We compare event-cameras with fast (global shutter) frame-cameras experimentally, asking: “What is the application domain, in which an event-camera surpasses a fast frame-camera?” Surprisingly, finding the answer has been difficult. Our methodology was to test event- and frame-cameras on generic computer vision tasks where event-camera advantages should manifest. We used two methods: (1) a controlled, cheap, and easily reproducible experiment (observing a marker on a rotating disk at varying speeds); (2) selecting one challenging practical ballistic experiment (observing a flying bullet having a ground truth provided by an ultra-high-speed expensive frame-camera). The experimental results include sampling/detection rates and position estimation errors as functions of illuminance and motion speed; and the minimum pixel latency of two commercial state-of-the-art event-cameras (ATIS, DVS240). Event-cameras respond more slowly to positive than to negative large and sudden contrast changes. They outperformed a frame-camera in bandwidth efficiency in all our experiments. Both camera types provide comparable position estimation accuracy. The better event-camera was limited by pixel latency when tracking small objects, resulting in motion blur effects. Sensor bandwidth limited the event-camera in object recognition. However, future generations of event-cameras might alleviate bandwidth limitations.

This article deals with the ballistic impact of the 7.62 mm FMJ M80 rifle projectile into the laminated Twaron/UHMWPE composite armor. The armor composition consisted of composite panels made from Twaron CT 747 para-aramid fabric and ultra-high-molecular-weight Endumax Shield XF33 polyethylene. To analyze the ballistic impact and to verify the resistance of the designed armor according to the NATO AEP 4569 STANAG standard, protection level 1, 7.62 × 51 mm FMJ NATO M80 rifle cartridges with lead projectiles were used in the ballistic experiment. After the projectile impact, the damage failure mechanisms of the composite panels were documented. As part of the evaluation of the experiments, the initial microstructure of the composite panels was documented, and subsequently, the damaged areas of the composite armor after the ballistic experiment were also documented. Optical and scanning electron microscopy were used to document the structures. The important parameter of composite armor is its mechanical properties. The surface hardness of the composite panels was measured by the Shore D method using the hardness tester DIGI-Test II. The results obtained from the ballistic experiment demonstrate that the designed Twaron/Endumax armor was not penetrated. This armor has sustained multiple impacts for all three 7.62 mm FMJ M80 projectiles and is suitable for the construction of armor protection.

This study addresses the critical need for lightweight and effective ballistic protection in military applications, focusing on layered composite systems designed to meet NATO STANAG 4569 Level I standard. The layered ballistic protection combines Hardox 450 wear-resistant steel with Twaron CT 747 para-aramid fabric and Endumax Shield XF33 Ultra-High-Molecular-Weight polyethylene (UHMWPE). Three configurations of ballistic protection were evaluated, each differing in steel thickness and areal weight. Configurations 1 and 2, with 6-mm and 4-mm Hardox 450 steel, and areal weights of 84.3 kg/m ² and 68.6 kg/m ² , respectively, successfully resisted 7.62-mm NATO FMJ M80 projectile impacts while maintaining structural integrity. Configuration 3, comprising 2-mm Hardox 450 steel (52.9 kg/m ² ), was not penetrated by the projectile but detached from the frame due to localized impact near the edge. Microscopic analysis identified delamination and cracking of the reinforcing fibers and matrix as dominant failure mechanisms. Combining experimental testing with numerical simulations confirms that these layered protection systems offer high ballistic resistance while maintaining low weight, offering significant advancements in the design of military vehicle protection systems.

The article deals with the replacement of hard chrome plating by applying the duplex system plasma nitriding + CrN coating (hereinafter referred to as PN + CrN). The goal of the research was to find a suitable alternative for steel surface treatment that would replace hard chrome plating and ensure similar mechanical and tribological properties. An exposed part of a small-bore weapon was selected for evaluation, namely the gas piston of the 42CrMo4 steel breech mechanism drive. The PN + CrN duplex system was compared with a hard chrome coating as well as a self-deposited CrN coating. The mentioned surface treatments were evaluated in terms of metallography, mechanical and tribological properties and surface texture. From the mechanical properties, the hardness of the surface was analyzed, an indentation test was performed (Mercedes test) and adhesive-cohesive behavior was evaluated (Scratch test). Furthermore, an instrumented penetration test was performed (an evaluation of plastic and elastic deformation work and indentation hardness). As part of the assessment of tribological properties, the Ball-on-Flat test, the measurement of the coefficient of friction and the measurement of traces of wear were performed. The surface texture was evaluated in terms of morphology and surface roughness measurement by selected 2D and 3D parameters. The PN + CrN duplex system showed higher hardness than hard chrome, better tribological properties (lower friction coefficient), but worse surface texture. The PN + CrN duplex system has proven to be a suitable alternative to the hard chrome coating for exposed parts of small-caliber weapons, which can be applied in arms production.

This article deals with the problems connected with the camera calibration techniques applied on a projectile velocity measurement using the single camera photogrammetry. The two methods of a camera calibration are compared. Furthermore, the results obtained using the camera measuring system are compared with the results using the classical ballistic measuring system of the third generation, the optical light screen.

The article analyzes the relationship between frangibility of frangible bullet and its impact velocity. Based on the results of extensive shooting experiment, the analytical functional dependence of frangibility coefficient on impact velocity of the bullet on standard hard target - plate Hardox 450 of thickness 10 mm is determined. The effect of the difference between the mass of the captured fragments and the mass of the bullet on the overall frangibility of the bullet is analyzed as well.