The paper performs numerical simulations using ANSYS AUTODYN to analyse the penetration performance of a 40 mm shaped charge equipped with a double-cone liner. The effects of standoff distance and liner thickness on jet formation and penetration into a steel target were analysed. The findings indicate that as the standoff distance increases, the penetration depth also increases; however, when the standoff distance exceeded four times the charge diameter, its influence on the penetration depth diminished significantly. Five cases of double-cone liner thickness with values ranging from 0.8 mm to 1.2 mm, corresponding to 2.2% to 3.3% of the charge diameter, were selected for the study. The simulation results at a standoff distance of 72 mm showed that increasing the liner thickness reduces the jet tip velocity, while the penetration depth into the steel target initially increases, reaches a maximum and subsequently decreases. For the 40 mm shaped charge design model, a double-cone liner with a thickness of 1.0 mm provides the best penetration performance. This study provides evaluations of the effect of double-cone liner thickness on jet characteristics and penetration performance, serving as a foundation for optimising the design of the double-cone liner to enhance penetration efficiency in a small shaped charge.
Accurate and reliable positional estimation remains a major challenge for autonomous UAV navigation, especially in complex operational environments where GPS signals are compromised by intentional jamming, spoofing, or intrinsic measurement errors. Furthermore, inertial navigation systems are prone to cumulative drift, which leads to diverging localization inaccuracies over time. This paper presents a visual-aided method for enhancing UAV localization by employing a sequential image correlation algorithm. The proposed approach estimates the relative motion of the observer by matching consecutive image frames, thereby leveraging a cumulative analysis of translation and rotation parameters. The algorithm has been implemented in MATLAB and validated on both real and synthetic datasets. Synthetic data were generated using the Blender environment, which provided a flexible framework for creating virtual scenes with controllable camera trajectories and sensor parameters. The method is designed to augment conventional GPS/IMU-based positioning systems.
This paper presents a literature review of the experimental methods most commonly used to investigate the mechanical properties of cellular materials under dynamic loading. The methods are briefly described, and examples of reported studies on such materials are provided. The paper focuses primarily on the split Hopkinson pressure bar method and its variants.
In contemporary armed conflicts, attacks using air assets are an important and often dominant form of combat operation. These assets include conventional aircraft and helicopters, as well as the increasingly common use of various types of unmanned aerial vehicles. The ability to detect them is becoming a fundamental requirement for an effective defence system. This role is fulfilled, among others, by ground-based radars. Consequently, suppressing these radars, including their physical destruction, becomes a priority objective for the attacker. One means of doing so is the use of anti-radiation missiles (ARMs), whose seekers home in on a radiation source and generate data for the missile control system. At the same time, each missile uses a different target-approach profile, selected both to reduce the probability of missile detection and to maximise strike effectiveness, including terminal velocity. This study analyses the effect of the target-approach trajectory on hit accuracy, including the possibility of disrupting the homing system by jamming generated by the defending radar system. The paper provides a general characterisation of contemporary anti-radiation missile designs, explains their operating principle, and analyses their accuracy in estimating the attack target for different approach trajectories, including under jamming conditions.
Ongoing technological advances in unmanned aerial vehicles (UAVs) have heightened the relevance of systems that integrate augmented reality (AR) and artificial intelligence (AI) to simulate UAV behaviour in realistic three-dimensional environments. AR-based solutions can substantially enhance an operator’s situational awareness by improving environmental perception and enabling more proactive flight-path planning. To be credible and operationally useful, such a simulation model should capture key physical and environmental properties, including flight dynamics, responses to wind disturbances, terrain obstacles, and time-varying ambient conditions. Integrating AI allows an appropriately implemented 3D UAV model – here referred to as a drone simulant – to make autonomous decisions, such as collision avoidance, selection of an optimal route, and real-time adaptation to scenario changes. In response to these needs, this paper proposes a conceptual algorithm for simulating realistic UAV behaviour in a battlefield environment using Unreal Engine and its built-in AI toolset. The proposed approach is intended to support training and mission rehearsal under conditions that approximate real-world operations without requiring physical UAV deployment, thereby enabling operator training, evaluation of flight strategies, and mission design while maintaining full immersion and safety.
The purpose of this article is to propose and verify the concept of an autonomous control system capable of precisely manoeuvring and safely landing unmanned aerial vehicles on a mobile platform under highly variable environmental conditions. The first part presents a hybrid control architecture that combines an extended Kalman filter and a PID controller with an artificial intelligence model based on a recurrent neural network that learns from sensor-fed data sequences (LIDAR, infrared sensor, proximity sensor, GPS). A simulation environment that takes into account random disturbances (wind, obstacles, platform movement) to generate training data has been proposed as well. The results demonstrate that RNN integration allows to dynamically adjust the flight trajectory, significantly increasing the stability and accuracy of the final approach phase. The analysis confirms that a hybrid approach combining classic control methods and sequential learning is a promising way forward for autonomous UAV missions .
In experimental studies concerned with firing upon soft targets, e.g., ballistic gelatine blocks, not only the penetration depth is important, but also the shape and size of the resulting temporary cavity, which is assumed to be the result of radial acceleration of the tissue in a direction that is perpendicular to the bullet's penetration path. The penetration of the bullet into the body, in addition to damaging the tissue as well as crushing and drilling the permanent cavity, creates a temporary cavity that may overstress and damage adjacent organs. During the pulsation of tissue around the gunshot wound, suction is created, likely to attract foreign objects and impurities. This may seriously complicate the process of healing the gunshot wound. Knowledge about these phenomena may contribute to a better understanding of clinical and radiological findings.
Shaped charges are widely used explosive devices designed for effective penetration of armoured and solid targets. Their performance depends on the controlled collapse of a metallic liner under detonation pressure, resulting in the formation of a high-velocity jet. Due to the extremely high strain rates and short time scales involved, experimental investigations are often limited. Numerical modelling has therefore become a key tool for analysing shaped-charge behaviour. This study aimed to construct a high‑fidelity LS‑Dyna model of a classical shaped charge, with particular focus on selecting appropriate material models and equations of state, implementing detonation physics, and analysing jet formation. The model incorporates the relevant material properties and boundary conditions. Simulation results were benchmarked against experimental data, including X‑ray radiographs of jet formation, and cross‑validated using the free-particles method. These analyses verified the numerical model and yielded deeper insight into the mechanisms governing jet formation and overall charge performance.
This study evaluates whether the hardness of 42CrMo4 high-strength steel can be determined using the Magnetic Barkhausen Noise method. Steel specimens were quenched and then tempered at different temperatures. Barkhausen noise measurements were performed, and magnetic parameters were determined. Hardness measurements were then carried out. Plots were prepared showing the relationships between hardness and the parameters determined from the RMS envelope of the Barkhausen noise signal. Lower steel hardness was found to correspond to higher magnetic parameters. Depending on the tempering stage, different magnetic parameters determined from the RMS Barkhausen noise envelope showed greater sensitivity to changes in hardness. This results from differences in the dynamics of microstructural changes in the steel at different tempering temperatures and from the interaction of the microstructure with domain walls moving under an alternating magnetic field. Changes in the crystalline microstructure of the steel also change its magnetic structure, for example, by changing the size of magnetic domains. The hardness of tempered 42CrMo4 steel can be assessed using the Barkhausen noise technique, and the accuracy of this assessment depends on the magnetic parameter selected.
This article examines existing technologies for free-space optical communications in both the atmosphere and water, with an emphasis on their practical potential. It presents data derived from studies on the performance of these technologies, addressing not only the parameters of current optical transceivers but also the characteristics of their operating environments. The research seeks to identify the key factors that primarily determine their configurations in underwater, terrestrial, and space communications scenarios.
This paper investigates the positioning accuracy of four standalone GNSS modules: Teseo-LIV4F, Teseo-LIV3F, NEO-6M, and SIM28 in restricted environments where differential correction methods such as RTK and DGPS are not available. The research aims to evaluate the feasibility of reliable localization using only raw GNSS data, with a specific focus on accuracy under satellite visibility and HDOP conditions. Two experimental approaches were employed: static tests, where modules were placed at a fixed, known position, and dynamic tests, conducted along a defined trajectory. Position estimates for each module were recorded over time and compared with a reference dataset. The analysis considered the influence of environmental conditions, HDOP values, and the number of visible satellites on the overall positioning error. The results show notable differences in accuracy between the modules tested, and Teseo-LIV4F generally outperforms others in both static and dynamic scenarios. The study highlights the impact of GNSS hardware design, satellite geometry, and firmware algorithms on the reliability of GNSS alone. These findings offer practical insights for developers and researchers designing navigation systems for constrained applications in which precise localization is required without access to correction services.
Explosion welding is a process in which one or more similar or dissimilar materials can be joined provided that suitable amount of explosive materials is used. After the explosion welding was performed the primary purpose is to identify the surface elemental composition to determine the amount and nature of the species in the welded zone. Several methods, e.g. SEM, EPMA etc., have been used to characterize the heterogeneous materials on very fine scale.
This article presents the results of experiments on rotating bands manufactured from iron powder, with the addition of tungsten disulfide (WS₂). Test samples were produced using different compaction pressures and varying amounts of the WS₂ lubricant. In the initial stage of the study, properties such as porosity, density, selected mechanical characteristics, and friction coefficient were measured. These results enabled the optimisation of the rotating band manufacturing process. In the subsequent phase, rotating bands were fabricated and assembled onto projectiles. Push-through force tests were then conducted to assess the behaviour of the rotating bands under quasi-static conditions. The results demonstrated that the addition of a lubricating material lowers the friction coefficient and reduces both engraving and push-through forces.
Several specialised implementations of military bridge systems may be distinguished. However, none of them is capable of simultaneously offering all of the following characteristics: versatility, scalability, immediate assembly, ground/terrain survey, low number of staff and low workload. The aim of the article is to present the progress of designing a rather new robotic military bridge system complying with MLC70 and MLC110 standards. It is composed of 11.5 m long mobile AI robots that resemble bridge spans. It is assumed that bridge span-robots are capable of walking short distances to the assembly location, using their strong telescopic legs. In the case of longer distances, the system needs to be transported on specialised semi-trailers. The robots are assumed to be able to disembark/embark such semi-trailers and are also expected to be able to configure themselves and couple with each other to create a bridge ribbon, using railway-like couplers for this purpose. The system is expected to be autonomous, as it is designed to rely on Collective Intelligence. Therefore, only truck drivers and 2-3 qualified technicians would be required to transport and supervise the operation of the robots. The article describes how the key elements of the solution have been combined into a single, compatible and economically feasible system. In order to provide a better understanding of the solution, additional articles are planned in the future. In accordance with military tactics, trucks and trailers transporting bridge span-robots will be attached to fast-moving armoured brigades, as long as local roads may be used. Then, the Intelligent Bridge will self-assemble and will enable to quickly pass through difficult local terrain with such obstacles as rivers, ravines, marshlands, and even engineering barriers consisting of anti-tank ditches and the so-called dragon's teeth. The assumption is that the robotized bridge will enable trucks and semi-trailers to pass a given obstacle. In the next phase, the bridge-robots will pass the obstruction as well, only to self-load onto the semi-trailers and to follow the armoured brigade they are embedded with. The use of telescopic legs as well as the individual and collective intelligence of robots are of crucial significance from the technological point of view. The article presents the outcomes of more than 10 years of research and VR modelling efforts.
Two-stage (multi-cyclone-pore-partition) air filters are what protects a vehicle's engine from sucking in mineral dust particles that cause an accelerated wear of internal components. Information on the air filtration process taking place in a two-stage system (multicyclone-baffle filter) of a vehicle's internal combustion engine is not provided often in the available literature. The purpose of this study was to experimentally evaluate paper filters operating directly behind and without a multicyclone system. An original methodology was used, consisting in testing a single cyclone and a paper filter with a suitably sized surface area. While testing the assembly (cyclone-paper filter test), parameters corresponding to those under which two-stage air filters actually operate were maintained, including filtration speed in the paper filter, dust concentration in the air and the cyclone’s inlet velocity. Filtration efficiency and accuracy, as well as pressure drop value were among the parameters determined as a function of dust mass delivered to the unit (cyclone-paper filter) or directly to the filter. The study showed that a paper filter operating downstream from a cyclone operates four times longer before reaching the permissible pressure drop value. During the initial (short) filtration period, separation efficiency values obtained were much lower (w0 = 93.3% without and wc0 = 53.6% with the cyclone, respectively) than the required threshold of 99.5%. The air behind the paper filter contained dust grains with a size of 35-40 m, compared to the required parameter of 2-5 m. Further operation of the filter is characterized by a high separation efficiency of 99.9%, a high accuracy dpmax of 2-5 m and a continuously increasing pressure drop, with the said drop being more intense in the filter without the cyclone system.
NATO Standardisation Agreements (STANAGs) 4241 and 4496 outline destructive testing procedures to determine how gun propellants in artillery munitions behave when struck by a 12.7 × 99 mm anti-tank projectile travelling at approximately 850 m/s, or by a standardised fragment (shrapnel) made from specific material and shape, moving at 1830 or 2530 m/s. Unlike traditional live-fire testing of complete munitions at test ranges, it is now possible to theoretically simulate the results of collisions between objects with specified dimensions, mass, and velocity, whether they involve individual grains or gun propellants (charge) confined within a shell case. These simulations, however, require detailed knowledge of the strength properties of propellant grains under both static and dynamic loading conditions, particularly at the high rates of deformation that can be generated in laboratory experiments using the Taylor impact test or the Split Hopkinson Pressure Bar (SHPB) method. A light-gas gun is often used in these experimental setups, propelling the test specimen by means of energy from compressed gas, such as hydrogen, nitrogen, or helium. Based on the author’s experience with maintaining a straight-line trajectory for expelled propellant grains, as well as ensuring a parallel contact plane between the grain’s leading face and the fixed partition, a new testing approach has been proposed. This approach uses the direct impact Hopkinson Pressure Bar (DIHPB) technique. Of the various Hopkinson methods available, DIHPB was selected. In this method, a propellant grain is attached to the output bar’s face, and the striker impacts the grain’s front face. Strain gauges on the output bar measure the crushing force. The deformation of the propellant grain is then tracked using a non-contact measurement setup (digital image correlation, or DIC).
During the Vietnam War, the Americans faced a problem with assessing the performance of Soviet combat aircraft. Therefore, the so-called Energy-Maneuverability (E-M) method was developed. Based on the cited method, ALR Aerospace has developed a commercial program used for preliminary calculations of aircraft performance. Recently, 5th generation aircraft such as the F-22 and the F-35 in America, the Su-57 in Russia and the J-20 in China have entered service, but little is known about their performance, just as it was the case during the Vietnam War. The author used the E-M method to calculate the so-called aircraft maneuver envelopes, allowing him to determine key aircraft performance metrics and features determining the superiority of jet fighters – e.g. maneuverability. However, the lack of relevant aircraft data (such information is not usually disclosed by manufactures) posed a significant problem. Therefore, the authors used the reverse-engineering method to determine aircraft parameters and characteristics in order to use them as input data for ALR software. Having completed their work, the authors obtained a set of aircraft characteristics and performance metrics allowing them to assess the capabilities of fighter jets and to determine the needs concerning air defense systems. The results have confirmed that the E-M method still remains effective, despite the fact that more than 70 years have passed since it was first introduced.
This article examines how increased wind flow velocity above the ridge of a gable roof influences the torque generated by a Savonius wind turbine. The study consisted of two stages: numerical simulations using SolidWorks Flow Simulation, and quasi-static wind tunnel measurements. The primary aim was to validate a simplified numerical model using experimental data, considering varying geometric parameters: specifically, roof pitch angles (30, 45, 60) and the distance from the turbine's axis to the roof ridge (450–710 mm). A grid sensitivity analysis was performed, and torque values were compared as a function of the rotor's angle of rotation. The observed flow blockage over the ridge resulted in a significant increase in torque, underscoring the importance of strategically positioning the wind turbine where wind speeds are highest. These findings can inform the optimal placement of small VAWT systems in urban settings.
Energy management is now a key topic for the synchronous operation of renewable energy sources and their consumers. Today's national power systems are increasingly unable to efficiently supply and receive electricity generated from renewable sources. The holistic approach to managing energy storage solutions takes all of the above aspects into account and focuses on a concept of using municipal waste to produce energy in a biogas plant supported by photovoltaic systems and shared energy storage to ensure uninterrupted power supply. The presented approach shows how energy storage can be managed throughout the process to adjust and manage the level of energy supply and demand within a community based on the optimisation of energy consumption, by applying the concept of a large-scale energy storage for small communities. The study offers a novel approach which serves as a basis for evaluating the energy storage capacity and the size of renewable energy sources required to balance the energy management process without relying on grid power, using only municipal biodegradable waste for biogas supply, and relying on solar power for generating energy, with a large-scale approach adopted.
Studies concerning the use of mini-class (2–20 kg) unmanned aerial vehicles (UAVs) in armed combat point to their increasingly important role and potential. UAVs may be used as classic strike platforms that are capable of carrying and dropping weapons and returning to the base to have their combat readiness restored. Other types of such vehicles serve as loitering munitions, where the entire UAV becomes a weapon, offering lower production and operating costs. The article presents a comparison of mini-class combat unmanned aerial vehicles and analyses the weapons systems they may be equipped with. The analysis has shown that in the mini UAV category, up to 87% of vehicles destroy the target by exploding the warhead they carry (self-destruction), and only 13% are used for dropping the carried weapons in a controlled manner. The analysis of weapon solutions dedicated for UAVs, conducted in this article, has shown that the number of solutions available for this class of equipment is very limited. The analysis included examples of bombs, missiles, and gun rounds weighing no more than 15 kg, as well as some improvised combat assets used by this category of platforms. The limited number of available weapon systems intended for this category of vehicles proves the need to develop new and effective solutions, with an emphasis placed on domestic technologies which will reduce dependence on foreign supplies.
