Vol 3, No 4 (2017)

The new scope of application for vehicles equipped with magnetic suspension is the fright container transportation. In order to realise the transit potential of the country, the increase in mean speed of the container trains is required.

Objective. The purpose of the work is to explore the possibilities to develop the high-speed transport system equipped with magnetic suspension for container transportation along Eurasian land bridge.

Methods. The following methods and analysis have been used as research instruments: case study, computer modeling, transport geography and technical and economic analysis.

Results. The market analysis results of the transit container transportation have shown that the major challenge for Russian transit development is the constrained traffic capacity of the existing transport corridors. The drastic solution of the problem can be the construction of a new high-speed transport system. The following factors determining the conditions for the creation of the new transport system have been identified: the use of the Azov-Black sea basin transportation facilities, provision of the accessibility of the northern areas; the development of technical solutions ensuring the design of the transport system with low cost infrastructure. The combined traction levitation system has been developed based on the extremely simple design of the linear switched reluctance motor. The experimental researches of the full-functional physical model of the transport platform have been performed. The assessment of investment project efficiency has shown that despite large start-up investment in the track infrastructure, the project has positive economic effect.

Practical importance. The computer model of the combined traction levitation system based on the linear switched reluctance motor has been designed.

The concept of the new transport system construction has been introduced taking into account the characteristics of the supposed operating test sites in poorly developed areas. The high-speed route has been proposed connecting the Azov-Black sea basin with the Pacific coastline and completely passing through the territories of Russia including some northern regions. The transit potential assessment has shown that due to the transit time reduction it is possible to attract the container freights with traffic volume of 1.52 million in twenty-pounds equivalent.

Introduction. With the development of hardware and computer systems, which improve qualitative characteristics of synthetic aperture radars, with their dimensions limited, many new systems have appeared that allow using more accessible and widespread mobile platforms such as a car, quadcopters, unmanned aerial vehicles (UAV).

Problem. The use of new types of platforms leads to additional distortions associated with features of the geometry of the radar performance and more severe trajectory instabilities. Thus, new synthetic aperture radar systems should have special requirements for both software and hardware, which differ from classical systems.

Objective. The aim of the work is the comparison various algorithms that are used in modern radiovision systems to obtain high-quality radar images that can be integrated into various kinds of mobile platforms.

Methods. The method of frequency scaling and various modifications of this method are taken as a basic algorithm, including additional algorithms for compensating trajectory instabilities. For comparison of algorithms, the system geometry for automobiles and aircraft systems are considered and simulations were performed with the presence of point reflectors at different distances and the distortion of the platform motion.

Results. The difference of the considered algorithms in the form of flowcharts and mathematical formulas is shown. Based on results of the simulation the use of the basic frequency scaling algorithm at distances corresponding to the geometry of the automobile system leads to the distortion of the response along the azimuth. In addition, the use of the modified algorithm for compensating trajectory distortion allows correct focusing the targets at different distances.

Conclusion. The proposed combination of modified algorithms of trajectory distortion and frequency scaling allows focusing the image evenly throughout the frame and improving the quality of the image in the near zone.

The system of equations comprising the Mohr-Coulomb yield condition and the stress equilibrium equations may be studied independently of the flow law. This system of equations is hyperbolic. Accordingly, to solve the aforementioned system of equations, it is reasonable to apply the method of characteristics. In the special case of plasticity theory for materials whose yield criterion does not depend on the average stress, two methods are used to construct an orthogonal net of characteristics and to determine the stress field: the R-S method and Mikhlin’s coordinate method. In the case of the Mohr-Coulomb yield condition, the angle between the characteristic directions depends on the internal friction angle. Therefore, the above-mentioned methods should be generalised in accordance with this property of characteristics.

Purpose. In the case of Plasticity theory for materials whose yield strength does not depend on the average stress, to calculate the stress filed, Mikhlin’s coordinate method is widely used. The purpose of this study is to generalise this method for the equation system consisting of the Mohr-Coulomb yield criterion and the pressure equilibrium equations.

Methods. The geometrical properties of the characteristics of the equations’ system consisting of the Mohr-Coulomb yield condition and the equilibrium equations are used to introduce the generalised Mikhlin coordinates.

Results. It’s been pointed out that solving equation system consisting of the Mohr-Coulomb yield condition and equilibrium equation comes to solving equation of telegraphy and to subsequent integration.

Practical Significance. The developed method of system of equations’ solution, consisting of the Mohr-Coulomb yield condition and equilibrium equation enables obtaining high precision solutions at insignificant computer time expenditures.

The article deals with linear induction motor (LIM) with a squirrel-cage winding of the secondary element (SE), which functions as the armature of the machine. Linear location of squirrel-cage winding of the secondary element of LIM allowed suggesting a number of options for the regulation of the winding resistance of SE.

Objective. Development and research of LIM with adjustable winding resistance of the secondary element for magnetic levitation transport, and the study of the properties of adjustable LIM.

At the modern level of development of the electrical engineering, asynchronous electric drive and magnetic levitation transport, the primary method of changing the frequency rotation of motor and speed of linear motion of high-speed transport vehicles is frequency control. Frequency control allows changing the frequency of rotation of the machine and linear speed of LIM smoothly and in broad diapason. The high cost of static electronic converters of high power limits the large-scale application of frequency control. The increase of the current frequency also leads to lower torque and traction.

Results. According to the authors, the application of the adjustable linear induction motors with variable resistances of short-circuited windings of the secondary elements will allow to expand the range of control of LIM, intended for high-speed magnetic levitation transport with the realisation of large traction, including the start (starting the vehicle) by means of current displacement in the groove of the secondary element of the LIM.

Conclusion. The linear induction motors of this type, as well as the calculation of the magnetic field in the groove of the secondary element, and evaluation of the influence of the current displacement on the starting and controlling features of the machine are considered.

Introduction. At the present stage of developing methodological approaches to assessment of social and economic efficiency, all the external effects of the project are divided into effects that can be estimated in value terms, and effects that cannot be expressed in monetary units. In turn, the latter are divided into effects that have a quantitative expression and effects, described only on a qualitative level. External effects, which can be estimated in monetary terms, are directly included in the calculation of the social and economic efficiency of the project in the form of additional inflows and outflows of money.

Problem. The conceptual basis for assessing the social and economic efficiency of new high-speed lines is the comprehensive consideration of all external effects from the implementation of the investment project (economic and non-economic) that do not affect the cost parameters of the project participants.

Objective. The aim of the work is to develop a system of indicators for assessing the social and economic efficiency of the strategy of the development of high-speed urban transport.

Methods. Study of existing methods of assessing social and economic efficiency, searching for disadvantages and advantages, exploring the advantages of magnetic levitation technology.

Results. The development of this system of indicators for magnetic levitation transport, which is distinguished by such advantages as the impossibility of derailment, greater route speed, hence less time travel, less noise and vibration than light-rail transport and metro, complete absence of dust, is especially important.

Conclusion. The proposed system of indicators for assessing the social and economic efficiency of the strategy of the development of high-speed urban transport takes into account all the advantages of magnetic levitation technology and makes it a priority when choosing high-speed urban transport.