SCIENCE & EDUCATION

On the basis of mathematical simulation the author proposes an algorithm of an earthmover’s active suspension control; the algorithm provided the required degree of deformation of the main coupled modes. An active force was applied in the function of oscillatory velocities to one linear and two angular coordinates. The combination of an elastic element and the control device, sequentially connected to it, in suspension allows to decrease oscillations of the case over a wide range of frequencies. In this case, high-frequency indignations are filtered by the elastic element, and the low-frequency oscillations of the case are damped by the active system. Decrease of oscillations leads to productivity improvement of the machine

This paper describes the existing constructions of cushioning systems of transport vehicles. The main advantages and disadvantages of each system were identified; a modernized cushioning system on the basis of the existing cushioning system of TV with HMP was developed. A comparative study was carried out by means of simulation of soft riding of transport vehicles with existing and planned cushioning systems. Field tests were conducted for one of the existing systems. The authors analyzed adequacy of the model and drew conclusions regarding the most promising ways of upgrading existing cushioning systems. This work shows the direction of possible upgrading of existing systems and improving the accuracy of selection of elastic and damping characteristics of suspension.

 The article gives an analysis of the structure of energy consumption connected with motion of walking machines of "heavy" weight category with cycle propellers. The analysis is based on the results of theoretical studies and field tests of a 5-ton walking robot "Vosminog". The most significant components of energy consumption at different speeds were identified. It was shown that the speed of walking machines was significantly constrained with overgrowth of energy in order to overcome inertia forces.

In the contemporary world motor industry due to the increase in operational speeds and use of pneumatic and hydro-pneumatic suspension brackets there is a tendency to a wider distribution of adjustable and operated suspension systems. Many factors influence the functionality and quality of controlling the suspension bracket: they are accuracy of measurement and transfer of parameters used for calculation of control; accuracy of working off the control by executive powers; system speed, i.e. the time passing from the moment of gauging of parameters till the moment of control realization. The author proposes a performance test of continuous and relay control systems for a suspension bracket of multi-wheeled vehicles. A comparative estimation of efficiency of the specified control systems was carried out, and optimum areas of applicability of both algorithms were specified

In our days suspension systems of modern multi-wheeled vehicles (MWV) are facing a wide range of inconsistent requirements: maintenance of high smoothness of a course; maintenance of high indicators of profile passableness; dynamic stabilization of the frame of the MWV during individual external influences; increase of the movement stability. Algorithms of management should be developed during the stage of the development of the MWV suspension control system, which provide a principle of separate management, i.e. performance of each of the algorithms of management should be carried out in a certain range of system phase coordinates. Author develops adaptive algorithm of dynamic stabilization of the frame of the MWV, which allows to provide a high indicators of stability of the frame under external influences connected with turning, braking, coming over an individual roughnesses. Thus not only stability and traffic safety of the MWV is increased, but also working conditions of the driver is improved. The technique of synthesis of the adaptive dynamic continuous law of stabilization of the case of the MWV was described in this article, and also the results of the simulation confirming high efficiency of developed algorithm of management were included.

Now in the Russian army and in the national economy of Russia a considerable quantity of cars with number of axes four and more is used. Operating experience of these cars showed that the problem of increase of mobility of these cars at the expense of decrease vibration crew and transported cargo was urgent. One of directions of improvement of the given property is management of damping in a suspension bracket by compulsory change of factor of damping. Developed algorithm of management of two-level damping of a suspension bracket multi-wheeled vehicles allows to decrease essentially the level of fluctuations of the case of the cars and to raise their speed on dirt roads. The algorithm is simple in implementation, provides fast reaction of suspension system on changing road conditions and doesn't demand high-speed executive powers of a suspension bracket that positively affects their durability. On the basis of the analysis of the results of modeling for various traffic conditions of the car with the wheel formula 8x8 the conclusion about the efficiency of the developed algorithm was made.

The requirement of increase in mobility of wheel technics at movement on all variety of kinds of the basic basis causes necessity of development of large quantity of specialized algorithms of management of suspension systems of multi-wheeled vehicles (MWV) raising such operational qualities as smoothness of a course, controllability, stability. The author developed adaptive algorithm of dynamic oscillation damping of the case of the MWV, which allowed to provide high indicators of smoothness of a course and mobility of the car. In this article the technique of synthesis of the adaptive dynamic continuous law of oscillation damping of the case of the MWV was described, and also the results of the simulation confirming high efficiency of developed algorithm of management were included.

Increasing of requirements on average speeds of movement, under all other equal conditions, demands permanent improvement of suspension system of multi-wheeled vehicles (MWV), suspension bracket creation as a difficult mechatronic system. The traditional design of a suspension bracket of wheels can't resolve the contradiction set in the technical project on the MWV – maintenance of high average speeds of movement on road and district and mobility in the case of overcoming of large individual roughnesses. The algorithm of the automated overcoming of the trench was developed, not only allowing to reduce loadings on bearing system of the MWV and corners of a longitudinal list of the case, but also to increase the width of an overcome trench at invariable quantities-dimensional characteristics of the chassis. The results of simulation allowing to visualize the process of moving across the trench by wheel car 8х8 were included in the article.

Increasing of requirements on average speeds of movement, under all other equal conditions, demands permanent improvement of suspension system of multi-wheeled vehicles (MWV), suspension bracket creation as a difficult mechatronic system. The traditional design of a suspension bracket of wheels can't resolve the contradiction set in the technical project on the MWV – maintenance of high average speeds of movement on road and district and mobility in the case of overcoming of large individual roughnesses. The algorithm of the automated overcoming of the escarp was developed, allowing to reduce loadings on bearing system of the MWV and corners of a longitudinal list of the case that promoted traffic safety increase. The results of simulation allowing to visualize the process of moving across the escarp by wheel car 8х8 were included in the article.

Required level of a damping of multi-basic oscillatory system depends on character of external indignation. In connection with this, regulation of the characteristic of damping, depending on operating modes of amortization systems, is one of the basic directions of their further improvement. This direction for improvement of quality of suspension systems of multi-wheeled vehicles (MWV) with quantity of axes more than three is rather perspective. Mathematical model and design procedure of design parameters of a pneumo-hydraulic spring with counter-pressure and two-level damping were developed for operated suspension brackets of MWV. The example of calculation of spring for suspension bracket of the MWV with the wheel formula 8x8 in the lump of 60 tons was included in this article.

Along with widely used theoretical methods of research of internal dynamics with use of imitating mathematical simulation, only natural tests can provide the final conclusion about working capacity of a design and correctness of a choice of options. Natural tests also allow to verify imitating mathematical models that is to estimate their adequacy and accuracy. The mathematical model of a two-volume pneumo-hydraulic spring (PHS) suspension brackets of new generation automobile platforms of average and big load-carrying capacity was developed. Benchmark tests of the natural sample of such PHS to check the adequacy of the developed model and research of behavior of a design were conducted at various kinds of loading. It was shown that the mathematical model described the processes, proceeding in a design two-volume PHS, precisely enough.

The author presents an approach to development of mathematical models of multi wheeled traffic systems and justifies the urgency of forecasting service properties of complexes at the design stage in order to improve the construction. The author gives a detailed account of the mathematical model of curvilinear motion of a two-link road-train; special attention is paid to the mathematical model of the link articulator. The author considers the principle of transport system simulation subject to the design features of the drawbar. Design diagrams for creating mathematical models of multi-tier transport systems are presented by the example of a three-link road-train subject to the number of wheels in the roller module of the level trailer. The author describes the principle of forecasting road-train dynamics based on using the mathematical model represented by rectilinear motion of two-link road-train off-the-road. The results of benchmark computing experiments as the visualization of movement of transport complexes are included in the article.

Some ways to improve the passability of multi-component wheeled transport systems were presented. Urgency of the development of mathematical apparatus for conduction of theoretical studies of rectilinear dynamics of various road-trains at the design stage with different characteristics of hitch mechanisms and in case of separate component movement. The results of mathematical simulation of two-component wheeled transport system’s dynamics on rock mantle for the following cases: combined component movement with different characterisrics of hitch mechanism and separate movement of passive trailed unit by means of auxiliary in case of different character of draft force application. Conclusions about conducted theoretical studies of transport system’s dynamics were generalized.

The required level of damping a multi-basic oscillatory system depends on the character of external disturbance. In connection with this, regulation of the characteristics of damping, depending on operating modes of amortization systems, is one of the basic directions of their further improvement. This direction for improving the quality of suspension systems in multi-wheeled vehicles (MWV) with the quantity of axes more than three is fairly promising. The authors show that for multi-wheeled vehicles, due to a narrow-band low-frequency spectrum of fluctuations of the case, the characteristics of damping which provides automatic reception in the zone of resonance of attenuation factor nearly 
ψ =0,4 … 0,6 on longitudinal-angular and vertical fluctuations irrespective of the weight of object and change of restoring force, was desirable. At the same time in the above-resonance zone, the damping level should be reduced, which leads to a significant decrease of vibro-load of the MWV. This leads to the necessity of creation of a suspension bracket of variable structure where there is an automatic change of the damping level depending on the kind of road roughness impact on the MWV. Two levels are enough: the basic (high), and low which joins only in the case of high-frequency road profile influence. The design procedure of elastic and damping characteristics of a suspension bracket with two-level damping was developed. The example of calculation for the MWV with the wheel formula 8x8 in the lump of 60 tons was included in this article.

The authors give a detailed description of car electromechanical transmission control at the individual distribution of power in the wheels, the main essence of which is proportional to the relative distribution of the normal load to be carried by the wheel. The law is adapted for two versions of drive control: "angular velocity" and "torque". Effectiveness of the law is proved by the results of mathematical simulation of car motion with 8×8 wheel formula on the basis of non-deformable reference to two cases: upgrading (with “angular velocity” control) and curvilinear motion with a fixed radius (with “torque” control). The directions of future research is the need to study car movement with the proposed transmission control in a wide range of external influences ("mixed doubles" motion, acceleration, motion on a deformable substructure, etc.), and also in comparison with the results of movement with traditional transmission patterns.

Nowadays there is no method reliable enough to calculate the set of important screw oil-filled compressor parameters analitically, in particular, parameters of inner compression and injection. The results of the survey, included in the article, have allowed creating a mathematical model of different processes, taking place in screw oil-filled compressor, and developing the methods for the calculating of inner compression and injection parameters. The comparative analysis of theoretical and experimental results showed good correlation between each other, that means this method can be recommended for the forecasting of the compressor working mode and calculating the basic parameters of this mode.