Optimization methods play a key role in the design and control of modern powertrains in the current automotive industry. Emphasis is placed primarily on the implementation of optimization algorithms and predictive models that are used by engine control units. These are intended to ensure effective control of torque, fuel consumption and vehicle dynamics in real time depending on driving conditions and driver requirements. The aim of the paper was therefore to describe the results of research conducted in the field of multi-parametric optimization of fuel consumption and performance of a four-cylinder atmospheric internal combustion engine with a cylinder capacity of 1,390 cm3. Optimization of the operating parameters of the powertrain, such as fuel consumption and performance, was carried out with a view to the possibility of implementation into control algorithms and predictive models applicable to engine control units. The benefit of the proposed optimal operating mode of the powertrain, aimed at minimizing fuel consumption and maximizing its output power, is the achievement of high operating efficiency while maintaining favorable dynamic characteristics of the engine.
This paper investigates the relationship between the physical properties of a controlled dynamic system and the optimal configuration of hyperparameters in the multi-objective evolutionary algorithm NSGA-II (Non-dominated Sorting Genetic Algorithm II). The aim is to determine whether, and to what extent, the optimal hyperparameter settings of NSGA-II change in response to physical modifications of the system. The test model is a rotary inverted pendulum, whose physical characteristics are altered by shifting the position of its center of mass. For each tested center-of-mass position, NSGA-II generates a Pareto front of optimal settings of a linear quadratic regulator with respect to maximum overshoot and settling time of the controlled system. The search for optimal hyperparameters for each configuration is performed using Bayesian optimization. Experimental results show that some hyperparameters exhibit weak dependence on the physical changes in the model, while others remain stable. These findings may serve as a basis for establishing general guidelines for effective tuning of evolutionary algorithms depending on the characteristics of the controlled dynamic system.
Optimization methods play a key role in the design and control of modern powertrains in the current automotive industry. Emphasis is placed primarily on the implementation of optimization algorithms and predictive models that are used by engine control units. These are intended to ensure effective control of torque, fuel consumption and vehicle dynamics in real time depending on driving conditions and driver requirements. The aim of the paper was therefore to describe the results of research conducted in the field of multi-parametric optimization of fuel consumption and performance of a four-cylinder atmospheric internal combustion engine with a cylinder capacity of 1,390 cm3. Optimization of the operating parameters of the powertrain, such as fuel consumption and performance, was carried out with a view to the possibility of implementation into control algorithms and predictive models applicable to engine control units. The benefit of the proposed optimal operating mode of the powertrain, aimed at minimizing fuel consumption and maximizing its output power, is the achievement of high operating efficiency while maintaining favorable dynamic characteristics of the engine.
The aim of the research is to assess the energy efficiency of proposed heat, electricity and hot water supply systems for apartment buildings. Schematic solutions of heat and power generating units based on liquid-vapor jet devices. The proposed schemes are improved solutions for mini-TPP and heat pump unit, and fundamentally new decisions have been developed, the so-called combined scheme of heat-&-electricity power generating aggregate, which has all the advantages of the previous two schemes. For the studied building, the parameters determining the heating system operation were previously determined, including hot water consumption based on the number of residents and electricity consumption defining the required turbine power. To determine feasibility of using heat-&-electricity power generating aggregate based on liquid-vapor jet devices, thermodynamic, exergetic and thermoeconomic analyses were performed. As a result of thermodynamic analysis, the load and power of devices included in proposed scheme solutions were determined, as well as the values of the main material flows participating in the energy conversion process in the proposed schemes. As a result of the exergetic analysis, the efficiency of the proposed schemes was determined. The most effective was the combined scheme, which is 23% better than the heat pump unit and 11% better than the mini-TPP. According to the results of the thermoeconomic analysis, the tariffs at which residents will receive heat, hot water and electricity were determined and compared with the current state ones. The combined scheme turned out to be the best. For it, the tariffs are on average 32-35% lower than the state ones for civil consumers.
The work establishes a number of features regarding the mechanics of freezing wet quartz sands when manufacturing products of limited sizes from them. Products of limited sizes from frozen sand in foundry production are casting models used for manufacturing volumetrically closed and detachable casting molds using the SMS-process method, frozen casting molds and rods, etc. The work used quarry quartz sand of the 1K2O202 brand and tap water. The mass was measured on a VTA-60/6-73-AL-2 scale with an accuracy of +/- 1 g. The temperature was measured with an alcohol thermometer of the TTZ type and a chromel-copel thermocouple complete with an electronic device of the STC-1000 brand with an accuracy of +/- 1 degrees & Scy; with video recording of temperature changes over time with an interval of 1 s. Drying of sand was carried out in a microwave oven with a magnetron power of 900 W and a microwave radiation frequency of 2.45 MHz. Freezing of wet sand was carried out in a refrigeration chamber with a capacity of 17 kg/day at a temperature of-20 degrees C. According to the results of the research, it was found that flat products with a thickness of 10 mm, regardless of the water content (up to 12.5% above), under conditions of unidirectional heat removal, cool to 0 degrees C faster than dry quartz sand. Freezing of wet sand under conditions of multidirectional heat removal from it leads to a significant migration of water in the sand in the direction of gravity, i.e. from the solidification front of wet sand to a surface with a higher temperature, which is in the direction of movement of unfrozen water. Increasing the initial temperature of wet sand contributes to an increase in the rate of its cooling to 0 degrees C and the time of solidification of water, but increases the total time of solidification of wet sand.
The article presents an experimental methodology for evaluating fluid muscle stiffness using a controlled linear drive and a measuring chain based on a strain gauge force sensor. The measuring assembly consists of a strain gauge sensor, a signal converter, a programmable logic controller, and an electric actuator ensuring precise positioning. The measurements were performed at a vacuum level of 95% and at three extension lengths, i.e., muscle deflection from the base position (30, 60, and 90 mm), in order to test multiple load conditions. The results demonstrate a change in force response under vacuum loading and highlight the influence of granule rearrangement on stiffness variability at larger deformations. The proposed methodology ensures repeatability, diagnostic reliability, and suitability for characterizing soft robotics actuators, while also creating a robust experimental framework for the systematic evaluation of the stiffness characteristics of fluid muscles across a wide range of testing and loading conditions.
This paper addresses the problem of community detection (clustering) in self-organizing systems consisting of a large number of similar interacting elements. A three-dimensional neural network is chosen as a model example, where neurons act as elements and synaptic connections serve as edges of a weighted graph. An adaptation of the Louvain method, one of the most efficient algorithms for community detection in large graphs, to this class of systems is proposed. The mathematical foundations of the method are presented: definition of modularity considering the effective distance between elements (length of axons and dendrites), description of the two-phase iterative procedure, and formulas for modularity gain. Quality metrics specific to three-dimensional neural structures are discussed. The results can be used to analyze the functional organization of neuronal ensembles in neurophysiological studies.
This paper deals with the kinematic analysis of multimember mechanisms and robotic manipulators using MSC ADAMS simulation software. Attention is focused primarily on the analysis of trajectories, positions, velocities and accelerations of selected points of mechanisms, as well as the determination of the working space of manipulators. Analytical relationships and numerical calculations performed in the MATLAB environment were used to solve direct and inverse kinematics tasks, and the resulting trajectories were subsequently verified using simulations in MSC ADAMS. The results obtained confirm the suitability of integrating analytical methods and computer simulation for accurate analysis of the motion of mechanical systems, effective trajectory planning and visualisation of the behaviour of mechanisms in real operating conditions.
Among the known standardized bronze grades, there are currently no foundry structural bronzes that would simultaneously combine both non-magnetism and corrosion resistance, in particular, in tap water and seawater. The presence of bronze with such a list of preferential properties will allow not only to expand the boundaries of bronzes as a structural material using, but also to provide prospects for increasing and expanding the technical and technological capabilities of new equipment and technologies in the field of shipbuilding, aircraft construction, instrument making, etc. Today, the only bronze with such a list of properties is aluminum bronze BrA7K2O1.5Mts2, in which, nevertheless, corrosion resistance in comparison with known standardized bronze grades has not yet been studied. All bronzes studied in this work, except for bronze BrO6C6C3, are absolutely stable in warm standing tap water with a cyclic change in temperature from 30 to 50 degrees & Scy;. With the exception of BrA9Zh3L bronze brand, all other bronzes studied in the work are stable in warm standing artificial seawater with a daily change in temperature from 30 to 50 degrees & Scy; and on a ten-point scale have the 4th point of corrosion resistance. The greatest corrosion resistance is possessed by bronze BrA7K2O1.5Mts0.3 with a value of KR = 0.47...0.63. Corrosion in samples of BrA7K2O1.5Mts0.3 bronze, which are after their heat treatment and without heat treatment, is equally continuous. Bronze BrA7K2O1.5Mts0.3 without heat treatment in cold standing artificial seawater is more corrosion-resistant if it is cast in a chill mold. At the same time, in all corrosive environments used in the work, the corrosion resistance of bronze BrA7K2O1.5Mts0.3 is more affected by its heat treatment than by in its chemical composition changing. Further development was received by ideas about the corrosion resistance of non-magnetic structural cast aluminum bronzes in tap water and artificial seawater, taking into account the initial state of the bronzes and the corrosive environment condition. For the first time, in comparison with standardized corrosion- resistant bronze grades, data were obtained on the corrosion rate of "as-cast" and heat-treated non-magnetic bronze BrA7K2O1.5Mts0.3 in warm tap water, warm and cold artificial sea water. This will allow making a well-founded choice bronzes for the operation of products made of them in the environments and conditions used in this work or close to them. This will save time, financial costs and material resources for developers of new machines, assemblies and units to make rational or optimal technical decision regarding a rational product material.
A nondestructive optical method for determining the complex dielectric permittivity e(omega) of silicon photovoltaic converters (PVC) surfaces modified with silver nanoparticles is developed and experimentally validated. The method is based on backscattered radiation analysis and enables reconstruction of both real and imaginary components without altering the structure of objects under study [Kuric 2022]. Modified PVCs demonstrate a 2-5-fold increase in backscattering intensity and a 9-30% increase in photovoltaic pow er is observed, attributed to localized surface plasmon resonance. Compared to conventional ellipsometric approaches, the proposed method provides a simpler and robust alternative for in-situ diagnostics of plasmonic coatings. The obtained results indicate that the imaginary part of the dielectric permittivity plays a crucial role in determining the efficiency of electromagnetic energy absorption. The experimentally observed increase in photovoltaic power correlates with both the enhancement of the local electromagnetic field and the rise in effective dissipative losses in the near-surface region. Despite the theoretically predicted high absorption of electromagnetic energy, the overall efficiency gain of photovoltaic cells remains limited due to the localized nature of localized surface plasmon resonance, as well as scattering effects and structural inhomogeneity in the nanoparticle distribution.
This article addresses the problem of constructing an accurate and reliable navigation system for autonomous mobile robots (MR) operating in environments where Global Navigation Satellite System (GNSS) signals are unavailable. A hybrid approach is proposed, combining data from odometry, an electronic compass, and an active ultrasonic beacon system. Based on the technical specification for the development of a heavy mobile robot (mass 200 kg with payload), the selection of sensors and control algorithms is justified. Mathematical modeling includes a trilateration method with temperature compensation of the speed of sound and data filtering based on an Extended Kalman Filter (EKF). Experimental results confirm the possibility of achieving positioning accuracy of +/- 10 cm in steady-state operation: the coordinate determination error did not exceed 12 cm in dynamic mode and 8 cm in static mode. Initial transient errors during EKF convergence (up to 2 m) are effectively suppressed within 3-5 seconds of system operation.
The increasing penetration of photovoltaic systems in modern power grids creates stability challenges caused by the low inertia of inverter-based generation. This leads to higher frequency deviations and reduced robustness during dynamic operating conditions. This paper proposes an enhanced adaptive Virtual Synchronous Generator control strategy combined with Particle Swarm Optimization for optimal tuning of proportional-integral controller parameters. The proposed method improves the system response under varying load conditions compared with conventional control approaches. A mathematical model of a grid-connected photovoltaic system is developed, including electrical dynamics, DC-link behavior, and frequency and voltage control loops. The control strategy is evaluated in MATLAB/Simulink under several operating scenarios, including sudden load changes. Simulation results show that the proposed adaptive VSG-PSO method reduces settling time by approximately 77% and frequency deviation by nearly 89%, while improving damping and transient stability.
This paper addresses the design and thermal-hydraulic analysis of a heat exchanger designed for cooling sampled process air from a fermenter prior to its transport to a mass spectrometric analyzer. Due to the high humidity of the sampled air, effective cooling is required to prevent unwanted condensation during transport over a distance of 200 m. A tube-in-tube counter-current heat exchanger was selected and analyzed with respect to heat transfer, condensate formation, cooling water demand, and pressure losses. The results show that the proposed design achieves the required outlet air temperature with a minimal heat transfer area and acceptable hydraulic losses. Although the amount of condensate is low, periodic purging of the air-side tube is recommended to prevent a reduction in heat transfer efficiency. The proposed solution provides a reliable and efficient method for conditioning humid process air in fermenter monitoring applications.
This paper presents a method for robust tracking of multiple pendulums using video analysis under imperfect lighting conditions. The experimental setup consists of five pendulums recorded by a stationary camera at 30 frames per second. Object detection is performed using color-based segmentation in the HSV color space implemented in Python with the OpenCV library. Two approaches are compared: a baseline method with a non-robust color mask and an improved method with optimized masking parameters. The quality of tracking is evaluated using temporal derivatives of the detected trajectories, specifically the second-order derivative, which highlights high-frequency noise caused by unstable detection. The results show a significant reduction in noise and improved trajectory smoothness when using the optimized mask. The proposed approach provides a simple and effective solution for motion tracking in suboptimal lighting conditions.
The effects of high-pressure abrasive water jet (AWJ) machining strongly depend on the dimensions and distribution of the abrasive grains. This study explores how abrasives break down during the generation of AWJ operations. Following formation in the cutting head, the abrasive material's grain size was measured, and the Folk and Ward technique was used to assess grain distribution. Grain distribution was examined first concerning the various abrasive grain concentrations in the jet, such as alumina, ilmenite, and industrial glass. The recovery analysis was also conducted for each tested abrasive material, and the recycling factor was calculated. The recovery analysis was also conducted for each tested abrasive material, and the recycling factor was calculated.
Computational Fluid Dynamics (CFD) simulations are a valuable tool for hydrodynamic pump flow analyses. Recently, emphasis has been placed on the analyses of all pump modes such as turbine mode, pump mode, dissipative modes etc. Some regimes are very difficult to simulate numerically, especially transition states. These regimes must be analysed using multiple modelling approaches, considering different levels of model complexity. The CFD simulations are very useful for predicting emergency scenarios such as a pump failure, counter-pressure from the pipeline system, reverse flow, water-hammer events, etc. The future validation of simulations by experimental research is self-evident. The pump test bench is currently being prepared, for this purpose, as shown in this article. The pump test bench consists of two identical centrifugal pumps: a measured pump and feed or auxiliary (it depends on the regime in the four-quadrant characteristic) pump. These pumps, together with the pipeline system including a bypass, make it possible to measure the complete (four-quadrant) pump performance characteristics. This paper is focused on numerical simulations of the dissipative operations and non-standard pump regimes with emphasis on the analysis of the transition state between the first and second quadrant and between the second and third quadrant. The article describes and presents a comparison of different modelling approaches from the view of varying model geometry complexity. The simulation results are compared based on the performance characteristics, which could represent future test bench limits. The flow behaviour in the pump and piping system is also visualized, and it is a valuable result that can be considered in the future experiment.
Currently, emphasis is placed on the quality of production in connection with its efficiency. The emphasis is mainly on machining processes in which the material removal rate is low. These machining processes include wire electrical discharge machining (WEDM). This is a technology that allows material removal using cyclically repeated electrical discharges. It is characterized by high production quality, but low productivity and process efficiency. This is due to the very nature of the electrical discharge process in conjunction with inappropriate settings of the main technological parameters. Therefore, their optimal setting is important to achieve favourable efficiency of the machining process. Moreover, low material removal rate is a particular problem of WEDM technology when machining sintered carbides. This is because these materials exhibit a greater degree of inhomogeneity of the structure and a significant reduction in material removal rate associated with it. The aim of the experimental research was therefore to analyse the mechanisms and interdependence of the quality of the machined surface in terms of roughness parameters and material removal rate in WEDM of tungsten carbide with Co binder. In addition, through graphical optimization, to define the qualitative area in which favourable values of the eroded surface roughness parameters Ra and Rz and at the same time a sufficiently high material removal rate is achieved.
Quenching is a commonly used method of heat treatment of steels with the objective of achieving the desired properties, most often increasing of hardness. To achieve the desired properties, it is important to correctly set the technological and process parameters, especially the correct quenching temperature, time endurance, the cooling rate and the quenching medium selection. The influence of the selected quenching conditions on the steel hardness modification is monitored in the submitted contribution. The hardness modification dependent on the variable quenching conditions is monitored during the heat treatment of N690 steel. The monitored parameters are the time endurance at the quenching temperature and the use of various quenching media. The time endurance at the quenching temperature was chosen to be 0 min., 10 min., and 17 min. The quenching media selected were water, Mogul TK 22 oil, and compressed air cooling. The results achieved show that the highest average hardness values were reached by N690 steel samples cooled in oil with an endurance time of 10 min.
The article focuses on optimizing the transmission and processing of information within airport information systems. To solve this problem, it is necessary to know the absolute information flow and the method of signaling emergency conditions, which complement the overall reliability of the systems and also have an economic impact on their operation. Using logit models and prognostic simulations, the hierarchy of weights of various types of airport information that affect the safety, smoothness, and operational readiness of the airport is analyzed. The research focuses on identifying critical paths in information flows, their delays, and the probabilities of failure of individual airport systems. Another important element is the observation of other factors in the area of technology optimization and the implementation of backup solutions, which are key to increasing reliability and minimizing the risk of operational failures. The presented model provides a framework for decision-making in the optimization of airport information systems from both a technical and economic point of view, which can significantly contribute to increasing the performance and safety of the entire aviation infrastructure.
This paper presents the development of a web application for automated cutting tool selection in machining, addressing the limitations of manual, experience-based choice that is timeconsuming and difficult to standardize. The system is implemented as a three-tier client-server application, featuring a Java backend, a PostgreSQL database, and a React frontend. A proposed hybrid decision-making procedure that contains constraint satisfaction (CSP) is first used to filter feasible tool-holder-adapter sets, followed by multi-criteria decision-making (Analytic Hierarchy Process for criteria weighting, Weighted Sum Model and Technique for Order of Preference by Similarity to Ideal Solution for ranking) to select the most suitable alternative. The database combines Entity-Relationship and Entity-Attribute-Value models to store machines, parts, materials, and user-generated technical solutions, enabling the accumulation and reuse of experience. The approach is validated on a semi-finishing turning case of Inconel 718, where the system automatically ranks available sets and generates an order statement.
