<ns3:p>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).</ns3:p>

<ns3:p>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.</ns3:p>

This article presents research concerning the recognition of road traffic lights. Initially, vision algorithms were analysed regarding their suitability for implementation in vehicle control systems dedicated to individuals with specific communication needs. The paper presents the results of experimental studies on a vision system for recognising traffic lights, conducted using convolutional neural networks (CNNs). For the experiment, a custom database of traffic light images was prepared. This database was utilised to train a selected Xception CNN model and for processing by a classic algorithm based on colour analysis in the HSV colour space. The obtained classification accuracy results, reaching 98.75%, could serve as a 'green light' for implementing the developed technology to assist driving. The research findings may also find application in driver assistance systems, with particular attention given to the mobility of people with specific needs, such as those with visual impairments.

Research conducted on hybrid drive systems of working machines is quite often limited to simulation studies, omitting the experimental determination of the parameters of a real machine. The article describes the course and results of experimental identification studies, which, in the further part of broader research, will be used to validate the hydrostatic model of the wheel loader drive system, which will be used to research the effectiveness of the energy recovery system. After defining the machine and identifying the structure and components of its drive system, the parameters that were determined during the research were determined. The identification tests were divided into two groups. The first of them was aimed at determining the operating parameters of the real object under different operating conditions, while the second one enabled the determination of dynamic parameters in response to impulse forcing. Based on the measurements, the time courses of the measured quantities and all assumed parameters were determined.

This paper presents a study of the effect of chemical treatment using pure acetone on strength specimens made from PLA polylactide produced by 3D FDM/FFF printing technology. The strength specimens were designed in accordance with the ISO 527 standard. The chemical treatment was carried out using baths at different time intervals. The hardness of the samples was measured, and a tensile test was performed. The results show that with prolonged contact with acetone, the hardness of the material decreases by approximately 45% compared to untreated samples. When analysing the tensile tests, it was noted that the tensile strength decreases with longer chemical bath time. At the same time, the material becomes more ductile, resulting in a high elongation at break in tension of up to 40% relative to untreated samples.

In this article, the concept of determination of a complete set of distinguishable diagnostic states has been utilised, which has been well known since the 1980’s and, in essence, could refer to any item with any application and any structural features. The only condition set for this item, is its ability to be described by a structure consisting of single exit-point elements. As a consequence, it can become possible to assess, amongst other things, its layers, strong cohesions, transitive and antitransitive closures. Typical tools of such assessment are matrices: transition and reachability. The reason that a centrifugal pump has been selected is not only its importance and common use, but also specifics of interaction of its elements. It is possible to identify for them: independence, dependence, and interdependence. For particular distinguishable diagnostic states, the probabilities of its occurrence have been determined. These probabilities have become a starting point to estimate structure entropy and intensity of transition from the health to any particular failure state. Results of such estimation have been depicted by relevant graphs. A reference has been made to the Bayesian methods and the inseparable ‘serial reliability structure’, to identify their flaws that result particularly from simplifications leading to false and ambiguous diagnoses. The probabilities of health for particular elements have been differentiated by the selection of adequate Weibull indices.

This paper aims to assess the quality of composite joints made with the Fused Filament Fabrication (FFF) additive manufacturing technique through strength tests. The first part of this paper details the design of different test sample versions with standardised geometry and the methods of joining plastics by application of 3D printing. The details cover the test apparatus used in the research, sample preparation methodology, as well as tensile and impact testing methodology. The test sample versions were selected according to the test types to have the results fully reproduce the mechanical response of the composite materials to the input forces. The second part of this paper analysis of the test results, presenting the fabrication accuracy of the test samples and their mechanical response recorded during the tests. Five test specimens of each version were produced to enable statistical analysis of the test results, which was indispensable for a reliable data analysis. The tests made it possible to determine how the proposed joints of plastic materials responded to the input forces, the maximum transmitted force limit, and the flaws of each version’s design. The test results made it possible to adapt the suggested solutions in the design engineering of programmable energy-absorbing structures.

For two decades, AREX Sp. z o.o. (Gdynia, Poland), belonging to WB Group (Warsaw, Poland), has been dealing with special-purpose production, in particular mechatronics, and its solutions are used in electromechanical accessories for 155 mm KRAB gun-howitzers and 120 mm RAK self-propelled wheeled gun-mortars. The operations of WB Group on international markets has given a boost to its further development. The solutions of the remotely controlled weapon platform presented in this paper can be adapted to weapons with ammunition fed from the left or right side, owing to the self-diagnostics and verification system as well as the modular design. The intention of the designers was to create functional and intuitive equipment that allows the operator to focus on firing operations. The remotely controlled weapon platform is also equipped with covering capacity, such as smoke grenades, and is also electrically operated, can be operated manually in emergencies, is intended for installation on various combat vehicles and is remotely controlled by the operator remaining inside the vehicle compartment, which ensures full armoured protection against enemy direct fire. Remote control is based on two operating components a fire control unit and a control grip. Additionally the system is capable of remote weapon loading, weapon cocking, and firing. Tracking and remote controlling capabilities of the integrated weapon platform ensure high probability of hitting stationary and moving targets during the first round, and the platform can be operated manually as required.

The subject of the analysis involves the trajectories of 7.62 mm Lapua Scenar GB432 projectiles and “Ball” lead core projectiles manufactured by MESKO S.A. (Poland) fired at different initial velocities from 16, 20 and 26 inch long barrels. Calculations in the scope of the external ballistics concerning the characteristics of the trajectories of projectile fired from the analysed weapons were made using the PRODAS 3.5 software by Arrow Tech, using a mathematical model of the solid body movements with six degrees of freedom. During the analyses, the phenomena of the internal and transient ballistics and barrel vibrations were not taken into account. The subject of the study was only the trajectory of a projectile fired with a specific initial velocity corresponding to a barrel of a given length. The impact of wind was assessed by modifying the atmosphere model by adding a side wind blowing at a constant velocity throughout the distance. The results allowed the analysis of the effect of the barrel length and the associated initial velocity of the projectile on the nature of the projectile trajectory, especially the obtained overheight path and projectile range. The impact of the side wind on different types of projectiles was also assessed. When shooting precision rifles, it is better to use rounds with heavy projectiles, optimized for long-distance shooting. Lightweight-projectile rounds can be successfully used in the semi-automatic rifles used for support at the lowest levels, where more manoeuvrability (including barrels with a length not exceeding 20 inches) and higher fire rate is required, and, at the same, where shooting at distances exceeding 500 m is not necessary. Lightweight-projectile rounds can also be successfully used for marksmanship training at distances below 500 m, where the differences between the trajectories of different projectiles are the least.

The paper presents the operating principle of the Man-Portable Counter Miniature Unmanned Aerial Vehicles System (MPC-MUAVS), with particular reference to the development of its firing solution settings and the methodology and structure of development of the firing tables implemented in the ballistic calculator of the MPC-MUAVS. This ballistic calculator has been applied in the MPC-MUAVS targeting sight assembly, while the entire MPC-MUAVS is intended to counter UAVs within 50 m of the MPC-MUAVS operator. The MPC-MUAVS is being developed under project DOB-1P/02/18/2016, funded by the Polish National Centre for Research and Development.