Tractive Effort Research Articles

Оценка балластирования тракторов 5-6 тяговых классов

To increase productivity in agricultural production, combined wide-grip machines are being created, aggregated with tractors of traction classes from 5 and higher. In addition, according to agrotechnical requirements, the pressure of the mover on the soil should be minimal, as well as the number of passes over the surface of the field. These contradictions can be solved by ballasting of tractors, which allows using engine power to increase tractive effort. Ballasting affects energy saturation. Increased energy saturation with appropriate ballasting makes it possible to compose machine-tractor units (MTU) according to a more accurate ratio of the tractor pulling force and the unit's pulling resistance. The most in demand in modern agriculture are tractors of 5-6 traction classes produced by domestic and foreign tractor-building plants with an internal combustion engine with a capacity of 220-320 kW and an operating weight of 115-150 kN. The article contains a two-way analysis of variance, which makes it possible to determine the greatest influence on the ballasting of a tractor. A diagram is constructed that gives an idea of which of the studied brands of tractors can be recommended for performing agricultural operations, taking into account ballasting and compliance with agrotechnical requirements. Keywords: TRACTOR, BALLASTING, ENERGY SATURATION, TWO-FACTOR ANALYSIS OF VARIANCE

Optimization of machine-tractor parameters units for target functions with minimum costs total energy

The article is aimed at developing the parameters and operating modes of a multifunctional unit for the simultaneous sowing of row crops and the introduction of the main and pre-sowing solid mineral fertilizers. The minimization of the target function in terms of the total energy consumption for the process is ensured by the combination of these technological operations in combination with the substantiation of the parameters and operating modes of the proposed unit, which ensures the introduction of a new resource-saving technology for sowing row crops. The difference between the methodological approach to solving the problem lies in the use of typical traction characteristics of tractors, linking their tractive power, tractive effort, working speed, specific fuel consumption of the engine in combination with the working width of the seeding unit, its traction resistance and operating conditions: type of soil, working length of rut, capacity of the fertilizer hopper, rate of consumption of seeds and fertilizers, etc. The standard indicators used in calculating the target function are taken from the reference literature. The urgency of the problem of reducing the energy intensity of the process is determined by a further increase in the competitiveness of the field crop production, where scientifically grounded parameters of machines and their mode of operation are of decisive importance. The regularities of the process and the dependence of the optimization criterion on the parameters and operating modes of the proposed multifunctional unit, obtained as a result of the research, make it possible not only to obtain their optimal value, but also to outline further directions for improving the design.

DC RAILWAY POWER FLOW ANALYSIS FOR ADDIS ABABA LIGHT RAIL TRANSIT USING NEWTON RAPHSON METHOD

This paper uses Newton–Raphson method for DC power flow analysis of the Addis Ababa light Rail Transit (AALRT). The study focuses onthe line section from Menilik II square station up to Lideta station. First the tractive effort required by the trains for different scenarios such as train movement in a straight line, a curved line, and a line with gradient is computed as the chosen line section contains all these scenarios. Then the total input power will be calculated using computed tractive effort obtained for each scenario and using other input parameters obtained from AALRT, and different papers. The input power for the different loads is computed, and the input power is used to analyse the bus voltage for different loads and train positions. Newton Raphson Method is used to solve the DC Power bus problem assuming that the train requires constant power while moving between two feeding stations. Even if using the rail as the return conductor for DC traction systems has economic advantages, it has some limitations like the rail potential and stray current. A rail potential study is carried out and conclusions are drawn. The result shows that the maximum voltage drop was 0.1 p.u and the train power consumption increases by 136.73 kW as the train takes a gradient of 3.92% and keep increasing again by 29.17kw with a curve resistance (100 meters). The Rail potential moves from 6.0139V to 29.85V proportionally with the variation of the total ground resistance.

Individual Drive-Wheel Energy Management for Rear-Traction Electric Vehicles with In-Wheel Motors

In-wheel motor technology has reduced the number of components required in a vehicle’s power train system, but it has also led to several additional technological challenges. According to kinematic laws, during the turning maneuvers of a vehicle, the tires must turn at adequate rotational speeds to provide an instantaneous center of rotation. An Electronic Differential System (EDS) controlling these speeds is necessary to ensure speeds on the rear axle wheels, always guaranteeing a tractive effort to move the vehicle with the least possible energy. In this work, we present an EDS developed, implemented, and tested in a virtual environment using MATLAB™, with the proposed developments then implemented in a test car. Exhaustive experimental testing demonstrated that the proposed EDS design significantly improves the test vehicle’s longitudinal dynamics and energy consumption. This paper’s main contribution consists of designing an EDS for an in-wheel motor electric vehicle (IWMEV), with motors directly connected to the rear axle. The design demonstrated effective energy management, with savings of up to 21.4% over a vehicle without EDS, while at the same time improving longitudinal dynamic performance.

Design and Testing of Solar/Electric Cart

In the current study we report design and testing of a light-weight electric/solar four-wheel drive cart capable of running at speeds in the order of 30mile/hour. The cart can carry 4 passengers and transport attached additional load of about 500 kg. The battery block consists of LiFePO4 cells and provides 6000Watt power to 4 hub motor wheels, each of which are rated 1500Watt. The 600Watt solar array secured on the roof provides steady recharging for the lithium-ion batteries. The power distribution and control of hub motors is executed by special programmed microchip controllers and is very important for safe operation of this of four-wheel drive vehicle. The commercial MPPT charge controller is installed to operate the amount of power for battery recharging. During operation the battery recharge could be executed using power of solar panels. Willingness to minimize dependence on the grid which operates 120V 15A, has led us optimize the required tractive effort while minimizing the weight of the cart. The cost of experimental electric/solar four-wheel drive cart is presented by table 1. Many elements of discussed prototype are taken from the shelf, i.e. purchased at the market price. So, the commercial cost of such prototype in mass production is expected to be significantly cheaper.

Adhesion Characteristic Slope Estimation for Wheel Slip Control Purpose Based on UKF

Slip controllers are crucial for railway vehicle operation when a high tractive effort is required. The slip controllers have been developed for decades, and their developments continue. The developed slip controllers are based on many more or less effective principles. One of the perspective slip controllers determines a phase shift between an injected excitation signal to the required torque of the electric drive and the signal representation in a measured wheel angular velocity. The slip controllers that are based on the principle can effectively work with any adhesion conditions. However, the slip controller principle has some drawbacks like high filtration requirements, possible failure due to mechanical shock in the wheel-rail contact and long response time. The paper proposes a novel phase shift detection method for the slip controller based on an unscented Kalman filter that can cope with the known disadvantages of the original slip controller. When the proper output of the UKF is used, the slip controller becomes faster, more reliable and can work when the original slip controller fails. The proposed slip controller was verified on the measured data in an open-loop calculation and the mathematical model in the closed-loop simulation.

DYNAMIC BEHAVIOUR MAINLY ON PERFORMANCES, ENVIRONMENTAL, SAFETY AND HEALTH BENEFITS OF EUROPEAN HIGHSPEED TRAINS (MADRID- BARCELONA HIGHSPEED LINE)

The main aim of this project is to study the Dynamic Behavior mainly focused on Environmental, Safety and Health benefits of different High-Speed Trains which are ETR500, ETR1000, ICE 3, Talgo 350, and TGVThalys with respect to their performance in the HighSpeed line of Madrid – Barcelona which has a speed limit of 300 km/hr. The main input parameters which are taken into consideration are Mass, Line Speed, Distance, Tractive Effort, Time, Speed, Energy Consumption, etc., Ratios of Mass/Passengers, Energy Consumption/Wheel, Etc. From this comparison, we get to know the performances of different type of high-speed trains in Madrid – Barcelona high-speed line and we can suggest the best one considering all Railway System factors considering all these factors. Railway Systems provide substantial benefits for the Energy-Consuming to the Environment. By using electrical Energy sources and more efficient mobility, Railway Transport can lower energy use and reduce CO2 and Pollutant Emissions.

Digital Data Processing Methods for Estimating Tractive Force of Tractors

Introduction. When carrying out an energy assessment of agricultural machines and traction tests of tractors, the most important indicator is the value of the tractive effort. The existing methods for determining the tractive effort of tractors imply the use of specialized measuring instruments, such as strain gauges and devices for processing and displaying information. The accuracy of determining the tractive effort is significantly influenced by the physical and mechanical properties of soil. To process the useful signal during the measurement of tractive effort, the data stream of the strain gauge sensor must be subjected to additional digital filtering taking into account the operating conditions of the agricultural unit. Materials and Methods. The functions of changing the tractive effort obtained on the K-744R2 tractor in various gears have been analyzed. An algorithm for digital processing of the signal of a strain gauge force meter based on a median filter has been developed that makes it possible to increase the measurement accuracy. The advantage of the proposed method is the ability to cut off sharp short-term impulse noise and sharp fluctuations in the amplitude of the measured value. Results. A method for determining the amount of tractive effort using median signal processing has been proposed. A device for determining the tractive effort during testing of agricultural tractors and units has been developed. The choice of the main components of the device for determining the magnitude of the tractive effort has been substantiated. As a result of the research, a device for measuring and digital processing of the signal of a force meter based on a microcontroller and specialized software for processing initial data in real time was designed and manufactured. Discussion and Conclusion. The developed method makes it possible to exclude the negative effect of impulse noise arising in the process of measuring the tractive effort of the tractor. The proposed device for measuring the tractive effort of tractors is compatible at the level of the exchange protocol with existing devices, has a high speed of operation in real time, multi-channel operation.

Numerical simulation and testing verification of the interaction between track and sandy ground based on discrete element method

Tractive effort of tracked vehicles plays an important role in military and agricultural fields. In order to solve the problem of low precision in numerical simulation of the interaction between track and sandy ground, a systematic and accurate discrete element modeling method for sandy road was proposed. The sandy ground was modeled according to the mechanical parameters measured by soil mechanics tests. The interaction coefficients of sandy soil were measured by the repose angle test and triaxial compression test combined with the corresponding simulation. On this basis, a discrete element interaction model of track-sandy ground was established, which can be used to test the tractive effort of track. Numerical simulation calculation of track model at different speeds was carried out, and the simulation results were compared with the results of indoor soil bin test for verification. The verification results show that the interaction between track and sandy ground based on DEM simulation is consistent with the actual soil bin test. The discrete element modeling method in this paper can be used to model the track and sandy ground accurately, and the simulation model can be used to test the tractive effort of tracked vehicle.

Non-Hertzian contact analysis of heavy-haul locomotive wheel/rail dynamic interactions under changeable friction conditions

Wheel/rail dynamic interactions of heavy-haul locomotives are highly nonlinear and complicated due to large traction/braking loads, frequent anti-slip control and complex wheel/rail interface environment. The wheel/rail dynamic interactions, as well as the interface wear, have been broadly studied by means of Hertzian contact analysis, but the wheel/rail contact is essentially a non-Hertzian contact matter. This paper presents an investigation of wheel/rail dynamic interaction characteristics of a heavy-haul locomotive subjected to traction loads and dry/wet/greasy contact conditions by using a non-Hertzian contact method. For this purpose, a comprehensive dynamics model for heavy-haul train-track coupled system is established. A non-Hertzian normal contact algorithm and the corresponding creep algorithm are employed to solve wheel/rail normal and tangential contact forces, respectively. The locomotive wheel/rail dynamic interactions under different contact conditions and traction efforts are discussed. The simulation results indicate that traction effort and friction conditions have a significant influence on the contact forces, distributions of contact stress, and adhesion-slip region in the wheel/rail contact patch. The adhesion-slip distributions were found to reach full-slip under the lowest-adhesion conditions, and the wear index was found to be much greater than that under dry condition.

Traction asynchronous electric drive of mine electric locomotivesimulation model structure improvement

The article discusses the solution to the problem of underground railway transport slipping in dynamic modes, which occurs when there is a significant difference in the speeds of the driving and driven pairs of wheels. The state of the rail surfaces largely determines the coefficient of adhesion, therefore, using a mathematical model, the condition for the dependence of the magnitude of slipping and tractive effort is selected. For effective acceleration and deceleration of an electric locomotive, it is necessary to control the coefficient of adhesion at a certain level. A simulation model of rolling stock has been created, which for the first time takes into account a mechanical system with distributed parameters. In the structural diagram of the automatic control system of traction electric drives with frequency regulation, such factors as the volume of goods being moved, rolling friction, slope (rise) levels and the state of the rail track are taken into account. The simulation results show the features of the movement and stops of the freight train not only by the diagrams of speed and forces in the modes of acceleration-deceleration and uniform movement, but also the positions of the plungers and tractive forces on the couplings of the electric locomotive and all trolleys involved in the movement of goods. The practical application of the proposed method lies in the possibility of starting a heavily laden train from its place on the ascent section in conditions of insufficient adhesion coefficient with contaminated roads.

Modelling the movement of log trucks with a hydro-mechanical transmission

The paper proposes a mathematical model of the movement of log trucks with hydro-mechanical transmission, which represents the analytical functional dependence of the speed of the log truck on the covered path. On the basis of real data it is shown that the traction characteristic of hydro-mechanical transmission is best approximated by hyperbolic regression. In this case, the solution of heterogeneous nonlinear differential equation of motion can be obtained by the approximate analytical method through decomposition of a logarithmic component in series. The calculation example showed that the obtained approximate analytical solution deviates from the numerical solution by no more than 0.002%. The obtained model allows one to determine the analytical dependencies for speed and time, which can be used to calculate the modes of movement of log trucks with the hydro-mechanical transmission.

Analytical determination of speed coefficient in the formula of V.P. Goryachkin for plow resistance

For almost all tillage implements traction resistance is calculated by the rational formula of academician V. P. Goryachkin with possible refinements of incoming parameters in accordance with the design of working bodies or operating conditions. The rational formula includes three coefficients associated with the unstable properties of the soil and the variable form of the working bodies. For this reason, the coefficients may not be the same for all tool designs and soil types. Each coefficient contributes an element of uncertainty to its ccomponent of the formula. The third component of the formula with a speed coefficient determines the part of the tractive effort to push back and turn the soil layers. The article calculates the power required for both of these actions of the working body. This power is determined by the lateral force acting on the soil layer. Lateral force analytically is associated with the tractive effort of the tractor taking into account the angle of setting of the moldboard and the coefficient of friction of the soil. This data is sufficient to compile a method for analytically calculating the speed coefficient. It turned out that it does not depend on the speed of the plough or the depth of plowing. It is influenced only by the density of the soil, the angular dimensions of the moldboard and the angle of friction on the soil. The calculated dependency graphs are given. At the usual values of the friction angle of 28-30° and the angle of inclination of the moldboard 43°, the speed coefficient is 2400 kg / m3. If we apply vibration, the friction angle is reduced to 25-26°, and the speed coefficient becomes equal to 2000 kg/m3. High-speed moldboards, having their design features, have a speed coefficient of 1700-1800 kg / m3.

Improving the efficiency of the process of burnishing splined holes under the influence of an ultrasonic field

The essence of finishing and hardening processing of slotted holes with shaped mandrels is described. The analysis of the technological parameters of the mandrel process has been carried out. It is shown that the main technological parameter that determines the efficiency of processing is the tractive effort. A technological scheme is proposed for mandrel drilling of spline holes of gear wheels, which provides by imposing an ultrasonic field on the workpiece. reduction of it by 40%. creation of favorable compressive stresses in the surface layer.

Ways to increase the traction efficiency of modular draft device

The versatility of tractors can be increased by using them as a part of a modular draft device (MDD). MDD consists of energetic (EM) and technological (TM) modules. EM is a high-energy tractor with a 2WD or 4WD wheel arrangement and a traction force of 14-16 kN. TM is an additional axle with an active drive of its wheels. By connecting TM to the rear hitch linkage (RHL) of EM, the tractive effort of the entire MDD, which has a 4WD or 6WD wheel arrangement, increases to 32-36 kN. MDD can function as a road-rail vehicle. Depending on the traction resistance, MDD can be used both as part of an EM+TM or as a single EM. According to the research results, it was found that the maximum traction efficiency (TE) of MDD with a 6WD wheel arrangement is about 10% higher than that of MDD with a 4WD wheel arrangement. The TE value of MDD increases with an increase in the inclination of EM rear hitch linkage top link. The increase in MDD’s tractive efficiency is facilitated by an increase in the coefficient of kinematic discrepancy in the drive of the EM and TM wheels from 1.00 to 1.05.

Uticaj vučne sile i brzine kretanja na čvrstoću osovina lokomotive

The article presents the dependencies obtained when researching the load on the locomotive axles, depending on the traction force and the speed of movement of the locomotive. The traction characteristic of the locomotive is the relationship between the traction force achieved by the traction motors and the speed of movement, and it is different under different driving conditions. Different modes of operation of locomotive axles are considered. A simulation of the axles' behaviour has been developed. The strength and deformation characteristics of the locomotive axles under different loading modes are calculated. A comparative analysis of the strength characteristics of locomotives with different classes of transmission mechanisms has been made

Electromechanical Transmission of Skid Steer Loader

The article analyzes the power train components of skid steer loaders. The choice of the scheme and the design of the transmission units of the loader with a traction electric drive is substantiated. The results of calculating the traction characteristic of the straight-line movement of the loader taking into account different values of the coefficient of resistance to movement are presented.

Comparison of Ideal Traction Hyperbola Curves with Matlab-Simulink in Vehicles

The gearbox is part of the powertrain that transmits movement from the engine to the wheels. Gears, shafts and auxil-iary systems are used in Gearboxes. By using these systems, it is possible to control the movement of the vehicle at the desired tractive effort and vehicle speed in different gear ratios as well as in different direction situations. To increase vehicle performance, it is necessary to obtain curves close to the ideal traction hyperbola. In this study, vehicle speed and tractive efforts of two different 12-speed vehicles with the same engine characteristics were calculated with Matlab/Simulink. According to obtaining the results, the tractive effort curves based on vehicle speed were estimated and ideal traction hyperbola curves were formed. The comparison of ideal traction hyperboles for both types of gearboxes showed that the curves have a similar structure.

Linear asynchronous traction drive in urban rail and maglev transport systems

The development of transport infrastructure of large cities with high population density and development should be carried out on the basis of innovative technical solutions, that allow to simplify the conditions of laying of tracks, reduce the cost of construction, reduce noise, provide comfort to passengers and reduce the cost of operating rolling stock. One such solution, the effectiveness of which is confirmed by foreign experience, is the use of linear asynchronous traction drive (LATD) in urban rail and maglev transport systems. This, in particular, allows to increase the allowable value of slope paths to 6065, reduce the vertical dimensions of rolling stock to 3.15 m, reduce the diameter of the tunnel by 2530%. The release of the wheel pair from the function of the implementation of traction effort makes it possible to apply on the wagons the articulated semi-frames of trolleys, that ensures better rolling stock in curves, and as a result - less wear of wheels and rails and less noise.
 This article analyzes the advantages and disadvantages of LATD compared to the traction drive of traditional execution, considers variants of constructive performance of linear induction motors (LIM), processes of electromechanical energy conversion in LIM, the option of building a LATD control system is presented. The article examines the flat LIM, which have found use in the transport systems of major cities in Asia and America. The processes of energy conversion in LIM are distinguished by the presence of a longitudinal edge effect, which determines the distortion of the resulting magnetic field, which is manifested in the reduction of induction and the displacement of the peak of the induction distribution curve to the escaping edge of the inductor. This effect is particularly manifested in high-speed LIMs with high quality. When the linearity of the magnetic environment is allowed, the resulting electromagnetic force of the LIM can be considered as the sum of electromagnetic forces created by the main field, as well as the direct and reverse fields of the longitudinal edge effect. The edge effects reduce efficiency and power ratio of LIM. The article discusses ways to compensate for the edge effects, as well as an overview of the world experience of the use of LATD in rail and maglev transport systems.
 The advantages of LATD and the world experience of its use suggest that for urban transport systems at speeds of up to 100-120 km/h this drive can be a real competition to traditional urban rail systems.

INFORMATIONAL PHASE OF THE DEVELOPMENT OF EQUIPMENT FOR ANALYSIS OF DIRECT SHEAR AND PRE-COMPACTION OF THE SOIL

Given the real need for advances in studies such as the relationship of soil-machine dynamics, it is clear that there are almost no innovative systems developed to attend this demand. The design of agricultural machinery and equipment can be facilitated by having information and mechanisms that allow the prediction of the mechanized-set behavior in real work situation, especially regarding the traction effort demanded by the tractor, due to the energy demand of the equipment that interact directly with the soil. Obtaining this information usually requires high-cost imported laboratory equipment. Thus, the objective of this work was to obtain the design specifications for the development of a direct shear and soil pre-compaction analysis equipment with low manufacturing cost. The Phases Methodology was used to obtain the necessary parameters, in the informational phase of the desirable aspects for each design requirement. Through a step-by-step analysis, it was possible to obtain customers’ needs, together with the establishment of the desired criteria, and the design requirements for the new product development was generated. The use of the Phases Model allowed the transformation of customers’ requirements into the design requirements, enabling hierarchization by degree of importance and thus enabling the execution of future steps.