Introduction. An automobile vehicle consists of a large number of parts that affect traffic safety in different ways. The elements that critically affect the safety of the vehicle include automobile pneumatic tires. Their technical condition is currently being assessed visually, without the use of special equipment. This diagnostic method does not provide detection of hidden tire damage. This article describes the proposed method of diagnosing pneumatic tires of passenger cars, as well as the scheme of the stand for its implementation.Materials and methods. Based on previous studies, it was proposed to use the static stiffness of automobile tires as a diagnostic parameter when assessing their technical condition. To implement the use of this diagnostic parameter, a new method for assessing the technical condition of tires was proposed. It consists in determining and comparing the values of the static stiffness of the tire at its various points with the average stiffness value at all measurement points. To implement this method in the laboratory, a schematic diagram of the stand was proposed.Results. In accordance with the proposed scheme of the stand, a volumetric model of the stand was developed for the implementation of the proposed method in laboratory conditions, and the frame of the stand was made and its main elements were selected. As a converter of the rotational movements of the potentiometer handle into the electronic signal, it was decided to use the Arduino Uno R3 analog-to-digital converter. Software was also developed to automate the reading and processing of bus diagnostic results.Discussion and conclusions. The proposed method of tire diagnostics and the stand implementing it can increase the efficiency and simplicity of assessing the technical condition of pneumatic tires of passenger cars. Further research is needed to assess the effectiveness of the proposed solutions.

Introduction. Road safety is largely determined by the technical condition of the vehicle, and especially control systems. The braking system is one of them. To improve its efficiency, various assistive electronic systems are now widely used. These systems control the vehicle through wheel braking mechanisms. Brake pads are a constituent element of a friction-type wheel brake mechanism. The efficiency of the vehicle braking system depends on its quality, regardless of the presence of auxiliary electronic systems. The use of brake pads with a wide spread of friction coefficients can have a significant impact on braking performance.Materials and methods. To conduct experimental studies, a methodology for conducting them and processing experimental data was developed, as well as a laboratory setup was made. Arduino Uno R3 analog-to-digital converter was used as an instrumental component of the stand for converting mechanical movements into an electronic signal.Results. In accordance with the proposed methodology, four pairs of brake pads were tested. As a result of processing the experimental data, it was found that the difference in the values of the friction coefficients of the brake pads can cause a difference in the magnitude of the braking forces on the wheels from 8 to 19%.Discussion and conclusions. The difference in the coefficients of friction of the brake pads has a significant impact on the magnitude of the braking forces and the stability of the vehicle during braking. One of the reasons for this may be the poor quality of the pad material or a violation of operating conditions. The proposed improved technique for determining the coefficients of sliding friction makes it possible to obtain more accurate values through the use of an analog-to-digital converter, reducing the influence of the accuracy of measuring instruments and the human factor.

The article provides substantiation for the possibility of diagnozing latent damage to car tyres by comparing the average value of the static tyre rate at different points. The degree of uneven static stiffness of the tyre along its circumference was estimated by the size of the tyre contact spot with the support surface. An original method for approximate determination of the tyre spot area contacting with the supporting surface is proposed. The results of determining the area of the tyre contact spot at various points with several values of air pressure in the tyre are presented.

The improvement of the technological process of preparing dry loose feed mixtures is associated with an increase in the structure of feed rations for farm animals in the conditions of farms. It is noted that an increase in the digestibility and palatability of feed, a decrease in the specific energy consumption for the production of feed mixtures depends on the quality of their mixing. The methodological basis of the work was the results of studies of recent years by leading domestic scientists in the field of improving the technological processes for preparing feed mixtures, design and operating parameters of mixers. The analysis of sampling methods is given: periodic for batch mixers; cumulative, allowing to obtain a generalized sample, more representative of the mixing process, also applicable to the study of batch mixers; using special devices - samplers to obtain the most accurate samples. The importance of selecting a control component oriented to the functional features of the mixers, regardless of the sampling method used, is highlighted when monitoring the homogeneity of the mixture. The analysis of existing studies showed a wide range of control components, methods of sampling and separation of components in the study of the mixing process by machines of various designs and principles of operation. The analysis of the works showed that in order to reduce the time spent on isolating the control component and ensure the reliability of the studies, it is necessary to take into account the nature of the mixed cultures. When choosing seeds of sweet clover, clover, millet as control components, a sample mass of 5 grams is sufficient; seeds of beets, buckwheat, wheat and barley, a sample mass of 100 grams is sufficient; seeds of peas, corn, a sample mass of 300 grams is sufficient. A sieve classifier with optimal selection of the mixture with the possibility of separating in sieve or sieve analysis is noted as the most applicable for the isolation of the control component. It is recommended to focus on the method of periodic sampling when examining batch mixers. The cumulative sampling method using samplers is recommended for investigating the performance of continuous mixers and evaluating the overall quality of mixing in batch mixers.

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