Dynamic Processes of Loader Cranes Manipulators with Excessive Backlashes and Elastic Damping in Their Hinges

This research is aimed at developing a mathematical model and the methodology for computer simulation of hydraulically driven manipulators of mobile cranes having excessive backlashes in cylindrical joints. The authors proposed a structural design and considered the mechanism of reducing the additional impact load in the hinges by means of elastic damping of oscillatory processes. This method allows estimating the degree of influence of the backlash and stiffness of the elastic damper on the change in the quantitative characteristics of the dynamic loading of the manipulators metalwork and the motion parameters of the transported load. While in operation, the excessive backlashes may cause an increase in the level of dynamic loading of manipulators up to 2 times or more. However, the rational choice of the elastic dampers stiffness allows an effective solution to this problem to the point of complete elimination of the additional impact load

Комплексная математическая модель манипуляционной системы мобильной транспортно-технологической машины

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT Manipulation systems are used as executive mechanisms of mobile transport-technological machines. The article offers approaches to modeling of dynamic processes in the operation of such systems. These approaches are based on the complex mathematical model developed by the author, which takes into account the interaction between the elements of the five-component system «Working body - Manipulation System - Basic Machine - Reference Base - Environment». By the method of statistical tests or simulation modeling, combinations of load factor values within each cycle of the system operation are determined. Then, for each combination of factors, a piecewise implementation of the process of changing dynamic forces or mechanical stresses in the elements of the structural steel that are of interest is constructed. For piecewise implementations, the loading of the manipulation system during the entire service life is estimated. Keywords: manipulation system, transport-technological machine, bearing surface, mathematical model, dynamics, loading.Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Манипуляционные системы применяются в качестве исполнительных механизмов мобильных транспортно-технологических машин. В статье предложены подходы к моделированию динамических процессов при эксплуатации таких систем. Эти подходы базируются на разработанной автором комплексной математической модели, учитывающей взаимодействие между элементами пятикомпонентной системы «Рабочий орган - Манипуляционная система - Базовая машина - Опорное основание - Окружающая среда». Методом статистических испытаний или имитационного моделирования определяются сочетания значений факторов нагруженности в пределах каждого цикла работы системы. Затем для каждого сочетания факторов строится кусочная реализация процесса изменения динамических усилий или механических напряжений в интересующих элементах несущей металлоконструкции. По кусочным реализациям оценивается нагруженность манипуляционной системы в течение всего срока эксплуатации

MULTI-OBJECTIVE OPTIMIZATION OF THE MAIN DESIGN PARAMETERS OF THE HYDRAULIC CRANE-MANIPULATOR INSTALLATIONS OF MOBILE MACHINES

Presents a methodology for optimal design of crane-manipulator installations of mobile transport technological machines at the pre-design stage of development of the technical proposal. Predesign optimization allows to comprehensively determine the optimum combination of a sufficiently large number of basic design parameters – the characteristic dimensions of metal structures of installation (lengths and dimensions of cross sections, links, and mounting dimensions for hydraulic cylinders) and characteristics of the hydraulic system (working pressure and flow rate of the working fluid)

OPTIMAL SYNTHESIS OF DRIVE SWING CONNECTIONS OF MOBILE CRANES HYDRAULIC MANIPULATING SYSTEMS

The design, operation features and the optimal design method for the drive swing connections are considered. These are proposed as an alternative design variant of the articulation of adjacent links of hydraulic manipulation systems of mobile boom cranes are considered. The design of the device allows to combine two functions: to ensure a continuous, uninterrupted kinematic connection between adjacent links of the manipulation system by creating a cylindrical hinge for performing the reciprocating relative motion of adjacent links and to form an integrated rotary hydraulic gate type hydraulic motor. A mathematical model is developed, the problem of the optimal synthesis of the drive joint on the basis of minimization of the device mass is formulated and solved, while observing the nonlinear system of design, installation, power, strength and kinematic constraints. Analysis of the results of the performed optimization calculations showed that the mass of the optimal version of the device increases with the growth of the overcome moment from the moved cargo and decreases with the increase in the number of chambers. The operating pressure of the hydraulic system does not have a practical effect on the optimum mass, which allows the pump unit of lower power to be used to provide the movement of the links of the manipulation system. Optimum values of the main design dimensions of the drive articulation are determined both by the value of the operational load and by the installation conditions of the device taking into account the dimensions of the cross sections of adjacent links of the manipulation system. When designing manipulation systems, the swing joints allow to abandon remote power hydromotors, eliminate operational failures due to wear and fatigue failure of hinge elements, and also increase the energy efficiency of loader cranes by transferring the hydraulic system to lower operating pressure levels while maintaining the required load-altitude characteristics

Cabin dynamics simulation of “Rope Metro” transport system

Introduction. The study results of the passenger ropeways (PRW) applicability in the highly urbanized environment are presented. Issues on the development of mathematical models for designing and simulating work processes of the advanced “Rope Metro” transport system are considered. The proposed transport system differs significantly from the customary PRW. For its successful design, a mathematical model for estimating the operational loading of the key components is developed. Likewise, a mathematical submodel of the passenger cabin of the cable car which will be then integrated into the composite mathematical model of the system is offered by the authors. The work objective is to study the passenger cabin oscillations during its movement along the section of the transport system.Materials and Methods. A new mathematical model describing the oscillations of the passenger cabin and its suspension members is proposed. This model should be integrated into the composite mathematical model of the transport system using part of its output capacity. Numerical simulation of the cabin movement is carried out. The derived equations represent a mathematical model for studying the dynamics of the pendular oscillations of the passenger cabin of the advanced “Rope Metro” transport system. In the paper, the integration of the equations is carried out by the Runge-Kutta method in the program package of the in-home design.Research Results. New mathematical models and software for the numerical simulation are developed. The damping devices’ effect on the maximum oscillation amplitude of the passenger cabin is shown.Discussion and Conclusions. The results obtained can be used under designing and modeling work processes, and optimizing the transport system components. It is proved that the damping device reduces the amplitude of the oscillations which stabilize at lower values (0.3-0.5 degrees) after the transient process end. In the future, it is required to integrate the developed mathematical model into a composite model of the system under investigation to refine the conclusions reached

Prospects for the Development of Transport and Technological Machines for Logging on Slopes

The article discusses promising machines for logging on slopes. The relevance of the use of such machines is associated with the depletion of the stock of wood in the plains. The study was supported by Presidential Grant for Governmental Support to Young Russian Scientists No. МD-422.2020.8.В статье рассматриваются перспективные машины для заготовки леса на склонах. Актуальность использования таких машин связана с истощением запаса древесины на равнинных территориях. Исследование выполнено при финансовой поддержке гранта Президента РФ для государственной поддержки молодых российских ученых — докторов наук № МД-422.2020.8

THE STUDY OF THE PURCHASE PROPENSITY OF THE USER OF THE ONLINE STORE ON THE BASIS OF TECHNICAL DATA ON VISITS OF VISITORS TO THE ONLINE STORE

The paper describes the development of an automatisation service for marketing campaigns on the basis of web usage data mining. The source web usage data were obtained from Yandex.Metrika service. On the basis of exploratory data analysis it was decided to divide the work into the following stages: analysis, building an assembly of models, assesing the efficiency of the models and selecting the best one, and publishing the web service with the purpose of its further usage in the Internet shop CMS within marketing campaigns. The data mining was conducted on the basis of Loginom Analytics Platform which allows to create analytic models as well as to present them out as web services. For the data mining 3 approaches - association rules, time series and scoring - were used. The scoring model demonstrated the best results, it showed excellent results on test data, with that the coefficient expert analysis confirms its correctness and applicability. In case of necessity the developed analytic model can be learned on web usage data of any Internet shop provided by Yandex.Metrica service

Оценка влияния объектов капитального строительства на прилегающую улично-дорожную сеть при организации дорожного движения посредством регулируемых пересечений

The paper discusses problems of assessing the impact of mass attraction centers on the adjacent street and road network in the process of their functioning, expansion or conversion. The choice of criteria for assessing the organization of traffic flow, given in the Russian and foreign literature, has been substantiated, in particular, it is proposed to use v/c ratio for adjacent junction and corresponding level of traffic service (LOS). The main models for estimating capacity of signalized intersections are presented. The procedures of forming a mathematical model for estimating the load factor of signalized intersections is shown. The concepts of lane group capacity, total lost time per cycle, phase coefficients, saturation flow rate, and coefficients taking into account the decrease in the ideal saturation flow rate are explained. A mathematical model for estimating transport demand is presented, which allows to calculate the intensity of traffic flow to and from the center of mass attraction on the basis of the total traffic flow of correspondence, share of visitors in individual transport, average filling of individual transport, and coefficient of daily irregularity upon arrival and departure of visitors on an individual transport. An integrated mathematical model of loaf factor is proposed which includes parameters for estimating transport demand for centers of mass embarrassment and parameters that determine the signalized intersections capacity. The uniqueness of the integrated model is that it simultaneously involves parameters reflecting the demand and capacity of loading intersection. Recommendations are made on assessing the level of traffic service flows and the v/s ratio, based on the data of transport demand and capacity, adjacent to the centers of mass attraction of the road network. The presented method of estimating the LOS based on the capacity of the signalized intersections allows us to estimate the influence degree of mass attraction centers on the adjacent urban road network.Рассмотрены проблемы оценки влияния центров массового тяготения на прилегающую улично-дорожную сеть в процессе их функционирования, расширения или перепрофилирования. Обоснован выбор критериев оценки организации дорожного движения, приведенных в отечественной и зарубежной литературе, в частности предлагается использовать коэффициент загрузки запитывающих пересечений и соответствующий ему уровень обслуживания движения (LOS). Представлены основные модели оценки пропускной способности регулируемых пересечений. Показан механизм формирования математической модели оценки коэффициента загрузки регулируемых пересечений. Разъяснены понятия пропускной способности группы полос, продолжительности потерянного времени в цикле, фазовых коэффициентов, потока насыщения и коэффициентов, учитывающих снижение идеального потока насыщения. Приведена математическая модель оценки транспортного спроса, позволяющая рассчитывать интенсивность транспортного потока как к рассматриваемому центру массового тяготения, так и от него на основе общего объема корреспонденций, доли посетителей на индивидуальном транспорте, среднего наполнения индивидуального транспорта, а также коэффициента суточной неравномерности по прибытию и отправлению посетителей на индивидуальном транспорте. Предложена интегрированная математическая модель коэффициента загрузки, включающая параметры оценки транспортного спроса к центрам массового тяготения и параметры, определяющие пропускную способность регулируемых пересечений. Уникальность интегрированной модели состоит в том, что в ней одновременно задействованы параметры, отражающие транспортный спрос и пропускную способность запитывающего пересечения. Приведены рекомендации по оценке уровня транспортного обслуживания потоков и коэффициента загрузки на основе данных значений транспортного спроса и пропускной способности прилегающей к центру массового тяготения улично-дорожной сети. Представленная методика оценки уровня обслуживания движения на основе пропускной способности регулируемых пересечений позволяет оценить степень влияния центров массового тяготения на прилегающую улично-дорожную сеть