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Empirical study on effect of surface texture and grain size on displacement measurement of optical flow sensors
, Article 2014 2nd RSI/ISM International Conference on Robotics and Mechatronics, ICRoM 2014 ; Oct , 2014 , p. 493-497 ; ISBN: 9781479967438 ; Vossoughi, G ; Sharif University of Technology
Abstract
Although, the optical flow sensors which are used in optical mouse have high resolution in measuring displacement, their error refrain us from a precise and reliable measurement. Besides, these sensors require calibration based on the surface. Their error has different sources and the most important is surface texture in micro level. In this research, we have worked to find surface conditions on which sensor measurement is more precise. For this aim, we used an 800 DPI low cost optical flow sensor. For making different surface textures and grains, we printed different textures with 600 and 1200DPI resolution on white paper with certain length. Then we used optical flow sensor for measuring...
Robustness enhancement of optical flow sensors accuracy to surface texture variations using point tracking algorithm
, Article 5th RSI International Conference on Robotics and Mechatronics, IcRoM 2017, 25 October 2017 through 27 October 2017 ; 2018 , Pages 406-410 ; 9781538657034 (ISBN) ; Vossoughi, G ; Sharif University of Technology
Abstract
Novel architecture of high precision localization using optical flow sensor (OFS) combined with Iterative Point Tracking Algorithm (IPTA) is proposed. This work focuses on attenuation of OFS' sensitivity dependency on texture of surface over which sensor is moving. The aim for the design of experimental setup is to verify how much a robustness of OFS's sensitivity on various surfaces improves. In this regard, four different surfaces' texture including iron, paper, textile and granite stone is opted. Experimental results indicate that sensor's resolution via IPTA on surfaces of iron, paper, textile and granite stone respectively equal to 382, 460, 528 and 448 CPI. Optimal value of the...
Combined Optical flow Algorithm and Simultaneous Localization and Mapping for Localization Robust to Surface Texture Variations
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Gholamreza (Supervisor) ; Moradi, Hamed (Supervisor)
Abstract
The research field of localization with high precision (precision of 10 micrometers) has greatly attracted attentions in recent years. Optical flow sensor is one of the inexpensive solutions for the localization of robot, which have been used in computer mice. The most important application of this thesis is to localize walking micro robot. The main challenge of previous research is the fact that sensor's precision is highly dependent on the surface texture. The aim of this research is to implement an appropriate algorithm on optical flow sensor in order to increase the robustness of sensor's precision to surface texture. In this regard, firstly experimental hardware has been designed and...
Laser textured novel patterns on Ti6Al4V alloy for dental implants surface improvement
, Article Journal of Laser Applications ; Volume 33, Issue 4 , 2021 ; 1042346X (ISSN) ; Sadrnezhaad, S. K ; Shoja Razavi, R ; Nourbakhsh, A. A ; Hassanzadeh Nemati, N ; Sharif University of Technology
Laser Institute of America
2021
Abstract
Creating laser texture on dental implants is a novel method for accelerating osseointegration and prolongation of lifespan. The purpose of this research was twofold: (1) Creating intersecting lines pattern with different angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°) on the surface of Ti6Al4V, using pulse Nd:YAG laser with a wavelength of 1064 nm and a pulse length of 170 ns and (2) comparing optical and SEM images, EDS analyses, contact angles (CAs), and surface free energies (FEs) for different intersecting lines angles. CA and FE depended on the intersecting lines angle according to Y = Y 0 + A sin (x B + C), where Y is the CA or FE; x is the intersecting lines angle; and Y0, A, B, and C...