Browsing NTNU Open by Author "Aftab, Muhammad Faisal"
Now showing items 1-11 of 11
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A Delay Vector Variance based Approach for Detecting and Isolating the Non-linearity Induced Oscillations in Control Loops
Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Journal article, 2017)Non-linear time series analysis based methods are a popular choice for industrial control loop data analysis. In this paper a delay vector variance (DVV) based approach is presented to analyze the source of oscillations ... -
An Adaptive Non-Linearity Detection Algorithm for Process Control Loops
Aftab, Muhammad Faisal; Hovd, Morten; Huang, Norden E; Sivalingam, Selvanathan (Journal article; Peer reviewed, 2016) -
Adaptive Nonlinear Control of the Czochralski Process Via Integration of Second Order Sliding Mode and Iterative Learning Control
Bukhari, Halima Zahra; Aftab, Muhammad Faisal; Hovd, Morten; Winkler, Jan (Chapter, 2017)This paper utilises nonlinear second-order sliding mode (SOSM) combined with an iterative learning control (ILC) scheme for the control of interface dynamics primarily focused on diameter control in the Czochralski (CZ) ... -
Analysis of Iceberg Drift Trajectories Using the Multivariate Empirical Mode Decomposition
Andersson, Leif Erik; Scibilia, Francesco; Copland, Luke; Aftab, Muhammad Faisal; Imsland, Lars Struen (Journal article; Peer reviewed, 2018)In this study we show how to detect and extract the tidal and inertial oscillation from iceberg velocity data by using the multivariate empirical model decomposition. Due to the similar frequencies of both oscillations in ... -
Controller Performance Monitoring: Detection and Diagnosis of Oscillations in Control Loops
Aftab, Muhammad Faisal (Doctoral theses at NTNU;2018:187, Doctoral thesis, 2018)The profitability of any industrial process is closely related to its ability to maintain near optimal operating conditions; therefore robust methods for root cause detection of any control performance degradation is crucial ... -
Convergent cross mapping (CCM) based approach for isolating the source of plant-wide disturbances
Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Chapter, 2017)Disturbances originating in one control loop of a large industrial plant can propagate far from the source, giving rise to plant-wide oscillations. The underlying interactions among the different control loops make it hard ... -
Data Driven Filtering of Bowel Sounds Using Multivariate Empirical Mode Decomposition
Kölle, Konstanze; Aftab, Muhammad Faisal; Andersson, Leif Erik; Fougner, Anders Lyngvi; Stavdahl, Øyvind (Journal article; Peer reviewed, 2019)Background The analysis of abdominal sounds can help to diagnose gastro-intestinal diseases. Sounds originating from the stomach and the intestine, the so-called bowel sounds, occur in various forms. They are described ... -
Design of parallel compensator and stabilizing controller to mitigate non-minimum phase behaviour of the Czochralski process
Bukhari, Syeda Halima Zahra; Hovd, Morten; Aftab, Muhammad Faisal; Winkler, Jan (Peer reviewed; Journal article, 2020)This paper addresses the design of a parallel compensator and a stabilizing controller for the simplified crystal growth dynamics of the Czochralski (CZ) process, i.e., the process for the production of monocrystalline ... -
Detecting non-linearity induced oscillations via the dyadic filter bank property of multivariate empirical mode decomposition
Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Journal article, 2017)Non-linearity induced oscillations in control loops are characterized by the presence of higher order harmonics. In this paper the dyadic filter bank property of the multivariate empirical mode decomposition (MEMD) is ... -
Improved oscillation detection via noise-assisted data analysis
Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Journal article; Peer reviewed, 2018)Oscillation detection is usually a precursor to more advanced performance monitoring steps such as plant wide oscillation detection and root cause detection. Therefore any false or missed detection can have serious ... -
Plant-wide oscillation detection using multivariate empirical mode decomposition
Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Journal article; Peer reviewed, 2018)Plant-wide oscillation detection is an important task in the maintenance of large-scale industrial control systems, owing to the fact that in an interactive multi-loop environment oscillation generated in one loop may ...