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A wide linear range Eddy Current Displacement Sensor equipped with dual-coil probe applied in the Magnetic Suspension Flywheel.

Fang J, Wen T - Sensors (Basel) (2012)

Bottom Line: The Eddy Current Displacement Sensor (ECDS) is widely used in the Magnetic Suspension Flywheel (MSFW) to measure the tiny clearance between the rotor and the magnetic bearings.Wide clearances must be measured in some new MSFWs recently designed for the different space missions, but the coil diameter is limited by some restrictions.The effectiveness of the linear range extension ability and the dynamic response of the designed ECDS are confirmed by the testing and the applications in the MSFW.

View Article: PubMed Central - PubMed

Affiliation: Science and Technology on Inertial Laboratory, School of Instrumentation Science and Opto-Electronics Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China. fangjiancheng@buaa.edu.cn

ABSTRACT
The Eddy Current Displacement Sensor (ECDS) is widely used in the Magnetic Suspension Flywheel (MSFW) to measure the tiny clearance between the rotor and the magnetic bearings. The linear range of the ECDS is determined by the diameter of its probe coil. Wide clearances must be measured in some new MSFWs recently designed for the different space missions, but the coil diameter is limited by some restrictions. In this paper, a multi-channel ECDS equipped with dual-coil probes is proposed to extend the linear range to satisfy the demands of such MSFWs. In order to determine the best configuration of the dual-coil probe, the quality factors of the potential types of the dual-coil probes, the induced eddy current and the magnetic intensity on the surface of the measuring object are compared with those of the conventional single-coil probe. The linear range of the ECDS equipped with the selected dual-coil probe is extended from 1.1 mm to 2.4 mm under the restrictions without adding any cost for additional compensation circuits or expensive coil materials. The effectiveness of the linear range extension ability and the dynamic response of the designed ECDS are confirmed by the testing and the applications in the MSFW.

No MeSH data available.


Related in: MedlinePlus

Comparison of the Q-factors of the four dual-coil probes and the single-coil probe (a) Q(∞)-f curves of the different probes; (b) Q(0)-f curves of the different probes; (c) ΔQ-f curves of the different probes.
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f8-sensors-12-10693: Comparison of the Q-factors of the four dual-coil probes and the single-coil probe (a) Q(∞)-f curves of the different probes; (b) Q(0)-f curves of the different probes; (c) ΔQ-f curves of the different probes.

Mentions: The Q-factor of the coil is determined by the measured clearance, the frequency of the exacting current in the coil and the material of the measuring object. The Q-factors of the different probes are measured when the resonance frequency of the exciting current in the coil is varying from 50 Hz to 5 MHz. As shown in Figure 8, there are the Q-factors of the different probes. Figure 8(a) is the Q-factor when the measuring object is removed far away from the probes, which denoted as Q(∞). Figure 8(b) is the Q-factor when the measuring object is closed to the probes without any clearance which denoted as Q(0). Figure 8(c) is the difference of the two Q-factor curves listed in (a) and (b), which denoted as ΔQ. The linear range of the ECDS could be evaluated by the ΔQ.


A wide linear range Eddy Current Displacement Sensor equipped with dual-coil probe applied in the Magnetic Suspension Flywheel.

Fang J, Wen T - Sensors (Basel) (2012)

Comparison of the Q-factors of the four dual-coil probes and the single-coil probe (a) Q(∞)-f curves of the different probes; (b) Q(0)-f curves of the different probes; (c) ΔQ-f curves of the different probes.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472851&req=5

f8-sensors-12-10693: Comparison of the Q-factors of the four dual-coil probes and the single-coil probe (a) Q(∞)-f curves of the different probes; (b) Q(0)-f curves of the different probes; (c) ΔQ-f curves of the different probes.
Mentions: The Q-factor of the coil is determined by the measured clearance, the frequency of the exacting current in the coil and the material of the measuring object. The Q-factors of the different probes are measured when the resonance frequency of the exciting current in the coil is varying from 50 Hz to 5 MHz. As shown in Figure 8, there are the Q-factors of the different probes. Figure 8(a) is the Q-factor when the measuring object is removed far away from the probes, which denoted as Q(∞). Figure 8(b) is the Q-factor when the measuring object is closed to the probes without any clearance which denoted as Q(0). Figure 8(c) is the difference of the two Q-factor curves listed in (a) and (b), which denoted as ΔQ. The linear range of the ECDS could be evaluated by the ΔQ.

Bottom Line: The Eddy Current Displacement Sensor (ECDS) is widely used in the Magnetic Suspension Flywheel (MSFW) to measure the tiny clearance between the rotor and the magnetic bearings.Wide clearances must be measured in some new MSFWs recently designed for the different space missions, but the coil diameter is limited by some restrictions.The effectiveness of the linear range extension ability and the dynamic response of the designed ECDS are confirmed by the testing and the applications in the MSFW.

View Article: PubMed Central - PubMed

Affiliation: Science and Technology on Inertial Laboratory, School of Instrumentation Science and Opto-Electronics Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China. fangjiancheng@buaa.edu.cn

ABSTRACT
The Eddy Current Displacement Sensor (ECDS) is widely used in the Magnetic Suspension Flywheel (MSFW) to measure the tiny clearance between the rotor and the magnetic bearings. The linear range of the ECDS is determined by the diameter of its probe coil. Wide clearances must be measured in some new MSFWs recently designed for the different space missions, but the coil diameter is limited by some restrictions. In this paper, a multi-channel ECDS equipped with dual-coil probes is proposed to extend the linear range to satisfy the demands of such MSFWs. In order to determine the best configuration of the dual-coil probe, the quality factors of the potential types of the dual-coil probes, the induced eddy current and the magnetic intensity on the surface of the measuring object are compared with those of the conventional single-coil probe. The linear range of the ECDS equipped with the selected dual-coil probe is extended from 1.1 mm to 2.4 mm under the restrictions without adding any cost for additional compensation circuits or expensive coil materials. The effectiveness of the linear range extension ability and the dynamic response of the designed ECDS are confirmed by the testing and the applications in the MSFW.

No MeSH data available.


Related in: MedlinePlus