4 research outputs found
An Adaptive Nonparametric Modeling Technique for Expanded Condition Monitoring of Processes
New reactor designs and the license extensions of the current reactors has created new condition monitoring challenges. A major challenge is the creation of a data-based model for a reactor that has never been built or operated and has no historical data. This is the motivation behind the creation of a hybrid modeling technique based on first principle models that adapts to include operating reactor data as it becomes available.
An Adaptive Non-Parametric Model (ANPM) was developed for adaptive monitoring of small to medium size reactors (SMR) but would be applicable to all designs. Ideally, an adaptive model should have the ability to adapt to new operational conditions while maintaining the ability to differentiate faults from nominal conditions. This has been achieved by focusing on two main abilities. The first ability is to adjust the model to adapt from simulated conditions to actual operating conditions, and the second ability is to adapt to expanded operating conditions. In each case the system will not learn new conditions which represent faulted or degraded operations. The ANPM architecture is used to adapt the model\u27s memory matrix from data from a First Principle Model (FPM) to data from actual system operation. This produces a more accurate model with the capability to adjust to system fluctuations.
This newly developed adaptive modeling technique was tested with two pilot applications. The first application was a heat exchanger model that was simulated in both a low and high fidelity method in SIMULINK. The ANPM was applied to the heat exchanger and improved the monitoring performance over a first principle model by increasing the model accuracy from an average MSE of 0.1451 to 0.0028 over the range of operation. The second pilot application was a flow loop built at the University of Tennessee and simulated in SIMULINK. An improvement in monitoring system performance was observed with the accuracy of the model improving from an average MSE of 0.302 to an MSE of 0.013 over the adaptation range of operation. This research focused on the theory, development, and testing of the ANPM and the corresponding elements in the surveillance system
Benelux meeting on systems and control, 23rd, March 17-19, 2004, Helvoirt, The Netherlands
Book of abstract
Intelligent Sensors for Human Motion Analysis
The book, "Intelligent Sensors for Human Motion Analysis," contains 17 articles published in the Special Issue of the Sensors journal. These articles deal with many aspects related to the analysis of human movement. New techniques and methods for pose estimation, gait recognition, and fall detection have been proposed and verified. Some of them will trigger further research, and some may become the backbone of commercial systems
Investigation of wireless power transfer-based eddy current non-destructive testing and evaluation
PhD ThesisEddy current testing (ECT) is a non-contact inspection widely used as non-destructive
testing and evaluation (NDT&E) of pipeline and rail lines due to its high sensitivity to surface
and subsurface defects, cheap operating cost, tolerance to harsh environments, and capability
of a customisable probe for complex geometric surfaces. However, the remote field of
transmitter-receiver (Tx-Rx) ECT depends on the Tx-Rx coils gap, orientation, and lift-off
distance, despite each coil responding to the effect of sample parameters according to its liftoff distance. They bring challenges to accurate defect detection and characterisation by
weakening the ECT probe’s transfer response, affecting sensitivity to the defect, distorting the
amplitude of the extracted features, and responding with fewer feature points at non-efficient
energy transfer. Therefore, this study proposed a magnetically-coupled resonant wireless power
transfer (WPT)-based ECT (WPTECT) concept to build the relationship between Tx-Rx coil at
maximum energy transfer response, including shifting and splitting (resonance) frequency
behaviour.
The proposed WPTECT system was investigated in three different studies viz., (1)
investigated the multiple resonance point features for detection and characterisation of slots on
two different aluminium samples using a series-series (SS) topology of WPTECT; (2) mapped
and scanned pipeline with a natural dent defect using a flexible printed coil (FPC) array probe
based on the parallel-parallel (PP) topology of WPTECT; and (3) evaluated five different
WPTECT topologies for optimal response and extracted features and characterised entire
parameters of inclined angular Rolling Contact Fatigue (RCF) cracks in a rail-line material via
an optimised topology. Multiple feature extraction, selection, and fusion were evaluated for the
defect profile and compared in the study, unattainable by other ECT methods.
The first study's contribution investigated multiple resonances and principal component
analysis (PCA) features of the transfer response from scanning (eight) slots on two aluminium
samples. The results have shown the potential of the multiple features for slot depth and width
characterisation and demonstrated that the eddy-current density is highest at two points
proportionate to the slot width. The second study's contribution provided a larger area scanning
capability in a single probe amenable to complex geometrical structures like curvature surfaces.
Among the extracted individual and fused features for defect reconstruction, the multi-layer
feed-forward Deep learning-based multiple feature fusion has better 3D defect reconstruction,
whilst the second resonances feature provided better local information than the first one for
investigating pipeline dent area. The third study's contribution optimised WPTECT topology
for multiple feature points capability and its optimal features extraction at the desired lift-off
conditions. The PP and combined PP and SS (PS-PS) WPTECT topologies responded with
multiple resonances compared to the other three topologies, with single resonance, under the
same experimental situation. However, the extracted features from PS-PS topology provided
the lowest sensitivity to lift-off distances and reconstructed depth, width, and inclined angle of
RCF cracks with a maximum correlation, R2
-value of 96.4%, 93.1%, and 79.1%, respectively,
and root-mean-square-error of 0.05mm, 0.08mm, and 6.60
, respectively.
The demonstrated magnetically-coupled resonant WPTECT Tx-Rx probe characterised
defects in oil and gas pipelines and rail lines through multiple features for multiple parameters
information. Further work can investigate the phase of the transfer response as expected to offer
robust features for material characterisation. The WPTECT system can be miniaturised using
WPT IC chips as portable systems to characterise multiple layers parameters. It can further
evaluate the thickness and gap between two concentric conductive tubes; pressure tube
encircled by calandria tube in nuclear reactor fuel channels.PTDF Nigeri