Innovative Information Model to Improve Quality and Collaboration on Stone Industry

Stone market requirements demand for increasing quality and monitoring criteria, so the need for new innovative solutions that allow to monitor and control entire value chains. IoT4Stone solution proposes a new innovative approach to monitor and control the stone value chain through its entire lifecycle. That is done through the automation and control of the production processes and the definition of an information model to process and optimize the entire value chain increasing collaboration efficiency. This goal is achieved through a digital-twin between the machinery used in the shop-floor and CPPS.

Eccentricity of Rotor Prediction of Aero-Engine Rotor Based on Image Identification and Machine Learning

The eccentricity of rotor seriously affect the vibration and reliability of aero-engine. Due to the machining error of parts, it is very important to accurately predict the error propagation in assembly. A method based on image recognition and machine learning is proposed to predict the eccentricity of rotor. Firstly, by analyzing and calculating the axial and radial runout error data, the error is mainly concentrated in the first 30 orders of the Fourier series. Secondly, based on the mapping relationship between profile trajectory and eccentricity of rotor, the feature information of the profile trajectory is extracted by constructing the complex domain autoregressive (CAR) model for the radial and axial direction error profile trajectory. Then use the finite element method to calculate the rotor eccentricity. Using the feature information as the input of the neural network, the rotor eccentricity is assembled as the output of the neural network, and the radial basis function (RBF) neural network is built to predict the rotor eccentricity. Theoretical and experimental results show that the proposed method has good enforceability, high accuracy, short calculation time and high engineering application value. In addition, this method can not only be applied to predict the eccentricity of aero-engine rotor flange assembly, but also can be used in the general field of interference fit of assembly.

Remaining Useful Life Prediction Based on Spindle Load and Cutting Process Parameters in Machining

Tool wear increases machining resistance, part dimensional inaccuracy and machining vibration. Tool wear monitoring and Remaining Useful Life (RUL) prediction of the tool during machining operation will assist a machine operator to provide tool wear compensation at the right time and plan the tool change activity. These aspects become significantly important for economical and quality production. This work focuses on a physics and data-based approach for monitoring cutting tool wear state and Remaining Useful Life (RUL) during a machining operation by adapting a well-known empirical wear-rate equation. The constants in the model are estimated based on machine heuristics which depends on the tool-machine-workpiece combination. The proposed model takes real-time spindle power and machining process parameters as inputs, which are obtained directly through querying the CNC controller. Therefore, it does not require the mounting of any external sensors on the CNC machine tool. Hence, the proposed method is a more economical and convenient way to predict tool wear and RUL in a machining shop floor. The model is validated from experimental data and it can capture the progression of tool wear and RUL of the tool at any point of time during a machining operation. Since the model captures the physics of tool wear and machining heuristics, it is more robust than a purely data-based model.

Rapid Qualification of Additive Manufactured Parts Using OpenMETA

This paper focuses on a method to integrate additive manufacturing (AM) structure, processing, and property-geometry modeling methods to facilitate the qualification and certification of AM-fabricated metal parts and enable their rapid deployment. The conventional approach to qualifying AM parts is to destructively evaluate a significant number of parts, measure the properties of interest, and look for anomalies in each part. This approach also requires statistical sampling of parts for destructive testing to verify the process is still operating correctly over time. This is costly, time consuming, and negates much of the benefits offered by AM. The approach outlined in this paper leverages OpenMETA, a suite of tools that provide a unified design space, a unified system representation across engineering specialties, and multidisciplinary workflow for optimization, design-of-experiments, and trade-off studies. OpenMETA provides the ability to conduct high-fidelity, low-fidelity, and hybrid analyses within one framework. Test benches are built within OpenMETA that capture the requirements for the component in an executable manner to support automated analysis such as thermal analysis, finite element analysis, and high-fidelity physics-based (HFPB) analysis. Test benches also describe the intended environment in which the component will be used after manufacture. This description of the environment might include details of the surrounding components, the interfaces to those components, and corrosive agents. Test bench results are used to estimate and assess component performance related to requirements. This paper focuses on one technology for manufacturing the parts, a wire-fed, robotic, pulsed-arc AM process, although the OpenMETA platform can be applied to other AM technologies.

Integration of Vibration Absorbers in Milling Chucks

The use of cutting tool systems with a high slenderness ratio is encountered in the machining of deep cavities in the mechanical engineering industry, especially in the manufacturing of tools and dies. Cutting tool systems with a large slenderness ratio, owing to their dynamic compliance, are prone to vibrations during machining processes. These vibrations affect the quality of the machining process and the life of machine components. Integration of a vibration absorber in the cutting tool system helps in the reduction of machining vibrations. The reduction in vibrations is due to a shift in the resonance frequency of the modified system. This experimental study presents the identification of design possibilities of a vibration absorber for integration in the cutting tool system. The mass and geometry of the vibration absorber are varied and its integration in the milling chuck is explored. Firstly, experimental modal analysis is conducted to determine the effects of the dynamic vibration absorber on the frequency response function of the modified cutting tool system. Secondly, the effects of the dynamic vibration absorber on the machining process for a range of technology parameters are illustrated. During the machining process, the cutting forces are measured using a three-component dynamometer in time domain. Finally, the results are evaluated based on process quality, i.e. surface roughness and analysis of cutting force signal in the frequency domain. This study provides an understanding of the relationship between the mass and the geometry of the vibration absorber integrated in the cutting tool system and their influence on process stability.

Digital Twin: Concept of Hybrid Programming for Industrial Robots — Use Case

Modern Industrial Robot (IR) programming process is mainly performed by using three different methods — manual, offline, and online programming. Each of these methods has various advantages and disadvantages. Prominent automotive industries often use a combination of them, as there is no way to avoid one or another form of programming on one factory. However, the use of a combination of different programming methods is time-consuming and demands the operator’s presence on site for reconfiguration of the IR. The primary goal of this study is to introduce and test the concept of a hybrid IR programming method, which combines both: offline and online robotic cell design, programming, and re-configuration methods. Testing of this method is based on fully synchronized robotic cell’s Digital Twin (DT), developed in Industrial Virtual and Augmented Laboratory of Tallinn University of Technology. Usage of the virtual replica allows to plan and program robotic cell on the means of telepresence and interfere with the predefined path of the robot by online programming method. Moreover, this approach reduces the time for robotic cell design and re-programming, enables to minimize downtime of the robotic cell on the factory shop floor. Included Virtual Reality (VR) environment allows simulating a full-scale operator presence on site. Thus, the proposed approach supports an immersive and safe environment for the IR and similar equipment programming purposes.

Influence of the Form of Pulse of Excitation on the Speed and Power Parameters of the Linear Pulse Electromechanical Converter of the Induction Type

Linear pulse electromechanical converters (LPEC) of induction type allow providing a high speed of the actuating element in the short active section and creating powerful power impulses with its insignificant movement. One of the ways to improve the electromechanical indicators of LPEC is the formation of current excitation pulses in the inductor using electronic power supply circuits containing a capacitive energy storage device. This publication is a continuation of our previous work on the influence of different parameters and conditions on the performance of LPEC. Using the developed chain mathematical model, recurrent relations are obtained for calculating the interconnected electromagnetic, mechanical and thermal parameters of LPEC. It has been established that the speed and power electromechanical indicators of LPEC with aperiodic excitation pulse are better than those of LPEC with unipolar excitation, but worse than those of LPEC with oscillating-damped excitation pulse. LPEC with a unipolar excitation pulse, by the end of the working cycle, the smallest temperatures of the inductor and the armature are observed, while for LPEC with a oscillating-damped excitation pulse, the greatest efficiency is ensured, being 24.88%. The highest speed and power electromechanical indicators are provided at LPEC with a step-aperiodic excitation pulse. Experimental studies of LPEC were conducted when operating as an electromechanical accelerator and a shock-power device. In studies of LPEC, a piezoelectric transducer was used as a shock-power device, which converted mechanical vibrations arising from the impact of the striker on the impact plate into electrical signals. In studies of LPEC, a displacement sensor was used as an electromechanical accelerator. It was established experimentally that the movement of the armature begins with a delay relative to the moment of occurrence of the current pulse and is almost linear in the initial part of the acceleration.

An Application of a Digital Twin to Robotic System Design for an Unstructured Environment

An experimentable digital twin is created to aid in a design decision (beginning of life stage) for a robotic system. This product is meant to automate a material-feed system. The robot comprises a six-axis manipulator mounted on a mobile base. Due to variability in the dimensions of the material-feed system and positioning error of the mobile base, the material-placement routine is considered to take place in an unstructured environment. Working therein requires exteroceptive sensors, in this instance taking the form of computer vision. Data from this subsystem are used to match the geometry of the digital twin to the physical environment. This close correspondence between physical and virtual embodiments allows for significant design decisions to be reached from simulated experiments. In this case, two motion-planning approaches are compared and it is determined that the costs associated with implementing the dynamic one in the lab for testing are merited by its ease of use and reliability, since simulation-based control employs all current information.

Digital Twin in a Manufacturing Integrated System: Siemens TIA and PLM Case Study

The new industrial revolution called Industry 4.0 embraces diverse Digital Manufacturing Tools (DMT). Trying to improve Product Life-cycle Management (PLM), some companies are trying to implement DMT to create Digital Twins (DT). New Product Introduction (NPI) demands large effort in digitalization and virtual simulation through the PLM process. Sometimes a new product could be only the development of a single component and/or an entire manufacturing process including complex instruments and controls. In this direction, it is important to accelerate Manufacturing Integrated Systems (MIS) by improving the automation not only in the NPI, but also in the PLM. This paper integrates Siemens PLM software as DMT called Tecnomatix Process Simulate (TPS), Totally Integrated Automation (TIA) and PLCSIM advanced. The scope in the NPI is showing how a Digital Twin could help the MIS. The aim of this paper is to evaluate the interconnectivity of a small physical prototype with its virtually simulated clone to support the virtual commissioning for a NPI.

Experimental Study on Geometric Precision of Microholes Drilling by Picosecond Laser

The geometric precision of the film cooling hole has a great influence on the cooling efficiency and fatigue life of the turbine blade. In the paper, the processing of film cooling holes on DD6 single crystal superalloy by picosecond laser is investigated. The pulse laser at pulse duration of 2.1ps, the wavelength of 1030 nm and the repetition frequency of 75 kHz are selected to study the pulse energy, scanning speed, defocus and scanning width on the geometric precision of the film cooling hole. After drilling, the three-dimensional coordinates of the entrance and exit plane of the film cooling holes are obtained by using the three-dimensional surface measuring instrument. The diameter, roundness and taper of the film cooling holes are calculated by extracting and processing the coordinate points of the contour around the microholes. The experimental results show that defocusing has the greatest influence on the taper and roundness of film cooling holes. Negative defocusing can produce severe plasma shielding, which makes the exit roundness and taper larger. With larger pulses, positive defocusing and larger scanning width, smaller roundness and taper can be produced.