Papers by Keyword: Magnetic Dipole

Abstract: The precision of magnetometer positioning is affected by the geomagnetic anomaly, and traditional positioning technology cannot be applied to the motion sensor positioning. A magnetometer localization method based on a variable magnetic source is proposed. The method localizes a magnetic sensor by the absolute value of the magnetic field. Positioning process does not use geomagnetic coordinates to avoid the effects of geomagnetic anomalies. The method uses time-division multiplexing technology to achieve the motion sensor positioning. Simulation results show that the average positioning error is 0.3% and the maximum positioning error is 1.3% when the tilt angle of the magnetic source is ±1 degree. It has the advantages of high precision.

Abstract: In the conditions of magnetic dipole model, this paper proposed forward a centroid localization algorithm on magnetic anomaly target based on wireless sensor network node which distribution are random and the improved the weighted centroid localization algorithm based on magnetic induction intensity. According to the fluctuation of magnetic field intensity which detected by magnetic sensors, that can detect the existence of magnetic anomaly target and its location. Established an experimental system of the wireless sensor network for magnetic anomaly detection whose core designs including the HMC1043 three-axis magnetic resistance sensor and the CC2530 Zigbee RF chip. The experimental results show that the algorithm can accurately positioning the magnetic anomaly target within the network.

Abstract: A compressed multiple band loop antenna that has multiple superimposed compressed loops. Each compressed loop is formed from numerous segments arrayed in multiple diverse directions so that the enclosed area of that loop and the overall size of the antenna are decreased. Multiple loops are arrayed and superimposed to provide multiple frequency bands of operation and are used to broaden the useful bandwidth of individual-bands. The small size of the compressed antenna facilitates its use in small mobile communications devices requiring internal antennas that operate in close proximity to conductive surfaces. Multiple loops are arrayed in several configurations that include nested and non-nested loops as well as closely located and spatially separated superimposed loops.

Abstract: As traditional measurement while drilling (MWD) method cannot meet the high reliability, high precision requirements for drilling complex structure wells. A guided-orientation method based on rotating magnetic field has prominent advantages on the twin parallel horizontal wells and can apply in twin parallel horizontal wells. In this paper, RMRS, namely Rotating Magnet Ranging system, its operating principle was gave firstly while applied for drilling twin parallel horizontal wells. The rotating magnetic sub was characterized by a pair of orthogonal magnetic dipoles, and then build the model for positioning the twin parallel horizontal wells Finally, the authors used the Maxwell software to simulate the algorithm based on the scene environment, and then proves that algorithm is correct and useful for guiding the well to drill and keeping the twin wells parallel.

Abstract: The model of remote underwater magnetic target was set up by the single magnetic dipole. A closed formula that describes the distributing of magnetic dipoles at arbitrary position was gained by means of extracting the transfer matrix. The location and magnetic moment equation of magnetic dipole was set up by using the formula. Then a calculation result for the location and magnetic moment of target at arbitrary position was acquired. The location method in this paper need not know the magnetic moment of target in advance, so it provides a new practical method for the remote location of underwater magnetic target.

Abstract: The effect of noise on the reversal of a magnetic dipole is investigated on the basis of computer simulation of the Landau-Lifshits equation. It is demonstrated that at the reversal by the pulse with sinusoidal shape, there exists the optimal duration, which minimizes the mean reversal time (MRT) and the standard deviation (SD, jitter). Both the MRT and the jitter significantly depend on the angle  between the reversal magnetic field and the anisotropy axis. At the optimal angle the MRT can be decreased by a factor of 7 for damping =1 and up to 2 orders of magnitude for =0.01, and the jitter can be decreased from 1 to 3 orders of magnitude in comparison with the uniaxial symmetry case. It has been demonstrated that fluctuations can not only decrease the reversal time, as it has been known before for the magnetic systems and is correct for small angles only, but it can also significantly, up to the factor of two, increase the reversal time.