Metal Obstacle Research Articles

Enhancing RODNet detection in complex road environments based on ESM and ISM methods

In autonomous driving, accurately identifying traffic targets is crucial for ensuring the safe and reliable operation of autonomous vehicles. Millimeter-wave radar, known for its low cost, long detection range, and excellent performance under various weather conditions. Deep learning algorithms, particularly the radar object detection network (RODNet), have been effectively applied to radar target detection by analyzing the range-azimuth (RA) heatmaps that capture complex target features. However, the low angular resolution of radar RA heatmaps, combined with the high sensitivity of millimeter-wave radar to metal objects, makes adjacent targets prone to misdetection and increases the likelihood of misclassification of target types due to metal reflections from road obstacles. To address these issues, this paper proposes an innovative extension suppression method to enhance RA heatmaps, reducing interference between adjacent targets and significantly improving target resolution. Additionally, the paper incorporates Gaussian filtering, peak detection, and amplitude suppression algorithms to design an interference suppression method, accurately identifying and mitigating strong reflections from non-target regions, thereby improving detection efficiency in complex environments. The effectiveness and superiority of these methods have been fully validated, with AP improvements of 18% in overlapping scenarios, 2% in metal obstacle scenarios, and around 10% in high-speed scenarios compared to the latest methods.

Dynamic Alloying of Steels in the Super-Deep Penetration Mode.

The dynamic effects observed in collisions represent a specific area of high-energy interaction located at the boundary of mechanics, hydrodynamics, shock wave physics, and alternating high-pressure regions. The paper shows that in the volume of a solid metal body, as a result of dynamic alloying by a high-speed stream of powder particles in the super-deep penetration mode (SDP), fiber structures of altering material arise, forming the framework of the composite material. The stream of powder particles in the metal obstacle following the path of least resistance and the impact of shock waves on particles results in a volumetric framework from the products of interaction between the injected and matrix materials. When using SDP, defective structural elements (channeled)—germs of reinforcing fibers arise. At the subsequent heat treatment, there is an intensive diffusion. The growth process of reinforcing fibers shifts to higher temperatures (as compared to the standard mode), leading to an increase in the bending strength of the fiber material up to 13 times for W6Mo5Cr4V2 high-speed tool steel. As a result of the completion of the growth of reinforcing fibers in the volume of the W6Mo5Cr4V2 high-speed tool steel, the material’s bending strength in 1.2 times is realized. Simultaneously, it provides an increase of wear resistance 1.7–1.8 times.

MULTIPURPOSE SECURITY ROBO USING ARDUINO MICROCONTROLLER

In this Paper, Military Robo using Arduino UNO microcontroller with cost-effective is implemented for three applications: Metal Detection, Gas Detection and Obstacle Detection. Metal detection is mainly to detect the bombs, metals in undergrounds. It is mainly for Security Purpose. Gas Detection is mainly for the purpose of coal mining. High-Risk Areas, Pharmaceutical gases, toxic gases can be detected. Obstacle Detection mainly to detect the obstacles where echo methodology is used. An ultrasonic sensor with transmitter and Receiver is used. These three Applications with a robot make an effective resource for real-time working.

RSSI-based Localization Zoning using K-Mean Clustering

This document discusses the novel approach to localize human location based on the current zone via k-mean clustering. A pilot experimental analysis of k-mean clustering to group similar RSSI pattern is compared to user defined zones. The dataset collected has demonstrated the difficulties of deploying trilateration and fingerprinting methods in dynamic conditions, as it introduces fluctuating RSSI measurements. The k-mean clustering was proposed to validate antenna placement to divide the testbed into zones, and to create a baseline accuracy which can be compared with other algorithms in the future. It was found that, for Zones 2, 3 and 4, the k-mean clustering of antennas agree with the planned antenna placement grouping. However, for Zone 1, there are differences, which may be attributed to a large metal obstacle occupying the zone. The k-mean clustering also recorded a peak accuracy of 79% with k=4, which agrees with the number of planned zones.

A comparative analysis of several material models in LS-DYNA at high velocity impact

The questions of application of the LS-DYNA finite element analysis package for describing the interaction of a spherical projectile and a massive metal obstacle are considered. Based on a comparison of the results of numerical simulation with experimental data, a qualitative possibility has been shown to determine the magnitude of the dynamic hardness of the obstacle material.A simulation of the collision of a spherical impactor and a massive metal barrier shaped as a cube is performed. Data are obtained on the penetration of the striker into the barrier.Using the simulation curve, the values of the dynamic hardness of the obstacle were restored and a comparison was made with their experimental values. The qualitative correspondence is shown.

Comparative Study of Metal Obstacle Variations in Disturbing Wireless Power Transmission System

In order to study and compare the disturbances to the wireless power transmission (WPT) system caused by the presence of different metal obstacles, the equivalent parameters that determine the transmission efficiency of a two-coil WPT system are derived and analyzed by circuit theory. Then, the changing rules of equivalent parameters brought by three typical metals, are studied by a 3-D finite-element model coupled with an external circuit. In addition, transmission efficiency parameters changes caused by material electromagnetic parameters are discussed. The impacts of metal obstacles with permeability variations to the WPT system are studied. Finally, the experiment results from the prototype qualitatively verified the obtained numerical results.

Flow structure formed due to interaction of a supersonic jet with a porous obstacle

Results of studying impingement of a supersonic underexpanded air jet onto a finite-thickness porous metal obstacle whose frontal plane is normal to the jet axis and whose side surface is impermeable for the gas flow are reported. The case of a non-porous obstacle of the same diameter is considered for determining the effect of porosity on gas-dynamic characteristics of jet–obstacle interaction.

Theoretical and Experimental Analysis of the High-Velocity Interaction of Solid Bodies in Water

Methods of estimating the penetrating ability of a metal striker into an aquatic medium and its interaction with obstacles in it have been developed. The penetration of a needle-shaped metal body into a water with a high velocity and its interaction with a metal obstacle found in it was investigated and calculated within the framework of continuum mechanics with the use of an elastoplastic model for definition of the solid body with account for its destruction and a hydrodynamic model for the water. It has been established that in the case where the indicated striker enters into the water with a velocity of 1.0–2.5 km/s, the developed-cavitation regime is realized, the head of the striker is subjected to the plastic deformation, and, in some cases, it is destroyed.

Production of a large-volume negative-ion source using a multistring-type CF4 magnetized plasma

A multistring-type CF4 plasma has been produced by setting a multihole-type metal obstacle plate in a magnetized electron cyclotron resonance plasma. Separative diffusion of negative ions (F−) has been realized in the region downstream of the obstacle plate around the string-type plasma columns. Langmuir probes are used to estimate negative-ion density using the modified Bohm model. The experiment reveals that F− density is of the order of 1015–6 × 1015 m−3 around the multistring-type plasma. A column-type negative-ion source with a diameter of about 20 cm and a cross section of about 300 cm2 is realized, which could be scaled up by introducing more string plasmas. The ratio of negative-ion density to electron density around the plasma column is in the range 10–150.

Influence of a Flux of High-Velocity Microparticles on the Parameters of Integrated Circuits Placed Behind a Thick-Walled Obstacle

Experimental data showing that on collision of a flux of high-velocity microparticles (which is close to the fluxes of space particles in parameters) with a thick-walled metal obstacle we have failure of integrated circuits placed behind this obstacle have been given.

An investigation of the ion beam of a plasma focus using a metal obstacle and deuterated target

The results of an experimental study of the ion beam properties of a 3.3-kJ, 15-kV plasma focus are reported. The plasma focus is operated at 3 torr deuterium, and neutron yield measurements are made with a copper obstacle or deuterated target placed at various axial positions from the end of the anode. It is found that in the normal operation of the focus without an obstacle or target, less than 15% of the neutrons are produced within the pinch column, and that more than 85% of the neutrons arise from the deuterium-ion-beam bombardment of the deuterium gas in the region 20-60 mm from the end of the anode. The neutron production is highest between 30-40 mm from the anode. The results are valid only for a small focus.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Theoretical model of high-current relativistic electron-beam interaction with a metal obstacle

A method is described and results are presented for a numerical computation of crater and plasma-flare formation under the effect of a high-current relativistic electron beam on an aluminum obstacle.

Electrification of water by splashing and spraying

The experiments of Lenard and Sir J. J. Thomson on the electrification produced by the splashing of pure water and other liquids are well known. It was found that distilled water when splashed at a metal obstacle took up a positive charge, giving a negative charge to the air. Very dilute solutions of different substances gave very remarkable results, the sign and magnitude of the charge on the liquid depending on the dissolved substance and the degree of concentration of the solution. In all cases the electrification ultimately approached zero as the strength of the solution increased, so that for solutions of quite moderate strength the effect was inappreciable. Simpson has shown that if drops of distilled water are allowed to fall into a vertical jet of air of sufficient velocity, the drops are broken up and acquire a positive charge. Investigations of the electrification produced in the air when splashing takes place have been made by Kähler, Aselmann and Simpson. Similar investigations have been made in connection with bubbling and spraying of liquids by Townsend, Sir J. J. Thomson, Kosters, Eve and M. Bloch. A complete account of the subject will be found in a memoir by J. J. Rey. The work described in this paper was undertaken with a view to obtaining some precise data from which it might be possible to establish a connection between the charge produced on the liquid and the extent to which it had been broken up.