Tạp chí của Tổng hội Cơ khí Việt Nam
DESIGN OF AN ENERGY RECOVERY SYSTEM FOR A HYDRAULIC EXCAVATOR COMBINING FUZZY CONTROL ALGORITHM
Energy recovery and reuse from the boom lifting system of hydraulic excavators contribute to energy savings and a reduction in harmful emissions during machine operation. To achieve high system efficiency, an intelligent control strategy is required. In this study, the energy recovery and reuse system is modeled and simulated using the Amesim software, while a Fuzzy Logic Controller (FLC) is employed to coordinate energy management between the hydraulic pump and the electric generator. Simulation results indicate that the energy recovery efficiency reaches approximately 57.1%, whereas the energy demand required to drive the main pump is reduced by about 43.3%.
APPLICATION OF NUMERICAL METHODS TO STUDY THE EFFECTS OF CAVITATION ON THE HYDRODYNAMIC CHARACTERISTICS OF THE HYDROFOIL NACA 4412
Cavitation is the phenomenon in which a liquid undergoes local vaporization in regions having pressure below the saturated vapor pressure. When the vapor bubbles are transported to regions of higher pressure, they collapse violently, generating intense pressure pulses that damage the surface of impeller blades, cause noise and vibration, and reduce the hydraulic efficiency of the machine during operation. For a hydrofoil, cavitation typically occurs on the suction side, at the leading edge, and at the trailing edge; it leads to a reduction in the lift coefficient, an increase in the drag coefficient, and induces fluctuations in the loads acting on it. Therefore, investigating the influence of cavitation on the hydrodynamic characteristics of a hydrofoil is of great importance for the design and performance prediction of hydraulic machinery blades operating efficiently under cavitating conditions. In this study, a computational fluid dynamics (CFD) approach is employed to investigate the effects of cavitation on the hydrodynamic performance of the hydrofoil NACA 4412. The full cavitation model coupled with the RNG k-ε turbulence model is used to simulate the formation, development, and collapse of cavitation bubbles occurring on the suction side, leading edge, and trailing edge of the hydrofoil NACA 4412. The simulation results indicate that the occurrence of cavitation significantly reduces the lift coefficient and increases the drag coefficient, while also causing large pressure fluctuations in the trailing-edge region of the hydrofoil. At the attack angle α = 15°, the lift coefficient Cl of the hydrofoil NACA 4412 decreases about 14%, whereas the drag coefficient Cd increases about 34%.
RESEARCH ON OPTIMIZING THE STRUCTURE OF A CO2 LASER ENGRAVING MACHINE USING CNC TECHNOLOGY
This paper presents a study on the design and optimization of a CO2 laser engraving machine using CNC technology to improve accuracy, processing speed, and operational stability. Based on a survey of existing small-power CO2 laser machines, the system is designed with four main parts: mechanical system, optical system, CNC control system, and cooling system. The machine frame structure is optimized using numerical simulation to increase rigidity, reduce vibration, and improve thermal stability. The machine has overall dimensions of 1000×1000×500 mm, a working area of 600×600×200 mm, and uses a 40W CO2 laser tube with a wavelength of 10.6 µm. Simulation and testing results show that the optimized structure ensures durability, reduces weight by approximately 12%, achieves machining accuracy of 0,01 mm, a maximum engraving speed of 500 mm/s, and stable operation within a temperature range of 25÷30°C. The results confirm the feasibility and effectiveness of the proposed solution for training and small-scale production.
SIMULATION AND EVALUATION OF A REGENERATIVE BRAKING SYSTEM USING A PMSM MOTOR FOR ELECTRIC VEHICLES
This paper presents the research results on the development and simulation of a regenerative braking system for electric vehicles based on a Permanent Magnet Synchronous Motor (PMSM). The system is modeled and implemented on the MATLAB/Simulink platform, comprising the main components: vehicle dynamics model, inverter, PMSM drive, control system, and energy storage system. Simulation results demonstrate that the proposed regenerative braking system is capable of effectively recovering energy during vehicle deceleration, thereby improving the overall energy efficiency of the electric vehicle. The outcomes of this study can serve as a reference for teaching, learning, and scientific research, and contribute to enhancing the quality of training for staff and lecturers in the field of automotive engineering at Quang Ninh University of Industry as well as other technical institutions nationwide.
EXPERIMENTAL INVESTIGATION AND DETERMINATION OF FORCES ACTING ON THE RECOILING MASS FOR THE CALCULATION, DESIGN, AND FABRICATION OF AN ARTIFICIAL RECOIL DEVICE FOR GROUND ARTILLERY
The experimental research process determined the dimensional parameters of the recoil braking unit and the counter-recoil (recuperator) unit; identified the initial and final counter-recoil forces of the recuperator; and established the variation law of the regulating rod diameter with respect to the recoil length, which provides a basis for calculating the recoil resistance force of artillery during artificial recoil operation. The calculated recoil resistance forces are presented in both graphical form and tabulated characteristic parameters, showing the minimum and maximum values of the recoil resistance force for two types of ground artillery, namely the 85 mm D-44 and the 152 mm D-20, at different elevation angles in accordance with the prescribed artificial recoil conditions. The research results clearly indicate that the maximum recoil resistance force for each artillery type decreases as the elevation angle increases. Specifically, when the elevation angle of the 85 mm D-44 gun increases from 0° to 25°, the maximum recoil resistance force decreases by 6.59%, whereas for the 152 mm D-20 gun, the maximum recoil resistance force decreases by 14.14% as the elevation angle varies from 0° to 45°. Furthermore, the study determined the maximum recoil resistance force to be used as the basis for the calculation and design of artificial recoil devices for ground artillery, with a value of 143.439 kN corresponding to the artificial recoil of the 152 mm D-20 gun at an elevation angle of 0°.
MODELING AND SIMULATION OF ENERGY FLOW IN HYBRID VEHICLE SYSTEMS USING OCTAVE
This paper presents a mathematical modeling and simulation method for a Hybrid Vehicle (HEV) control system based on a Power Split Device (PSD) architecture. The study focuses on developing the dynamic equations for the Internal Combustion Engine (ICE), two electric motors (MG1, MG2), and the energy storage system (Battery). Energy coordination algorithms for the HV ECU controller and the influence of the air conditioning (A/C) load are integrated to evaluate the battery's State of Charge (SoC). Simulation results using Octave software show a strong correlation between the electromechanical components in the system.
EXPERIMENTAL STUDY ON BANANA PSEUDOSTEM DRYING USING A COMBINED SOLAR ENERGY AND AUXILIARY HEATING
Dried banana pseudostem sheaths with a moisture content below 12% have experienced increasing global demand in recent years. However, an economically efficient drying solution for this product has not yet been widely established. This study presents key operating parameters of a solar-assisted drying system combining direct and indirect drying modes with auxiliary heating to reduce the moisture content of banana sheaths from 92.9% to below 12%. The drying process was conducted at a hot air temperature of 50°C for 25 hours, compared to 40 hours required under traditional sun drying. These parameters can serve as a basis for the development of a large-scale greenhouse-type drying system, offering improved efficiency in terms of energy consumption, labor, and processing time for dried banana sheath production.
OPTIMIZATION OF TOTAL COST OF OWNERSHIP (TCO) OF ELECTRIC VEHICLES IN CONGESTED URBAN ENVIRONMENTS: A CASE STUDY IN HANOI, VIETNAM
This paper presents a comprehensive analysis and optimization of the Total Cost of Ownership (TCO) for Electric Vehicles (EVs) versus Internal Combustion Engine (ICE) vehicles within Hanoi's unique congested urban environment. A mathematical model incorporating battery degradation under high temperatures, energy consumption variability in stop-and-go traffic, and local incentive policies is developed. Our findings, based on a comparative case study involving popular EV and ICE models, reveal that while initial acquisition costs for EVs remain higher, strategic charging, Governmental subsidies, and the inherent inefficiencies of ICE vehicles in heavy congestion contribute to a significantly lower TCO for EVs over a 7-year ownership period. This study provides critical insights for policymakers and consumers in similar developing urban contexts.
OPTIMIZING REALTIME PERFORMANCE FOR EMBEDDED SYSTEM IN 3 AXIS DYANOMETER: A COMPARISION BETWEEN TECHNIQUES
The highly accurate, high-speed acquisition of cutting force data is a fundamental prerequisite for the real-time monitoring and optimization of machining processes. To date, the predominant focus of research has been on the mechanical design and calibration accuracy of dynamometers, with comparatively limited attention devoted to the optimization of embedded data acquisition architectures. This study addresses this gap by presenting a systematic performance comparison of four distinct data acquisition strategies implemented on a three-axis real-time force measurement system in turning process. The architectures: (i) Polling, (ii) Polling with Interrupts, (iii) a Real-Time Operating System (RTOS) with Interrupts, and (iv) an RTOS with Direct Memory Access (DMA) utilizing a double buffering mechanism were evaluated on an STM32 microcontroller platform integrated with a 24-bit ADC operating at 32 kSPS. Performance was quantitatively assessed based on CPU utilization and sampling rate stability. The empirical results demonstrate that while conventional Polling and Interrupt-driven methods achieve the target sampling rate, they do so at the cost of nearly 100% CPU utilization. The RTOS-Interrupt architecture offered a substantial improvement, reducing the CPU load to approximately 97.51%. Most significantly, the RTOS-DMA configuration demonstrated superior efficacy, achieving an average CPU load time of 87.23% while maintaining high sampling rate stability (33,145.09 ± 36.64 samples/s). These findings validate that the RTOS-DMA architecture provides an optimal balance between high data throughput and computational efficiency. This approach effectively decouples data acquisition from the CPU, thereby enabling parallel execution of critical tasks such as signal processing and communication, establishing it as the most suitable architecture for robust, multi-tasking smart machining monitoring systems.
DEVELOPMENT OF A CRANIAL MOLDING HELMET FOR INFANTS WITH FLAT HEAD SYNDROME HFS2025
The paper presents a development for cranial molding helmets tailored to infants with flat head syndrome. The helmet is built using 3D scanning of the infant's head, featuring optimized circular ventilation holes through ANSYS thermal simulation. The prototype molding shell is fabricated through 3D printing technology. By specifically analyzing stress symptoms through heart rate and blood oxygen saturation data, this paper proposes using sounds to reduce infant stress.
BIRUNI: A ROS 2-BASED AUTONOMOUS MECANUM-WHEELED MOBILE ROBOT WITH MULTI-SENSOR FUSION, REAL-TIME SLAM, AND NAVIGATION IN GAZEBO FORTRESS -2025
This document presents Biruni, a ROS 2-based autonomous mecanum-wheeled mobile robot designed and evaluated in a high-fidelity Gazebo Fortress simulation environment. The robot integrates a multi-sensor perception architecture consisting of a 2D LiDAR, an RGB camera, an Inertial Measurement Unit (IMU), and wheel encoders. A unified Extended Kalman Filter (EKF) is implemented to fuse inertial and odometry data, generating a stable and drift-minimized state estimate for real-time navigation. Cartographer SLAM is used to produce consistent 2D occupancy maps, while the Navigation2 (Nav2) framework provides global and local planning, obstacle avoidance, and autonomous waypoint following. The complete system is structured around a modular ROS 2 package architecture with a fully validated TF tree, URDF/Xacro robot model, and synchronized sensor frames. Simulation results demonstrate accurate localization, reliable mapping, and smooth path execution with omnidirectional control using mecanum kinematics. The Biruni platform offers a reproducible foundation for education, research, and future deployment on physical hardware.
STUDY OF THE SIDELINE DYNAMICS OF PASSENGER CARS USING NUMERICAL SIMULATION SOFTWARE
Vehicle stability during cornering is a critical factor directly affecting traffic safety, particularly at high speeds and under abrupt steering maneuvers. This study investigates the lateral dynamic characteristics of a passenger car during cornering using a simulation-based approach. A multi-degree-of-freedom lateral–yaw dynamics model is developed and coupled with a nonlinear Pacejka tire model to describe tire–road interactions. The model is implemented to simulate representative steering scenarios, including single lane change and double lane change maneuvers. The effects of vehicle speed and steering inputs on key lateral dynamic responses – such as lateral velocity, yaw rate, lateral acceleration, and vehicle trajectory – are analyzed. The simulation results show that increases in vehicle speed and steering severity significantly amplify lateral dynamic responses, leading to larger tire slip angles and wider trajectories; notably, the double lane change maneuver exhibits a more pronounced tendency toward instability. These findings provide a scientific basis for evaluating vehicle handling stability and support the development of driver assistance and stability control systems for passenger cars.
RESEARCH ON THE DESIGN OF A PROCESS FOR ROLLING V3600 BARS FROM 0.3MM THIN STEEL PLATES USING SLAB METHOD AND VERIFICATION BY FINITE ELEMENT SIMULATION
This paper presents a study on the design of a roll-forming process for producing V3600 profiles from thin steel sheets with a thickness of 0.3 mm. Based on an analysis of the product geometry, the number of forming passes is determined and a sequential roll-forming process is established. Rolling stress and total resisting force acting on the roll shafts are calculated using an analytical slab-based model. Finite element simulations are performed in ABAQUS to evaluate stress distribution and to validate the analytical results. The comparison confirms the feasibility of the proposed roll-forming process for thin sheet steel.
DESIGN AND MANUFACTURE 3D LASER SCANNER MODEL FOR TEACHING AND AND EXPERIMENTING AT NAM DINH UNIVERSITY OF TECHNOLOGY EDUCATION
The development of computer science has significantly assisted people in designing and simulating in industry from the dimensions measured on the product. In industry, 3D laser scanners can instantly digitize the shapes of various industrial parts... The digitized data can be accurately simulated on the computer screen. With those practical and effective applications, the authors proposed the idea of ​​researching and manufacturing a 3D laser scanner model to serve teaching and experimenting at Nam Dinh University of Technology Education in the most complete form and at the lowest cost.
DYNAMIC MODELING, STABILITY ANALYSIS, AND TRAJECTORY OPTIMIZATION OF MOBILE AND TELESCOPIC CRANES: A REVIEW STUDY
This paper presents a comprehensive synthesis of research conducted over the past three decades on the dynamic modeling, stability analysis, and trajectory optimization of mobile and telescopic cranes. Based on an analysis of eight representative studies from Poland, China, and Russia, the work integrates mathematical models, simulation methodologies, and stability criteria that have been applied in the field of modern lifting machinery. The reviewed approaches include nonlinear dynamic models derived from Lagrange’s equations, aerodynamic models of payloads under wind excitation, and trajectory optimization methods aimed at minimizing energy consumption and load oscillations. The paper also discusses emerging research trends in intelligent control, numerical simulation, safety standardization, and machine learning–based design of modern cranes.
STUDY ON METAL TRANSFER IN GMAW UNDER THE INFLUENCE OF SHIELDING GAS
This paper investigates the effect of shielding gas on metal transfer behavior in gas metal arc welding (GMAW) using a conventional solid wire electrode. Welding experiments were carried out with three shielding gases, including pure Ar, an Ar + 20% CO2 mixture, and 100% CO2, at three welding currents of 220, 250, and 280 A. Under pure Ar shielding, the transfer mode gradually changed from projected droplet transfer to streaming transfer as the welding current increased. When the CO2 content in the shielding gas increased to 20%, the metal transfer mode evolved from globular transfer to projected droplet transfer as the current increased from 220 A to 280 A. In contrast, under 100% CO2 shielding, globular transfer was observed at all three current levels. These experimental observations clarify the fundamental differences in the mechanisms governing metal transfer as influenced by the shielding gas during GMAW.
INFLUENCE OF SOME PARAMETERS CUTTING REGIME ON SURFACE ROUGHNESS OF TITANIUM ALLOY Ti-5Al PARTS IN CNC TURNING
The gyroscope components are made from Titanium alloy Ti-5Al, having high demands on surface quality. Surface quality is evaluated through surface roughness that depends on cutting regime parameters. This article introduce the findings of study on the influence of cutting parameters on surface roughness of Titanium alloy Ti-5Al parts in CNC turning. Based on the experimental results, a matematical model has been established to describe the effect of cutting speed (V), feed rate (S), cutting depth (t) on surface roughness of Titanium alloy Ti-5Al parts with their corresponding coefficients: K = 132,436; a1 = -0,1579; a2 = 1,791; a3 = 0,0819. The regression model was validated using statistical analysis tools with a confidence level greater than 98.2%. The model proposed in this study can be applied to improve the surface quality during CNC turning of Titanium alloy Ti-5Al parts.
OPTIMIZATION RESEARCH ON MULTI-AGV CONTROL ALGORITHMS ON A CENTRALIZED – ROBOT CONTROL SYSTEM
This paper presents an optimization study of multi-AGV control algorithms on a centralized Robot Control System (RCS). AGVs (Automated Guided Vehicles) are autonomous mobile units used for material handling in warehouses and factories, requiring efficient path planning, task assignment, and collision-free coordination. The research focuses on three main algorithmic approaches: Find the shortest path with the fewest Robots with the upgraded A*, a dynamic task allocation method responsive to real-time robot status, and a time-prediction-based collision avoidance algorithm. All methods were simulated and evaluated using Python, with a multi-robot communication mechanism integrated to assess performance, scalability, and practical deployment potential.
DESIGN AND FABRICATION OF A TOXIC GAS SUCTION PUMP FOR RAID-M100 AUTOMATIC CHEMICAL AGENT DETECTORS AND RAID-XP RADIATION MEASUREMENT DEVICES
The RAID-M100 automatic chemical agent detector and the RAID-XP radiation measurement device require a stable and continuous gas flow to ensure the accuracy of the ion mobility spectrometry (IMS) analysis chamber. This paper presents the design and fabrication of a miniature toxic gas suction pump developed to meet the specific technical requirements of these two devices. The pump is designed with a high-sealing structure, low flow rate, and stable suction pressure, ensuring reliable gas sampling under continuous operating conditions. The study focuses on structural design, material selection, manufacturing processes, and performance evaluation through experimental testing. The results show that the pump achieves stable airflow, low leakage, and reliable operation within the required voltage and pressure ranges, fully satisfying the conditions for integration into the RAID-M100 and RAID-XP devices. The proposed solution contributes to domestic component localization and enhances the technical readiness of specialized detection equipment.
STUDY ON THE CALCULATION AND SIMULATION OF POWER SOURCE SWITCHING MODES ON A GASOLINE – ELECTRIC HYBRID PASSENGER CAR, TOYOTA COROLLA ALTIS HYBRID 1.8HEV
In this article, the authors present the results of a simulation study of power conversion modules on a Toyota Corolla Altis 1.8HEV hybrid vehicle, including a DC-DC converter that steps up the battery voltage from 201.6V to 650V, and an inverter that converts the DC source voltage U = 650V to a three-phase AC supply for the permanent magnet synchronous motor. Using numerical simulation software Matlab - Simulink, the study allows for the calculation and control of the speed and torque on the electric motor shaft. The research results and simulations help learners gain a more comprehensive understanding and more accurate assessment of the speed control methods used in hybrid vehicles (gasoline-electric hybrid) as well as electric cars, thereby fostering better scientific thinking in technical consulting, maintenance, and repair of hybrid and electric vehicles. This also provides a foundation for supporting teaching, learning, scientific research, and improving the quality of training for staff and lecturers in the automotive engineering technology field at the University of Technology.
IMAGE PROCESSING APPLICATION FOR ROBOTIC ARM TO RECOGNIZE AND PICK UP 3D OBJECTS MOVING ON CONVEYOR BELT
The application of image processing to identify the position of moving objects on the conveyor belt and control the manipulator to pick up the object for assembly is one of the very popular applications in industry today. However, most of the applications are for 2D flat objects. 3D objects have not been studied much, especially in Vietnam due to the complexity of calculation and long execution time using traditional methods. This study presents a method that can increase the productivity of an assembly line by identifying and picking up 3D objects moving on the conveyor belt using image processing and manipulators. The system includes a camera placed above to detect the object to be assembled in any direction and position on the conveyor belt. Then the 3D coordinates and angular orientation of the object in the 3D coordinates are calculated. The calculated data will be transmitted to the manipulator to perform the picking task. The assembly process will be performed based on the known position and orientation of the object to check for errors. Through experimental verification, the accuracy as well as the recognition time, the system proves to be applicable to the assembly industrial environment to help increase the productivity of the system.
A HYBRID MCDM APPROACH FOR MINING ROBOT SELECTION BASED ON ANALYTIC HIERARCHY PROCESS
Amidst the 4.0 industrial revolution, technological advancements have created vast opportunities for enhancing automation within manufacturing processes. The integration of robots to supplant human labor stands as a pivotal development. These robots, now ubiquitous across various sectors, are instrumental in bolstering precision, speed, and quality control in production lines. However, the multiplicity of different robotic kinds with differing characteristics like load capacity, speed, and cost makes it difficult to choose the best robot for a given application. To address this issue, the adoption of multi-criteria decision-making (MCDM) methods has emerged as a valuable strategy for facilitating informed choices. Recent research endeavors have leveraged MCDM techniques to assess and compare robots across a spectrum of criteria. By employing these methodologies, industries can optimize robot selection processes, thereby enhancing operational efficiency. In our current investigation, we introduce a novel hybrid MCDM approach that amalgamates analytic hierarchy process (AHP) weighting with Additive Ratio ASsessment (ARAS), Complex PRoportional ASsessment (COPRAS), and Measurement of Alternatives and Ranking according to COmpromise Solution (MARCOS) methodologies to evaluate and rank mining robots. This methodology involves constructing weights based on expert insights, while also acknowledging the significance of pairwise criterion comparisons. Our findings indicate that robot 7 emerges as the most favorable choice, while robot 2 ranks as the least optimal option, demonstrating consistent outcomes across all three proposed methodologies. These findings have significant ramifications for manufacturers, providing them with crucial direction in negotiating the complex network of factors involved in choosing robots that meet production requirements.
DESIGN, MANUFACTURE AND EXPERIMENT ON ROTARY DRUM HEAT PUMP DRYING SYSTEM
This paper presents the results of the design, manufacture, and experimental evaluation of a rotary drum heat pump dryer for drying green peas (Pisum sativum L.) with a batch capacity of 2 kg. The technical specifications of the dryer are as follows: the drying drum has a length of 892 mm and a diameter of 223 mm; the refrigeration system employs a 1 HP compressor using R404A refrigerant; the cooling capacity of the evaporator is 3 kW; the heat rejection capacity of the main condenser is 2,65 kW; and the auxiliary condenser has a heat rejection capacity of 1,1 kW. No-load experimental results indicate that the heat pump system operated stably, with an evaporation temperature of 5.2°C and a condensation temperature of 50.2°C; the drying air supplied to the drying drum maintained a stable temperature over time. The rotary drum system operated stably and allowed adjustable rotational speed. Drying experiments were conducted on green peas with an initial moisture content of 68,35% (wet basis), corresponding to 2,16 kg water per kg dry matter (dry basis), under the conditions of a drying air velocity of 3 m/s and a drum rotational speed of 8 rpm, at drying air temperatures of 40, 45, 50, 55, and 60°C, until a final moisture content of 13%, corresponding to 0,15 kg water per kg dry matter, was achieved. The results indicate that increasing the drying temperature from 40°C to 60°C reduced drying time by more than 50% and decreased energy consumption by 23.89%. Specifically, at a drying temperature of 40°C, the drying time was 10,35 hours and the electrical energy consumption was 13,77 kWh; at 50°C, the drying time decreased to 6,47 hours and the electrical energy consumption was 12,33 kWh; and when the drying temperature increased to 60°C, the drying time was reduced to 3,97 hours and the electrical energy consumption was 10,48 kWh. Green pea products dried using the heat-pump rotary drum drying system exhibited good color and flavor retention.
STUDY ON THE INFLUENCE OF THE LINER APEX ANGLE AND LINER THICKNESS ON THE STEEL PENETRATION PERFORMANCE OF A 40 MM ROTATING SHAPED CHARGE
This paper investigates the influence of the liner apex angle and liner thickness on the penetration performance of a rotating shaped charge. The authors employed three-dimensional numerical simulations using the mesh-free Smoothed Particle Hydrodynamics (SPH) method implemented in ANSYS Autodyn to analyze the effects of the liner apex angle and liner thickness on the performance of the rotating shaped charge. The object of study is a 40-mm caliber shaped charge warhead. The liner apex angle α was considered in five configurations: 24°, 27°, 30°, 33°, and 36°, while the liner thickness δ was investigated in six configurations: 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, and 1.6 mm. Numerical simulations were carried out for two rotational conditions about the charge axis of symmetry: non-rotating and rotating at 10000 rpm. The simulation results indicate that, in the non-rotating case, there exists an optimal set of liner design parameters at which the penetration depth reaches a maximum value. Similarly, for the rotating case at 10000 rpm, an optimal liner design parameter set is also observed. The proposed research approach can be applied to optimize the structural design of rotating shaped charges.
A SIMULATION STUDY OF CONTROL FOR A SYNCHRONOUS DIESEL GENERATOR SYSTEM SUPPLYING A LARGE POWER LOAD USING ARTIFICIAL NEURAL NETWORKS
This paper, presents the theoretical basis for controlling a diesel-synchronous generator system, a common power supply system on ships. Based on this, a simulation of the voltage and frequency control system for the synchronous generator is built using Matlab and Simulink. The simulation results show that the neural network controller meets the system requirements, automatically stabilizing the voltage and frequency of the synchronous generator when the load power changes significantly. The application of neural networks in control engineering offers natural noise filtering and better nonlinear control capabilities than conventional control. Furthermore, the content of this paper provides a foundation for students and trainees to further research neural networks in identification and and control techniques.
MECHANICAL ENGINEERING APPLICATIONS IN THE DESIGN AND DEVELOPMENT OF BIOMIMETIC TEXTILE MATERIALS
Biomimicry has emerged as an important approach in mechanical engineering applications for the textile industry, particularly in the design of fiber structures, fabrics, and material surfaces with enhanced functional performance. By investigating optimized structures and mechanisms found in nature, mechanical engineering principles enable the transformation of biological concepts into engineering solutions through structural design, numerical modeling, manufacturing technologies, and process control. This paper analyzes the role of mechanics of materials, structural mechanics, manufacturing engineering, and numerical simulation in the development of biomimetic fibers and textile structures. Furthermore, the potential applications in technical textiles and the contribution of this approach to the sustainable development of the textile industry are discussed.
STRENGTH CALCULATION AND VERIFICATION OF A 30-TON-PER-DAY COTTON BALE OPENER IN A SPINNING PRODUCTION LINE
This paper presents the strength calculation and verification of a cotton bale opener designed for a capacity of 30 tons per day. Based on the analysis of working conditions and load characteristics, key parameters such as opening force, drum shaft torque, and driving power were determined, and an 11 kW electric motor was selected. In addition, finite element method (FEM) simulations were carried out using ANSYS software to evaluate the structural strength of the machine casing under different loading conditions. The results indicate that the structure satisfies strength requirements and operates safely within the load range from 1000 kg/h to over 3000 kg/h. The study provides a scientific basis for the design, manufacturing, and optimization of cotton bale openers in the textile industry.
STRENGTH CALCULATION AND VERIFICATION OF A FABRIC CONVEYOR WITH A CAPACITY OF 30 TONS PER DAY IN AN INDUSTRIAL GARMENT FACTORIES
The paper presents the research results, design calculations, and strength verification of a fabric conveyor system used in an industrial garment manufacturing plant with a capacity of 30 tons per day. Based on the analysis of technological requirements, fabric material characteristics, and actual operating conditions, the main conveyor parameters – including belt width, conveying speed, motor power, and supporting frame structure – were determined. Mechanical calculations were conducted to evaluate the load-bearing capacity, strength, and structural stability of the principal components, such as the conveyor belt, rollers, shafts, and supporting frame. The strength verification results indicate that the stress acting on the conveyor frame is [σ] = 170 MPa, and the selected motor power is 2.0 kW. The conveyor system satisfies the requirements for strength, safety, and reliability under continuous operating conditions.
RESEARCH ON THE MANUFACTURING OF THE ĐC100M-PST MORTAR SHELL BODY BY CASTING AS AN ALTERNATIVE TO THE CURRENT STAMPING METHOD
This study presents the research outcomes and assessment of manufacturing the ĐC100M-PST mortar shell body using a casting process as an alternative to the conventional stamping method. This approach utilizes ProCAST software to design the casting blank and mold, and to determine an optimized casting scheme that meets current technological conditions, thereby facilitating production tasks at Factory Z115. Experimental evaluation of mortar shells produced by the casting method demonstrates that the products fully satisfy the approved tactical – technical requirements of the 100 mm mortar shell ĐC100M-PST. The findings have significant scientific and practical implications, particularly in fostering research and prototyping of new weapon systems at the Factory based on casting technology. This approach contributes to reducing production costs while ensuring compliance with stringent technical standards, as well as enhancing self-reliance in materials and domestic manufacturing capabilities.
HYDRODYNAMIC CALCULATIONS FOR A CATAMARAN-TYPE USV
The catamaran configuration plays a crucial role in USV design due to its high stability, large deck area, and lower hydrodynamic resistance compared to monohull vessels of equivalent displacement. The twin-hull arrangement effectively reduces roll motion and maintains precise maneuverability when the USV operates under complex wind and wave conditions. Additionally, the spacing between the two hulls provides favorable conditions for integrating sensors, survey equipment, and autonomous control systems. These characteristics make the catamaran an ideal platform for long-duration missions such as ocean observation, surveillance, and seabed mapping. However, the wave-hull interactions and the complex pressure distribution between the two hulls highlight the need for in-depth hydrodynamic investigations of this configuration. Among the commonly used catamaran models, the 2016 design by Chao Wang is selected for reconstruction and analysis in this study, serving as the basis for CFD model validation before being applied to a prototype in the subsequent development phase.