Pre-sowing tillage under irrigated agriculture is associated with high energy demand and increased risk of soil structural degradation, particularly in heterogeneous loam soils of arid and semi-arid regions. This study presents the engineering optimization and field validation of a combined implement for single-pass rotary strip tillage and precision seeding developed for irrigated sierozem soils of Southern Kazakhstan. The research integrates analytical modeling of soil–blade interaction, optimization of rotary blade geometry, and comparative field experiments using an experimental prototype (FS-2.1). Analytical optimization identified an optimal blade installation angle of 54–56°, resulting in an approximately 22% reduction in specific cutting area. Field results demonstrated that the single-pass system formed a high-quality seedbed, with 85.2% of soil aggregates smaller than 25 mm and a surface leveling deviation below 5 mm. Compared with a conventional multi-pass technology, traction load, fuel consumption, and total energy input were reduced by 38%, 43%, and 54.5%, respectively. The results confirm that combining optimized rotary blade geometry with strip-based soil disturbance enables substantial energy savings without compromising agronomic performance. The proposed engineering solution provides a reproducible framework for low-traction, resource-efficient tillage–seeding systems suitable for irrigated agriculture in Southern Kazakhstan and comparable agroecological regions.

In modern gear mechanics, transmission mechanisms play a crucial role in converting the rotational motion of a driving shaft into the rotational motion of another shaft with varying angular speeds and torque. To achieve optimal designs for the next generation of transmission mechanisms, it is essential to develop mathematical models of their dynamic behavior, conduct computer simulations of the meshing geometry of key components, and visualize the operation of the mechanism. Despite the widespread use of involute gearing in mechanical transmissions, there is ongoing research into new types of gearing that offer advantages over traditional systems. The main challenges facing the industry include increasing the gear ratio in a single stage, enhancing load capacity, and improving efficiency compared to standard gear transmissions. This paper presents the results of mathematical and computer modeling, along with a comparative analysis of the eccentric-cycloid (EC) engagement with the involute gear transmission. Through analytical calculations, the energy-force parameters of the EC gearbox were determined, equivalent stresses and static deflections of transmission shafts were obtained. The paper includes the results of static analysis of elements of the new EC transmission, as well as an algorithm for computer modeling of contact stresses occurring in the engagement. Conclusively, by comparing contact stresses in traditional involute gear transmission, calculated using various analytical methods, with those in EC engagement determined through computer simulation, the advantages of the new transmission type and its potential application in mining equipment transmission mechanisms are highlighted.

The application of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) composites in osteosynthesis implants represents a promising approach to mitigating the stress-shielding effect associated with the high stiffness of conventional metallic implants. This study aimed to experimentally and numerically evaluate the effects of short carbon fiber content and the orthotropic mechanical properties of CFR-PEEK on the structural strength of osteosynthesis plates and load distribution within the bone–plate system. The investigation employed a multiscale approach integrating micromechanical modeling using the Mori–Tanaka homogenization method in Digimat-MF, experimental mechanical testing of FDM-fabricated CFR-PEEK specimens containing 10 wt.% carbon fibers, and finite element analysis of osteosynthesis plates made of CFR-PEEK with 10 and 30 wt.% carbon fibers and Ti-6Al-4V using MSC Patran/Marc. CFR-PEEK 30% specimens were neither fabricated nor experimentally tested. Their mechanical properties were predicted using Digimat-MF by applying correction factors derived from experimental data obtained for CFR-PEEK 10%. The results demonstrated that increasing the carbon fiber content from 10 to 30 wt.% enhanced the longitudinal elastic modulus. Experimental testing of CFR-PEEK containing 10 wt.% carbon fibers revealed an elastic modulus ranging from 1.76 to 3.10 GPa and a tensile strength of 47–54 MPa. Following process-related adjustments to the material properties, finite element simulations of the bone–plate system were performed under an axial load of 50 N. The calculated load shielding indices were 94.3% for Ti-6Al-4V, 28.6% for CFR-PEEK 10%, and 54.3% for CFR-PEEK 30%, indicating the potential of composite implants to improve mechanical load transfer to the surrounding bone tissue. A preliminary strength assessment based on the three-dimensional Tsai–Hill failure criterion yielded failure indices of 15.577 and 1.112 for CFR-PEEK 10% and CFR-PEEK 30%, respectively, under the assumed material strength parameters. Critical stress concentrations were predominantly localized around the fixation holes. These findings highlight the trade-off between reducing stress shielding and ensuring the structural integrity of composite osteosynthesis plates. The results further emphasize the need for localized optimization of fixation regions to improve mechanical reliability without increasing the overall implant thickness.

Human following by quadruped robots is a coupled perception–control problem in which detection availability, identity continuity, ranging reliability, and latency jointly determine behavior. This study experimentally evaluates a camera-based human-following pipeline on Boston Dynamics Spot. The final RGB-only follow loop combines YOLOv8n person-detection, DeepSORT tracking, monocular geometric ranging from bounding-box width, and bounded linear/yaw velocity control; spot depth was evaluated only as an alternative range source. YOLOv8n achieved 59.0% frame-level detection success indoors (36/61; 95% CI 46.5–70.5%) at 113.7 ms mean inference latency, and 38.75% outdoors (31/80; 95% CI 28.8–49.7%) at 118.1 ms. DeepSORT produced zero observed ID switches and fragmentations in 51 indoor and 45 outdoor multi-person frames, at about 3.2 FPS. On 12 outdoor frames with field-reference distances, geometric ranging yielded MAE 0.264 m and RMSE 0.323 m; spot depth was valid in only three frames. Continuous velocity control provided qualitatively smoother following than discrete commands and stopped on target loss. The study contributes a reproducible system-level analysis of practical design trade-offs and failure modes in camera-based human following by a commercial quadruped robot.

Introduction. Eccentric–cycloidal gear reducers represent a promising type of drive for mining conveyor equipment due to their high shock resistance, multi-tooth load distribution and tolerance to contamination. However, the dynamic behavior of the contact interaction between the eccentric tooth and the cycloidal wheel has not been sufficiently quantified. This limits their large-scale implementation in heavy industrial environments. A detailed analysis of vibration stability, contact force patterns, and geometric conformity of the tooth profile is required to assess operational reliability. Purpose of the study. The aim of this research is to perform a numerical investigation of dynamic contact forces and vibration processes in an eccentric–cycloidal gear reducer used in mining conveyor drives and to evaluate the geometric conformity of the transmission by means of spectral and time-domain analysis. Materials and methods. A multibody dynamic model was developed in MSC Adams. The reducer geometry was imported from Autodesk Inventor, including real bearing parameters, material properties, inertial characteristics, and kinematic constraints. The tooth contact was described using a nonlinear Hertzian model with damping and Coulomb friction. Simulations were performed at an input speed of 750 rpm, gear ratio i = 9 and load torque of 2 kN·m. Vibration acceleration, contact force histories, frequency spectra, and impulse loads during tooth engagement were analyzed. Results. The acceleration of the eccentric shaft reached 350 mm/s2 due to local oscillations in bearing units, while vibrations in the gear mesh were effectively damped to 0.004 mm/s2. The contact force exhibited a pronounced impulse of approximately 300 N during tooth engagement. Frequency analysis revealed a single dominant harmonic corresponding to the meshing frequency, without additional resonance peaks, indicating high geometric conformity of the cycloidal profile. The minimal contact area reduces the likelihood of pitting and surface chipping. Discussion. The results demonstrate high vibration resistance of the eccentric–cycloidal transmission and its suitability for mining conveyor applications with variable dynamic loads. The impulse nature of the contact force was quantified and shown to be within acceptable limits. Validation on a laboratory conveyor confirmed the accuracy of the numerical model and uniform motion transfer without phase delays. Conclusions. The investigated gear reducer exhibits low dynamic losses, stable load transfer and high vibration resistance. Numerical simulation confirms its potential for reliable operation in mining conveyor drives and its feasibility for replacing traditional gear systems under harsh industrial conditions. General conclusions. The eccentric–cycloidal reducer demonstrates favorable dynamic behavior, with low contact stresses and absence of detrimental resonant harmonics. The results support its further industrial implementation and optimization. Practical significance and future research. The findings may be used for designing energy-efficient conveyor drives, optimizing cycloidal tooth profiles, estimating fatigue life and developing digital twins of gearbox systems. Future research should focus on wear modeling, shaft misalignment effects, and thermo-mechanical behavior of the gear mesh.

Современные требования к безопасности эксплуатации тракторов и самоходных машин требуют точной оценки их поперечной устойчивости, особенно при эксплуатации на склонах и пересечённой местности. В статье рассматривается проектирование испытательного стенда с гидравлическим опрокидывающим механизмом, который обеспечивает плавное изменение угла наклона платформы и фиксацию момента потери устойчивости техники. Разработанная методика испытаний включает алгоритм измерений, фиксацию положения машины и регистрацию ключевых параметров, а также построение математической модели функционирования подъемного механизма, что позволяет рассчитать оптимальное расположение гидроцилиндра и обеспечить высокую точность измерений. Использование современных подходов к испытаниям сельскохозяйственной техники позволяет воспроизводить натурные условия эксплуатации и учитывать реальные нагрузки на агрегаты и системы. При этом оценка угла статической устойчивости на стенде базируется на координатах центра тяжести и геометрических параметрах машины, таких как ширина колеи, колесная база и распределение массы. Дополнительно учитываются изменения радиусов колес и смещения вектора центра тяжести, что позволяет корректно рассчитывать момент устойчивости при движении по склону. Современные испытательные стенды оснащаются автоматизированными системами управления, что позволяет проводить испытания в автоматическом режиме, фиксировать динамические и статические параметры, а также обеспечивать аварийное отключение в случае отклонения от нормы. Применение энергосберегающих технологий в конструкции стенда повышает эффективность и снижает затраты энергии. Разработка соответствует требованиям ГОСТ 12.2.019, ГОСТ 33691-2015 и ISO 16231-2 и может быть использована при создании нормативных методик испытаний самоходных машин и тракторов. Ключевые слова: угол поперечной устойчивости, испытательный стенд, последовательное взвешивание, гидроцилиндр, взвешивание по бортам, испытания, расчетная модель.