Proceedings of the Technical University of Sofia

Abstract: The current study aims to show a comparison between the fuel efficiency of conventional excavator Volvo EC300EL and the hybrid version of the same model. The main parameters of the tested model are presented. The scheme of hydraulic hybrid technology is described. Real measurements of fuel consumption and loaded volume of material were performed over three days. The selected results underpin conclusions regarding the hybrid version’s fuel-efficiency advantages.

Abstract: This study presents results from four-day field tests comparing wheel loaders with hydrodynamic and hydrostatic transmissions. After clarifying the concepts of “fuel efficiency” and “fuel consumption,” criteria for their evaluation are set, followed by a description of the two transmission types and their pros and cons. Test-site conditions, results, and conclusions are detailed.

Abstract: The paper underscores the need to embed cybernetics in the aerospace sector. Cybernetics—spanning technical, bio-, and social branches—addresses the management of diverse systems. Aerospace cybernetics, within technical cybernetics, relies on system planning and control for aircraft and spacecraft. Infrastructure development and personnel training lead to effective planning and control of aerial and space vehicles.

Abstract: The paper outlines the design and FDM 3D-printing of a racing-car intake velocity stack made from heat-resistant polymer. Structural/production parameters are detailed, followed by simulation and experimental analyses of its first two natural frequencies (439 Hz vs 377 Hz and 960 Hz vs 883 Hz). Findings highlight resonance-avoidance considerations.

Abstract: Driving simulators provide cost-effective alternatives to on-road trials for motorsport and research. Delivering visual, aural, haptic, and sometimes motion cues, they enable immersive driver training and data capture. This article reviews and compares simulator types by objective, design, and complexity, synthesizing insights from selected studies.

Abstract: EU transport policy seeks seamless, safe, and efficient multimodal movement while addressing climate and passenger-rights concerns. Driver selection critically affects transport-company performance. An analysis of a Ruse-based company shows that strategic driver management cuts trip durations and stabilizes fuel use, boosting productivity, compliance, and customer satisfaction.

Abstract: Response time is critical to public safety. Weather, traffic, and communication hurdles often impede emergency services. Harnessing drones, GIS, and 5G can cut delays and extend reach where ambulances or helicopters cannot. Combined with AI-enabled surveillance, such technologies promise near-instant response and enhanced safety.