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This research examines the influence of various pavement types on vehicle dynamics, specifically concentrating on vertical acceleration and its implications for unsprung mass, including the wheels and suspension system. The objective of this project was to categorize pavement types with accelerometer data, enabling a deeper comprehension of the impact of road surface conditions on vehicle stability, comfort, and mechanical stress. Two categorization methods were utilized: a neural network and a multinomial logistic regression model. Accelerometer data were gathered while a car navigated diverse terrain types, such as grates, potholes, and cobblestones. The neural network model exhibited exceptional performance, with 100% accuracy in categorizing all surface types, while the multinomial logistic regression model reached 97.14% accuracy. The neural network demonstrated exceptional efficacy in differentiating intricate surface types such as potholes and grates, surpassing the logistic regression model which had difficulties with these surfaces. These results underscore the neural network's effectiveness in the real-time categorization of road surfaces, enhancing the comprehension of vehicle dynamics influenced by pavement conditions. Future studies must tackle the difficulty of identifying analogous surfaces by enhancing methodologies or integrating more data attributes for greater precision. [ABSTRACT FROM AUTHOR]

The paper represents numerical and experimental investigation of ultrasonic piezoelectric transducer which operation is based on three different vibration modes. Multifrequency operation of the transducer allows to obtain sound pressure fields with different patterns, sound fields intensities and frequencies which allows to obtain more flexible and adjustable agglomeration process of fine and ultrafine. Results of numerical investigations have shown that vibration modes of transducer at 25.83 kHz, 34.73 kHz and 52.41 kHz frequencies are suitable for acoustic pressure generation. Moreover, the calculations revealed that at these frequencies sound pressure levels (SPL) reaches up to 142 dB while SPL patterns at different frequencies are different. Experimental investigations have confirmed results of numerical investigations and showed that resonant frequencies of transducer are at 25.65 kHz, 31.1 kHz, 50.8 kHz while SPL values reaches up to 132.5 dB. [ABSTRACT FROM AUTHOR]

Advanced microfabrication technologies have revolutionized the field of reflective encoders by integrating all necessary optical components and electronics into a miniature single-chip solution. Contemporary semiconductor sensors could operate at wide tolerance ranges that make them ideal for integration into compact and lightweight modular encoder kit systems. However, in order to achieve the high accuracy of the operating encoder, precise mechanical installation is still needed. To overcome this issue and exploit the full potential of modern sensors, the self-calibratable absolute modular rotary encoder is developed. The equal division average (EDA) method by combining the angular position readings from multiple optical sensors is used to simplify the installation process and ensure the high accuracy of the system. The produced prototype encoder is experimentally tested vs. the reference encoder and the measurement deviations of using different numbers and arrangements of optical sensors are determined. The obtained results show encoder ability to handle the mounting errors and minimize the initial system deviation by more than 90%. [ABSTRACT FROM AUTHOR]

Car trailers are quite a popular means of transport and are offered in many versions, from single axle light trailers with a maximum permissible weight of 750 kg, through two- or more-axle specialized trailers. The issues of research car trailers focus on two directions: testing the driving properties and analysing the strength of the supporting frame system. Issues related to the construction of light trailers are often common to trailers used in agriculture or general transport. In this article, based on a mass-produced car trailer, an analysis was carried out regarding the choice in the technology of making the supporting structure consisting of a lower frame and an upper frame. The term upper frame should be understood as the structure on which the lifted load box rests. The costs of materials, assembly and technological possibilities of small-scale production were taken into account. In addition, strength analyses of the numerical models were carried out for critical areas of the frame during operation. After considering the unit costs for each of the analysed assembly technologies, it was shown that riveting would be the cheapest. However, the most suitable method of assembly is welding, as it allows the use of standard profiles. [ABSTRACT FROM AUTHOR]

A powerful soundwave from shooting a firearm can travel great distances harming the shooter as well as anyone or anything standing nearby. To address this, a nontypical firearm suppressor is used. A suppressor muffles the soundwave to a level that is usually safe for the shooter and its environment. A suppressor usually has 3-4 main parts that highly influence its effectiveness. The study aims to investigate how non-typical baffle design and placement selection influence the suppressor effectiveness. The study consists of 162 different non-typical baffle design configurations. Suppressors with 3 to 9 baffles, angled from 30 to 60 degrees as well as rounded from 10 mm to 30 mm radius, are simulated in a CFD environment. Suppressors with the best designs were then produced and evaluated on a firing range. At the firing range, a result of 32.24 dB delta was achieved and was only 4,67% different than the result presented in the CFD study, which was 30.8 dB, respectively. The 9 straight geometry baffle, angled at 30 degrees, suppressor, with an average chamber volume proved to be the most efficient and combined with a large initial chamber was the most efficient design in this study. [ABSTRACT FROM AUTHOR]

The reliability of internal combustion engines becomes an important aspect when traditional fuels with biofuels. Therefore, the development of prognostic models becomes very important for evaluating and predicting the replacement of traditional fuels with biofuels in internal combustion engines. The models have been made to model AVL 5402 engine emission, vibration, and sound pressure parameters using a threestage statistical regression models. The fifteen parameters might be accurately predicted by a single statistic presented here. Both fuel type (diesel fuel and HVO) and engine parameters that can be adjusted were considered, since this analysis followed the symmetry of the methods. The data analysis process included three distinct steps and symmetric statistical regression testing was performed. The algorithm examined the effectiveness of various engine settings. Finally, the optimal fixed engine parameter and the optimal statistic were used to construct an ANCOVA model. The ANCOVA model improved the accuracy of prediction for all fifteen missing parameters. [ABSTRACT FROM AUTHOR]

With the rapid development of the military industry and the increasing focus on the safety of those in these fields, there is an increasing search for solutions to existing and emerging weapons for the user and the environment. In this case, components for firearm suppression are used to reduce the effects of noxious impulse sound, to minimize the severity of the weapon's recoil to the user's body, and maintain important accuracy, maneuverability and other parameters. The analysis and investigation of silencer designs can provide essential values for acoustic characteristics that reduce risk in real situations. The gun silencer analysis was performed in two steps. The modeling processes of the silencer configuration were performed to choose the optimal construction, and the main parameters were selected, including different angles and forms of the tilt. The angle of inclination of the partitions was changed to 60° and 135°. Due to the reduced results observed in the last zones with closed cavities and created additional configurations, the number of partitions was shortened by three partitions and the angle of inclination was adjusted to 60°; the simulation of the initial variant was also supplemented with 135° partitions. The second step was an experimental validation of the optimal tilt angle and form according to the modeling data. The silencer was found to achieve a sound pressure damping value and the sound pressure level during the shot was reduced to below a dangerous level. The search to find the optimal configurations will lead to the parameters of production and efficiency. [ABSTRACT FROM AUTHOR]