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Switching algorithm for maglev train double-modular redundant positioning sensors.

He N, Long Z, Xue S - Sensors (Basel) (2012)

Bottom Line: The prediction errors are used to trigger sensor switching.The time delay characteristics of the method are analyzed to guide the algorithm simplification.Finally, the effectiveness of the simplified switching algorithm is verified through experiments.

View Article: PubMed Central - PubMed

Affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. hening0606@126.com

ABSTRACT
High-resolution positioning for maglev trains is implemented by detecting the tooth-slot structure of the long stator installed along the rail, but there are large joint gaps between long stator sections. When a positioning sensor is below a large joint gap, its positioning signal is invalidated, thus double-modular redundant positioning sensors are introduced into the system. This paper studies switching algorithms for these redundant positioning sensors. At first, adaptive prediction is applied to the sensor signals. The prediction errors are used to trigger sensor switching. In order to enhance the reliability of the switching algorithm, wavelet analysis is introduced to suppress measuring disturbances without weakening the signal characteristics reflecting the stator joint gap based on the correlation between the wavelet coefficients of adjacent scales. The time delay characteristics of the method are analyzed to guide the algorithm simplification. Finally, the effectiveness of the simplified switching algorithm is verified through experiments.

No MeSH data available.


The experimental results of the two-modular switching.
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f12-sensors-12-11294: The experimental results of the two-modular switching.

Mentions: The switching experiment results are shown in Figure 12. For a maglev train, there are two positioning sensors in one set of speed and position detection system. As Figure 11 shows, when the train is passing a large joint gap, the phase signal distortions of two sensors occur one after another. At about the 220th step, the phase signal of sensor 1 (denoted by the red dash line) begins to be distorted, and then the final signal (denoted by the black line) is switched to sensor 2, which is normal at present. About three tooth-slot periods later (at about the 440th step), the phase signal of sensor 2 (denoted by the blue line) begins to be distorted, and then the final signal is switched to sensor 1. Therefore, when the train is passing a large joint gap, the final signal always keeps normal.


Switching algorithm for maglev train double-modular redundant positioning sensors.

He N, Long Z, Xue S - Sensors (Basel) (2012)

The experimental results of the two-modular switching.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472885&req=5

f12-sensors-12-11294: The experimental results of the two-modular switching.
Mentions: The switching experiment results are shown in Figure 12. For a maglev train, there are two positioning sensors in one set of speed and position detection system. As Figure 11 shows, when the train is passing a large joint gap, the phase signal distortions of two sensors occur one after another. At about the 220th step, the phase signal of sensor 1 (denoted by the red dash line) begins to be distorted, and then the final signal (denoted by the black line) is switched to sensor 2, which is normal at present. About three tooth-slot periods later (at about the 440th step), the phase signal of sensor 2 (denoted by the blue line) begins to be distorted, and then the final signal is switched to sensor 1. Therefore, when the train is passing a large joint gap, the final signal always keeps normal.

Bottom Line: The prediction errors are used to trigger sensor switching.The time delay characteristics of the method are analyzed to guide the algorithm simplification.Finally, the effectiveness of the simplified switching algorithm is verified through experiments.

View Article: PubMed Central - PubMed

Affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. hening0606@126.com

ABSTRACT
High-resolution positioning for maglev trains is implemented by detecting the tooth-slot structure of the long stator installed along the rail, but there are large joint gaps between long stator sections. When a positioning sensor is below a large joint gap, its positioning signal is invalidated, thus double-modular redundant positioning sensors are introduced into the system. This paper studies switching algorithms for these redundant positioning sensors. At first, adaptive prediction is applied to the sensor signals. The prediction errors are used to trigger sensor switching. In order to enhance the reliability of the switching algorithm, wavelet analysis is introduced to suppress measuring disturbances without weakening the signal characteristics reflecting the stator joint gap based on the correlation between the wavelet coefficients of adjacent scales. The time delay characteristics of the method are analyzed to guide the algorithm simplification. Finally, the effectiveness of the simplified switching algorithm is verified through experiments.

No MeSH data available.