Introduction (statement of the problem and relevance). While gasoline-powered vehicles generate a significant amount of hydrocarbons in the form of the fuel system emitted vapors, the main element of the system being the fuel tank, modern requirements for evaporative emission limits are significantly tightened. At the same time, the vaporization process parameters and the fuel vapor amount are determined by the dynamics of fuel heating in the tank under various modes of vehicle operation.

The purpose of the research was to develop a “vehicle fuel tank” energy model, seeking to create an open thermodynamic system which can exchange matter and energy with the environment depending on the variable amount of fuel in the tank.

Methodology and research methods. The analysis of heat flush connected to the fuel tank and taken away from it was being carried out. As a result of solving equations for open and closed thermodynamic systems, the parameters characterizing the thermal properties of the fuel tank were obtained.

Scientific novelty and results. Additional complex parameters have been proposed, the main of which are: heat transfer of the tank; tank heat capacity; supplied heat flux; the rate of heat capacity change; tank emptying time; fuel heating acceleration factor; the maximum rate of change in temperature difference. To assess the heat and power properties of the fuel tank, an additional parameter of the sphere surface area ratio to the surface area of the same volume tank has been proposed, which allowed estimating the fuel tank heat transfer to the environment.

Practical significance. Equations have been obtained that allow estimating the level of fuel temperature depending on the thermal properties and shape of the fuel tank in the absence and presence of fuel pump control.

Introduction (statement of the problem and relevance). Starting an internal combustion engine (ICE) at negative ambient temperatures is difficult for a number of reasons. A decrease in the volatility of gasoline leads to the liquid fuel deposition on the cylinder walls, as a result of which the fuel-air mixture ignition is difficult or impossible. Another reason is the geometric dimensions reduction of the gaps in the plain bearings, which is a consequence of the use of materials with different thermal expansion coefficients in the engine design. The high kinematic viscosity of the oil creates a higher hydraulic resistance in the system. These factors complicate the engine oil flow to friction pairs, which can lead to an oil starvation and bearing shell life reduction.

The purpose of the research was to determine the optimal pre-heating mode from the point of view of the process energy efficiency and the preservation of the engine resource.

Methodology and research methods. To control the thermal state, the internal combustion engine and the cooling circuit were equipped with measuring equipment. The values of temperature, pressure and volume flow sensors were recorded. To implement the pre-heating modes proposed in the article, an engineering engine control unit was used, which allowed making changes in the basic software configuration.

Scientific novelty and results. An alternative method of pre-heating has been proposed, including preheating of the engine oil-water heat exchanger to reduce the time for reaching the minimum oil pressure at the main gallery inlet during a cold start. The article provides descriptions of the regular and proposed pre-heating cycles, their assessment in accordance with the represented criteria. Experimental data on pre-heating cycles and cold starts at an ambient temperature of –40°C are presented. The necessity of warming up the engine standard water-oil heat exchanger before a cold start has been experimentally proved, the curves of pressure changes at the main gallery inlet, depending on the pre-heating mode, are given.

Practical significance. Reducing the negative influence of cold start on the ICE resource.

Introduction (statement of the problem and relevance). The available methods for testing automatic emergency braking systems (AEBS) do not take into account the specific features of Russian operating conditions (lighting, weather conditions, real traffic accidents statistics (RTAS), etc.). Therefore, reasonable adaptation and correction of such methods is of necessity.

The purpose of the study was to develop and test an AEBS effective methodology to prevent a collision with a pedestrian.

Methodology and research methods. The methods of statistical research data and mathematical analysis of road accidents have been applied. Based on the traffic accidents pedestrian collision statistics in 2020, the most common scenarios and pedestrian collision causes in the Russian Federation were determined. Considering these data different types of automatic emergency braking systems (AEBS) tests including the function of preventing collision with pedestrians were proposed. AEBS tests were planned to be carried out in daylight and at night without artificial lighting.

Scientific novelty and results. The scientific novelty of the research is an AEBS system effectiveness assessment when working on “adult pedestrian”. The criterion for evaluating AEBS effectiveness was the maximum speed at which it was possible to prevent a collision with a pedestrian. The final assessment of the action effectiveness was determined when the weighting factor of each type of test was taken into account. The weight coefficients were substantiated by real accident statistics. The results of AEBS testing efficiency for a Toyota RAV4 car, performed according to the developed methodology, have been presented. A parametric record of the field test characterizing the features of the Toyota RAV4 AEBS functioning has been presented as well.

Practical significance. The developed methodology can be taken as the basis for the formation of the Russian national safety rating for new vehicles RuNCAP.

Introduction (problem statement and relevance). The insurance of the required safety level is getting more relevant in connection with the intensive implementation of remote control systems being developed for vehicles with varying degrees of motion autonomy. When transporting bulky and heavy loads off-road by remote-controlled tracked trains it is advisable to use the methods of full-scale mathematical modeling at the design stage to evaluate the operational properties of the remote-controlled tracked trains associated with undetermined actions of the driving operator.

The purpose of the study was to evaluate the controllability of caterpillar trains transporting goods off-road with the help of a natural-mathematical modeling complex.

Methodology and research methods. To assess the controllability of caterpillar trains, the mathematical model requirements for a complex of full-scale mathematical modeling were worked out, taking into account the mathematical model of caterpillar train motion. Using the method of natural-mathematical modeling, the controllability of a caterpillar train was evaluated when moving along a “snake” type trajectory.

Scientific novelty and results. The methods presented in this paper and the developed mathematical model, suitable for a complex of natural-mathematical motion modeling, allow to determine the indicators of tracked trains operational properties associated with non-deterministic control actions of the driver operator and the disturbing effect of the road conditions. The novelty of the work lies in the developed mathematical model and the possibility of its application in the complex of natural-mathematical motion modeling for the study of operational properties and load modes of unmanned tracked trains. As a result of the study, the caterpillar trains controllability evaluation has been made when moving along a “snake” type trajectory as well as assessment of the caterpillar trains transmission load.

Practical significance. The developed mathematical model allows determining the indicators of caterpillar trains operational properties at the design stage using a complex of natural-mathematical motion modeling. In addition, when performing virtual races, one can get data on the modes of transmission and select required characteristics.

Introduction (statement of the problem and relevance). Mathematical modeling of the car units, mechanisms and systems functioning strongly depends on the used calculation parameters values, for example, on the power radius of the wheel. Nowadays to research the power radius of a wheel with an elastic tire both the radius of the driving wheel and the dynamic radius are taken into account. The article is to consider which of the two is the power radius of a wheel with an elastic tire.

The purpose of the study was to evaluate the influence of the chosen wheel power radius on the longitudinal characteristics mathematical modeling results of the tire adhesion with the supporting surface.

Methodology and research methods. Methods of mathematical modeling and experimental studies were applied, followed by the comparative analysis of both the experimental and analytical data.

Scientific novelty and results. The experimental dependences of the tire longitudinal adhesion coefficients on slippage have been obtained and compared using both the dynamic radius and the rolling radius as the power radius of the wheel in the driven mode.

Practical significance. The mathematical descriptions parameters of the tire adhesion characteristics have been refined which allowed reducing the errors of the calculation results significantly.

Introduction (statement of the problem and relevance). Currently, the development of technical products, especially as complex as a modern car, requires solving a huge number of tasks. For this, new research methods are being created that allow testing vehicles or its components simultaneously at several development companies in the X-in-the-Loop environment.

The purpose of the study is to improve the accuracy of virtual physical tests in the X-in-the-Loop environment by experimentally searching for the optimal location for installing the hot-wire anemometer on the temperature control system research stand to determine the average air flow rate at each time point.

Methodology and research methods. An experimental study was carried out and an analysis was made of the flow of incoming air through the radiator of the temperature control system.

Scientific novelty and results. Using the described method, the location of the hot-wire anemometer was chosen, and the correction necessary in the mathematical model was determined to conduct virtual-physical tests of the temperature control system in the X-in-the-Loop environment.

Practical significance. The obtained results make it possible to carry out virtual-physical tests of the temperature control system in the X-in-the-Loop environment with high accuracy, in particular, the simulation of the driving conditions of a vehicle (speed and airflow rate) in real time.

Introduction (statement of the problem and relevance). At present, little attention is paid to the analysis of vehicle climate systems operation, though maintaining a comfortable temperature in the cabin under some conditions makes up the majority of energy costs. In some cases, lack of energy leads to the use of diesel heaters. In this respect, the assessment of the climate system impact on energy consumption is an urgent task of today.

The main purpose of this article was to calculate and analyze the specific costs in various temperature conditions on the example of M3 passenger electric bus category.

Methodology and research methods. In the article the methods to construct a mathematical model of the temperature effect on the air inside the vehicle using the heat balance equation were proposed. Also, a method of car traction balance was used to build a model of vehicle motion.

Scientific novelty and results. As a result of an electric bus motion modeling according to the OCB cycle, energy costs at temperatures from –40°С to +40°С have been determined. The highest energy consumption in winter was 2.63 kW·h/km at –40°C.

Practical significance. At the first approximation the article allows to determine the specific costs for M3 passenger vehicle category, and basing on earlier developed methods, makes it also possible to build a mathematical model to determine the energy costs for any type of wheeled vehicle.

Introduction (statement of the problem and relevance). The forthcoming vehicle environmental regulations to be introduced in the European Union (EU) in 2025–2026 involve aggressive emission limit scenarios combined with new real-world test conditions. The new environmental concept sets ambitious goals in relation to the power line of traditional vehicles with an internal combustion engine (ICE), such as: the main source of energy for automotive technology; high efficiency (more than 50% efficiency); ultra-low fuel consumption and ultra-low emissions (CO2, NOx, PM).

The purpose of the study was to analyze the prospective fuel efficiency and environmental safety requirements for wheeled vehicles to determine the main directions of internal combustion engines development to meet these requirements.

Methodology and research methods. The analytical methods of research included: the analysis of the commercial engines market; the investigation of world projects to tighten the requirements for environmental safety of wheeled vehicles; the study of the main internal combustion engines development concepts. Results. The prospective requirements for internal combustion engines have been analyzed, and as result of it, the concept of ICE development, the promising internal combustion engine view and an exhaust gas after-treatment system (EGATS) were worked out.

Practical significance. The results of the study can be used for determining the requirements and main directions of research and development work when creating the new generations of internal combustion engines.

Introduction (statement of the problem and relevance). The article is devoted to the study of engine oil in the course of numerous engine and automotive tests; therefore it is of an overview nature and considers general issues of assessing engine wear based on the engine oil condition. The article discusses the operating modes of the oil in the engine, its physical and chemical parameters, and the additives effect on the preservation of these indicators, as well as the issues of engines and oils conditions monitoring.

The objectives of the study included the determination of the influence of the main engine oil indicators on the engine operation followed by the monitoring peculiarities of the engine condition.

The purpose of the study was to consider general issues of assessing engine wear depending on the engine oil condition.

Methodology and research methods. The analytical method of research was applied.

Results. The main indicators of engine oil and the factors influencing their change have been considered. The criteria to help the assessment of the engine oil condition when conducting physical and chemical analyzes were determined. A group of indicators necessary to monitor and analyze the causes of engine wear was established. The main peculiarities of the engine oil state monitoring were considered and the monitoring began at the early stages of engine, oil and other fluids development.

Practical significance. Engine oil is a carrier of information that can be used to improve the reliability of internal combustion engines and extend their life. Like a blood test, thanks to which it is possible to draw conclusions about the correct functioning of the human body, physical and chemical studies of engine oil allow us to assess the correct operation of an individual engine components, identify malfunctions and prevent breakdowns, extending the life of the engine.