The Library
Optical wireless data transfer for rotor detection and diagnostics
Tools
Huang, Peng, Ph.D. (2012) Optical wireless data transfer for rotor detection and diagnostics. PhD thesis, University of Warwick.
|
Text
WRAP_THESIS_Huang_2012.pdf - Submitted Version Download (5Mb) | Preview |
Official URL: http://webcat.warwick.ac.uk/record=b2581844~S1
Abstract
A special application of optical wireless data transfer, namely on-line monitoring
and diagnostic of rotors in turbines and engines, has been considered in this thesis. In
this application, to maintain line of sight, i.e. data transfer, between a sensor placed on a
rotating component inside the turbine and a monitoring point placed in a fixed position
outside the turbine, a periodic fast fading channel is generated, which gives the
transceivers more flexibility regarding their mounting location. The communication in
such a channel is affected by the intermittency and variation of the signal power, which
produces a unique channel condition that influences the performance of the optical
transceiver.
To investigate the channel condition and the error rate of the periodic fast fading
channel with signal fluctuation, a model is developed to simulate the optical channel by
considering the variation of signal power as a result of the change in the relative
position of the photodiode with respect to the Lambertian radiation pattern of the LED,
in a simplified linear geometry. The error rate is estimated using the Saddlepoint
approximation on a specific threshold strategy. The results show that the channel can
afford the sensor data transmission and the performance can be improved by modifying
several parameters, such as geometrical distance, transmitter power and load resistor.
Compared to a normal channel, a higher load resistor on the photodiode front end has
the advantage of decreasing the noise level and increasing the data capacity in the fast
fading channel. The analysis of the automatic gain control amplifier indicates that a
higher load resistor needs a lower loop gain and from the model of the Transimpedance
amplifier (TIA), the bandwidth extension from the amplifier is more significant for a
higher resistor.
In addition to the theoretical model, an experimental setup is built to emulate the
channel in practice. The degree of similarity between the experimental setup and the
theoretical model of the channel is estimated from the comparison of the generated communication windows. Since it has been found that differences exist in the duration
of the communication window and the variation of the signal power, scaling factors to
ensure their compatibility have been derived. Transceiver hardware which
implemented the modelled functionality has been developed and a protocol to
establish the communication with the required error rate has been proposed. Using the
hardware implementation, a detection method for both rising and falling edges of the
signal pulses and a threshold strategy have been demonstrated. The device power
consumption is also estimated.
What is more, the electromagnetic environment of a squirrel cage motor is
simulated using the finite element method to investigate the interference and the
possibility of providing power to the IR communication devices using power
scavenging.
In the conclusion, the key findings of the thesis are summarised. A solution is
proposed for sensor data transfer using an optical channel for rotor monitoring
applications, which involves the design of the IR transceiver, the implementation of
the developed protocol and the power consumption estimation.
Item Type: | Thesis (PhD) | ||||
---|---|---|---|---|---|
Subjects: | T Technology > TK Electrical engineering. Electronics Nuclear engineering | ||||
Library of Congress Subject Headings (LCSH): | Wireless communication systems, Data transmission systems, Rotors | ||||
Official Date: | May 2012 | ||||
Dates: |
|
||||
Institution: | University of Warwick | ||||
Theses Department: | School of Engineering | ||||
Thesis Type: | PhD | ||||
Publication Status: | Unpublished | ||||
Supervisor(s)/Advisor: | Iliescu, Daciana ; Leeson, Mark S., 1963- ; Hines, Evor L. | ||||
Extent: | xi, 177 leaves : ill., charts | ||||
Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year