Rahman Yousefi Moghaddam
Education:
·
PhD Candidate, Mechanical
Engineering, University of
·
PhD Candidate, Mechanical
Engineering,
·
MSc, Mechanical Engineering,
·
BSc, Mechanical Engineering,
Selected Publication:
·
Yousefi Moghaddam R. and Lipsett Michael G.,
Developing a Shovel Test Rig for Fault Diagnosis Studies of Time-varying
Systems, to be Submitted to Journal of MSSP
·
Yousefi Moghaddam R. and Lipsett Michael G., Design,
Commissioning & Modeling of A Shovel Test Rig For Fault Diagnosis Of A
Time-Varying System, 8 pages, CSME 2010
·
Yousefi Moghaddam R. and Lipsett Michael G.,
Modeling, Simulation & Fault Detection in Excavators with Time-Varying
Loading, 6 pages, IEEE/ASME AIM 2010
·
Yousefi Moghaddam R. and Lipsett Michael G.,
Reliability Assessment and Condition Monitoring of a Shovel Test bed, 8
pages, 3rd World Congress on
Engineering Asset Management (WCEAM-IMS),
·
Yousefi Moghaddam R. and Lipsett Michael G., Dynamic
Effects of Ground Looseness on Hydraulic Shovel Performance,8th
International Workshop on Bifurcations and Degradations in Geomaterials
(IWBDG), Lake Louise, Canada, May 2008
Project Title: Design,
Commissioning & Modeling of A Shovel Test Rig for Fault Diagnosis of A
Time-Varying System
Motivation: The time-varying
nature of the soil-tool interaction forces, causes stresses in machine
components and may result in damage. Avoiding fault propagation in the system
depends on identifying and isolating the faulty component in the early stages
of failure, which requires close observations of the tool-ground interaction
period.
Objectives: Assuming that a
fault does not occur instantaneously, there would be a degradation process that
shifts the state of the system from normal to abnormal over a period of time,
and this variation is identifiable in most cases using fault detection
techniques. Having a proper test rig, we would like to investigate the
application of FDI techniques on the performance of the system.
Solution
methodology: A variant of crank-slider mechanism is equipped with a thin plate
mounted on the slider to fragment the soil. The whole system is modeled as a
rigid-body, lumped-parameter, dynamical system. The Coulomb-Mohr earth pressure
model used to represent the soil-tool interaction. The rig is equipped with
sensors that acquire data from different machine parts to monitor the process
as well as machine condition. Residual signals need to be defined based on the
difference between the actual readings and the predictions.
Progress to date: Cutting force
prediction and soil parameter estimation achieved by digging through a certain
medium at various depths of penetration and blade angles. Processing the
acquired signals, fault signatures are successfully identified for certain
types of fault in the rig components, without any prior knowledge of the fault
type or position. Next steps are: Design of experiments, Detailed soil
parameter estimation, Model validation, Model-based FDI, and finally study the
application of fault tolerant control on the system and its effect on the reliability
of the system.
Limitations: A failure modes
and effects analysis (FMEA), might be required in advance. Compared to
signal-based approaches, an accurate model of the system is necessary for any
model-based fault detection technique, which is not always available through
the conventional methods. Additionally, If the system behaves nonlinearly,
linearization is also required. Simplifications in the model might affect the
accuracy of the study.
Expected completion date: December 2011
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