone utvrđena niska klijavost polena (20,88%). Najveći broj zametnutih plodova i broj ubranih plodova ustanovljen je kao rezultat slobodnog oprašivanja (51,43%; 36,94%). Od proučavanih kombinacija kontrolisanog oprašivanja najmanji broj zametnutih plodova i broj ubranih plodova imala je kombinacija Bagrina x Šardone (29,32%; 15,93%). Najveći broj zametnutih plodova dobijen je u kombinaciji Bagrina x SV 12-375 (39,10%), a najveći broj ubranih plodova dobijen je u kombinaciji Bagrina x Smederevka (23,90%). Ustanovljena je zavisnost između funkcionalne sposobnosti polena sorti oprašivača i stepena zametanja plodova sorte Bagrina. Dobri oprašivači za sortu Bagrina bile su sorte SV 12-375 i Smederevka

Genetička divergentnost klonova Oblačinske višnje (Prunus ceratus L.)

Based on examination of 10 important pomologic and technologic properties, genetic divergence of 10 selected Oblačinska sour cherry clones was established. The genetic divergence between the analyzed clones was determined using the hierarchical cluster analysis. The UPGA method was used and the Euclidean distance in order to determine the difference between the groups. Four similar clone groups were obtained on the dendrogram. The objective of clone differentiation was primarily yield, although other properties were taken into account as well. As the most yielded clones for the production, that can be recommended, were clone D8 or clone D4 that are genetically very similar, and clone D3.Oblačinska višnja predstavlja sortu populaciju koja obuhvata veliki broj formi različitih po bujnosti, rodnosti, vremenu sazrevanja, krupnoći, boji i kvalitetu plodova. Pošto Oblačinska višnja nije jedan klon već smeša velikog broja klonova (genotipova) nameće se potreba izdvajanja genetički divergentnih formi za eksploataciju i dalji oplemenjivački rad. U ovom radu prikazani su rezultati analize 10 selekcionisanih klonova Oblačinske višnje. Ogled je izveden na OD "Radmilovac" Poljoprivrednog fakulteta u Beogradu. Tokom trogodišnjeg perioda istraživanja analizirane su sledeće osobine: vreme sazrevanja, prinos, masa ploda, masa koštice, randman, dužina peteljke ploda, sadržaj rastvorljivih suvih materija, sadržaj ukupnih šećera, sadržaj invertnih šećera i sadržaj ukupnih kiselina. Genetička divergentnost između proučavanih klonova ustanovljena je primenom hijerarhijske klaster analize. Korišćenje UPGA metod, pri čemu je razlika između grupa izražena preko Euklideanovog rastojanja. Na dobijenom dendrogramu izdvojeno je četiri grupe srodnih klonova. Razdvajanje klonova u grupe bilo je prvenstveno u funkciji njihovog prinosa, mada su uticaj na razdvajanje imale i ostale proučavane osobine. Kao najprinosniji za proizvodnu praksu mogu se preporučiti klon D8 ili klon D4 koji su genetički veoma bliski i klon D3

Genetic divergence of Oblačinska sour cherry (Prunus cerasus L.) clones

Based on examination of 10 important pomologic and technologic properties, genetic divergence of 10 selected Oblačinska sour cherry clones was established. The genetic divergence between the analyzed clones was determined using the hierarchical cluster analysis. The UPGA method was used and the Euclidean distance in order to determine the difference between the groups. Four similar clone groups were obtained on the dendrogram. The objective of clone differentiation was primarily yield, although other properties were taken into account as well. As the most yielded clones for the production, that can be recommended, were clone D8 or clone D4 that are genetically very similar, and clone D3