This paper reviews and analyzes three types of vertical-axis wind rotors: the classic Savonius, spiral Savonius, and Darrieus designs. Using numerical modeling methods, including computational fluid dynamics (CFD), their aerodynamic characteristics, power output, and efficiency under different operating conditions are examined. Key parameters such as lift, drag, torque, and power coefficient are compared to identify the strengths and weaknesses of each rotor. Results highlight that the Darrieus rotor demonstrates the highest efficiency at higher wind speeds due to lift-based operation, while the spiral Savonius offers improved stability, smoother torque characteristics, and adaptability in turbulent or low-wind environments. The classic Savonius, though less efficient, remains simple, cost-effective, and suitable for small-scale urban applications where reliability is prioritized over high performance. In addition, the study outlines the importance of blade geometry, tip speed ratio, and advanced materials in enhancing rotor durability and efficiency. The integration of modern optimization approaches, such as CFD-based design improvements and machine learning techniques, is emphasized as a promising pathway for developing more reliable and sustainable vertical-axis wind turbines. Although the primary analysis relies on numerical simulations, the observed performance trends are consistent with findings reported in experimental studies, indicating that the results are practically meaningful for design screening, technology selection, and siting decisions. Unlike prior studies that analyze Savonius and Darrieus rotors in isolation or under heterogeneous setups, this work (i) establishes a harmonized, fully specified CFD configuration (common domain, BCs, turbulence/near-wall treatment, time-stepping) enabling like-for-like comparison; (ii) couples the transient aerodynamic loads p(θ,t) into a dynamic FEA + fatigue pipeline (rainflow + Miner with mean-stress correction), going beyond static loading proxies; (iii) quantifies a prototype-stage materials choice rationale (aluminum) with a validated migration path to orthotropic composites; and (iv) reports reproducible wake/torque metrics that are cross-checked against mature models (DMST/actuator-cylinder), providing design-ready envelopes for small/medium VAWTs. Overall, the work provides recommendations for selecting rotor types under different wind conditions and operational scenarios to maximize energy conversion performance and long-term reliability.

This study presents a comprehensive dynamic analysis of mechanical systems incorporating elastic joints and introduces an adaptive vibration actuator with an integrated transmission variator. The system’s behavior is modeled through kinematic and dynamic formulations, utilizing both analytical and numerical methods. The analysis reveals that the inclusion of elastic elements enables a force adaptation effect, allowing the output element to adjust dynamically to variations in external loading. Under conditions of constant input power, the output speed varies inversely with the load, ensuring reliable adaptive performance. Furthermore, the elastic joints facilitate internal force redistribution, enhancing energy efficiency and reducing mechanical losses. These findings hold relevance for applications in industrial automation and robotics, where consistent functionality under variable load conditions is essential.

This paper proposes a physically based hybrid architecture for controlling mobile robot drives. It combines a model-based controller, an adaptive neural network compensator for residual dynamics, and a Lyapunov-based stability supervision mechanism. Unlike existing hybrid control approaches, the proposed architecture implements a structured injection of neural network correction directly into the physical drive model with a controlled Lyapunov-based adaptation constraint. A mathematical model of the electromechanical drive of a differential mobile platform is developed, taking into account electrical and mechanical dynamics, wheel-to-surface contact interaction, and the system’s energy characteristics. Numerical simulation results demonstrate that the hybrid approach improves tracking accuracy, improves transient response, and ensures stable operation of the control system under parametric uncertainty, adhesion changes, and external disturbances. The proposed architecture maintains the physical interpretability of the model while simultaneously enhancing the system’s adaptability. The obtained results confirm the effectiveness of the developed method and its potential for application in control systems for mobile robotic platforms.

The rapid development of CubeSat technologies has increased the demand for compact and energy-efficient antenna systems capable of providing stable inter-satellite communication under strict limitations of size, mass, and onboard power. This paper presents the design and electromagnetic evaluation of a narrow- directional Yagi–Uda antenna integrated with a solar panel for S-band CubeSat applications. The proposed configuration combines communication and power generation within a single structural element, allowing more efficient utilization of the spacecraft surface while reducing the number of individual components. The antenna dimensions were determined using analytical calculations and subsequently optimized by numerical simulation in the Ansys HFSS environment. Electromagnetic analysis was performed to evaluate the reflection coefficient, voltage standing wave ratio, radiation pattern, operating bandwidth, and antenna gain. The simulation results demonstrate a resonant frequency of 2.29 GHz, an operating bandwidth of approximately 300 MHz, and a directional radiation pattern with a gain of 9.53 dBi. These characteristics indicate that the proposed design can improve communication efficiency while reducing transmission energy consumption. The developed antenna represents a practical solution for future CubeSat missions requiring compact, lightweight, and energy-efficient inter-satellite communication systems.

Stable motion of differential-drive mobile robots on uneven surfaces remains a challenging control problem because local variations in rolling resistance and wheel–terrain interaction generate asymmetric traction forces, trajectory deviation, and heading instability. This study investigates a dual-motor mobile robot in which the left and right driving wheels are actuated independently and coordinated through a coupled control structure that simultaneously regulates linear speed and suppresses yaw motion. A control-oriented nonlinear dynamic model is developed by combining the longitudinal and yaw dynamics of the platform with first-order actuator models and resistance terms that represent uneven-terrain effects through side-dependent rolling losses. Based on this model, a coordinated control law is formulated to redistribute the control effort between the two drives in response to both speed and angular-velocity errors. Numerical experiments are carried out for nominal motion, localized asymmetric resistance, prolonged uneven-surface excitation, robustness-boundary analysis, and actuator-dynamics sensitivity. The results show that the proposed strategy improves directional stability under uneven-surface disturbances, limits the degradation of forward motion, and enlarges the admissible operating region compared with decoupled drive action. The study demonstrates that coordinated inter-wheel control provides a physically interpretable and computationally efficient solution for enhancing the stability of wheeled mobile robots operating on irregular terrain.

This article is devoted to the design of three-axis orientation and navigation systems of CubeSat small spacecraft. The article discusses the problems of controlling the movement of spacecraft along the X, Y and Z axes and designing navigation systems. The design methodology of the navigation control system is presented, which considers modern trends and ensures high quality of control and navigation. The hardware component of the control system included an Arduino Nano microcontroller, ADXL335 accelerometers, an NRF24 radio frequency module, and motor driver and electromechanical executive bodies. GPS data and a ground station were used to receive navigation and telemetry information. The CubeSat body and internal component layout was modeled in a SolidWorks environment, and a physical prototype was later prepared. During the experiment, a given angle for the X, Y and Z axes, the actual angle of the apparatus and the control signal of the actuator were recorded. The results obtained showed that the real angle converges toward the reference value due to the applied control action and allows the developed experimental system to implement the principle of stabilization along the three coordinate axes. The proposed experimental platform can be used to further study and improve the orientation algorithms of CubeSat-type apparatuses.