Tracked vehicles are integral for maneuvering diverse terrains, with hybrid propulsion systems offering potential benefits in terms of fuel efficiency and performance. However, research in hybrid electric tracked vehicles remains limited, thus necessitating a comprehensive analysis to maximize their advantages. This study presents a numerical analysis focusing on optimizing hybridization in speed-coupled parallel hybrid electric powertrains for tracked vehicles. A dynamic programming algorithm and custom drive cycle are utilized to determine optimal hybridization factors and assess parameter sensitivities. The study reveals that a hybridization factor of 0.48 is optimal for speed-coupled parallel configurations. Furthermore, the sensitivity analysis underscores the substantial impact of factors such as the engine displacement and bore-to-stroke ratio on the fuel economy, with a 10% change in these parameters potentially influencing the fuel economy by up to 2%, thus emphasizing the importance of thorough consideration during powertrain sizing. Parallel hybrid configurations exhibit considerable potential for tracked vehicles, thus highlighting the viability of choosing them over series configurations.

The research of influencing factors on the electricity consumption of electric buses Higer KLQ6125GEV3 in real working conditions is the result of experimental measurements conducted on the EKO 1 line in Belgrade over a long period which included typical seasonal periods (winter, summer, transitional) of electric bus operation as well as characteristic periods of work during the day (peak load, intermediate period, first/last departures). The results of this research are the basis for reviewing and ranking the influential factors on the electricity consumption of electric buses that are of great importance in planning operations of the line, analysis of energy efficiency and operating conditions.

Limited reserves of oil and the increasing environmental effect of its usage as a motor fuel represent global issue related to the constantly increasing number of motor vehicles. Therefore, the reduction of the fossil fuel consumed and the emission produced in internal combustion engines is the primary goal of the development of motor vehicle propulsion systems. In that sense, the present and the future of motor vehicles relies on hybrid drive systems, electric drive systems and drive systems which use hydrogen as a fuel (either by its combustion or by production of electric energy with the help of fuel cells). In this paper, the authors have presented the aforementioned motor vehicle propulsion systems by explaining their function and design, their basic elements and their functions. Authors have also analysed advantages and disadvantages of the mentioned propulsion systems in comparison to conventional internal combustion engine based systems, both technically and environmentally speaking, but also in relation to available infrastructure and energy resources.

High-speed tracked vehicles have complex powertrains that, in addition to power transfer and transformation, also perform the functions of vehicle steering and braking systems, as well as power supply system for various subsystems on the vehicle. Analyzing the power balance of a tracked vehicle, especially in specific moving scenarios such as the turning process, is of great importance for understanding the power requirements and workload of the powertrain components and their optimization. A simulation model was developed, based on the construction parameters of an experimentally tested high-speed tracked vehicle to reduce the time and material resources required for experimental testing. Both the simulation and experimental tests were conducted using the same input parameters and driving conditions for different vehicle turning scenarios. Simulation and experimental test results are compared to verify the accuracy of the simulation model. The analysis of the obtained results shows that the average value of the relative rpm error is about 5%, the average value of the relative torque error is about 7%, while the average value of the relative power error is about 6.5%.

Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines

All recent technological developments in the field of power distribution in hybrid electric tracked vehicles are often hard to apply and carry high computational burden which makes them impractical for real-time applications. In this paper, a novel control strategy is proposed for parallel hybrid electric tracked vehicle based on robust and easy to implement thermostat strategy with added merits of power follower control strategy (PFCS). The goal of the control strategy is enhanced fuel economy. Serbian infantry fighting vehicle BVP M80-A is chosen as the reference vehicle. For the purpose of validation, a backward-looking, high fidelity model is created in Simulink environment. Investigation of the results indicates that the proposed control strategy offers 12.8% better fuel economy while effectively maintaining battery state of charge (SOC). Even better results (23.2%) were achieved applying the proposed strategy to a model with an additional generator. It is concluded that further improvements can be made with combined sizing and control optimization.