On-line calculation of fatigue in hydraulically actuated heavy equipment using IoT and Digital Twin concepts

The method and its implementation is proposed for on-line calculation of fatigue in structure components of hydraulically actuated heavy equipment. The method does not use any stress or strain gauges and relies just on the data about the pressure and position of hydraulic cylinders. This data is measured in real-time during the machine operation and is transmitted via internet for processing in the cloud. The simulation model of the machine (Digital Twin) is used for simulation of machine motion on the basis of received data. The Digital twin provides input for finite-element analysis of machine’s components in order to calculate the stress history of each component. The results of these calculations are used for fatigue life estimation of the component. Applicability of the method is tested by comparing its results with similar simulation verified by experimental measurements

Digital twin for faster than real-time simulation of mobile crane operations

The article discusses the problem of real-time prediction of the mobile crane movement based on the analysis of the dynamic and kinematic models of the crane. These models form the digital twin that can be used to facilitate the crane operation. As the crane displacements can be comparable to the load dimensions and the crane can move rather fast, thus the crane dynamics, rather than kinematics, becomes more important in its movement prediction. However, in order to be calculated faster than real-time the model should be simplified. The article considers an example of the mobile crane for which two models are developed: the detailed reference model and the simplified model, which includes the dynamic and kinematic equations. The accuracy and the calculation speed of the simplified model are estimated with respect to the reference model. Two models are compared and some assumptions are proposed for building the models for the faster than real-time calculations required for the movement prediction of mobile cranes

In-situ Monitoring and Defect Detection of Selective Laser Melting Process and Impact of Process Parameters on the Quality of Fabricated SS 316L

Selective Laser Melting (SLM) is an advanced Additive Manufacturing (AM) technique for the 3D printing of metals. SLM process parameters and different types of defects that may appear during the manufacturing process affect the quality of the final product. Setting laser parameters and online defect detection contributes to improving the quality of parts fabricated through SLM technology. In this study, the effect of the process parameters on the properties of the product built by the SLM process was investigated, and an in-situ monitoring platform was developed to detect two types of defects during the SLM process. Different samples were built from stainless steel AISI 316 L powder, utilizing various laser process parameters. Using microscopy imaging technique, the melt structure features of the constructed samples were tested, and the results were analyzed. The dependency of porosity formation on laser process parameters and scan strategy was investigated. Moreover, hardness test was performed for all built samples. The platform developed for in-situ monitoring purposes includes an AM machine equipped with pulsed laser, camera, illumination system, and powerful industrial computer equipped with Cameral Link Adapter, FPGA, and Real-Time (RT) modules. An algorithm was designed using LabVIEW® software based on Particle Analysis (PA) to cease the process in the event of detection of defect in any fused layers. The first defect was caused by changing the laser spot diameter, which altered the energy intensity of the laser on the surface, and the second defect was created by the uneven thickness of powder on the platform. The monitoring system detected both defects and stopped the process immediately according to the designed algorithm. Images were taken from the melting process layer by layer using a high-performance camera.</p

Utilization of virtual prototyping in development of CMM

The characteristic advantages of hydraulics (high power density, simple construction and reliability) together with the characteristics of water as the pressure medium (fire and environmentally safe, chemically neutral, not activated nor affecte

Design of parallel intersector weld/cut robot for machining processes in ITER vacuum vessel

This paper presents a new parallel robot Penta-WH, which has five degrees of freedom driven by hydraulic cylinders. The manipulator has a large, singularity-free workspace and high stiffness and it acts as a transport device for welding, machini