Charu Pathak
@mru.edu.in
Professor Department of ECE
Manav Rachna University
RESEARCH INTERESTS
Digital image processing, acoustic signal processing, wavelets
FUTURE PROJECTS
EEG artifacts removal
Applications Invited
researchers/ students
Automated tool positioning system for CNC machines
Applications Invited
students/ researchers
Scopus Publications
Scholar Citations
Scholar h-index
Scopus Publications
Anuranjan Kansal, Varun Saxena, and Charu Pathak
Institute of Electrical and Electronics Engineers (IEEE)
Dynamics inside a dual-frequency Paul trap is theoretically analyzed in the presence of excess micromotion on account of stray electric field and the field due to a mismatch of potential at the electrodes. The fields contributing to the excess micromotion have a strong influence on the kinetic energy of a single-charged particle, however, their influence is not profound when the collective dynamics of many charged particles is considered inside the trap. The collective dynamics is encapsulated by a distribution function whose time average is double-humped with respect to the velocity. The spatial variation of energy is asymmetrical. The temporal fluctuations of the energy are periodic with a period of variation depending upon the ratio of the two applied RF frequencies.
Shweta Kumari, Charu Pathak, Shruti Vashist, and Prasant Kumar Mahapatra
IEEE
This paper presents a study on the importance of correct lathe tool positioning in various applications, including mechanical, medical, and manufacturing fields. The objective of this study is to analyze tool position error and the distance travelled by the tool when the work piece is stationary, with the aim of reducing positional inaccuracy of the lathe tool. Accurate positioning is critical in applications that require precision in the micrometer range. To achieve this, various image segmentation techniques such as Graythresh, Multithresh, and Adaptthresh have been applied and evaluated for estimating the actual tool position and error in tool movement distance. Results show that Multithresh provides the least mean absolute deviation of error and the least variance of error, making it the most accurate technique for determining the tool position at the micrometer scale, compared to Graythresh and Adaptthresh.
Shweta Kumari, Charu Pathak, Shruti Vashist, and Prasant Kumar Mahapatra
IEEE
Accurate positioning of tool in mechanical devices used in smart manufacturing, mechanical automation is of utmost importance. In applications like manufacturing of micro parts, an accuracy of micrometer is required. Thus, it is proposed to opt for an economic fast and accurate tool positioning system which may directly work on the images of the tool taken by a high-resolution camera. This work contributes to estimate the position of a lathe tool using image processing. The tool is considered to move in x-y plane. The movement of the tool is calculated from its origin using Euclidean distance. The coordinates of the vertices of the tool are detected using Edge detection technique. These coordinates are used to estimate the distance travelled by the tool from the origin. Prewitt and Sobel operators are applied for edge estimation and the errors obtained in both Prewitt and Sobel are compared. As a result of experimental analysis Sobel operator is found to give better results. The maximum error obtained is 272.2 µm and the minimum error obtained is 0.1 µm.
Anuranjan Kansal, Varun Saxena, and Charu Pathak
Institute of Electrical and Electronics Engineers (IEEE)
The article investigates the influence of electric field imperfections that manifest themselves as hexapole and octopole aberrations in a dual frequency planar Paul trap. The characteristics of the charged particle motion are analyzed by formulating equation of motion in a pseudo-potential well wherein the hexapole and octopole field effects get superimposed to yield a Duffing type of an equation. Perturbation and harmonic balance methods are applied to estimate the axial frequency shifts and the displacement of the charged particle from the axis of the trap. The axial frequency is dependent upon whereas the displacement of the charged particle from the center of the axis is independent of the variation in voltage and frequency ratio applied to the Paul trap.
Anuranjan Kansal, Charu Pathak, and Varun Saxena
IEEE
This paper provides a theoretical analysis of excess micro-motion on account of stray electric field and phase mismatch in a radio frequency dual frequency Paul trap. The time averaged velocity points out to a considerable rise in temperature for the single particle dynamics. The temperature increase is significantly larger when compared to the increase in a conventional single frequency Paul trap in presence of excess micro-motion. The contribution of the stray electric field is several orders in magnitude higher than that of the electric field due to phase mismatch.
Anuranjan Kansal, Charu Pathak, and Varun Saxena
IEEE
The dynamics of charged particles inside a Paul trap is a superposition of a slow secular motion and a fast micro-motion. The conventional methods, such as harmonic balance, approximate the particle trajectory with harmonic terms of the same order contributing equally to the motion. However, a careful analysis will show that in the analytically approximate solution, the harmonic terms have an unequal amplitude contribution to the particle dynamics given a set of operating conditions. In this paper we apply the modified Lindstedt Poincare method to highlight these unequal contributions. The harmonic terms surely become a significant factor in affecting the dynamics and hence in various applications inside Paul traps.