Vol 17, No 2 (2023)

BACKGROUND: Import substitution has become the most important direction of the development of the country's economy in the conditions of the sanctions policy. In this regard, high requirements are imposed on the production to ensure the competitiveness of automotive machinery. Automotive machinery is a key component of the country's economy that is confirmed by the growth of road transport. Meanwhile, growth of the vehicle fleet leads to increase in consuming of petroleum-derived fuel, which main disadvantage is emission of harmful substances, therefore, internal combustion engines of automotive machinery should ensure low fuel consumption and less emissions of harmful substances with exhaust gases. However, the engine operating modes largely depend on the loads generated in the vehicle transmission.

AIMS: To determine the possibilities of expanding the ranges of power regulation of an internal combustion engine of a vehicle, on the one hand, ensuring low fuel consumption and less emission of harmful substances with exhaust gases, and on the other hand, providing with the power required for a vehicle to move, regarding the type of transmission and propulsion.

METHODS: The analysis of possible conventional and unconventional operating cycles of an internal combustion engine is carried out. The method of mathematical modeling of the formation of torques in various types of vehicle transmission is used.

RESULTS: Possible ways of expanding the ranges of power regulation of an internal combustion engine providing with the required power, low fuel consumption and less emission of harmful substances with exhaust gases, as well as transmission layouts and processes of forming the required power in them to ensure the vehicle movement are considered.

CONCLUSIONS: The considered in the article approach of expanding the ranges of power regulation of an internal combustion engine of a vehicle makes it possible to conclude that it is necessary to use the principles of a scientific approach to the process of development of vehicle transmissions capable of controlling an internal combustion engine depending on loads, ensuring its operation with minimal fuel consumption and emission of harmful substances.

BACKGROUND: Innovative technologies and design solutions aimed at using hydrogen in internal combustion engines and hydrogen power plants are reviewed in the paper. The advantages of hydrogen fuel are shown and the main problems that Western automakers face and which determine the ways to solve problems in road transport are identified. In this regard, the method of using hydrogen energy in internal combustion engines and hydrogen power plants becomes a decisive factor.

AIMS: Search for a reasonable and effective method of using hydrogen in transport.

METHODS: The technologies of hydrogen production with the electrolysis method and on-board generation of hydrogen using hydrogen-containing components are considered. It is proposed to use ammonia as a hydrogen carrier reagent for operation in dual-fuel diesel internal combustion engines.

RESULTS: It is noted that ammonia, with a high level of hydrogen content in the molecule, is relatively safe, has a low cost and a significant volume of production. It is easier to store and transport compared to hydrogen. For internal combustion engines operating on hydrocarbon fuel, the use of ammonia and hydrogen, its derivative product, is attractive due to the need to remove highly toxic nitrogen oxides containing in the exhaust gases of diesel internal combustion engines.

One of the main problems of creating an environmentally friendly diesel engine associated with reducing the NOx content to an environmentally safe level is considered. A positive factor of using ammonia is the on-board production of hydrogen in the thermal reactor, as well as the possibility of organizing an effective process of neutralizing nitrogen oxides in a diesel engine.

CONCLUSIONS: The use of ammonia to generate hydrogen allows the diesel engine to implement the process of selective reduction of nitrogen oxides when ammonia is injected into the combustion chamber at the exhaust stroke. This method will significantly increase the efficiency of NOx neutralization in a diesel internal combustion engine due to the possibility of temperature regulation of the NOx neutralization reaction directly in the cylinder and in the exhaust system of the internal combustion engine.

BACKGROUND: Fuel cells are one of the promising directions in the development of electrified transport as it is capable of providing with mileage comparable to conventional vehicles powered by internal combustion engines, with no harmful emissions into the environment during the vehicle motion. The long-lasting process of development of fuel cells was associated with the inability to realize the potential of fuel cells and the availability of more accessible and reliable energy sources at that time. The present programs and measures to support electric vehicles and fuel cells set targets for reducing emissions of harmful gases and increasing the share of electric vehicles on the roads.

AIMS: The study of the history of the development of fuel cells and their relevance to the use in vehicles.

METHODS: The calculations to determine the specific parameters were performed with solving the differential equation of the force balance of vehicle motion using the numerical Euler method.

RESULTS: The results of the scientific research are the determination of specific parameters of power units and the analysis of the history of the development of fuel cells. By comparing the specific parameters, it was revealed that the most effective are combined power units on fuel cells. When using these power units, a 2.5-fold decrease in mass was recorded compared to other types of power units.

CONCLUSIONS: The use of fuel cells helps to reduce the weight of the power units and to improve the environmental safety of the vehicle. Fuel cells have undergone several long stages of development and reached their peak of development after the beginning of active space exploration. Currently, the development of hydrogen technologies is actively continuing, programs for the development of electrified transport have been issued in many countries, including the Russian Federation.

The authors note the relevance of scientific research in this area and assume that vehicles powered by electrochemical generators will receive their further development in the coming years.

BACKGROUND: In the process of developing suspension systems for modern high-speed wheeled and tracked vehicles, having the selected optimal elastic characteristic curve of the suspension system, its unsatisfactory damping characteristic curve can have a significant negative impact on the overall operation of the suspension unit. Therefore, the search for a method for obtaining the optimal damping characteristic curve is a relevant task.

AIMS: Description the method for selecting the damping characteristic curve of a single-level pneumohydraulic spring for a wheeled vehicle considering the motion along tracks with a harmonic profile and a rough cobblestone road.

METHODS: The damping characteristic curve of the spring is selected using simulation mathematical modeling in the MATLAB/Simulink software, which makes it possible to take into account the nonlinearity of the suspension characteristics. In the process of building the characteristic curve, the limit values of the forces at the front wheels tires are fixed for the sections of the characteristic curve that operate with the valves of the pneumohydraulic spring turned off. Accelerations at the driver's seat and the pressure in the spring chamber are fixed for the sections of the characteristic curve that operate with the valves are turned on.

RESULTS: The results of the selection of an optimized damping characteristic curve showed an improved contact of the wheels with the surface and an increase in the stability of the vehicle, a decrease in vibration accelerations at low disturbance frequencies.

CONCLUSIONS: The practical value of the study lies in the possibility of using this method to develop suspension systems for new wheeled and tracked vehicles.

BACKGROUND: The current level of research and development work involves the use of systems based on programmable electronics. At the current level of engineering, the development of these systems is expedient to carry out using specialized software. At the same time, a systemic approach to the methodology for using the mentioned tools has not been fully formed yet, which necessitates the consideration of the relevant issues of theory and practice.

AIMS: The attempt to form the principles of the mentioned systemic approach, based on the idea of the integrated hardware and software use, where the complementarity of their capabilities ensures the appearance of a pronounced emergence.

METHODS: The article contains an analytical review and categorization of modern tools that allow to support research in their preparation, carrying out and results processing. As a particular example of their successful combined application, a computerized educational laboratory installation designed by the authors for balancing and calibrating the torque measurement system at a driveshaft of a passenger car is considered.

RESULTS: The article materials contain a description of design and an operation principle of the mentioned installation, a consistent consideration of those specific tools that were used in its development, а information regarding the basic capabilities, the most significant characteristics and features of these tools, as well as the trial tests results and their interpretation.

CONCLUSIONS: The approach described by the authors makes it possible to rationally approach the solution of problems related to the development and use of data measurement systems for experimental studies of automotive and tractor machinery.

BACKGROUND: The development of electric and hybrid vehicles is impossible without the creation of schemes in which torque is generated by electric motors independently on the front and rear axles or on each wheel and the best dynamics is achieved. The development of a function for distributing torque between the axles or wheels of a car is a relevant technical task.

AIMS: Creation of a mathematical model for the torque distribution requested by the driver to the front and rear electric motors in order to assist the course stability system and counteract wheel slip when driving in a turn close to drifting/skidding or driving on surfaces with a low or variable grip coefficient.

METHODS: The algorithm model was built in the MATLAB/Simulink environment, was tested in the model-in-the-loop mode on a simulation model developed in the Simcenter Amesim environment, was tested in the hardware-in-the-loop mode on the LabCar real-time machine (ETAS GmbH) and was tested in a vehicle.

RESULTS: The function based on the abovementioned methods was built in MATLAB/Simulink. Testing in simulation mode on the simulation model developed in Simcenter Amesim was performed and the initial values of calibration parameters were determined. Implementation of the function into the software structure of the prototype and compilation of the executable C-code for the master file loaded into the control unit were completed. Testing of the function implemented into the control unit on the LabCar real-time test rig was carried out. After eliminating the shortcomings identified at the previous stages of testing, calibrations and tests of the function integrated into the vehicle were carried out, which showed the effectiveness of the described torque distribution model.

CONCLUSIONS: The practical value of the study lies in the possibility of using the proposed control laws to develop systems for torque distribution between the axles or wheels of modern vehicles.

On April 7, 2023, our colleague, Doctor of Technical Sciences, Professor, Honorary Worker of Higher Professional Education, Deputy General Director for Science of the Central Research Automobile and Automotive Institute (NAMI), a member of the editorial boards of the “Tractors and Agricultural Machines” and “Izvestiya “MAMI”” journals Sergey V. Bakhmutov passed away.
Sergey V. Bakhmutov was a prominent specialist in the following scientific fields: vehicle dynamics, active safety, optimization of design parameters, highly automated transport and technological facilities.
He was the author and co-author of about 170 scientific papers, including 20 books, 22 certificates of authorship and patents for inventions and utility models.