• MATHEMATICAL MODELLING OF TECHNOLOGICAL PROCESSES AND SYSTEMS

    RESEARCH OF MATHEMATICAL MODELS OF LITHIUM-ION STORAGES

    Mathematical Modeling, Vol. 3 (2019), Issue 4, pg(s) 127-130

    In modern industry self-powered devices are an important component. For such devices, the most important component is the energy storage device used, most often based on lithium-ion technology. The article presents an equivalent circuits of lithium-ion batteries and a mathematical description of charge-discharge processes. Investigated in Matlab / SimPowerSystems built-in library component of lithium-ion battery. Mathematical models of equivalent circuits of different types of lithium-ionic batteries have been analyzed.

  • MATHEMATICAL MODELLING OF TECHNOLOGICAL PROCESSES AND SYSTEMS

    STUDY OF STRESS-STRAIN STATE AND TEMPERATURE FIELD DURING ROLLING UNDER THE NEW SCHEME WITH ALTERNATING AND SHEAR DEFORMATIONS

    Mathematical Modeling, Vol. 3 (2019), Issue 2, pg(s) 55-58

    In this paper, a computer simulation of a new technology of thick-sheet rolling, including rolling in rolls with a relief surface followed by rolling on rolls with a smooth barrel to the desired size. The analysis of effective plastic deformation, hydrostatic pressure and temperature field was carried out according to the results of modeling. According to the results of the analysis of effective strain, maximum of processing in the first pass receives the ridge area, but after the second pass observed alignment distribution of this parameter over the cross section. The study of the temperature field showed that the greatest temperature difference in the cross section occurs when rolling in relief rolls, in the future when rolling in smooth rolls due to the increase in the contact surface area, this difference decreases. Analysis of hydrostatic pressure showed the presence of both compressive and tensile stresses in the deformation zone. Such distribution is caused by the presence of a relief surface after 1 pass in the further alignment of the strip profile, which occurs both in the longitudinal and transverse directions.

  • TECHNOLOGIES

    Planning the inflow of products for production levelling

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 10, pg(s) 439-442

    Production levelling, also referred to as production smoothing (jap. Heijunka), is an effective method for reducing unevenness in the production process and maintaining better control over stock levels. It helps keep production at a steady pace and ensure the desired level of flexibility. The authors present a study aimed at developing a method for planning the inflow of products from the production process, intended to be used in the scheduling of levelled production. Focus has been put on finding the right combination of lot size and production interval which, assuming certain input parameters (order size and placement rate, initial stock levels), yields the best outcome in terms of timely/untimely order fulfilment and minimum and maximum stock levels.

  • TECHNOLOGIES

    Method of permeable elements for simulation of powder metals forming processes

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 9, pg(s) 376-379

    For simulation of processes of compaction or forging of products from powder materials, a method of permeable elements is proposed. The essence of the method is to use elements whose shape is regulated in advance, and, unlike the finite element method, where the elements coincide with the material volumes and their masses are unchanged, here the masses elements are variable, and material can flow between adjacent cells. Examples of using the method for modeling the processes of forging of porous preforms in closed and open dies, as well as in a closed die with a compensation cavity, are presented.

  • Diagnostics of thermal pipes with symmetric structure thermal impact method

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 2, pg(s) 83-85

    On the basis of completed studies, including computer modeling of the morphology of the temperature field of heat pipes and thermal measurements in the framework of the experiment, a method was developed for diagnosing the quality of heat pipes with a symmetrical structure.

  • Computer modelling of radial-shear rolling of austenitic stainless steel AISI-321

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 12, pg(s) 497-500

    In this paper the results of modelling of radial-shear rolling process of austenitic stainless steel AISI-321 are presented. The simulation in Simufact Forming program complex was performed. The conditions of simulation for radial-shear mill SVP-08 of Rudny industrial Institute were adopted. The various parameters of stress-strain state (effective plastic strain, effective stress, mean normal stress and Lode-Nadai coefficient) and also microstructure evolution with rolling force were considered. It is revealed that radial-shear rolling is an effective process for obtaining of high quality round billets from stainless steels of austenitic class.

  • Experimental and simulation determination of friction coefficient by using the ring compression test

    Industry 4.0, Vol. 3 (2018), Issue 6, pg(s) 316-318

    One of the main problems in the plastic deformation of materials is the determination of the coefficient of friction as well as the subsequent application of the simulation for comparative analysis. However forecasting process and matching between simulation and experimental data is still a problem. Causes of this are factors such as roughness, mechanical properties of the material, chemical composition, etc. which strongly influence the behavior of the material in the simulation of the process.

    In this study, an approach is proposed to determine the changeable coefficient of friction in the deformation process experimentally, taking into account implicitly the influence of surface roughness on the friction curves. For the comparative analysis between experiment and simulation of the process, the experimental data for objective assessment was introduced. Nevertheless, there are differences between experiment and simulation, which is most evident in high loads, using lubricants differing from more than 12 units for graphite lubricant, with more than 6 units with oil and with dry friction with 8 units.

  • MODELLING, SIMULATION AND IMPLEMENTATION OF AUTONOMOUS UNMANNED QUADROTOR

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 8, pg(s) 320-325

    This research proposes modelling, simulation and implementation of autonomous unmanned quadrotor prototype based on Matlab Simulink software, and Mission Planner for communicating with APM control board of the quadrotor. The goal is to Control attitude and altitude over a desired trajectory of the Quadrotor using PID control, with high precision and reliability. The mathematical model used for simulation takes into account all differential equations of motion of the quadrotor. A full quadrotor prototype was assembled for real experiments to do a comparison between real and simulated data. This comparison reveals the reliability and the accuracy of the PID controller and the mathematical model used in Matlab.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    A SKY-HOOK CONTROL CONCEPT OF VEHICLE ACTIVE SUSPENSIONS

    Trans Motauto World, Vol. 3 (2018), Issue 3, pg(s) 106-110

    In the paper, fuzzy logic is used to simulate active suspension control of a one-half-car model. Velocity and acceleration of the front and rear wheels and undercarriage velocity above the wheels are taken as input data of the fuzzy logic controller. Active forces improving vehicle driving, ride comfort and handling properties are considered to be the controller outputs. The controller design is proposed to minimize chassis and wheels deflection (sky-hook concept) when uneven road surfaces, pavement points, etc. are acting on tires of the running car. As a result, a comparison of an active suspension fuzzy control and a spring/damper passive suspension is shown using MATLAB simulations.

  • MACHINES

    EXPERIMENTAL SIMULATION OF COMMON RAIL ELECTROMAGNETIC INJECTORS WEARING

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 5, pg(s) 208-211

    At the time of exploitation, the geometrical position of the control valve changes as a result of wearing, which leads to a change of residual electromagnetic gap stroke and force of control valve spring. The following study measures the hydraulic characteristic changes, based only on common rail injector increased stroke of control valve and residual electromagnetic gap. The results show that the increasing of control valve stroke and residual electromagnetic gap increase the fuel flow rate and return fuel flow. Increased fuel flow rate and return fuel flow are presented with short injector signal time and lower levels of working pressure. The increasing is lower with longer injector signal time and high level of working pressure. The follow-up results are practically significant by common rail electromagnetic injector diagnosing and repairing.

  • TECHNOLOGIES

    A PROCESSES CONTROL SIMULATION TOOL

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 4, pg(s) 182-184

    The paper deals with a variable multifunctional simulation tool that enables to design and assemble animated models of various technological processes controlled by externally connected fuzzy logic unit. It enables to verify the correctness of fuzzy controller settings in the future control of real technological processes in practice. This tool represents an effective, innovative, and creative concept important to understanding control approach of technological processes modeling as an insight to behavior of real industrial processes and their control which is based on fuzzy logic. On the base of this animated simulation, real technological processes control can be realized successfully according to producer demands afterwards. Models of technological processes assembled by this simulation tool can be then externally controlled by various control strategies (traditional PID controllers, ON-OFF controllers,PLC controllers, fuzzy logic controllers etc.) via a proper real controller connected to the computer. In the paper, two-conveyor-belt system for product packing is shown. The goal consists in control of synchronization of products and boxes placed on individual conveyor belts in order to pack the product into the box. The main concern here is to improve dynamic performance and control efficiency with the help of assembling an animated model of the controlled technological process and its external control by a fuzzy logic unit.

  • SOCIETY & ”INDUSTRY 4.0”

    SERVICE SIMULATION IN INDUSTRY 4.0: A COMPARISON OF SIMULATORS

    Industry 4.0, Vol. 3 (2018), Issue 2, pg(s) 101-104

    Web services are application components that can be linked together for creating new functionality. As such, they support industry environments by binding together inhabitant services with distributed on demand services for implementing the business strategies. However, web services are operating in dynamic environments and an important issue during the composition process is change management either at the local or at the web, in general. Therefore, service changes together with other nondeterministic behaviours must be efficiently propagated to ensure the validity and consistency of the enterprise plans. Simulations are effective tools for enhancing factory competitiveness. Simulating the operation of a developed composite service for verifying the developed product could be a solution to this problem. The results of the simulation will allow to predict and react to such behaviours before applying the developed service in real production. As such, this paper describes and compares the existing service simulators that could be used in smart industry environments in terms of their functionality. Based on this review, the identification of gaps in performing simulation of service composition in industrial environments is presented, and challenges to be met on the field are outlined.