The design of a new exoskeleton is presented based on four electric linear actuators for the flexion motion range of the ankle of a user. The exoskeleton system is designed to be easy to operate and fairly inexpensive so that it can be used as a tool for exercising and the rehabilitation of the ankle. A prototype of the ankle exoskeleton is presented with its electrical circuit and components, such as servomotors, microcontrollers, sensors, and power supplies. The prototype is distinguished by an innovative design, which uses linear electric actuators for angular-assisted motion, providing a controlled adaptive movement of the ankle joint in its basic movements, separately and combined. The key elements of the ankle exoskeleton prototype consist of a lower leg housing, front and rear servomotor mounts, and ball joints with the aim of mimicking and supporting the natural movements of the ankle for users with walking and mobility problems. The innovation of the proposed work can be recognized in the portable mechanical design with a proper mechatronic design with four actuators that control ankle motion in all its possibilities.

Lower-limb amputation remains a significant clinical and socio-economic challenge, while the high cost of microprocessor-controlled prostheses (MPKs) limits their widespread accessibility. This paper presents the design and preliminary laboratory-scale evaluation of a low-cost microprocessor-controlled ankle prosthesis intended as a feasibility-oriented alternative platform for future active prosthetic system development. Building upon the previously developed V1 mechanical architecture, an updated CAD model was created in the SolidWorks 2024 environment, and the kinematic configuration was refined using a ball-screw transmission (SFU1204-300) driven by a NEMA 17 stepper motor. The electronic control system integrates an ESP32 microcontroller, an MPU9250 inertial measurement unit (IMU), a limit switch for initial-position detection, and a WiFi-based REST API interface for communication and control. Laboratory no-load experiments demonstrated controlled positional behavior, repeatable angular response, and successful operation of the homing procedure within a motion range of 0–4200 motor steps. The prototype actively generated dorsiflexion–plantar flexion motion in the sagittal plane, while a passive inversion–eversion mechanism was incorporated and intended to improve structural adaptability. IMU-based measurements enabled preliminary monitoring of angular displacement and positional behavior during the experiments. The presented prototype represents an initial engineering feasibility study of a low-cost active ankle actuation architecture and provides a foundation for future investigations involving load-bearing experiments, biomechanical gait analysis, and closed-loop control implementation.

This paper presents a conceptual design of a robotic exoskeleton for active correction of spinal deformities. Unlike existing support-based systems, the proposed approach is correction-oriented and uses a multi-segment structure with linear electric actuators. A comparative analysis of actuation systems was conducted, and the FOCOTECK LA14C actuator was selected for wearable application. The exoskeleton is designed as a vest-based system with actuators mounted via articulated joints to improve kinematic compatibility. A CAD model was developed to evaluate the feasibility of the design. Future work will include simulation and experimental validation using a 3D-printed prototype

Background/Objectives: Lower-limb impairment can alter ankle-joint motion and reduce functional mobility during demanding locomotor tasks such as stair ascent and descent. This study presents the development and preliminary proof-of-concept evaluation of a BLDC-driven active ankle prosthesis incorporating a spherical gear coupling. Methods: Ankle kinematics were recorded using the CONTEMPLAS motion analysis system for one healthy participant and one participant with impaired lower-limb function during level walking, stair ascent, and stair descent. The resulting ankle-angle trajectories were used as reference profiles for unloaded bench testing of the prototype. Results: Static torque was measured using a handheld dynamometer and a fixed lever arm of 0.10 m. Adjustment of the BLDC controller parameters increased the measured static prototype torque from 0.44 N·m to 6.38 N·m, corresponding to a 14.5-fold increase relative to the initial controller configuration, without modification of the mechanical architecture. Under unloaded fixed-rig conditions, the prototype executed a prescribed cyclic ankle-angle trajectory within a range of 112–132°, corresponding to an amplitude of approximately 20°. The optimized prototype torque remained below the 17.17 N·m obtained from a preliminary static measurement of the healthy participant; however, this value should not be interpreted as a physiological torque requirement for dynamic locomotion. Conclusions: The results demonstrate a substantial control-based increase in the available static actuator output and the ability of the prototype to execute prescribed ankle-angle trajectories under controlled bench conditions. Further validation will require dynamic loading, kinetic measurements, foot–ground interaction, improved control strategies, and human-in-the-loop testing with individuals with lower-limb amputation.

This paper presents the kinematic design and experimental validation of a two-degree-of-freedom ankle mechanism based on stepper motor actuation and ball-screw transmission. The proposed system employs a hybrid architecture, combining actively controlled motion in the sagittal plane with passively compliant motion in the frontal plane. Experimental evaluation under no-load laboratory conditions demonstrated a strong linear relationship between motor steps and joint angle within an operating range of approximately ±22°, with coefficients of determination exceeding 0.97. The results confirm the predictability and repeatability of the kinematic transformation while revealing minor hysteresis effects associated with mechanical transmission. The proposed mechanism is intended as a validation platform for studying motion transformation in multi-DoF (degree-of-freedom) ankle systems, providing a basis for future work on load analysis, torque modeling, and closed-loop control.

В статье рассматривается процесс моделирования конструктивной компоновки оптической головки самонаведения (ГСН) противотанковой ракеты. Особое внимание уделяется использованию современных инструментов автоматизированного проектирования (Fusion 360, SolidWorks) для оптимизации размещения электронных компонентов и конструктивных элементов для улучшения характеристик системы управления и наведения. Также в работе рассмотрены компоновочная схема и алгоритм работы системы управления и наведения. Результатом исследований является изучение воздушных потоков и их влияния на аэродинамические характеристики компьютерной модели оптической головки самонаведения с модульным принципом компоновки.