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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

The sketch of the dual-coil ECDS. (a) Diagrammatic sketch of the dual-coil probe and the measuring ring; (b) Photo of the dual-coil probe.
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f5-sensors-12-10693: The sketch of the dual-coil ECDS. (a) Diagrammatic sketch of the dual-coil probe and the measuring ring; (b) Photo of the dual-coil probe.

Mentions: In order to extend the linear range of the ECDS, not only the Q-factor of the probe coil but also the coupling between the probe coil and the eddy current circle should be strengthened. As the diameter of the measuring ring used in the MSFW is much larger than the diameter of the coil, the measuring ring could be regarded as a trap for the probe coil. The details of the measuring ring are described in Figure 2(b). A dual-coil probe is designed by using two identical coils that work together to radiate oscillation signal to enhance the induced eddy current on the surface of the measuring ring. Figure 5 shows the structure of the proposed dual-coil ECDS. Two connected coils are located side by side along the circle of the measuring ring. The detecting circuits, the diameter of the coil and the width of the measuring ring keep the same as the single coil ECDS.


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)

The sketch of the dual-coil ECDS. (a) Diagrammatic sketch of the dual-coil probe and the measuring ring; (b) Photo of the dual-coil probe.
© Copyright Policy
Related In: Results  -  Collection

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

f5-sensors-12-10693: The sketch of the dual-coil ECDS. (a) Diagrammatic sketch of the dual-coil probe and the measuring ring; (b) Photo of the dual-coil probe.
Mentions: In order to extend the linear range of the ECDS, not only the Q-factor of the probe coil but also the coupling between the probe coil and the eddy current circle should be strengthened. As the diameter of the measuring ring used in the MSFW is much larger than the diameter of the coil, the measuring ring could be regarded as a trap for the probe coil. The details of the measuring ring are described in Figure 2(b). A dual-coil probe is designed by using two identical coils that work together to radiate oscillation signal to enhance the induced eddy current on the surface of the measuring ring. Figure 5 shows the structure of the proposed dual-coil ECDS. Two connected coils are located side by side along the circle of the measuring ring. The detecting circuits, the diameter of the coil and the width of the measuring ring keep the same as the single coil ECDS.

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