scholarly journals Precision Analysis and Design of Rotating Coil Magnetic Measurements System

2020 ◽  
Vol 10 (23) ◽  
pp. 8454
Author(s):  
Soontorn Odngam ◽  
Chaiyut Preecha ◽  
Prapaiwan Sanwong ◽  
Woramet Thongtan ◽  
Jiraphon Srisertpol
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Magnetic Measurements ◽  
Speed Control ◽  
Measuring Instruments ◽  
Dipole Magnet ◽  
Analysis And Design ◽  
Speed Control System ◽  
The Impact ◽  
The Magnetic Field

This research presents the design and construction of measuring instruments for a dipole magnetic field using a rotating coil technique. This technique is a closed-loop speed-control system where a Proportional-Integral (PI) controller works together with the intensity measurement of the magnetic field through the rotating coil. It was used to analyze the impact on the accuracy of the electromagnetic at speed ranges of 60, 90, and 120 rpm. The error estimation in the measurement of the normal dipole and skew dipole magnet caused by the steady-state error of the speed control system and the rotational search coil in whirling motion are demonstrated. Rotating unbalance, shaft coupling, and misalignment from its setup disturbed the performance of the speed control system as a nonlinear system.

Research on the Relationship between Speed Control System and Electromechanical Oscillations

2015 ◽  
Vol 710 ◽  
pp. 47-52 ◽  
Author(s):  
Ya Qing Zhu ◽  
Min Zhong ◽  
Yu Jia Ma ◽  
Feng Ping Pan ◽  
Ling Ling Shi ◽  
...  
Keyword(s):  
Control System ◽  
Steam Turbine ◽  
Time Constant ◽  
Response Rate ◽  
Speed Control ◽  
Servo Motor ◽  
Speed Control System ◽  
Hydraulic Servo ◽  
The Impact ◽  
The Relationship

The system damping of electric power systems is influenced by factors of many aspects. In this paper, we analyzed the impact of speed control system on the damping of the whole system in consideration of the Pole-Zero Analysis. The result shows that simple speed control would damp the oscillation, while the power-frequency control would excite the oscillation. Furthermore, the effect of steam turbine response rate on the system damping is analyzed. The time constant of hydraulic servo-motor would determine the response rate of the steam turbine, and as a result, an inflection point exists on the curve which describes the relationship between hydraulic servo-motor time constant and system damping. The result demonstrates that the characteristics of system damping can be used in parameter debugging of steam turbine.

Design of Hydraulic Cylinder Speed Control System Base on High-Speed on-Off Valve

2012 ◽  
Vol 220-223 ◽  
pp. 1661-1664
Author(s):  
Qin He Gao ◽  
Wen Liang Guan ◽  
Hai Zhou Song ◽  
Zhi Yong Yang
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
High Speed ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Pulse Control ◽  
Parallel Application ◽  
Speed Control System ◽  
Small Flow ◽  
The Impact

In order to study the Application of high-speed on-off valve in the hydraulic cylinder speed control system, series and parallel application schemes between high-speed on-off valve and hydraulic cylinder are proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed of hydraulic cylinder and weak the impact. The simulation curve compared with the experimental results show that, two application schemes can both control the speed of hydraulic cylinder effectively. Series application scheme can be only applied to small flow hydraulic system; parallel application scheme has wider application.

Research on Simulation of Electronic-Protection Circuit of Chopper Cascade Speed Control System

2014 ◽  
Vol 721 ◽  
pp. 569-574
Author(s):  
Zhao Yan Zhang ◽  
Xing Wu Wang ◽  
Yong Guang Ma
Keyword(s):  
Control System ◽  
Transient Process ◽  
High Voltage ◽  
Speed Control ◽  
Matlab Simulation ◽  
Power Failure ◽  
Speed Control System ◽  
Protection Circuit ◽  
Failure Conditions ◽  
The Impact

Firstly, according to the topology of conventional chopper cascade speed system to analyze the transient process of main loop during of contactor operation when device failure. Because the contactor action requires a longer time, Equipment is vulnerable to the impact of high voltage, high current during the contactor action, and cause damage to power electronic devices. For contactors drawbacks, the main circuit topology with electronic-protection circuit is designed. Then analyze transient process of chopper cascade speed control system with electronic-protection circuit under high-voltage power failure conditions. Finally, simulation model of chopper cascade speed control system with electronic-protection circuit is built respectively in Matlab. Simulation results show that electronic-protection circuits effectively solve the problem of high-voltage power failure under active inverter structure and inverter subversion.

Design of Direct-Control Hydraulic Cylinder Speed Control System Base on High-Speed On-Off Valve

2013 ◽  
Vol 273 ◽  
pp. 704-708
Author(s):  
Qin He Gao ◽  
Zhi Hao Liu ◽  
Ya Jun Shao ◽  
Ting Qiong Dong
Keyword(s):  
Control System ◽  
Duty Cycle ◽  
High Speed ◽  
Research Result ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Pulse Control ◽  
Direct Control ◽  
Speed Control System ◽  
The Impact

Application of high-speed on-off valve in the hydraulic speed control system was researched in this paper. The direct-control circuit application of high speed on-off valve is proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed and weak the impact. The speed and accelerated speed curves of hydraulic cylinder were achieved by the means of simulation with Simulink and experiment with FESTO is obtained, and research result shows that the applied scheme can effectively control the speed of hydraulic cylinder effectively.

Simulations of Magnetic Fields Produced by Asteroid Impact: Possible Implications for Planetary Paleomagnetism

2019 ◽  
Author(s):  
David A. Crawford
Keyword(s):  
Magnetic Field ◽  
Magnetic Measurements ◽  
Magnetic Anomalies ◽  
Iron Core ◽  
The Moon ◽  
Major Question ◽  
Asteroid Impact ◽  
Origin And Evolution ◽  
The Impact ◽  
The Magnetic Field

Abstract The origin and evolution of the Moon's magnetic field has been a major question in lunar science ever since Luna 1 made the first magnetic measurements in the vicinity of the Moon in 1959. Orbital measurements show that the magnetic field at the surface of the Moon has local scale lengths on the order of 1-100 km. While this could suggest a correlation with impact craters, most lunar magnetic anomalies don’t appear to correlate with known geologic structures, including impacts [1]. However, the magnetic field produced by impact events are spatially and temporally complex. Add in the complexity of remanence acquisition (localized regions of heating/cooling and/or shock that can produce remanence in the presence of a magnetic field) and we have the potential for a complex pattern to emerge. Wieczorek et al. [1] showed just how such complexity may play out. In their simulations, some lunar magnetic anomalies may be caused by regions of concentrated magnetic materials associated with fragments of the South Pole-Aitken impactor, especially if the impactor was differentiated with an iron core. More recently, Oliveira et al. [2] showed that magnetic anomalies associated with five large lunar basins may be caused by impact melt sheets that cooled in the presence of an early lunar dynamo. In this paper we will look at an alternative explanation for many lunar anomalies that doesn’t require the presence of a lunar dynamo. At least some lunar anomalies may be associated with a deeper, thicker yet more varied region of magnetization acquired by rocks that became hot and cooled rapidly enough during crater formation to have acquired the transient magnetic field produced by the impact itself.

Design of Bypass-Throttle Hydraulic Cylinder Speed Control System Base on High-Speed On-Off Valve

2013 ◽  
Vol 645 ◽  
pp. 405-408 ◽  
Author(s):  
Qin He Gao ◽  
Zhi Hao Liu ◽  
Hai Zhou Song ◽  
Li Ming Liu
Keyword(s):  
Control System ◽  
Duty Cycle ◽  
High Speed ◽  
Research Result ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Control Signal ◽  
Pulse Control ◽  
Speed Control System ◽  
The Impact

Application of high-speed on-off valve in the hydraulic speed control system was researched in this paper. The bypass-throttle circuit application of high speed on-off valve is proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed and weak the impact. The speed and accelerated speed curves of hydraulic cylinder were achieved by the means of simulation with Simulink and experiment with FESTO is obtained, and research result shows that the applied scheme can effectively control the speed of hydraulic cylinder effectively.

MAGNETIC FIELD IMPACT UPON TRIBOTECHNICAL CHARACTERISTICS OF PERMANENT CONNECTIONS IN RELATION TO FRICTION SHOCK ABSORBERS

2020 ◽  
Vol 2020 (10) ◽  
pp. 4-11
Author(s):  
Victor Tikhomirov ◽  
Aleksandr Gorlenko ◽  
Stanislav Volohov ◽  
Mikhail Izmerov
Keyword(s):  
Magnetic Field ◽  
Friction Factor ◽  
Physical Contact ◽  
Active Centers ◽  
Press Fit ◽  
Electro Magnetic Field ◽  
Investigation Methods ◽  
Electro Magnetic ◽  
The Impact ◽  
The Magnetic Field

The work purpose is the investigation of magnetic field impact upon properties of friction steel surfaces at fit stripping with tightness through manifested effects and their wear visually observed. On the spots of a real contact the magnetic field increases active centers, their amount and saturation with the time of dislocation outlet, and has an influence upon tribo-mating. The external electro-magnetic field promotes the increase of the number of active centers at the expense of dislocations outlet on the contact surface, and the increase of a physical contact area results in friction tie strengthening and growth of a friction factor. By the example of friction pairs of a spentonly unit in the suspension of coach cars there is given a substantiation of actuality and possibility for the creation of technical devices with the controlled factor of friction and the stability of effects achieved is also confirmed experimentally. Investigation methods: the fulfillment of laboratory physical experiments on the laboratory plant developed and patented on bush-rod samples inserted with the fit and tightness. The results of investigations and novelty: the impact of the magnetic field upon the value of a stripping force of a press fit with the guaranteed tightness is defined. Conclusion: there is a possibility to control a friction factor through the magnetic field impact upon a friction contact.

scholarly journals Qualitative and quantitative assessment of magnetic vestibular stimulation in humans

2020 ◽  
Vol 30 (6) ◽  
pp. 353-361
Author(s):  
Rebecca S. Dewey ◽  
Rachel Gomez ◽  
Chris Degg ◽  
David M. Baguley ◽  
Paul M. Glover
Keyword(s):  
Magnetic Field ◽  
Objective Measure ◽  
Quantitative Measure ◽  
Vestibular Stimulation ◽  
Initial Study ◽  
Clinical Test ◽  
Healthy Control ◽  
Student’S T ◽  
The Impact ◽  
The Magnetic Field

The sensation of phantom motion or exhibition of bodily sway is often reported in the proximity of an MR scanner. It is proposed that the magnetic field stimulates the vestibular system. There are a number of possible mechanisms responsible, and the relative contributions of susceptibility on the otolithic receptors and the Lorentz force on the cupulae have not yet been explored. This exploratory study aims to investigate the impact of being in the proximity of a 7.0 T MR scanner. The modified clinical test of sensory interaction on balance (mCTSIB) was used to qualitatively ascertain whether or not healthy control subjects who passed the mCTSIB in normal conditions 1) experienced subjective sensations of dizziness, vertigo or of leaning or shifting in gravity when in the magnetic field and 2) exhibited visibly increased bodily sway whilst in the magnetic field compared to outside the magnetic field. Condition IV of the mCTSIB was video recorded outside and inside the magnetic field, providing a semi-quantitative measure of sway. For condition IV of the mCTSIB (visual and proprioceptive cues compromised), all seven locations/orientations around the scanner yielded significantly more sway than at baseline (p < 0.01 FDR). A Student’s t-test comparing the RMS velocity of a motion marker on the upper arm during mCTSIB condition IV showed a significant increase in the amount of motion exhibited in the field (T = 2.59; d.f. = 9; p = 0.029) compared to outside the field. This initial study using qualitative measures of sway demonstrates that there is evidence for MR-naïve individuals exhibiting greater sway while performing the mCTSIB in the magnetic field compared to outside the field. Directional polarity of sway was not significant. Future studies of vestibular stimulation by magnetic fields would benefit from the development of a sensitive, objective measure of balance function, which can be performed inside a magnetic field.

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