Introduction. Currently, interest in the electric drive of transport vehicles has grown significantly. The electric drive is actual for both wheeled and tracked vehicles. The peculiarity of any tracked transport vehicle is that despite its rectilinear movement the transmission must also secure the machine turn provided by a mismatch in the speed of rewinding of the tracks on the left and right sides.

Methodology and research methods. The method of synthesis of planetary mechanisms with two degrees of freedom has been proposed to be used as part of electric transmissions of single-link tracked vehicles.

Scientific novelty and results. As a result of the proposed technique, kinematic schemes of planetary mechanisms have been synthesized, which consisted of two planetary rows and provided both rectilinear and curvilinear motion of single-link tracked vehicles.

Practical significance. The obtained kinematic schemes will allow the development of electric transmissions to provide the most efficient use of energy sources in both straight and curvilinear motion.

Introduction. The article is devoted to the description of the basic algorithms for controlling the stiffness of pneumatic elastic suspension elements of a vehicle with two stiffness values adjusted to disconnecting part of the working volume. This scheme of variable stiffness of the vehicles suspension is actively being implemented by world leaders of the industry. It allows one to ensure a quick change in the stiffness of the elastic element without tangible energy costs, and a significant increase in the mass and layout volume of suspension systems.

The purpose of the scientific research was to increase the comfort and safety of passenger vehicles by changing the properties of the suspension system components with regard to current traffic conditions.

Methodology and research methods. To achieve the goal, the development of control logic for adjustable suspension systems has been carried out, which allowed creating an algorithm for software suspension control systems. The following block diagrams of the switching algorithms for general operating mode of the suspension and the current control of the elastic elements stiffness for maneuvering were presented: the change of lane, wave road, braking and turning. The flowcharts were given in the format of developing the complexity of logic from the simplest to continuously responding ones to the environment.

Scientific novelty and results. The results of computer algorithms modeling for the current control of elastic elements stiffness for a number of maneuvers have been presented to consider general operating modes of the suspension. The simulation results showed the effectiveness of the system of pneumatic elastic suspension elements with variable stiffness. The operation of this system provided a significant reduction in the vibration load of passengers, together with a significant increase in a vehicle stability.

Practical significance. The developed logical circuits will make it possible to create a program for controlling the vehicle’s suspension, increasing its operational properties.

Introduction. One of the main stages in the design of special-purpose vehicles is the calculation of the brake system. When calculating the braking performance dynamically, the braking diagram is constructed in the form of a graph of deceleration dependence, the braking pressure or a specific time braking force. On each axis, the maximum braking force and traction limit are compared. Then, the increasing pressure time and the stopping distance are determined.

The purpose of the study was to identify the integral method shortcomings when calculating the braking distance and to carry out the necessary refinements.

Methodology and research methods. The integral and iterative methods for calculating the braking distance due to the braking diagram are known. More accurate results can be achieved by applying the iterative method at each step of differentiation. However, in the design and evaluation calculations, the accuracy ensured by the integral method is sufficient taking into account the refinements given in this article. The pressure rise time in the pneumatic brake actuator is determined by means of the linear approximation method.

Scientific novelty and results. In the course of research it has been found that the traditional integral method did not take into account the dependence of the clutch implementation time on the adhesion coefficient, mass of the load, vertical reactions redistribution under the deceleration influence and the mass center height of different parts of a road vehicle. Besides, the ratio of the maximum braking force and the adhesion limit was not also taken into consideration, as well as the influence of the brake chambers size and the friction coefficient between the friction surfaces of the brake mechanisms. The authors proposed a new refined method for calculating the braking properties.

Practical significance. The research results should be taken into account when developing brake systems, automatic emergency braking systems and autonomous control systems. They can also be used in the educational process.

Introduction. Energy efficiency increase, environmental friendliness and wheeled vehicles safety are three main trends in improving their designs. The high level of consumer vehicle properties depends on the technical level of all its components, including the technical and economic indicators of the drive axles. The functional and technical characteristics of the driving axles determine the most important vehicle operational properties such as traction and dynamic indicators, fuel efficiency, noise levels, smoothness, support patency, and other characteristics. Almost all of these properties are known to be largely determined by the design, lubrication regimes of rotating parts and transmission oil characteristics. Traditionally, the operating conditions studies of the drive axle mechanism and its lubrication system are carried out with the help of laboratory and bench tests. However, lately technologies of “digital testing” or computer simulation have been increasingly practiced in automotive vehicles designing.

The purpose of the study was to develop a computer simulation technique for the hydrodynamic lubrication processes in the drive axle housing applying the FlowVision software package.

Methodology and research methods. Classical hydrodynamic equations in the form of Navier-Stokes equations, methods for the numerical solution of partial differential equations and dynamics computer simulation of a continuous medium were used to develop the research methodology.

Scientific novelty and results. As a result of the work performed a special technique has been developed. The scientific novelty of the work is a new method for the solution of an urgent problem by means of computer modeling technology.

Practical significance. The developed technique will reduce the volume of field tests in the development and optimization of lubrication systems for transmission units.

Introduction. Mechanical impact tests of automotive emergency call systems, carried out in order to determine the overloads resistance arising from a vehicle collision and to verify automatically the possibility of determining the moment of an accident, require the use of (CFC) KCHKh60 or KChKh180 frequency characteristics, as a means of impact measuring characteristics. The requirements for low-pass filtering carried out by a 4th-order phase-free Butterworth filter, are specially distinquished from the other requirements for such a measuring system.

The purpose of the study was to analyze the possible limitations that arise when using the empirical method of binding transposed data before starting and after the comleting of data collection, regulated by ISO 6487 and developed by the international standardization organization. The domestic regulatory documents related to impact testing were based both on the above documents and SAE J 211-1, developed by the community of automotive engineers.

Methodology and research methods. The research method consisted of presenting the additive noise signal which accompanied the impact, in the form of a determinate sinusoidal signal with an initial phase characterized by specific resulting maximum spurious emission signal, and included the further analysis of the signal occurrence with a purpose of its minimization.

Scientific novelty and results. The result of the work carried out was the identified shortcomings in the methods of forced binding of transposed data regulated by ISO 6487 and SAE J 211-1 before and after the data collection and the possible limitations. Scientific novelty resulted in the proposition of the method for additional shift of transposed additional data for the purpose of significant reduction of the emerging transients effect. The proposed analytical expressions and the implementation of the algorithm minimized spurious emissions of the resulting shock acceleration pulse during testing.

The practical significance of the research consists of increasing the reliability of the test results by comparing the shape of the shock pulse filtered due to ISO 6487 and SAE J 211-1methods, as well as by the method proposed with the exception of the stray component.

Introduction. A “mega-trend” in the global automotive industry, aimed at the significant (up to 20–30%) lowering of fuel consumption and CO₂ emissions is the downsizing and simultaneous boosting of the gasoline internal combustion engine (ICE) to maintain or improve a passenger car rideability. The practical implementation of this concept requires solution of a number of problems the most difficult is the quality deterioration of the vehicle ride caused by the turbo lag.

Methodology and research methods. A review of the reasons and measures undertaken to minimize the turbo lag while lowering the internal combustion engine dimension is based on a comparative analysis of the results of experimental and calculated studies of the turbo lag presented in foreign and domestic publications over the past few years.

Scientific novelty and results. For the first time the main causes of the appearance of a turbo lag in a downsized gasoline engine as well as factors that allow them to be eliminated or reduced have been generalized and systematized. The best combination of ICE technology which permits turbo lag reduction is the one of a direct gasoline injection and the adjustment of a valve actuator. Both technologies increase filling due to the charge cooling, the first – due to the fuel evaporation in the cylinder, the second – due to the combustion chamber purge. The effectiveness of the new ICE technologies was evaluated: exhaust period separation, recompression, charge air supercooling, for extreme downsizing. A combined turbocharger with a mechanical or electric supercharger was recommended for extreme downsizing. The latter was compatible with the electrification of the power drive and allowed the internal combustion engine to operate almost without a turbo lag with reduced fuel consumption by 25–33% and CO₂ emissions.

The practical significance of work lies in the possibility of using its results when choosing a circuit and design solutions for a promising low-dimensional gasoline engine.

Introduction. The article dwells on the problem of reducing emissions of nitrogen oxides contained in the exhaust gases (exhaust) of diesel internal combustion engines (ICE) of vehicles. In their operation when controlling harmful substances it is necessary to take into account the local impact of emissions on settlements located near highways. It is noted that there is a problem of high pollution with nitrogen-containing emissions not only of the settlements environment through which highways pass, but of vehicles drivers as well.

The purpose of the study was to analyze the operation of the SCR-NH₃ neutralization system by supplying urea to the exhaust gas of diesel ICEs, as well as the study of the supplying urea method at its injection into the cylinders of the diesel ICE during the gas exhaust cycle.

Methodology and research methods. Studies show that the most important factor is the thermal effect on the reaction process which determined the effective neutralization reaction on a diesel ICE catalyst. The main contributions to the total NO_x emissions are made by rated power modes of the internal combustion engine and the maximum torque modes. The relationship between the maximum NO_x concentrations at M_k.max and N_e.max on the total NO_x emissions in the 13-step cycle of UN Regulation No. 49 was demonstrated.

Scientific novelty and results. The disadvantages of the SCR-NH₃ neutralization method have been analyzed. In this regard, it was proposed to improve the method of feeding urea and fuel into the cylinders of a diesel engine by means of a two-channel nozzle. Additional advantages could be obtained by injecting urea into the internal combustion engine cylinders.

Practical significance. The results of calculating temperature in a diesel engine cylinder with the diesel fuel maximum and minimum cyclic supply at a crankshaft speed corresponding to the maximum torque were presented. The temperature values showed that if urea was injected into the internal combustion engine cylinder after completion of the exhaust valve opening, then the conditions for the thermolysis and hydrolysis process of urea, as well as reducing reactions, would be favorable. The method of neutralizing NO_x emissions contained in the flue gases of thermal stations was analyzed, the purification process of which involved the treatment of flue gases with a solution of urea without the use of catalysts in the temperature range close to the diesel engine cylinder operation.

Introduction. The problem of using surrogate diesel fuel (DF) in Russia automotive engines is quite acute. The use of such fuel leads to the technical and economic deterioration indicators of both engine and vehicle, and to the increase in nitrogen oxides emissions contained in exhaust gases.

The purpose of the study was to determine the diesel fuel quality and to exclude the use of surrogate diesel fuel in KAMAZ vehicles operation.

Methodology and research methods. The research methodology is related to the analysis of fuel samples, during which the following is determined: cetane number and cetane index, kinematic viscosity, density, fractional composition, flash point in a closed crucible, cloud point, filtering temperature, mass fraction of sulfur, water content, lubricating fuel ability. The sulfur content is taken as an estimated fuel quality indicator, since in most cases, a fuel with a high sulfur content is surrogate.

Scientific novelty and results. During 2018 monitoring for sulfur content in diesel fuel samples, it was found that: 88.6% of the samples met the requirements of GOST R 52368-2005 and GOST 32511-2013 (sulfur content was not more than 350 ppm); 8.8% of the samples met the requirements of GOST 3052013 (sulfur content of was more than 350 ppm). 2.5% of the received fuel did not meet the requirements of regulatory documents.

Practical significance. The conclusion is that the problems associated with the production and sale of fuels that do not meet national standards can be solved by improving the regulatory framework, by introducing control over the automobile gas stations activity and tightening the liability of producers and sellers of surrogate diesel fuel.

Introduction. The development of intelligent transportation systems resulted in the emergence of highly automated and unmanned vehicles. At the same time, testing them is of great importance. The article considers some issues of testing unmanned vehicles.

The purpose of the study was to determine the main directions and opportunities for the test development of highly automated and unmanned vehicles.

Methodology and research methods. A system analysis method of test results based on domestic materials and foreign sources was used for highly automated and unmanned vehicles.

Results. The article gives a brief analysis of the test development of unmanned vehicles and related legal aspects.

Practical significance. The article covers the main trends in the development of unmanned vehicle testing, including the legal aspects of vehicles testing on public roads.

Introduction. Biofuel for a diesel generator operation is possible to be produced from microalgae within the immediate location of the consumer. The technology includes: growing algae in a bioreactor, plant materials processing, obtaining biodiesel under normal conditions of ordinary chemical reactions and resulting in generating electric and thermal energy by a diesel generator running on the resulting biofuel.

The purpose of the study was to determine the optimal technology for producing biofuel from algae and assess the possibility of using fuel without making changes in the design and control program of the diesel engine.

Methodology and research methods. The methodology included the simplest, cheapest and most friendly environmental technology cultivation of microalgae to produce biofuels followed by the observation of the results while using the fuel by the operating internal combustion engine.

Scientific novelty and results. Compared to other methods of electric energy distributed generation in the absence of a centralized electricity supply network, the methodology of producing biofuel and electricity generation can compete with wind generators and solar panels, or supplement these types of distributed energy production.

The practical significance lies in creating a possible facility for the distributed electricity production that can provide itself with a renewable energy source.

Introduction. This article considers the organization of generator gas production for the rolling stock of the Russian Federation automobile transport with help of gas generating stations to be used as motor fuel in the context of energy resources shortage. Wood or logging waste processing, and some other materials can be used as raw materials for generating generator gas. If necessary, gas generator production, cooling, purification (filtration), compression, storage, transportation, and refueling of vehicles equipped with gas equipment suitable for the use of compressed natural gas are carried out at the mobile gas generator station.

The purpose of the study was to develop a multi-component functional diagram of a mobile gas generator station taking into account its components for receiving, storing and/or transporting generator gas.

Methodology and research methods. The research methodology consisted of making the work of a mobile gas generator station systematic, logically structured system which could determine its activity process.

Scientific novelty and results. The scientific novelty of the study resulted in the developed scheme of a mobile gas-generating station (mobile road train).

The practical significance of the work is determined by the possibility to create a mobile gas generator station to provide fuel for vehicles in the context of energy shortages.