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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 9-channel ECDS applied in the MSFW (a) The probe configuration of the 9-channel ECDS; (b) The measuring ring assembled in the rotor; (c) The relations between the generalized displacements of the rotor and the clearance lengths measured by the 9-channel ECDS.
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f2-sensors-12-10693: The 9-channel ECDS applied in the MSFW (a) The probe configuration of the 9-channel ECDS; (b) The measuring ring assembled in the rotor; (c) The relations between the generalized displacements of the rotor and the clearance lengths measured by the 9-channel ECDS.

Mentions: The configuration of the 9-channel ECDS is described in Figure 2(a). The details of the measuring ring that is fixed in and rotates with rotor are described in Figure 2(b). Figure 2(c) shows the relations between the generalized displacements of the rotor and the gap lengths measured by the ECDS. The radial translation displacements [x y] of the rotor could be calculated from the four radial probes x+, x−, y+ and y−, the axial translation z and the two axial rotation displacements [α β] of the rotor could be calculated from the four axial probes z1–z4. The z0 probe is fixed in the ECDS and introduced to compensation the temperature drift of the z1–z4 probes. The transfer matrix from the outputs of the ECDS [x+x−y+y−z0 z1 z2 z3 z4] to the displacements [x y z α β] is described in Equation (1):(1){x=x+−x−y=y+−y−,{z=z′1+z′2+z′3+z′4α=(z′1−z′3)/Dsβ=(z′2−z′4)/Dsz′i=zi−z0,(i=1⋯4)


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 9-channel ECDS applied in the MSFW (a) The probe configuration of the 9-channel ECDS; (b) The measuring ring assembled in the rotor; (c) The relations between the generalized displacements of the rotor and the clearance lengths measured by the 9-channel ECDS.
© Copyright Policy
Related In: Results  -  Collection

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

f2-sensors-12-10693: The 9-channel ECDS applied in the MSFW (a) The probe configuration of the 9-channel ECDS; (b) The measuring ring assembled in the rotor; (c) The relations between the generalized displacements of the rotor and the clearance lengths measured by the 9-channel ECDS.
Mentions: The configuration of the 9-channel ECDS is described in Figure 2(a). The details of the measuring ring that is fixed in and rotates with rotor are described in Figure 2(b). Figure 2(c) shows the relations between the generalized displacements of the rotor and the gap lengths measured by the ECDS. The radial translation displacements [x y] of the rotor could be calculated from the four radial probes x+, x−, y+ and y−, the axial translation z and the two axial rotation displacements [α β] of the rotor could be calculated from the four axial probes z1–z4. The z0 probe is fixed in the ECDS and introduced to compensation the temperature drift of the z1–z4 probes. The transfer matrix from the outputs of the ECDS [x+x−y+y−z0 z1 z2 z3 z4] to the displacements [x y z α β] is described in Equation (1):(1){x=x+−x−y=y+−y−,{z=z′1+z′2+z′3+z′4α=(z′1−z′3)/Dsβ=(z′2−z′4)/Dsz′i=zi−z0,(i=1⋯4)

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