Virtual environment in control and programming system for reconfigurable machining robot

Robotski obradni sustavi imaju značajnu ulogu u modernoj proizvodnji. Radom se predlaže primjena virtualnih robota za off-line programiranje. Prikazan je rekonfigurabilni robot za obradu, programiran u G-kôdu, koji se može izravno koristiti od strane programera i operatora CNC alatnih strojeva. Predmet istraživanja su petoosni i šestoosni roboti vertikalne zglobne konfiguracije koji mogu biti konfigurirani tako da emuliraju alatne strojeve s petoosnim vertikalnim i horizontalnim gibanjem glavnog vretena. Razmatrani obradni sustavi su podržani ekvivalentnim virtualnim robotima u CAD/CAM okruženju i sustavu upravljanja. U cilju demonstracije učinkovitosti predložene arhitekture, obrađeno je nekoliko probnih izradaka.Robotic machining systems play an important role in modern manufacturing. The paper proposes the application of virtual robots for off-line programming. The reconfigurable machining robot, programmed in G-code, which can be directly used by CNC machine tool programmers and operators, is presented. The subject of study are 5- and 6-DOF vertical articulated robots that can be configured to emulate vertical and horizontal 5-axis spindle tilting machine tools. The considered machining systems are supported by equivalent virtual robots in the CAD/CAM environment and control system. Several test workpieces were machined to demonstrate the effectiveness of the proposed architecture

Wire EDM machining simulations based on STEP-NC program

Ovaj rad prikazuje mogućnosti primjene nove metode programiranja koja se temelji na STEP-NC standardima, koji je razvijen kao alternativa G kodu. U radu se raspravlja o mogućnosti primjene u području simulacije obrade i provjere programa prije obrade na erozimatu sa žicom. Rad prikazuje moguću metodologiju za simulaciju i verifikaciju programa temeljenih na STEP-NC pomoću IDEF0 dijagrama, kao i veze između softvera STEP-NC Machine i CAD/CAM sustava. Predstavljena metodologija je verificirana obradom ispitnog izradka, na temelju STEP-NC programa.This paper presents the possibilities of applying a new method of programming based on STEP-NC standards, which was developed as an alternative to the G code. The possibilities of application in the field of machining simulation and verification of the program before machining on the wire electrical discharge machine are discussed. The paper shows the possible methodology for simulation and verification of programs based on the STEP-NC using IDEF0 diagrams, as well as links between the software programs STEP-NC Machine and CAD/CAM system. The presented methodology is verified by the test workpiece machining, based on the STEP-NC program

Modelling and Simulating the Digital Measuring Twin Based on CMM

In order to perform the inspection planning process on the coordinate measuring machine (CMM), it is necessary to model the measuring system with workpiece, CMM and fixture. The metrological analysis of the workpiece is then conducted, followed by the creation of a measurement program for simulation on a virtual measuring machine in a CAD environment. This paper presents the modelling and simulation of a virtual measuring system based on a real CMM using PTC Creo Parametric 5.0 software. The simulation involved programming the measuring path and generating a DMIS (*.ncl) file, which represents the standard modelled types of tolerance. The analysis of the metrology of the measuring part for the given forms of tolerance (location, perpendicularity, flatness, etc.) was performed. The components of the CMM and the assembly with defined kinematic connections are also modelled. Following the simulation and generation of the output DMIS file in PTC Creo using the virtual CMM, the real CMM was programmed and used for actual measurements. Subsequently, a measurement report was generated. The main result of this paper is the modelling of an offline Digital Measuring Twin (DMT) based on the DMIS file

A New 3-DOF Spatial Parallel Mechanism for Milling Machines with Long X Travel

It is well known that the shape and volume of the workspace are one of the greatest weaknesses of parallel kinematic machine tools (PKM). Hexaglide and Triaglide mechanisms are examples where workspace extension is achieved by elongating one axis as a principal motion axis that is a common feature of all Cartesian machines. With the idea of principal axis of motion in mind, a new 3-DOF spatial parallel mechanism for horizontal and vertical milling machines has been developed. In comparison with similar developed mechanisms it has several advantages such as: rather regular shape of the workspace (slightly modified block) similar to serial machines; greater stiffness by nature of the struts arrangement; good force and speed ratio through the entire mechanism's workspace. The paper describes the structure of the mechanism, modelling approach and simulation on a developed vertical milling machine prototype

The influence of the expression of steroid receptors on angiogenesis, proliferation and apoptosis in myomas of pre-and postmenopausal women

© 2019, Serbia Medical Society. All rights reserved. Introduction/Objective The aim of this study was to determine the effects of the estrogen and progesterone receptor status on angiogenesis, proliferation, and apoptosis of myoma cells in premenopausal (PreM) and postmenopausal (PostM) women. Methods This was a cross section; clinical-experimental, retrospective, non-interventional study in the field of the study of fundamental pathogenesis mechanisms of disease using pathohistological materials from the existing archive. The research included 76 patients diagnosed with uterine leiomyomas, operatively treated in the Clinic for Gynecology and Obstetrics, Clinical Centre Kragujevac, Serbia. According to the menstrual status, we formed two experimental subgroups. The first group was PreM women (n = 35; 46.2 ± 5.02 years old), and the second group was PostM women (n = 41; 60.25 ± 5.41 years old). Hema-toxylin-eosin staining for myoma and myometrium was conducted, as well as immunohistochemistry for ERα, ERβ, PRа, vascular endothelial growth factor, endoglin, Ki67, and caspase-3. Results Progesterone receptor was overexpressed in myoma and myometrium of PreM compared to myoma and myometrium of PostM women. Expression of caspase-3 was a statistically significant increase in PostM women compared to PreM group. ERα and ERβ were not changed among groups neither in myoma nor in myometrium samples. Conclusion According to our data, PRа had higher influence on apoptosis and cell growth than estrogen receptors. Since PRа was increased in PreM in both myoma and myometrium, probably this expression led further to lower expression of apoptotic marker in PreM women