Introduction (problem statement and relevance). The article describes an X-in-the-Loop system intended for cyber-physical tests of electric vehicle's chassis components. The system allows connecting and synchronizing laboratories located in different geographic regions.

The purpose of the study is to elaborate an X-in-the-Loop system allowing to perform geographically-scattered cyber-physical testing of the components belonging to an electric vehicle chassis.

Methodology and research methods. The elaboration of the X-in-the-Loop system involves methods of cyber-physical testing whose functionality is extended by means of connecting and synchronizing the tested objects via a global network.

Scientific novelty and results. A new research and development technology has been proposed for electric vehicles allowing for cooperation of geographically scattered laboratories within a real-time coherent environment that synchronizes tests of the electric vehicle components (both hardware and software) belonging to those laboratories.

The practical significance. The proposed technology provides researchers and developers in the field of electric vehicles with advanced cyber-physical tools allowing them to increase the effectiveness of their cooperative work and shorten the time needed for producing development or research results.

Introduction (problem statement and relevance). The airbag belongs to the passive vehicle safety system (SRS - Supplementary Restraint System) and is the most important (together with the seat belt) restraint system that protects the driver and passengers in a collision with static or moving objects. The main task of the SRS is to minimize injuries to the driver and passengers and reduce deaths in various road traffic accidents. For the development and testing of modern high-tech airbag modules, it is necessary to have informative theoretical and experimental methods for studying the non-stationary processes of their functioning.

The purpose of the study was to develop an experimental-theoretical research method based on modern highly informative tools of experimental physics of fast processes and numerical methods for continuous media dynamics.

Methodology and research methods. To study the functioning dynamics of vehicle airbag modules, an experimental method for determining the kinematic and acoustic parameters has been developed and implemented, and a mathematical model of an airbag functioning process has been formulated and implemented in the LS-DYNA environment with the help of corpuscular particles method.

Scientific novelty and results. The created experimental-theoretical method allowed both to simulate the functioning processes of the developed and tested airbag modules, and to carry out field tests of these modules. In addition, the experiment made it possible to carry out a detailed verification of the numerical method for calculating the airbag operation, on the basis of which it was also possible to perform numerical calculations interaction of the airbag and an anthropometric dummy model.

Practical significance. The developed method for studying the processes of airbag modules functioning is an important and necessary component of creating a scientific, technical and experimental base for the development and production of passive safety systems.

Introduction (problem statement and relevance). Wheels are components that ensure the safety of vehicles. One of the main ways to test the fatigue strength of wheels is a rotating bending load test. The methodology of these tests, regulated by international and national regulatory documents, allows an indirect method for measuring the normalized force effect on the wheels, in which there are always risks of methodological errors.

The purpose of the study was to identify potential sources of methodological errors when testing wheels in the bending-rotating mode.

Methodology and research methods. Analytical research methods from the field of practical vibration theory were used in the article, considering the critical state of rotating shafts and rotors. Scientific novelty and results. The sources of potential methodological errors and their relationship with the design characteristics of the bench equipment and the wheel itself were determined.

Practical significance. Practical recommendations have been given on the change and control of the stand components design characteristics aimed at minimizing errors. The high-speed test modes were determined, in which the error of the test effect on the wheel did not go beyond the normative limits.

Introduction (problem statement and relevance). One of the main stages in the design of
special purpose vehicles is the calculation of the steering control. At that, engineers are guided by a
number of regulatory documents that lack one of the most important requirements, which is to minimize tire lateral deviation. The author notes the lack of scientific research in the field of geometric slip, which is caused by the non-compliance between the actual angles of wheels rotation and the calculated values for pure rolling and is an inherent property of any traditional steering linkage.

The purpose of the study was to develop a mathematical model of the steering drive of a special-purpose vehicle with two steering axles to assess the geometric and power slip.

Methodology and research methods. There is a known method for calculating the steering drive using trigonometric expressions, in particular the cosine theorem. The author proposed to use the coordinateiterative method developed by him and based on the equation of the sphere, with the steering wheel rotation angle in the kinematic calculation of the steering drive as a differentiation step. The choice of the steering drive parameters according to the conditions of symmetry and minimization of slip was carried out by the method of multivariable optimization.

Results. In the course of the research, it was found that the choice of the characteristic of geometric noncompliance was a multi-parameter task, and changing one parameter led to the necessity of adjusting the others. If it was not possible to achieve zero geometric slip for all steered wheels, the task of optimizing the steering drive parameters wasreduced to minimizing geometric or total slip. The value of the slip essentially depended on the selected differentiation step. When choosing the characteristic of geometric slip, it was necessary to observe the condition of the steering linkage symmetry when turning left and right. When the wheels were turned from the neutral position to the periphery, the power and geometric slip compensated each other, which led to the decrease of the total slip and tire wear.

The scientific novelty of the work lies in the development of a geometric slip model for a vehicle with two steerable axles, including a spatial model of the steering drive which allows to evaluate the influence of the geometric slip on the turn kinematics, as well as the mutual influence of geometric and power slip in order to select the steering drive optimal parameters of the multi-axle vehicle from the viewpoint of minimizing tire wear during curvilinear motion.

Practical significance. The research results must be taken into account in the development of steering drive and turning control systems for multi-axle special-purpose vehicles, including them in the educational process as well.

Introduction (problem statement and relevance). To create a competitive vehicle in modern conditions, it is important to be able to determine its power elements loads at the early stages of design. A vehicle dynamic mathematical models allows you to solve this problem.

The purpose of the study was to develop a dynamic mathematical model methodology of a quadricycle to determine its power elements loads under given operating conditions.

Methodology and research methods. The article presents a dynamic mathematical model of a wheeled vehicle (quadricycle) technique using a created mathematical model within a solids dynamics modeling program and a real object experimental study to verify the mathematical model with an example of the obtained frame strength calculation under computer simulation loads.

Scientific novelty and results. In the article the main stages of an utility quadricycle development and its dynamic mathematical model have been presented taking into account its design features and operating conditions. The main initial data necessary for creating an all-terrain vehicle dynamic mathematical model were identified. To confirm the developed dynamic model adequacy, a series of test site experiments was carried out. The obtained simulated results having been compared to the experimental data were highly convergent, which indicated the adequacy of the developed dynamic model of the ATV.

Practical significance. The technique presented in the article allows to carry out virtual experiments to determine the main structural elements loads for subsequent strength, optimization and durability calculations.

Introduction (problem statement and relevance). In recent years, attention to hydrogen as an alternative kind of transport fuel has been increasingly growing as hydrogen is considered to be capable of replacing petroleum traditional fuels. Moreover, it is believed that the use of hydrogen can solve the environmental problems of transport, reduce power plants energy driving costs and solve the problem of fossil resources depletion.

The purpose of the study was to analyze hydrogen as a possible alternative fuel, assess its advantages and disadvantages taking into account both the variety of its usage and power environmental and economic aspects of hydrogen production together with problems associated with its practical use.

Methodology and research methods. The analysis of hydrogen production has been carried out including its use as a possible fuel for motor vehicles.

Results. High energy consumption, environmental imperfection of hydrogen production processes and related problems of its storage, transportation, power units as well as of the scarcity of some necessary resources do not provide grounds for optimistic assessments of economic and environmental assessments of vehicles powered by hydrogen.

Introduction (problem statement and relevance). Hydrocarbon emissions from vaporization
tank fuel contribute significantly to the total emissions of hazardous substances from vehicles equipped with spark ignition engines. To meet the established standards for limiting hydrocarbon emissions caused by evaporation, all modern vehicles use fuel vapor recovery systems, the optimal parameters of which require the availability and application of mathematical models and methods for their determination.

The purpose of the research was to develop a model of vapor generation processes in the car fuel tank and a methodology for determining the main quantitative parameters of the vapor-air mixture.

Methodology and research methods. The analysis of the processes of vapor generation in the fuel tank was carried out. It was shown that the mass of hydrocarbons generated in the steam space was directly proportional to its volume and did not depend on the amount of fuel in the tank.

Scientific novelty and results. New analytical dependences of the vaporization amount on the saturated vapor pressure, barometric pressure, initial fuel temperature and fuel heating during parking have been obtained.

Practical significance. A formula was obtained to estimate the temperature of gasoline boiling starting in the tank, depending on the altitude above sea level and the volatility of gasoline, determined by the pressure of saturated vapors. Using the new equations, the vaporization analysis in real situations (parking, idling, refueling, explosive concentration of vapors) was carried out.

Introduction (problem statement and relevance). The ability to combine the advantages of hydrogen fuel cells and lithium batteries in a hybrid electric vehicle is a fundamental challenge in the development of highly efficient, environmentally friendly transportation. At the same time, the coordinated operation of onboard sources requires the creation of complex control algorithms for all involved power supply and power consumption systems.

The purpose of the research was to study the practical applicability of fuzzy logic algorithms when creating a fuel cells battery controller.

Methodology and research methods. The study used modern mathematical methods for processing the controller input signals of a hydrogen vehicle hybrid power unit and generating output control signals to provide the most optimal control modes for a fuel cells battery.

Scientific novelty and results. The proposed approach, based on the use of fuzzy logic algorithms, has made it possible to control the fuel cell battery power ensuring its efficient operation as part of a vehicle hybrid electric drive. The analysis of the obtained results indicated the effectiveness of the method.

Practical significance. The proposed algorithms make it possible to develop and implement advanced hydrogen power systems controllers for a vehicle.