776 research outputs found

    Control of mechatronic drives considering the type and number of the nonlinearities of a mechanical converter

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    In this article the particularities of the dynamics study of mechatronic drives that operate at low velocities are discussed; the origins of frictional self-exited oscillations to develop an algorithm for non-linearity correction are analyzed; a drive mathematical model and the qualitative picture of the self-exited oscillations regimes were presented for the three cases: a "system with clearance and friction-free"; a system without clearance with "dry friction" and a system with clearance and "dry friction". Therefore, an algorithm to compensate the frictional self-excited oscillations based on the feedback introduction for the sliding velocity of the linear motion output link was proposed

    Measurement of charged particle spectra in deep-inelastic ep scattering at HERA

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    Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 LT Q(2) LT 100 GeV2, and small values of Bjorken-x, 10(-4) LT x LT 10(-2). The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity (n(*)) and transverse momentum (p(T)(*)) in the range 0 LT n(*) LT 5 and 0 LT p(T)(*) LT 10 GeV in bins of x and Q(2). The data are compared to predictions from different Monte Carlo generators implementing various options for hadronisation and parton evolutions

    Self-stopping actuating mechanism with high coefficient of efficiency of the forward stroke for linear motion drives

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    In this article is examined the an approach to the design of linear motion mechanisms, which consist of self-stopping planetary transmissions of the type AH13 and AH31 with transmission values i = 7Ă·9 based on the type of self-stopping planetary transmissions and the RSM. That combination allows a reliable self-stopping in backward stroke and a high coefficient of efficiency of the forward stroke (up to 0.95). The dependences of the angles of inclination of the wheel of the self-stopping transmissions from the angle of the original profile were lead. The obtained conditions allow the transmissions work of the type AH31 and AH13 in release mode for the back-and-forth stroke

    Self-stopping actuating mechanism with high coefficient of efficiency of the forward stroke for linear motion drives

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    In this article is examined the an approach to the design of linear motion mechanisms, which consist of self-stopping planetary transmissions of the type AH13 and AH31 with transmission values i = 7Ă·9 based on the type of self-stopping planetary transmissions and the RSM. That combination allows a reliable self-stopping in backward stroke and a high coefficient of efficiency of the forward stroke (up to 0.95). The dependences of the angles of inclination of the wheel of the self-stopping transmissions from the angle of the original profile were lead. The obtained conditions allow the transmissions work of the type AH31 and AH13 in release mode for the back-and-forth stroke

    Modeling of the PG-CP4 coating hardness applied to H12M steel and subjected to laser treatment

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    The article considers the influence of the radiation power W, the longitudinal feed Spr of the laser beam and the distance L from the protective glass of the laser focusing head to the workpiece on the PG-CP4 coating hardness which was applied to H12M steel by plasma and then subjected to laser treatment. A multi-factor model is established that relates the PG-CP4 coating hardness to the input process factors and allows you to quickly assign a laser treatment mode and to control it in order to improve the quality of the processed surface layer. Increasing W, Spr and L leads to a increase in the HV parameter. The longitudinal feed Spr of the laser beam has the greatest effect on the surface layer hardness, then followed the distance L and radiation power W. The research results are relevant for manufacturing enterprises that implement laser processing processes of materials and design organizations that develop modern laser equipment

    Wear of the PG-CP4 powder coating applied to HVG steel and subjected to laser treatment

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    The article considers the influence of the radiation power W, the longitudinal feed Spr of the laser beam and the distance L from the protective glass of the laser focusing head to the workpiece on the PG-CP4 powder coating absolute wear which was applied to HVG steel by plasma and subjected to laser treatment. A multi-factor model is established that relates the absolute wear of PG-CP4 coating to the input process factors and allows you to assign a laser treatment mode to provide the minimum wear of the processed surface layer. The greatest influence on coating absolute wear is provided by the longitudinal feed of laser beam, with which the wear increases. Compared to Spr, the influence of factor W on the coating absolute wear is 24% less, and the factor L influence is 4.4 times less. The minimum absolute wear of the coating occurs at W = 5 kW, Spr = 40 mm/s, L = 85 mm. The results of the research are recommended for use in enterprises that implement the processes of plasma and laser processing of materials, as well as in design organizations that develop modern technological laser systems

    Application of CAD/CFD/RP-technologies for development of LVAD systems

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    The important problem of new Left Ventricle Assist Device (LVAD) systems development is to determine their hemodynamic and functional characteristics and reduce the design time. An effective method for achieving this is the use of approaches based on the application of CAD/CFD/PR-technologies. Methods of computer modelling were applied to determine the geometrical parameters of the blood pump, and methods of finite element analysis were used for the optimization of hemodynamic parameters of the LVAD system. The geometrical modelling was carried out in the Pro/Engineer WF5. The CAE-system Ansys was used to analyze the blood flow in the chamber of the pump. The motion of the flexible walls was simulated by normal flow through rigid walls. At the final stage some models were prepared for prototyping. The critical parameters of hemodynamic gave the possibility to optimize the shape of the blood pump. The LVAD system and its components were made using various RP-technologies. The hydraulic tests for the performance investigation and the analysis of implantability for implantable systems were carried out for manufactured prototypes of LVAD systems. The manufactured components of the LVAD system are completely operability and give the possibility to estimate the critical hemodynamic and functional parameters of the LVAD system

    Hardening Curve Plotting and Determination of the Coating Limiting State Criterion based on the Continuous Indentation Method and Computational Modelling

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    The article describes the method of determining the parameters of the hardening curve of homogeneous and structured coatings (modulus of elasticity, tangential modulus of elasticity and yield strength) required for the strength analysis of parts with coatings that determine their basic performance and strength characteristics. The dependence for determination of tangential (tangential) modulus of elasticity using the results of nanoindentation is proposed. An algorithm for determining the yield strength of the coating material is developed based on solving the problem of elastic-plastic deformation of the coating during the introduction of the indenter by the finite element method. According to the proposed method, the parameters of the TiN/AlN in coating hardening curve were determined based on the results of indentation of the sample of tool high-speed steel with the appropriate coating
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