Application of Ethernet Powerlink for communication in a Linux RTAI open CNC control system

In computerized numerical control (CNC) systems, the communication bus between the controller and axis servo drives must offer high bandwidth, noise immunity, and time determinism. More and more CNC systems use real-time Ethernet protocols such as Ethernet Powerlink (EPL). Many modern controllers are closed costly hardware-based solutions. In this paper, the implementation of EPL communication bus in a PC-based CNC system is presented. The CNC system includes a PC, a software CNC controller running under Linux Real-Time Application Interface real-time operating system and servo drives communicating via EPL. The EPL stack was implemented as a real-time kernel module. Due to software-only implementation, this system is a cost-effective solution for a broad range of applications in machine control. All software systems are based on GNU General Public License or Berkeley Software Distribution licenses. Necessary modifications to the EPL stack, Linux configurations, computer basic input/output system, and motherboard configurations were presented. Experimental results of EPL communication cycle jitter on three different PCs were presented. The results confirm good performance of the presented system

Stanowisko badawcze układów sterowania wieloosiowego napędami liniowymi poprzez magistralę EtherCAT

W artykule przedstawiono stanowisko badawcze przeznaczone do badania wieloosiowych układów sterowania z serwonapędami liniowymi. Stanowisko składa się z komputera pełniącego rolę sterownika nadrzędnego, serwosterowników oraz silników liniowych. Sterownik pracuje pod kontrolą systemu Linux z jądrem czasu rzeczywistego. Zaimplementowano również programowy stos EtherCAT do komunikacji z napędami. Przedstawiono budowę układu sterowania oraz strukturę oprogramowania sterownika. Przedstawiono również planowane badania, które będą realizowane na stanowisku dotyczące metod generacji optymalnych trajektorii ruchu, implementacji algorytmów regulacji położenia i prędkości w sterowniku oraz wpływu magistrali EtherCAT na jakość sterowania

PSO based feedrate optimization with contour error constraints for NURBS toolpaths

Paper presented at MMAR 2016 conference (Międzyzdroje, Poland, 29 Aug.-1 Sept. 2016)Generation of a time-optimal feedrate profile for CNC machines has received significant attention in recent years. Most methods focus on achieving maximum allowable feedrate with constrained axial acceleration and jerk without considering manufacturing precision. Manufacturing precision is often defined as contour error which is the distance between desired and actual toolpaths. This paper presents a method of determining the maximum feedrate for NURBS toolpaths while constraining velocity, acceleration, jerk and contour error. Contour error is predicted during optimization by using an artificial neural-network. Optimization is performed by Particle Swarm Optimization with Augmented Lagrangian constraint handling technique. Results of a time-optimal feedrate profile generated for an example toolpath are presented to illustrate the capabilities of the proposed method

Industrial robotics for ERP controlled smart factories

At product manufacturing the time-to-market factor, the profitability and the delivered value define the success of an enterprise. The increasing number of modules in Enterprise Resource Planning (ERP) programs is a facing problem, when there is a margin between the manufacturing cells and the ERP. Nowadays, the connection between the industrial machines and the ERP is an important requirement especially at automated warehouses and smart factories. Other concerns at manufacturing are the maintenance schedules of the machines, and flexible and easy reconfiguration of the production lines or the production cells. Information technology provides solutions and software environments to implement complex production supervisor ERPs at smart factories. At a production line or an automated warehouse several technical parameters and information can influence the planning of the resources at the enterprise, like maintenance, machine error, stockpile, product ID, defective product ratios, etc. When there is machine maintenance, the company needs to order the service parts, as well as schedule the service time and the stop of the production line. In case of a machine error, the system can estimate the length of the service time from error messages, and reorganize orders, transportation, or even maintenance schedules of other machines. Our plug and play type robot and industrial automation controller project gives a solution for these hardware demanding needs

Sustainable Secure Management Against APT Attacks for Intelligent Embedded-Enabled Smart Manufacturing

Intelligent embedded-enable smart manufacturing is an important infrastructure for future industries. Increasing security threats are disturbing the normal operations of smart manufacturing. As a novel type of threat, an advanced persistent threat (APT) has the novel features of strong concealment, latency, and long-term entanglement, which can penetrate the core systems of smart manufacturing, especially for intelligent embedded systems, and cause great destruction from the cyber side to physical side. However, the existing security schemes cannot provide sustainable resource management, which causes the core system in smart manufacturing not to perform sustainable secure detection and defense against APTs. To address this challenge, this paper proposes a sustainable secure management mechanism for smart manufacturing against APTs. The proposed mechanism includes two parts: sustainable threat intelligence analysis and sustainable secure resource management. Sustainable threat intelligence analysis provides sustainable discovery of the indications of potential APTs, which has features of a weak signal, low correlation, and slow time variation. The sustainable secure resource management provides deep and continuous protection for intelligent embedded systems in smart manufacturing. The evaluations show the defense capabilities and the feasibility of the proposed mechanism

Moduł komunikacyjny magistrali EtherCAT przeznaczony dla napędów elektrycznych

Badania zostały sfinansowane przez Zakład Energoelektroniki "TWERD" Sp. z o.o., w ramach grantu Voucher Badawczy województwa Kujawsko-Pomorskiego „Moduł komunikacyjny EtherCAT do inwerterów dla energetyki odnawialnej”W artykule przedstawiono moduł komunikacyjny magistrali EtherCAT przeznaczony dla napędów elektrycznych. Omówiono standard komunikacji EtherCAT wraz z opisem działania urządzenia podrzędnego wykorzysującego profil komunikacyjny CiA402. Omówiono budowę i działanie modułu komunikacyjnego. Przedstawiono opis stanowiska badawczego oraz badania weryfikujące poprawność działania opracowanego modułu

Metoda doboru prędkości posuwu w układach sterowania numerycznego maszyn wieloosiowych z wykorzystaniem algorytmów sterowania predykcyjnego oraz sztucznych sieci neuronowych

Rozprawa doktorska obroniona na Wydziale Elektrycznym Politechniki Warszawskiej z wyróżnieniem dnia 1.12.2014.Rozprawa doktorska dotyczy zagadnienia wyznaczania optymalnej prędkości posuwu w układach sterowania maszyn wieloosiowych w szczególności obrabiarek CNC (ang. Computerized Numerical Control - sterowanie numeryczne z użyciem komputera). W pracy omówiono problematyk˛e generacji trajektorii ruchu w układach sterowania maszyn CNC. Zaproponowano nowatorskie rozwiązanie doboru maksymalnej prędkości posuwu przy zachowaniu zadanej tolerancji błędów konturu. Algorytm wykorzystuje neuronowy model napędów posuwu maszyny w celu estymacji błędów konturu powstałych w procesie obróbki. Na tej podstawie algorytm optymalizacyjny wyznacza optymalny profil prędkości. Nielinowy problem optymalizacyjny rozwiązywany jest z wykorzystaniem algorytmu optymalizacji rojem cząstek (ang. Particle Swarm Optimization - PSO) rozbudowanego o metodę mnożników Lagrange’a. Algorytm zaimplementowano w sterowniku CNC w formie komputera PC z systemem czasu rzeczywistego Linux RTAI. Na podstawie uzyskanych wyników badań symulacyjnych i doświadczalnych wykazano zmniejszenie czasu realizacji zadanej trajektorii ruchu przy jednoczesnym zapewnieniu nie przekraczania zadanego poziomu błędów konturu

Real-Time Jerk Limited Feedrate Profiling and Interpolation for Linear Motor Multiaxis Machines Using NURBS Toolpaths

In this article, a NURBS toolpath feedrate profile generation algorithm for a biaxial linear motor control system is presented. High achievable velocities and accelerations of linear motor machines present new computational challenges in implementing feedrate generation and toolpath interpolation algorithms in real-time controllers. The proposed algorithm is capable of online generation of the feedrate profile with axial acceleration and jerk constraints. Each stage of the feedrate profiling algorithm is described with attention being given to both performance and implementation aspects. Furthermore, an alternative to the commonly used Taylor series interpolation method is also tested to ensure minimal interpolation errors. The feedrate profiling and interpolation algorithms’ implementation in a PC-based controller with real-time Linux kernel is described. Experimental results are presented that confirm that the algorithm is capable of limiting acceleration and jerk in the machine’s axes and it is low computation time enables real-time on-line operation in a PC-based CNC controller

Prototipo de máquina grabadora láser basada en control numérico computacional

This paper presents the development of a three-axed prototype laser machine for etching of different materials. We made a thorough investigation at national and international level, in order to build a prototype that has the necessary features and mechanical structure for implementation. The prototype has a size of 62 [cm] long and 48 [cm] wide and a height of 25 [cm], each one controlled by a stepper motor shaft 1.8 degrees. For the respective engine control the software LinuxCNC was used, and for the design and the engravings a vector design software with G codes is used.Este articulo presenta el desarrollo de un prototipo de maquina láser de tres ejes para el grabado de diferentes materiales. Se realizó una exhaustiva investigación a nivel nacional e internacional, para lograr construir un prototipo que cuente con las características y estructura mecánica necesario para la implementación. El prototipo cuenta con unas dimensiones de 62 [cm] de largo por 48 [cm] de ancho y una altura de 25 [cm], cada eje controlado por un motor paso a paso de 1,8 grados. Para el respectivo control de los motores se hace uso del software LinuxCNC, y para el diseño  de los grabados se hace uso de un software de diseño vectorial con códigos G

Cybersecurity issues in motion control – an overview of challenges

The fourth industrial revolution known as Industry 4.0 brings digitalization of manufacturing processes to a new level through ubiquitous interconnection and real-time information flow between information technologies (IT) and operational technologies (OT) as parts of Industrial Control Systems (ICS). This information flow is not limited to but expands beyond factory walls enabling manufacturing systems to adapt quickly and efficiently to changing customer demands and diversified products. The adaptation is carried out through physical and/or functional reconfiguration of manufacturing systems where Industrial Internet of Things (IIoT) based on Cyber-Physical Systems (CPS) represents the key technical enabler. These changes result in a transition from centralized to distributed control systems architecture where the whole control task is achieved through intensive cooperation between smart devices (e.g., sensors and actuators) with integrated communication and computation capabilities. However, introducing IIoT in ICS brings about new cybersecurity issues due to increased communication between system elements and connection to the global network, making ICS vulnerable to different cyber-attacks with potentially catastrophic consequences. Recently, the research in ICS cybersecurity has intensified leading to significant results for continuous time and discrete events-controlled systems. However, cybersecurity issues in motion control systems that are frequently employed in different manufacturing resources such as machine tools and industrial robots were not sufficiently explored. This work provides an overview of the cybersecurity related challenges in motion control tasks