Hossam Khalil | Gwangju Institute of Science and Technology (original) (raw)

Papers by Hossam Khalil

The Review of scientific instruments, 2017

An optical component called a Dove prism is used to rotate the laser beam of a laser-scanning vib... more An optical component called a Dove prism is used to rotate the laser beam of a laser-scanning vibrometer (LSV). This is called a derotator and is used for measuring the vibration of rotating objects. The main advantage of a derotator is that it works independently from an LSV. However, this device requires very specific alignment, in which the axis of the Dove prism must coincide with the rotational axis of the object. If the derotator is misaligned with the rotating object, the results of the vibration measurement are imprecise, owing to the alteration of the laser beam on the surface of the rotating object. In this study, a method is proposed for aligning a derotator with a rotating object through an image-processing algorithm that obtains the trajectory of a landmark attached to the object. After the trajectory of the landmark is mathematically modeled, the amount of derotator misalignment with respect to the object is calculated. The accuracy of the proposed method for aligning ...

2015 IEEE International Conference on Electronics, Circuits, and Systems (ICECS), 2015

A method for tracking laser Doppler vibrometer (TLDV) is introduced for operational deflection sh... more A method for tracking laser Doppler vibrometer (TLDV) is introduced for operational deflection shape (ODS) vibration measurement of a rotating object to take the advantage of tracking while an encoder is attached to the object. A digital signal processor (DSP) is used to capture the encoder angular position and calculating the signals required for Galvano motors. To verify the performance of the proposed method, comparison with the traditional method is carried out. Finally, the experimental results of ODS vibration measurements of the object without and with rotation are validated and compared to each other to see the effect of rotation on the measured ODS.

Measurement, 2016

The in-plane and out-of-plane vibration components are used for 3D vibration measurements. The la... more The in-plane and out-of-plane vibration components are used for 3D vibration measurements. The latter can be calculated by using three laser scanning vibrometers (LSVs) or by moving a single LSV to three different locations. These vibration components are calculated from the vibration signals measured at each of the three locations and the angles between the local coordinates and the LSV locations. The accuracy of the in-plane and out-of-plane vibration components can be degraded depending on the measurement angle. In addition to accuracy, the noise contained in the LSV can be amplified depending on the measurement angle. Hence, it is necessary to implement an analysis methodology for the angles, which is conducted for 2D vibration measurements first before extended to 3D. Finally, experiments are performed for both 2D and 3D at small and appropriate angles, and the elicited results are compared to those elicited using a 3D accelerometer.

AIP Conference Proceedings, 2016

An image-based tracking system using laser scanning vibrometer is developed for vibration measure... more An image-based tracking system using laser scanning vibrometer is developed for vibration measurement of a rotating object. The proposed system unlike a conventional one can be used where the position or velocity sensor such as an encoder cannot be attached to an object. An image processing algorithm is introduced to detect a landmark and laser beam based on their colors. Then, through using feedback control system, the laser beam can track a rotating object.

International Journal of Precision Engineering and Manufacturing, 2015

An image-based tracking system using a laser scanning vibrometer is developed for vibration measu... more An image-based tracking system using a laser scanning vibrometer is developed for vibration measurement of a rotating object in order to take advantage of rotation tracking without attaching an external sensor such as an encoder to the object. An image processing algorithm is used to detect a landmark and laser beam and track all vibration measuring points on a rotating object. To verify the performance of the proposed tracking system, processing time analysis of the image processing algorithm is carried out. The accuracy of the tracking system is also experimentally tested. Finally, the experimental results of modal analysis of the object without and with rotation are compared and the vibration measurement of the object is validated.

SPIE Proceedings, 2015

A modified algorithm for tracking laser Doppler vibrometer (TLDV) is introduced to measure the vi... more A modified algorithm for tracking laser Doppler vibrometer (TLDV) is introduced to measure the vibration of rotating objects. The proposed algorithm unlike the old algorithm for TLDV can be used when the speed of the object to be tracked varies continuously or alternating in a small range. The proposed algorithm is to use encoder only as a position sensor. The position from the encoder is used to calculate the driving signals to the galvanometers. To verify the proposed method, experimental modal analysis of the circular plate in stationary and rotating cases are made.

IEEE Transactions on Instrumentation and Measurement, 2014

The performance of a model-based control system depends strongly on the accuracy of the process m... more The performance of a model-based control system depends strongly on the accuracy of the process model used. LS-SVM is a powerful method for modeling nonlinear systems. The main objective of this paper is to implement a conventional controller based on LS-SVM model for hydraulic motor. An off-line model is first identified based on LS-SVM, then via simulation tests the parameters of the discrete PI-Controller and its velocity-form are obtained then the controller parameters are applied experimentally for the hydraulic motor as a speed controller. The system performance has been evaluated; results show good performance over a wide range of operating conditions and load disturbances.

Expert Systems with Applications, 2011