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Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †

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ABSTRACT

Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.

No MeSH data available.


(a) A quasi-distributed sensor array for twist/rotation setup; and (b) ILP with a semi-reflective mirror setup.
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sensors-17-00443-f018: (a) A quasi-distributed sensor array for twist/rotation setup; and (b) ILP with a semi-reflective mirror setup.

Mentions: As already mentioned, E-field vector displacement rotation sensors can be multiplexed to form a quasi-distributed rotation sensor array [85]. This is a unique property of the E-field displacement approach. In [85], special in-line fiber polarizers with high return loss were built, i.e., semi-reflection mirrors were placed behind polarizers, as shown in Figure 18b. Then, an array of these polarizers was interconnected with a straight SMF section (Figure 18a). The system was interrogated with very simple OTDR (consisting of an ordinary Telecom laser diode and PIN detector—mirrors provided high reflectance, thus, there was no need for a more complex detection stage). A single launched pulse produced a train of back-reflected pulses and ratios among neighboring pulses’ amplitudes encoded twist/rotation imposed to the individual sensor segments. This setup can be viewed as a sequence/chain of multiple all-fiber Malus arrangements as shown in Figure 16a (with added mirrors for easier signal interrogation).


Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †
(a) A quasi-distributed sensor array for twist/rotation setup; and (b) ILP with a semi-reflective mirror setup.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5375729&req=5

sensors-17-00443-f018: (a) A quasi-distributed sensor array for twist/rotation setup; and (b) ILP with a semi-reflective mirror setup.
Mentions: As already mentioned, E-field vector displacement rotation sensors can be multiplexed to form a quasi-distributed rotation sensor array [85]. This is a unique property of the E-field displacement approach. In [85], special in-line fiber polarizers with high return loss were built, i.e., semi-reflection mirrors were placed behind polarizers, as shown in Figure 18b. Then, an array of these polarizers was interconnected with a straight SMF section (Figure 18a). The system was interrogated with very simple OTDR (consisting of an ordinary Telecom laser diode and PIN detector—mirrors provided high reflectance, thus, there was no need for a more complex detection stage). A single launched pulse produced a train of back-reflected pulses and ratios among neighboring pulses’ amplitudes encoded twist/rotation imposed to the individual sensor segments. This setup can be viewed as a sequence/chain of multiple all-fiber Malus arrangements as shown in Figure 16a (with added mirrors for easier signal interrogation).

View Article: PubMed Central - PubMed

ABSTRACT

Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.

No MeSH data available.