SCIENCE & EDUCATION

Process of crystallization of metal of a bath after continuous welding is characterized by a number of physical and chemical laws which have the general character without dependence from a mode of influence of a source of heating. Existence of the oscillatory mechanism of hardening of metal of a welded bath in the form of formation of periodically repeating isotherms of crystallization, is characteristic for different metals and alloys. It is established that at influence of heat from an external periodically operating source with frequency to corresponding own frequency of crystallization of metal of a seam conditions of a resonance which promote crushing of cast structure of a seam and a zone of thermal influence are created.  The fine-grained structure of welded connection received for the account of efficient control by the oscillatory mechanism of moving of front of crystallization, allows to raise essentially resistibility to formation of hot cracks and, possibly, cold cracks at the expense of change of conditions of the structural transformations unattainable at usual welding

Article is devoted questions of modelling of movement of the active jointed transportno-technological cars. The objective approach to modelling of the jointed transportno-technological cars is considered. The universal model for research of influence of distribution of power streams between leading elements of the transport car is offered, allowing in a wide range to change the factors influencing efficiency of transport operation. Distribution of streams is offered to be regulated by means of change of parametres of elements distributing power streams (distributing boxes, differentials).

Existence of the oscillatory mechanism of hardening of metal of a welded bath in the form of formation of periodically repeating isotherms of crystallization, is characteristic for different metals and alloys.  Without dependence from a mode of influence of a source of heating a number of the physical and chemical laws connected with a heredity of properties of metal in a liquid state, are closely connected with transition not only to microlevel, but also to the macroscale sizes of elements of structure of a welded seam at its formation. Periodicity of process of crystallization of metal is connected with fluctuations of speed of crystallization of interphase border at its movement with accelerations both the subsequent delays and a stop.It is established that at influence of heat from an external periodically operating source with frequency to corresponding own frequency of crystallization of metal of a seam conditions of a resonance which promote crushing of cast structure of welded connection are created.  The fine-grained structure of welded connection received for the account of efficient control by the oscillatory mechanism of moving of front of crystallization, allows to raise essentially resistibility to formation of hot cracks at the expense of periodic changes of temperature in a germinal zone, overcooling of liquid metal and the subsequent changes of rate of internal shrinkable deformations in a temperature interval of fragility.

Article is devoted questions of modelling of difficult dynamic systems. The jointed transport system, its internal and external relations are presented in a kind three shares the column. The method of object-oriented programming in language of high level Python is applied. At modelling the two-step-by-step method of numerical integration is used. Such approach to modelling allows to reduce dimension of the equations of a solved problem, to increase speed of calculations and to facilitate drawing up of structure of model. Fragments of the program used for the numerical solution of equations of motion of articulated vehicles

Article is devoted research tests of the active lorry convoy, as special case of the active jointed transport system. The object of research, measurement and control system, the experiment plan are described. Tests have shown high efficiency of application of the active jointed transport systems. The results of research tests showing dependence of force of draught on a hook from a kinematic mismatch in a drive of the second section of the car are resulted. Recommendations about introduction in a drive of the second section of system of the kinematic mismatch providing the maximum value of force of draught on a hook of the car on various types of a soil surface are given

The article is devoted to structural synthesis of technical objects. It discusses an approach based on the representation of multiple analogs and prototypes in the form of directed hypergraph. The formulation of the problem of structural synthesis in the form of discrete mathematical programming is proposed. The system of constraints, describing the restrictions on the combination and terms of coercion is introduced.

It is shown that the search for ways to improve off-road capabilities of tracked vehicles in the snow must be based on comprehensive analysis of the influence of design parameters of the caterpillar drive as a quantitative resistance force, diving machines, traction control, and on the nature of the interaction of a caterpillar drive with snow cover. Computational and theoretical research, experimental-design work has shown that off-road capabilities of tracked vehicles in snow can be enhanced by quantitative changes in the geometric parameters of the chassis (track width, base, ground clearance) and a qualitative change in the nature of the interaction of caterpillar drive with snow cover (lining of the pressure diagrams and increasing the active length of the support surface caterpillar drive). There are shown the dependence of the resistance movement, traction and traction supply of track width, clearance and pressure drive in the snow.

This paper presents multi-section trunk robot-manipulator based on parallel kinematics “hexapod” mechanism. The paper purpose is working out of mathematical model and dynamics research of this manipulator. Means of program system MatLab/Simulink develop dynamic models of one-section and three-section manipulators. Research of transients and the maximum loadings in their drives is executed at various weight of tong and parameters of automatic control system.

The article discusses a series of works on the justification of durability of caterpillar’s flexible wideners, including the following milestones: development of a mathematical model and algorithm for calculating the deflections of wideners; the study of the deformed state in order to select the geometric and force parameters; the development of design wideners; conducting laboratory bench and road tests. There are compiled computational model that simulates the passage of widener single obstacle and widener dive into the snow.  There are shown the solution of the problem of determining the strain state of a rubber track widener in a geometrically and physically nonlinear formulation.  There are presented the results of computational studies on a rational choice of elastic stiffness widener caterpillars.

In this article we propose new generators of uniformly distributed pseudorandom sequences based on cellular automata. The advantages of such generators are good statistical properties of output sequences and high performance of hardware implementation. We justify the choice of the structure and parameters of generators and describe details of classical and non-uniform cellular automata usage in the structure of generators. We also compare hardware implementations of our generators and eSTREAM candidates.

The paper discusses ontology knowledge bases focused on support of decision making in corporate information systems. We assume that search of decisions in knowledge bases is performed using metadata of the document. Metadata are formed on the basis of the semantic network of the ontology. Relevance of the document is estimated by computing affinity in metrics of the semantic network of the document and the semantic network of the query.

The article considers execution level of trunk-manipulator, considers control system of the tripod as a section of the manipulator. The article describes classical nonparametric identification and neural network identification based on NNARX model. Both method of identification were implemented in Matlab with Neural Network Toolbox and System Identification Toolbox. The paper considers classical  and neural network nonadaptive control system of the tripod. Classical two-circuit control system based on PID controllers. Neural network control system based on inverse model of the tripod. Also the article describes adaptive control system. There are two method describe in article. First method  based on classical control system with the reference model of tripod. Other method based on neural network control system. All neural networks model were implemented in Matlab with Neural Network Toolbox.  Modeling of control systems were implemented in Matlab/Simulink.

We analyze the dependence of avalanche effect in classical and non-uniform cellular automata with balanced transition functions on the choice of cell neighborhood. We introduce space and integral characteristics to describe avalanche effect and also introduce a notion of optimal avalanche effect. We show that non-uniform cellular automata have better characteristics given the same neighborhood cardinality. The obtained results can be used in development of different algorithms such as block ciphers, hash functions and pseudorandom numbers generators.

Article is devoted questions of modelling of cars of double appointment. The analysis of system of elastic elements influence on fire power has allowed to formulate the basic requirements to mathematical model. Dynamic processes in real object are replaced by the simplified model in which properties of object essential to given research are kept only, and all other properties are not taken into consideration or replaced with more simple communications. The universal element with which help it is possible to receive any block diagramme wheel or a tracklaying vehicle is offered. In this case the two-mass model with two elastic elements and four degrees of freedom is considered. The model is constructed and the numerical decision of system of the equations is passed, allowing to estimate the response of the jointed car of double appointment to pulse influence from throwing installation.

For last two decades there was a wide spectrum of methods of the beam diagnostics, allowing to receive the detailed information on structure, properties and features of functioning of various members of the body by the qualitative analysis of biomedical images. Until recently the analysis of biomedical images has been based on badly formalized heuristic methods

One-section and two-section manipulators based on parallel kinematics “hexapod” mechanism are considered. Linear and angular dimensions optimization problem is set. Minimal guaranteed suppleness of construction under applied force is used as criterion of optimality. The research is carried out by means of MatLab software system. MatLab program implementing SQP optimization method is used for solving the optimization problem. Mathematical models of manipulators are obtained by means of MatLab/Simulink system.

Process of crystallisation of metal of a bath after pulse welding is characterised by a number of physical and chemical laws which have the general character without dependence from a mode of influence of a source of heating. Existence of the oscillatory mechanism of hardening of metal of a welded point in the form of formation of periodically repeating isotherms of the crystallisation having various density is experimentally confirmed. It is established, that own frequency of crystallisation of metal of a welded point remains a constant at moving from a line сплавления to the bath centre. The various density of isotherms allows to judge character of change of volume speed of crystallisation which according to a number of researchers can coincide with linear speed of moving of interphase border or carry the excellent tendency.  The account of heat conductivity of metal which нелинейно changes at temperature growth, allows to explain changing density of isotherms of crystallisation.                Possibility of regulation of frequency of hardening allows to operate effectively the oscillatory mechanism of moving of the interphase border, the dominating role in which is played by the internal reasons of periodicity. Achievement of resonant conditions at coincidence of frequency of action of an arc source and own frequency of crystallisation of welded metal, will allow to achieve substantial improvement of technological durability of welded connection for the account of crushing of cast structure of metal of a seam

Imitating modelling of movement of the active jointed transportno-technological system provides the analysis of all possible conditions of the system considering various road conditions, change of a kinematic mismatch in a drive of wheels of the second section and, as consequence, various variants of power interaction of links. The method based on representation of conditions of system in the form of the focused count, allows to systematise and realise modelling at a design stage and honing tests of the active jointed transport system.

  We consider the design of special lightweight tracked amphibious vehicle developed in the laboratory of TM and TTK the Nizhny Novgorod State Technical University named by RE Alexeev: all terrain tracked vehicle "Ukhtysh”; passenger and cargo versions all terrain tracked vehicle “Uzola"; two-tier all terrain tracked vehicle "Unzha”. The main technical characteristics of all terrain tracked vehicle: curb terrain vehicle, trailer weight, maximum speed, dimensions, track, ground clearance, the average ground pressure under full load, overcoming obstacles on firm dry ground, the minimum turning radius, power reserve of fuel, characteristics of the engine, transmission, suspension, caterpillars.

Process of fusion of metal at welding with its subsequent crystallisation is characterised by a number of features. Transition liquid расплава in the firm condition, occurring on interphase border in a so-called germinal zone, has a number of physical and chemical laws.                 A number of experimentally received facts allows to testify really to the existence, arising metal of a welded seam. In a germinal zone where there is an oscillatory mechanism at crystallisation, many processes influencing formation of a microstructure of a seam, mechanical properties of welded connection and especially the properties of technological durability defining reliability of work of a welded product as a whole originate.                 Management possibility the oscillatory mechanism of difficult and ambiguous process of the hardening, a dominating role in which is played by the internal reasons of periodicity, will allow to achieve substantial improvement of properties of welded connection for the account of crushing of cast structure of metal of a seam.                 Modelling of dynamics of movement of particles in simple liquids confirms transition of particles from a chaotic condition in ordered with preliminary formation кластеров from several particles.                 The mechanism of level-by-level stage-by-stage transition of particles is carried out at an establishment of a certain frequency mode of unstable balance or failure. Using an external source of fluctuations with synchronous to process of crystallisation by frequency, it is possible to operate structure formation, creating resonance conditions