No 3 (2016)


The study of “real-time” simulation of planar curvilinear motion of six-wheel drive vehicle

Buzunov N.V.


The main focus of this research is to verify the mathematical model of the vehicle motion, which operation is carried out in real time. The subject of this study is the model, which describes planar curvilinear motion of six-wheel drive vehicle. Correct operation of this model is based on the methods and criteria currently used in the foreign and domestic research. The estimating parameters for the model are the linear and angular kinematic characteristics of planar motion of the vehicle. The assessment criterion is the value of relative error no more than 10% when comparing at the same time the parameters of the model with the parameters of the reference model, which correctness of operation is confirmed by the results of experiments on the real object. Research is carried out in several stages at different driving modes and various parameters of the simulation. The duration of the test "races" is 30 sec. At the end of each race the comparison of the results with the data of "reference" model is made and determination of relative error of simulation and its comparison with the established criterion of correctness are done. According to the study was found out that the mentioned real-time verification of the model satisfies a predetermined criterion of verification when using step of no more than 0,001 sec. By increasing the steps of realization there are significant deviations of the model parameters on the results of "reference" model, in this case, the real-time model can be used to address a limited range of purposes. Reducing simulation step facilitates approximation to the behavior of the test object to the "reference" but in real-time operation this approach requires a significant increase in computing power.
Izvestiya MGTU MAMI. 2016;(3):2-8
pages 2-8 views

Mathematical modeling of the dynamics of manipulation system for mobile transport and technological machine with reference to the elasticity of elements

Kovalskiy V.F., Lagerev I.A.


The approaches to modeling the dynamics of mobile manipulators of transport and technological machines with reference to the elastic compliance of elements are shown. The equations of motion of the manipulator units are recorded using the method of Lagrange multipliers. As the main origin for each element were taken four Rodrigues-Hamilton parameters, coordinates of the element position as absolutely rigid body and elastic movements. The equations take into account the impact of external and internal elastic and quadratic forces. Internal elastic forces are calculated on the basis of the stiffness matrix, which formation is made through calculation of the manipulator by finite element method. To set the join couplings the required number of constraint equations is built. The methods of creating of widespread kinematic schemes of manipulators of cylindrical and prismatic joints using set of constraints involving mutual perpendicular vectors, which belong to articulated elements. Using the developed model the dynamics of articulated manipulator crane ACT-4-A was calculated. It was found that the inclusion of elements elasticity reveals oscillatory behavior of the kinematic and power factors of the process and, thus, increase the adequacy of modeling of manipulation system operation during machine use. Elastic elements causes their oscillations with a frequency, which is commensurable with the first lower natural frequency of metal manipulation system itself, that indicates the desirability of its test for the absence of resonance and, if necessary, the development of positive measures to improve the dynamic reliability of the manipulation system. It has been shown that to calculate manipulators for some machines the chassis dynamics should be taken into account.
Izvestiya MGTU MAMI. 2016;(3):9-15
pages 9-15 views

Experimental study of comparative indicators of agricultural tractors caterpillar drive

Kupryunin D.G., Shchelnitsyn N.A., Beyinenson V.D., Fedotkin R.S., Belyi I.F., Revenko V.Y.


Rubber reinforced caterpillars are becoming more common in agricultural tractors, harvesters and military tracked vehicles. The use of rubber reinforced caterpillars comparing to metal tracks allow: to reduce on 25-30% the sealing effect on soil; ensure the movement of vehicle on the roads with asphalt pavement without its damage; to increase vehicle road speed to 40 ... 50 km / h; to reduce noise and to improve working conditions for tractor driver; to increase reliability. Nowadays there are no comparative results of experimental evaluation on the application of rubber reinforced caterpillars and metal tracks on tractors. Traction tests of tractors with rubber reinforced caterpillars abroad are conducted on a specially prepared supporting surface in the form of a rubber blanket, where tractors with metal caterpillar tracks could not be tested. In this case the obtained tractor traction characteristics differ significantly from the actual operation. The paper presents the results of comparative tests of VK-150 tractor manufactured at Volgograd tractor plant on stubble of winter wheat with rubber reinforced and metal tracks with open metal joints. It was found that the developed domestic machines and manufacturing technologies of rubber reinforced caterpillars for agricultural tractors provide equal traction parameters of tractor with series metal and rubber reinforced tracks in zone in the area of nominal traction forces for tractors of class 3. By set of technical characteristics chassis with rubber reinforced caterpillars perform better than chassis with metal caterpillars with open joints (in terms of vibration loading, noise and flotation).
Izvestiya MGTU MAMI. 2016;(3):16-24
pages 16-24 views

Application of microelectromechanical sensors in the integrated navigation system of ground transport and agricultural technological vehicle

Novikov P.V., Gerdi V.N., Novikov V.V.


The questions of assessment of achievable performance values of the integrated inertial-satellite navigation system complexed with odometer sensor and used for ground transport and agricultural technological vehicle are considered. Construction of relatively cheap modern navigation systems for ground transport and agricultural technological vehicles is provided by integrating diverse navigation systems, which include inertial-satellite systems that combine into a single hardware system the inertial and satellite modules. Achievable accuracy of gaining the navigation parameters is achieved by using special algorithms for processing of measurement information in combination with complexion of the system with an external source of additional information, where odometer sensor belongs. The most promising sensors are sensors, built using the technology of production of microelectromechanical systems - MEMS / MEMC (Micro-Electro Mechanical Systems). The navigation systems based on MEMS sensors have several advantages. The main advantages are small weight and size characteristics (volume less 1sm3, and weighs less than 1 gram), low power consumption, high reliability, resistance to vibro-impact loads (up to 2000g), easy integration of sensors and electronic modules of the navigation system, low cost. The main disadvantage is the need for the synthesis of complex algorithms of processing of measuring information to obtain the desired accuracy of the estimate of navigation parameters. The navigation system, where as MEMS sensors were used gyroscopes ADXRS-150 in conjunction with accelerometers ADXL-210 manufactured by Analog Devices, was considered. The main design and technological characteristics of sensors were shown, the selection criteria for sensors were formulated, technical and economic effect assessment of the use of MEMS in the navigation system is provided. The practical importance has the estimation of achievable accuracy characteristics of system under actual operating conditions. The paper presents the results of field tests of the navigation system based on MEMS sensors and designed for forklift carrying out transportation in the sea port. The results of experimental studies confirmed the effectiveness of the MEMS application as a sensing element of inertial-satellite navigation system of ground transport and agricultural technological vehicle that creates the foundation for the new high-tech developments.
Izvestiya MGTU MAMI. 2016;(3):25-31
pages 25-31 views

Problems of process control for shifting gears on tractors without torque interruption

Timofievskiy A.A.


The article considers the problem of optimizing the process control for shifting gears on tractors without torque interruption. The opinion on the dynamics of process control for shifting gears is explained, it takes into account the occurrence of torque deficit in the shafts, when changing gear, and increasing of friction losses in spinning clutch. The formulas for calculating the dynamic parameters used in the mathematical model of the dynamics of the tractor when shifting gears without torque interruption are shown. With the help of the mathematical model developed in Scientific and Research Tractor Institute (NATI) for debugging the system of electro-hydraulic control of gear shifting process for CHN-6 tractor were calculated several variants of gear shifting. Particular attention is given to occurrence, development and completion of the power circulation process in the circuit of switched clutches, because the lack of circulation of power the majority of authors call the basis of optimal switching. The results of the calculations in terms of the circulation of power, failure to slipping of switching off the clutch and interlocking of switched on clutch are shown. Calculation results suggest that when the clutch of lowest gear is closed the torque growth in spinning clutch of switched on top gear causes an increase in friction losses of disks, which leads to a decrease in engine shaft speed and reduction of the tractor speed. The magnitude and duration of fall of the engine speed and the speed of the tractor are low, but due to a decrease in the speed of the tractor the moments of forces inertia are large enough and need to be taken into account in the calculations. In all experiments, where power circulation was present, it started earlier than top gear clutch created torque, which corresponds to the resistance movement. In all experiments, where power circulation was present, it ended as a result of reducing the pressure in the clutch booster of lower gear after its failure to spinning in the power circulation mode. The circulating power after the failure to spinning and clutch switching off is redirected to output shaft accelerating the tractor and accelerating the synchronization and interlocking of switched on clutch.
Izvestiya MGTU MAMI. 2016;(3):32-42
pages 32-42 views

Energy savings for heating cabins of mobile machines and production facilities for their maintenance and repair

Mikhailov V.A., Kutkov G.M., Dmitriev M.I.


The ways of energy saving in air heating of cabins of mobile machinery (tractors, trucks, harvesters) and production facilities are discussed. It is shown that in the cabins of mobile machines with a relatively small volume with no exhaust ventilation to reduce energy consumption for heating, while regulating temperature at workplace and relative humidity, is to use partial recirculation of treated air. Specific recommendations for the heating of the mobile machine cabins, which is characterized by basic parameters such as thermal performance, air flow and temperature are given. It was found that the partial recirculation of the treated air in the cabin of the mobile machine has allowed to reduce energy consumption for heating in 1.94 times and provided on working place of operator normalizable relative humidity without any additional units for humidification. It is shown that in areas of larger volume, where maintenance and repair is carried out in the presence of local exhaust ventilation, standard for relative humidity could be provided only with humidifier. Thus in order to reduce energy consumption for heating it is necessary to dispose the exhaust air heat flow to preheat the incoming air using the heat exchanger-recuperator provided with an exhaust air dryer to avoid freezing of apparatus at low ambient temperature conditions. The filler of drying unit could be silica gel as water absorption by silica gel is accompanied by increasing treated air temperature and in the heating system it leads to energy consumption and is a positive characteristic.
Izvestiya MGTU MAMI. 2016;(3):43-49
pages 43-49 views

Design features of fan assembly in automobiles

Petrov A.P., Sinitsyn S.N., Bannikov S.N.


Nowadays in the engine cooling system and in air-conditioning system of passenger compartment and cabin of tractor is applied a great variety of designs of fan units for the supply of cooling air. A distinctive feature of fan units of automobiles is that they need not only to supply cooling air, but also must make efficient use of air flow. This is not an easy task, because these two functions are almost always in conflict. The problem becomes even more complicated when a car air conditioner is installed. Efficiency factor of the incident flow is higher than the efficiency of the fan. It is therefore necessary to use more efficient the incoming air flow. The article analyzes the most common fan assemblies of automobiles used for the operation of the engine cooling and passenger compartment air conditioning system. Its strengths and weaknesses were evaluated. There were evaluated the most important characteristics: the effectiveness of the fan use, the rational use of air flow when the vehicle is moving, mass-dimensional characteristics and the noise produced by the fans in their work. The conclusions and recommendations for improving the fan installations were given. When choosing one or another variant of the fan assembly it is needed to take into account the features of the automobile design. High efficiency of fan can be obtained when the fan shroud has a full coverage of the radiator. In this case, for rational use of incoming flow is necessary to install in the fan cover the valves of a large cross-section in contrast to traditional, these valves must be driven to forced opening and closing.
Izvestiya MGTU MAMI. 2016;(3):50-57
pages 50-57 views

Design of four shaft misaligned semi-automatic transmissions for agriculture tractors

Sharipov V.M., Platonov V.F., Kryuchkov V.A., Alendeev E.M.


When designing semi-automatic transmissions for tractors and automobiles the engineers of machine-building enterprises face the lack of techniques that allow uniquely identifying their design parameters. In particular, when determining the shaft layout in four shaft semi-automatic transmissions with shaft misalignment design with the need to respect the minimum width the mutual influence arises of geometry parameters and design of gears to each other and to the overall width the same time. In solving this problem it is necessary to resort to the use of graphic-analytical method with a large number of iterations that is time-consuming and does not provide a guarantee of repeatability of result. The article describes a technique that allows choosing rational parameters of the basic kinematic units to ensure minimal overall width, and uniquely identify its position in space. Sequence of design of semi-automatic transmission is reduced to the choice of gear ratios and the formation of a rational layout of shafts through which minimizing of its overall width is achieved. It was established that, on the basis of the kinematic parameters of the units it is possible to build a rhombus which completely determines the location of the shafts in semi-automatic transmission. For a complete description of the geometry of the rhombus and its position in space were obtained the corresponding analytical dependences allowing to determine the dimensions of semi-automatic transmission and the distance between the input and output shafts without the use of graphic-analytical method with a large number of iterations. The developed method of design of semi-automatic transmissions can be used to create similar assemblies for automobiles.
Izvestiya MGTU MAMI. 2016;(3):58-65
pages 58-65 views

The first self-propelled carriages in the description of their inventors (domestic experience)

Rybina M.I., Baulina E.E., Kruglov S.M., Serebryakov V.V.


The authors considered first inventive period in the history of the domestic automotive industry, analyzed preserved to our days descriptions of the “horseless carriages” of Shamshurenkov and Kulibin. Relying on the presented material authors conclude that the main way to describe the new inventions became terminologization or specification of the existing term, as a rule, borrowed from related areas of technical knowledge. It is noted that over time, many Russian words have given way to the terms that came from French and German, and then English. This process was driven by the general internationalization of the automotive terminology as well as the superiority of the US automotive industry in the late XIX - the beginning of XX century, during the creation of the modern car. Analysis of inventions of Shamshurenkov and especially of Kulibin from a technical point of view (re-creation of models of self-propelled carriages, decoding surviving drawings), as well as their engineering judgment in a large number of special studies on the professional and amateur levels (model of Kulibin carriage is presented at the Polytechnic Museum in Moscow, periodically in Internet appear materials on tries of self-taught inventors to repeat experiments of Shamshurenkov or Kulibin) is widespread. But there are no works devoted to first attempts to describe the terminology of invented self-propelled structures. In this paper, the authors have tried to fill this gap and, as far as possible, to show how do imagine their inventions the creators Shamshurenkov and Kulibin. Analyzing the experience of Shamshurenkov in the creation of the horseless carriage authors relied on a deep study of engineer and technology historian E. I. Gagarin, who worked in Lomonosov Moscow Automotive Institute (now Moscow Polytechnic University).
Izvestiya MGTU MAMI. 2016;(3):66-71
pages 66-71 views

Methods of recycling of pneumatic and non-pneumatic tires

Kostrova Z.A., Mikheev A.V., Zezyulin Z.V., Makarov V.S., Belyakov V.V., Bushueva M.E., Struchkova I.V.


Paper discusses main reasons for the necessity of tires utilization. The tire is considered as a complex composite part which should satisfy the requirements for resistance to repeating and variable loads and the damaging effects of the environment, etc .; these properties make it difficult to recycle tires; to solve the problem an average composition of the tire is provided. Differences in the treatment of worn tires in different countries and ways of utilization of pneumatic and non-pneumatic tires are shown; variants for cold and hot recovery tires are provided; the economic effect of tire recovery comparing with tire replacement is shown; methods of processing used tires with the destruction of the rubber component that causes polymer degradation and without destruction of the rubber component are provided. The percentage of use of retreaded tires in the total amount of tires purchased in some countries is given. The analysis of options for further processing of tires as processing tires into rubber crumb and its further use was made. The general structural features of the tire without air (non-pneumatic) - “spoke” and “cellular” are described. A comparison of methods for utilization of pneumatic and non-pneumatic tires in terms of structure and the tire material was made. The generalized classification of methods of disposal of polyurethane materials is proposed; environmental issues of tires recycling are shown. The reasons to simplify recycling of pneumatic tires comparing to non-pneumatic (airless) tires are provided. The possibility of using biodegradability as one of the most economically and environmentally effective ways of recycling materials for non-pneumatic (airless) tires, namely polyurethane products was discussed.
Izvestiya MGTU MAMI. 2016;(3):72-79
pages 72-79 views

Applying the law of conservation of angular momentum in the analysis of switching in automatic transmissions

Salamandra K.B., Tyves L.I.


The solution of problems of the dynamics of mechanisms is based either on a differential principles of theoretical mechanics, or integrated principles. The first involves the drawing up of the Lagrange equations of the dynamics that characterize the state of the mechanism at any given time, and the analysis of their solutions. The second are related to the conservation laws (the law of conservation of energy, momentum conservation law) and allow making an integrated assessment of the results of movements for any interval. The differential principle is used for the analysis of dynamic processes in the switching at gearboxes of vehicles, and is acquitted in the analysis of switching at manual control gearboxes. In this case, the switching process takes seconds and all phases of the process are described mathematically correct. The use of this approach in the analysis of the dynamics of switching at automatic transmissions, lasting 0.2 ... 0.5 s, is connected with the involvement of a large number of assumptions. They relate to the description of alleged interactions of switched on and switched off mechanisms of gearbox control and are carried out on a fairly simple model of a two-stage gearbox. In the analysis of more complex models, such as the gearbox with dual switching (2 clutches off, 2 on) the application of differential principle becomes significantly difficult. Reducing (or increasing) of velocity of the inertial elements of transmission at a gear change in a short time is possible only under the action on switching on clutch of large forces. Therefore, considering the model of automatic transmission on a small time interval as a closed system, it is possible to apply the theorem of conservation of angular momentum. Using this integral principle in the article the velocity calculation is given in the input and output of the gearbox after the switch; the evaluation of the limit torque acting on the units of gears at switching was made; criteria for clutch selection corresponding to the required switch settings is proposed; and also the problem of controlling the process of double-shifting is solved. The approach complements the known methods of research and can greatly simplify calculations of dynamic loads.
Izvestiya MGTU MAMI. 2016;(3):80-88
pages 80-88 views

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