Digital Twin Modeling of a Five-Axis Linkage Crossbeam Mobile Gantry Milling Machine

In the innovative design stage of machine tool (MT), in order to understand the motion status of the MT under different conditions, shorten the development cycle, and improve machining accuracy, this paper proposes a digital twin modeling method for large crossbeam mobile gantry milling machines. By combining digital twin technology, the selection of MT motion components and the design of various motion mechanisms were completed, as well as the machining scheme design of the MT bed. Modeling and simulation were conducted to complete the workpiece machining function, By using digital twin technology to virtually simulate CNC MT and verify their properties in physical prototypes, new ideas are provided for the application of digital twin technology in the design process of CNC MT.</p

Digital twin control of multi-axis wood CNC machining center based on LinuxCNC

Abstrack: This paper presents an application of an open architecture control system implemented on a multi-axis wood computer numerical control milling machining center, as a digital twin control. The development of the digital twin control system was motivated by research and educational requirements, especially in the field of configuring a new control system by “virtual commissioning”, enabling the validation of the developed controls, program verification, and analysis of the machining process and monitoring. The considered wood computer numerical control (CNC) machining system is supported by an equivalent virtual machine in a computer-aided design and computer-aided manufacturing (CAD/CAM) environment, as well as in the control system, as a digital twin. The configured virtual machines are used for the verification of the machining program and programming system via machining simulation, which is extremely important in multi-axis machining. Several test wood workpieces were machined to validate the effectiveness of the developed control system based on LinuxCNC

Conceiving a Digital Twin for a Flexible Manufacturing System

Digitization and virtualization represent key factors in the era of Industry 4.0. Digital twins (DT) can certainly contribute to increasing the efficiency of various productive sectors as they can contribute to monitoring, managing, and improvement of a product or process throughout its life cycle. Although several works deal with DTs, there are gaps regarding the use of this technology when a Flexible Manufacturing System (FMS) is used. Existing work, for the most part, is concerned with simulating the progress of manufacturing without providing key production data in real-time. Still, most of the solutions presented in the literature are relatively expensive and may be difficult to implement in most companies, due to their complexity. In this work, the digital twin of an FMS is conceived. The specific module of an ERP (Enterprise Resources Planning) system is used to digitize the physical entity. Production data is entered according to tryouts performed in the FMS. Sensors installed in the main components of the FMS, CNC (computer numerical control) lathe, robotic arm, and pallet conveyor send information in real-time to the digital entity. The results show that simulations using the digital twin present very satisfactory results compared to the physical entity. In time, information such as production rate, queue management, feedstock, equipment, and pallet status can be easily accessed by operators and managers at any time during the production process, confirming the MES (manufacture execution system) efficiency. The low-cost hardware and software used in this work showed its feasibility. The DT created represents the initial step towards designing a metaverse solution for the manufacturing unit in question, which should operate in the near future as a smart and autonomous factory model.Thanks are due to Elkartek 2022 project LANVERSO, and in some sections (simulations) to Basque government university group IT 1573-22

A cyber-physical machine tools platform using OPC UA and MTConnect

Cyber-Physical Machine Tools (CPMT) represent a new generation of machine tools that are smarter, well connected, widely accessible, more adaptive and more autonomous. Development of CPMT requires standardized information modelling method and communication protocols for machine tools. This paper proposes a CPMT Platform based on OPC UA and MTConnect that enables standardized, interoperable and efficient data communication among machine tools and various types of software applications. First, a development method for OPC UA-based CPMT is proposed based on a generic OPC UA information model for CNC machine tools. Second, to address the issue of interoperability between OPC UA and MTConnect, an MTConnect to OPC UA interface is developed to transform MTConnect information model and its data to their OPC UA counterparts. An OPC UA-based CPMT prototype is developed and further integrated with a previously developed MTConnect-based CPMT to establish a common CPMT Platform. Third, different applications are developed to demonstrate the advantages of the proposed CPMT Platform, including an OPC UA Client, an advanced AR-assisted wearable Human-Machine Interface and a conceptual framework for CPMT powered cloud manufacturing environment. Experimental results have proven that the proposed CPMT Platform can significantly improve the overall production efficiency and effectiveness in the shop floor

INDUSTRIAL DEVICE INTEGRATION AND VIRTUALIZATION FOR SMART FACTORIES

Given the constant industry growth and modernization, several technologies have been introduced in the shop floor, in particular regarding industrial devices. Each device brand and model usually requires different interfaces and communication protocols, a technological diversity which renders the automatic interconnection with production management software extremely challenging. However, combining key technologies such as machine monitoring, digital twin and virtual commissioning, along with a complete communication protocol like OPC UA, it is possible to contribute towards industrial device integration on a Smart Factory environment. To achieve this goal, several methodologies and a set of tools were defined. This set of tools, as well as facilitating the integration tasks, should also be part of a virtual engineering environment, sharing the same virtual model, the digital twin, through the complete lifecycle of the industrial device, namely the project, simulation, implementation and execution/monitoring/supervision and, eventually, decommissioning phases. A key result of this work is the development of a set of virtual engineering tools and methodologies based on OPC UA communication, with the digital twin implemented using RobotStudio, in order to accomplish the complete lifecycle support of an industrial device, from the project and simulation phases, to monitoring and supervision, suitable for integration in Industry 4.0 factories. To evaluate the operation of the developed set of tools, experiments were performed for a test scenario with different devices. Other relevant result is related with the integration of a specific industrial device – CNC machining equipment. Given the variety of monitoring systems and communication protocols, an approach where various solutions available on the market are combined on a single system is followed. These kinds of all-in-one solutions would give production managers access to the information necessary for a continuous monitoring and improvement of the entire production process

Digital twin-based Optimization on the basis of Grey Wolf Method. A Case Study on Motion Control Systems

Nowadays, digital twins are fostering the development of plug, simulate and optimize behavior in industrial cyber-physical systems. This paper presents a digital twin-based optimization of a motion system on the basis of a grey wolf optimization (GWO) method. The digital twin of the whole ultraprecision motion system with friction and backlash including a P-PI cascade controller is used as a basement to minimize the maximum position error. The simulation study and the real-time experiments in trajectory control are performed to compare the performance of the proposed GWO algorithm and the industrial method called Fine tune (FT) method. The simulation study shows that the digital twin-based optimization using GWO outperformed FT method with improvement of 66.4% in the reduction of the maximum position error. The real-time experimental results obtained show also the advantage of GWO method with 18% of improvement in the maximum peak error and 16% in accuracy

Predictive Maintenance on the Machining Process and Machine Tool

This paper presents the process required to implement a data driven Predictive Maintenance (PdM) not only in the machine decision making, but also in data acquisition and processing. A short review of the different approaches and techniques in maintenance is given. The main contribution of this paper is a solution for the predictive maintenance problem in a real machining process. Several steps are needed to reach the solution, which are carefully explained. The obtained results show that the Preventive Maintenance (PM), which was carried out in a real machining process, could be changed into a PdM approach. A decision making application was developed to provide a visual analysis of the Remaining Useful Life (RUL) of the machining tool. This work is a proof of concept of the methodology presented in one process, but replicable for most of the process for serial productions of pieces

Virtual horizontal machining center LOLA HBG 80 for program verification and monitoring

Ovaj rad opisuje konfigurisanje virtuelnog horizontalnog obradnog centra LOLA HBG80 u okviru sistema za programiranje i verifikaciju, kao i u okviru sistema otvorene arhitekture upravljanja. Horizontalni obradni centar LOLA HBG 80 podržan je ekvivalentnom virtuelnom mašinom u CAD/CAM okruženju (PTC Creo i Catia), STEP-NC mašinskom okruženju, kao i u upravljačkom sistemu. Virtuelna simulacija je od suštinske važnosti za obradu, a razvijene virtuelne mašine koriste se za verifikaciju programa i monitoring procesa obrade. Virtuelna mašina u sistemu za programiranje omogućava verifikaciju programa pre slanja na stvarnu mašinu i može da uključuje verifikaciju putanje alata (CLF-Cutter Location File) i verifikaciju G-koda. U radu se takođe govori o mogućnosti primene novog metoda programiranja poznatog kao STEP-NC i pripremi odgovarajućeg okruženja koje uključuje virtuelnu mašinu. Virtuelna mašina u sistemu upravljanja predstavlja poslednji nivo za konačnu verifikaciju programa, kao i sistem za nadzor procesa.This paper describes configuring the virtual horizontal machining center LOLA HBG80 within the programming and verification system and the open architecture control system. The horizontal machining center LOLA HBG 80 is represented by an equivalent virtual machine in a CAD/CAM environment (PTC Creo and Catia), STEP-NC Machine environment, and the control system. Virtual simulation is essential for machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before sending it to the real machine and includes verification of the tool path (CLF-Cutter Location File) and G-code. The paper also discusses the possibility of applying a new programming method known as STEP-NC and preparing an adequate environment that includes a virtual machine. The virtual machine in the control system represents the last level for the final program verification and the process monitoring system

Virtual horizontal machining center LOLA HBG 80 for program verification and monitoring

Ovaj rad opisuje konfigurisanje virtuelnog horizontalnog obradnog centra LOLA HBG80 u okviru sistema za programiranje i verifikaciju, kao i u okviru sistema otvorene arhitekture upravljanja. Horizontalni obradni centar LOLA HBG 80 podržan je ekvivalentnom virtuelnom mašinom u CAD/CAM okruženju (PTC Creo i Catia), STEP-NC mašinskom okruženju, kao i u upravljačkom sistemu. Virtuelna simulacija je od suštinske važnosti za obradu, a razvijene virtuelne mašine koriste se za verifikaciju programa i monitoring procesa obrade. Virtuelna mašina u sistemu za programiranje omogućava verifikaciju programa pre slanja na stvarnu mašinu i može da uključuje verifikaciju putanje alata (CLF-Cutter Location File) i verifikaciju G-koda. U radu se takođe govori o mogućnosti primene novog metoda programiranja poznatog kao STEP-NC i pripremi odgovarajućeg okruženja koje uključuje virtuelnu mašinu. Virtuelna mašina u sistemu upravljanja predstavlja poslednji nivo za konačnu verifikaciju programa, kao i sistem za nadzor procesa.This paper describes configuring the virtual horizontal machining center LOLA HBG80 within the programming and verification system and the open architecture control system. The horizontal machining center LOLA HBG 80 is represented by an equivalent virtual machine in a CAD/CAM environment (PTC Creo and Catia), STEP-NC Machine environment, and the control system. Virtual simulation is essential for machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before sending it to the real machine and includes verification of the tool path (CLF-Cutter Location File) and G-code. The paper also discusses the possibility of applying a new programming method known as STEP-NC and preparing an adequate environment that includes a virtual machine. The virtual machine in the control system represents the last level for the final program verification and the process monitoring system