scholarly journals Countering the Deleterious Effects of Electromagnetic Pulse

2021 ◽  
Vol 2 ◽  
Author(s):  
Timothy Sands
Keyword(s):  
Electromagnetic Pulse ◽  
Adaptive Methods ◽  
Design Parameters ◽  
Parameter Estimates ◽  
Electromagnetic Pulses ◽  
Timing Accuracy ◽  
Circuit Performance ◽  
Adaptive Mechanisms ◽  
Robot Systems ◽  
Final Steady State

Robot systems like automated shipping swinging robots, wire transducer sensors and even computer indigenous time sensors (amongst others) often use oscillating circuits such as the famous van der Pol system, while this manuscript investigates protection of such sensor circuitry to spurious voltage spikes accompanying an electromagnetic pulse. These spurious voltages can lead to uncontrolled robot motion and even debilitation. A very brief discussion of electromagnetic pulses yields design parameters to evaluate circuit responses to realistic disturbing pulses. Recent research in nonlinear-adaptive methods to protect circuits are described to highlight the proposed novelty: utilization of feedback rules as adaptive mechanisms to modify the otherwise nonlinear feedforwards systems improving the results in recent literature. Feedback is iterated to select adaption parameters that simultaneously produce favorable circuit performance in addition to effective parameter identification inherent in the adaption (to provide meaningful parameter estimates to unspecified future applications). Spurious voltages were rapidly rejected with a mere 0.3% trajectory deviation, stabilizing quickly with a final (steady state) deviation of 0.01%. The demonstrated abilities to reject the deleterious spurious effects are compared to nominal figures of merit for timing accuracy of various computer systems to conclude the proposed methods are effective for some applications, but insufficient for others.

scholarly journals Excitation of ion wakefields by electromagnetic pulses in dense plasmas

2009 ◽  
Vol 75 (1) ◽  
pp. 15-18 ◽  
Author(s):  
P. K. SHUKLA
Keyword(s):  
Wave Equation ◽  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Pulse ◽  
Dense Plasma ◽  
Ponderomotive Force ◽  
Electromagnetic Pulses ◽  
Dense Plasmas ◽  
High Energies

AbstractThe excitation of electrostatic ion wakefields by electromagnetic pulses in a very dense plasma is considered. For this purpose, a wave equation for the ion wakefield in the presence of the ponderomotive force of the electromagnetic waves is obtained. Choosing a typical profile for the electromagnetic pulse, the form of the ion wakefields is deduced. The electromagnetic wave-generated ion wakefields can trap protons and accelerate them to high energies in dense plasmas.

scholarly journals FERRITATIVE WASTEWATER TREATMENT FROM CHROMIUM (VI) COMPOUNDS USING ELECTROMAGNETIC PULSE ACTIVATION

2021 ◽  
pp. 65-73
Author(s):  
Dmitry Pakhomov ◽  
Gennadii Kochetov ◽  
Dmitry Samchenko
Keyword(s):  
Magnetic Field ◽  
Wastewater Treatment ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Electromagnetic Pulse ◽  
X Ray Diffraction ◽  
Electromagnetic Pulses ◽  
Industrial Enterprises ◽  
Chromium Vi ◽  
Washing Water

Issues related to the prospects of implementing the latest technologies aimed at achieving energy efficiency in the field of water supply, resource conservation in material-intensive processes at industrial enterprises and prevention of environmental pollution are considered. A study of ferritative wastewater treatment from chromium compounds, which belong to the first class of danger. The efficiency of thermal and electromagnetic pulse activation of the process is compared. Appropriate experimental setups were developed and the main parameters of the purification process were studied and determined: the ratio of iron (II) and chromium (VI) ions, magnetic field strength, frequency of electromagnetic pulses, ferritization process duration, temperature and pH of the reaction mixture. The expediency of using electromagnetic pulse activation of the reaction mixture by passing electromagnetic pulses through the reaction mixture has been studied and scientifically substantiated. Rational values ​​of the strength and frequency of the electromagnetic field when using this method of activation, which are 0.01 - 0.14 Tl and 1 Hz, respectively, as well as the ratio of concentrations of heavy metal ions Fe2 + / Cr6 + = 10/1 for washing water chrome plating line . It is shown that purified water meets the requirements of category 1 when reused in production. The results of X-ray diffraction analysis of ferritization sediments showed that stable crystalline phases, such as chromium ferrites and magnetite, are formed with increasing magnetic field strength. The chemical resistance of sludge allows them to be safely disposed of. It is established that this method of electromagnetic pulse activation is not inferior to thermal, and the technical and economic calculations confirmed a significant reduction in industrial costs in its application

scholarly journals Dynamic analysis of two-link flexible manipulator considering the link length ratio and the payload

2017 ◽  
Vol 39 (4) ◽  
pp. 303-313
Author(s):  
Duong Xuan Bien ◽  
Chu Anh My ◽  
Phan Bui Khoi
Keyword(s):  
Mechanical Design ◽  
Flexible Manipulator ◽  
Length Ratio ◽  
Elastic Displacement ◽  
Design Parameters ◽  
Nonlinear Dynamic Model ◽  
Link Length ◽  
Modeling And Analysis ◽  
Robot Systems ◽  
And Control

Dynamic modeling and analysis of flexible manipulators play an essential role in optimizing mechanical design parameters and control law of real robot systems. In this paper, a nonlinear dynamic model of a manipulator is formulated based on the Finite Element Method. To analyze the dynamic behavior effectively, a numerical simulation scheme is proposed by taking full advantages of MATLAB and SIMULINK toolboxes. In this manner, the effect of varying payload and link length ratio of the manipulator to its elastic displacement is dynamically taken into account. The simulation results show that the payload and length link ratio have significant influences on the elastic displacements of the system. In particular, a proper spectrum of the link length ratio, in which the flexural displacement of the end point of the manipulator is smallest, is demonstrated. To this end, the proposed methodology could be used further to select optimal geometric parameters for the links of new robot designs.

Electromagnetic Protection Method Based on Sorting Technique

2013 ◽  
Vol 442 ◽  
pp. 311-314
Author(s):  
Yong Qiang Zhang ◽  
Ling Sheng Wu ◽  
Bing Xun Xu
Keyword(s):  
Electromagnetic Pulse ◽  
Experimental Results ◽  
Sequence Difference ◽  
Sorting Algorithm ◽  
Electromagnetic Environment ◽  
Electromagnetic Pulses ◽  
Protection Method ◽  
Sorting Technique ◽  
Difference Histogram

Under complex electromagnetic environment, various equipment is likely to be disturbed by electromagnetic pulses and to fail. In order to increase their immunity ability of electromagnetic pulses, the electromagnetic protection method based on the sorting technique was proposed. Through signal transform in signal level using the sequence difference histogram sorting algorithm, signal is separated from electromagnetic pulse. So these equipment were protected finally. Experimental results and simulation demonstrate that the method is effective.

scholarly journals Design, Optimization and Evaluation of a New Cylinder Attachment Geometry to Improve the Hopping Height of the Bionic One-Legged Robot

2021 ◽  
Vol 11 (8) ◽  
pp. 3676
Author(s):  
Donglai Zhao ◽  
Wenjie Ge ◽  
Xiaojuan Mo ◽  
Yuzhu Li ◽  
Zhuo Wang
Keyword(s):  
Energy Efficiency ◽  
Dynamic Models ◽  
Impedance Control ◽  
Weight Ratio ◽  
Design Parameters ◽  
Legged Robot ◽  
Large Pressure ◽  
Robot Systems ◽  
Hydraulic Cylinders ◽  
The Relationship

Due to the high power-to-weight ratio and robustness, hydraulic cylinders are widely used in the actuation area of the legged robot systems. Most of these applications are focused on the motion stability, gait planning, and impedance control. However, the energy efficiency of the legged robotic system is also a very important point to be considered. Hopping locomotion requires a fast extension of the tibia leg at the end of the take-off phase, which causes a continuous increment of the cylinder velocity under the normally direct attachment geometry (DAG) of the cylinder. This leads to a high flow requirement, large pressure drop, and low energy efficiency. Therefore, we propose a four-bar mechanism attachment geometry (FMAG) to improve the energy efficiency by refining the relationship between the joint angle and cylinder displacement trend. The kinematic and dynamic models of the bionic one-legged robot are built to calculate the hopping process during the take-off phase. Based on the established dynamic models, the design parameters in both the DAG and FMAG are optimized to maximize the hopping height, respectively. The hopping experiments are conducted to verify the effectiveness of the new attachment geometry. The experimental results show that the robot hopping energy at the end of the take-off phase increases 14.8% under the FMAG.

scholarly journals Review and Case Study of Sounds Associated with the Lightning Electromagnetic Pulse

2009 ◽  
Vol 137 (9) ◽  
pp. 3129-3136 ◽  
Author(s):  
Timothy A. Coleman ◽  
Kevin R. Knupp ◽  
John T. Tarvin
Keyword(s):  
Light Intensity ◽  
Electromagnetic Pulse ◽  
Digital Video ◽  
Video Camera ◽  
Electromagnetic Energy ◽  
Electromagnetic Pulses ◽  
Earth’S Atmosphere ◽  
Significant Period ◽  
Video And Audio

Abstract The electromagnetic pulses (EMPs) associated with two lightning flashes on 22 July 2008 in central Alabama produced audible clicking sounds. These clicks were observed almost simultaneously with the lightning flashes, but a significant period of time before the thunder. The lightning flashes and associated sounds were recorded in digital video and audio by a video camera. Based on theories primarily developed to explain reports of sounds associated with aurora and meteors entering the earth’s atmosphere, it appears that the sounds were associated with transduction of the electromagnetic energy at audible frequencies into vibrations in objects near the camera. Coronal discharges are also possible. Examination of spectrograms of the clicks and the subsequent thunder, and comparison to measurements of the normalized light intensity in each frame of video, show that the clicks must have been associated with sounds in nearby objects. Therefore, the sounds were associated with the lightning EMP.

scholarly journals Improving Roadway Operations and Safety for Large Truck Vehicles by Optimizing some Critical Geometric Design Parameters

2017 ◽  
Vol 1 (2) ◽  
pp. 330-336
Author(s):  
S. P. Galadima ◽  
O. R. Ogirigbo ◽  
J. O. Ehiorobo
Keyword(s):  
Functional Class ◽  
Geometric Design ◽  
Design Parameters ◽  
Parameter Estimates ◽  
Highway Infrastructure ◽  
Lane Width ◽  
Before And After ◽  
Length Width ◽  
Design Deficiencies ◽  
Horizontal Curvature

Large truck vehicles are constrained by their physical and operational attributes such as length, width, height and axle loading, which affect their performance on highway infrastructure. In recent times, car-truck and truck only crashes have increased due to the complex interactions of such vehicles on geometrically deficient roadway systems. By adjusting geometric design parameters in accordance with stipulated requirements across deficient roadway sections it is possible to estimate using crash rate index the degree of improvements observed. A total of 189.4 kilometers of three roadway lengths (Benin-Ore, Benin-Agbor and Benin-Sapele) were investigated for geometric design deficiencies across crash sections. Adjustments were made using AAHSTO design specifications based on speed limit, terrain type and roadway functional class for three critical geometric design parameters namely: degree of horizontal curvature, vertical grade and roadway lane width. Comparison of parameter estimates before and after adjustments showed corresponding cumulative percentage improvements of 6.5%, 13% and 4.7% for Benin-Ore, Benin-Agbor and Benin-Sapele roadways respectively. This implies that adjustments to critical design parameters at deficient roadway sections can help in mitigating large truck crash rates and allow for better accommodation and operation of such truck vehicles on plied roadways.

scholarly journals Robustness of Adaptive Survey Designs to Inaccuracy of Design Parameters

2017 ◽  
Vol 33 (3) ◽  
pp. 687-708 ◽  
Author(s):  
Joep Burger ◽  
Koen Perryck ◽  
Barry Schouten
Keyword(s):  
Simulation Study ◽  
Optimization Problems ◽  
Distance Measures ◽  
Design Parameters ◽  
Parameter Estimates ◽  
Design Features ◽  
Simple Simulation ◽  
Minimum Number ◽  
Survey Designs

Abstract Adaptive survey designs (ASDs) optimize design features, given 1) the interactions between the design features and characteristics of sampling units and 2) a set of constraints, such as a budget and a minimum number of respondents. Estimation of the interactions is subject to both random and systematic error. In this article, we propose and evaluate four viewpoints to assess robustness of ASDs to inaccuracy of design parameter estimates: the effect of both imprecision and bias on both ASD structure and ASD performance. We additionally propose three distance measures to compare the structure of ASDs. The methodology is illustrated using a simple simulation study and a more complex but realistic case study on the Dutch Travel Survey. The proposed methodology can be applied to other ASD optimization problems. In our simulation study and case study, the ASD was fairly robust to imprecision, but not to realistic dynamics in the design parameters. To deal with the sensitivity of ASDs to changing design parameters, we recommend to learn and update the design parameters.

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