LinuxCNC – Napredni sustav CNC upravljanja: primjena i kritički osvrt

Ovaj rad prikazuje osvrt na implementaciju upravljačkog sustava otvorene arhitekture, tzv. Enhanced Machine Controller-a (EMC2), koji je primijenjen na glodalici kao ispitnom postavu. Razvoj ispitnog postava motiviran je edukacijskim i istraživačkim potrebama, osobito u području razvoja i analize algoritama za nadzor i upravljanje procesima obrade odvajanjem. EMC2 sustav je razmatran s obzirom na kompatibilne hardverske komponente i mogućnosti prilagodbe specifičnostima obradnog stroja, kao i mogućnostima za industrijsku primjenu. U radu su također prikazane tehničke karakteristike ispitnog postava i upravljačkog sustava

On-Line Workpiece Hardness Monitoring in Stone Machining

The application of four types of process signals in the indirect on-line monitoring of stone hardness has been analysed in this paper. Cutting forces, servomotor currents, vibration and acoustic emission signals were measured during the drilling of three types of stones characterised by different hardness and heterogeneity values. A group of features were extracted from each signal from the time and frequency domain. Their capacity to correctly classify stone hardness was analysed using an artificial neural network classifier. Stone samples were drilled with new drill bits and drill bits worn to three different wear levels in order to analyse the influence of tool wear on the hardness classification process. Nine combinations of cutting parameters were applied for each drill wear level and stone type. Features extracted from the vibration signals obtained the best results in the stone hardness classification. The results indicate their potential industrial application, since they have achieved a high classification precision regardless of the drill bit wear level

Application of Machine Tools in Orthoses Manufacture

CNC technology is widely used in the manufacture of medical products. An area in which CNC technology has proven to be extremely useful and innovative is Orthotics and Prosthetics (O&P). O&P laboratories are engaged in the manufacture of individual orthoses and prostheses. The usual manual manufacture of such products takes a long time and requires tremendous experience and skill. In this regard, any engineering solution that improves the quality of the production process; reduces production time, production costs, and physical human labor; and at the same time improves the environmental conditions of the production environment will be desirable. Various designs of CNC machine tools for the manufacture of orthoses or molds for their production are in use today. In most cases, customized commercially available numerical control lathes and milling machines are used, as well as industrial robotic arms, but there are also highly specialized designs. For the mentioned purpose, we also encounter the application of additive manufacturing (AM) devices. Due to the fact that issuing of orthoses is often the subject of cost reduction in healthcare systems, the pursuit of production systems that will be cost-effective and functional, easily implemented, and used primarily in small manufacturing practices is imperative

LinuxCNC – the enhanced machine controller: application and an overview

Ovaj rad prikazuje osvrt na implementaciju upravljačkog sustava otvorene arhitekture, tzv. Enhanced Machine Controller-a (EMC2), koji je primijenjen na glodalici kao ispitnom postavu. Razvoj ispitnog postava motiviran je edukacijskim i istraživačkim potrebama, osobito u području razvoja i analize algoritama za nadzor i upravljanje procesima obrade odvajanjem. EMC2 sustav je razmatran s obzirom na kompatibilne hardverske komponente i mogućnosti prilagodbe specifičnostima obradnog stroja, kao i mogućnostima za industrijsku primjenu. U radu su također prikazane tehničke karakteristike ispitnog postava i upravljačkog sustava.This paper presents an application and a critical overview of the Enhanced Machine Controller (EMC2), a Linux based CNC open architecture control system (OAC) implemented in an industrial milling testbed platform. The development of such a machine tool was motivated by educational and research requirements, especially in the field of design and analysis of machining process monitoring and control algorithms. The EMC2 was analysed in view of compatible hardware components and software interfaces, configuration abilities and industrial applicability. Also, characteristics of the developed testbed together with the basic implementation details are depicted

LinuxCNC – the enhanced machine controller: application and an overview

Ovaj rad prikazuje osvrt na implementaciju upravljačkog sustava otvorene arhitekture, tzv. Enhanced Machine Controller-a (EMC2), koji je primijenjen na glodalici kao ispitnom postavu. Razvoj ispitnog postava motiviran je edukacijskim i istraživačkim potrebama, osobito u području razvoja i analize algoritama za nadzor i upravljanje procesima obrade odvajanjem. EMC2 sustav je razmatran s obzirom na kompatibilne hardverske komponente i mogućnosti prilagodbe specifičnostima obradnog stroja, kao i mogućnostima za industrijsku primjenu. U radu su također prikazane tehničke karakteristike ispitnog postava i upravljačkog sustava.This paper presents an application and a critical overview of the Enhanced Machine Controller (EMC2), a Linux based CNC open architecture control system (OAC) implemented in an industrial milling testbed platform. The development of such a machine tool was motivated by educational and research requirements, especially in the field of design and analysis of machining process monitoring and control algorithms. The EMC2 was analysed in view of compatible hardware components and software interfaces, configuration abilities and industrial applicability. Also, characteristics of the developed testbed together with the basic implementation details are depicted

Tool wear classification using decision trees in stone drilling applications: A preliminary study

AbstractProcess parameters of stone drilling with a small diameter twist drill were used to predict tool wear by means of a machine learning decision tree algorithm. The model links tool wear with features extracted from the force sensor and the main and feed drive current sensors signals recorded under different cutting conditions and different tool wear states. Signal features extracted from both the time and frequency domain were used as input parameters for construction of a decision tree which classifies the tool state into sharp or worn. The model was refined by selecting only the feature sources most important for classification. The best model achieves 90% accuracy in classification and relies only on features of the current signals, which simplifies its implementation in a CNC system for industrial applications

Automation Systems Design and Laboratory Prototyping Aimed at Mature Petroleum Drilling Rig Retrofitting

This paper presents a control system design methodology for the drill-string rotary drive and draw-works hoist system aimed at mature drilling rig retrofitting. The rotary drive is equipped with an active damping speed control system featuring a proportional-integral speed controller readily available within modern controlled electrical drives, extended with drill-string back-spinning prevention scheme for the case of stuck tool. The draw-works hoist system features a tool normal force (Weight-on-Bit) controller with tool longitudinal speed (Rate-of-Penetration) limiting functionality. The design of proposed control systems has been based on suitable control-oriented process models and damping optimum criterion which guarantees a desired level of closed-loop system damping. The proposed drilling control systems have been verified on a downscaled laboratory experimental setup, which represents a necessary pre-requirement before these systems are tested in the field