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Total 52 records
Particle filter-based object tracking using adaptive histogram
, Article 2011 7th Iranian Conference on Machine Vision and Image Processing, MVIP 2011 - Proceedings ; 2011 ; 9781457715358 (ISBN) ; Gholami, A. R ; Kasaei, S ; Sharif University of Technology
Abstract
Object tracking is a difficult and primary task in many video processing applications. Because of the diversity of various video processing tasks, there exists no optimum method that can perform properly for all applications. Histogram-based particle filtering is one of the most successfu1 object tracking methods. However, for dealing with visual tracking in real world conditions (such as changes in illumination and pose) is still a challenging task. In this paper, we have proposed a color-based adaptive histogram particle filtering method that can update the target model. We have used the Bhattacharyya coefficients to measure the likelihood between two color histograms. Our experimental...
Mobile-target tracking via highly-maneuverable VTOL UAVs with EO vision
, Article Proceedings - 2016 13th Conference on Computer and Robot Vision, CRV 2016, 1 June 2016 through 3 June 2016 ; 2016 , Pages 260-265 ; 9781509024919 (ISBN) ; Samsami, K ; Mehrandezh, M ; Ramirez Serrano, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
Design of a vision-based target tracking control strategy for a dual-rotor UAV with tilting rotors is presented. In this research, the under-study UAV is equipped with a sliding mass that can slide over a motorized linear track attached to the UAV's fuselage enabling it to perform sophisticated maneuvers by monitoring its five controllable degrees of freedom. The dynamic model of the system is first derived and then a model-based controller using vision based pose estimation, obtained via an onboard down-looking camera, is designed enabling the UAV to: (1) pitch hover in position, (2) servo towards a target position, and (3) track a moving target. Simulations show the premise of the proposed...
Micro-optoelectromechanical systems accelerometer based on intensity modulation using a one-dimensional photonic crystal
, Article Applied Optics ; Volume 55, Issue 32 , 2016 , Pages 8993-8999 ; 1559128X (ISSN) ; Abedi, K ; Jafari, K ; Gholamzadeh, R ; Sharif University of Technology
OSA - The Optical Society
Abstract
In this paper, we propose what we believe is a novel sensitive micro-optoelectromechanical systems (MOEMS) accelerometer based on intensity modulation by using a one-dimensional photonic crystal. The optical sensing system of the proposed structure includes an air-dielectric multilayer photonic bandgap material, a laser diode (LD) light source, a typical photodiode (1550 nm) and a set of integrated optical waveguides. The proposed sensor provides several advantages, such as a relatively wide measurement range, good linearity in the whole measurement range, integration capability, negligible cross-axis sensitivity, high reliability, and low air-damping coefficient, which results in a wider...
Compressive sensing for elliptic localization in MIMO radars
, Article 24th Iranian Conference on Electrical Engineering, 10 May 2016 through 12 May 2016 ; 2016 , Pages 525-528 ; 9781467387897 (ISBN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
In this paper, a sparsity-aware target localization method in multiple-input-multiple-output (MIMO) radars by utilizing time difference of arrival (TDOA) measurements is proposed. This method provides a maximum likelihood (ML) estimator for target position by employing compressive sensing techniques. Also, for fast convergence and mitigating the mismatch problem due to grid discretization, we address a block-based search coupled with an adaptive dictionary learning technique. The Cramer-Rao lower bound for this model is derived as a benchmark. Simulations results are included to verify the localization performance
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...
Control tuning of a اeart motion tracking system in off-pump heart surgery
, Article 5th RSI International Conference on Robotics and Mechatronics, IcRoM 2017, 25 October 2017 through 27 October 2017 ; 2018 , Pages 445-450 ; 9781538657034 (ISBN) ; Behzadipour, S ; Sharif University of Technology
Abstract
Design, implementation and experimental evaluation of a classic PID, and a modern Generalized Predictive Control (GPC) for an off-pump heart tracking system were carried out. Following the design and simulation analysis of the controllers, experimental evaluation was conducted on the slave robot of SINA tele-operational surgical system. Results revealed that considering the volatile high-frequency/speed pattern of heart motion, the agility of the controlled system is the most influential factor on its performance. With this in mind, unlike the Ziegler-Nichols-based tuned PID with emphasis on steady-state condition, the PID control with more transient behavior showed a superior performance....
Positioning of geostationary satellite by Radio Interferometry
, Article IEEE Transactions on Aerospace and Electronic Systems ; 2018 ; 00189251 (ISSN) ; Behnia, F ; Haghshenas, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
There are several perturbations that force the satellite orbit to deviate from the elliptical form. To cope with these perturbations, station keeping is applied. For accurate station keeping, determination of the true satellite orbit is necessary. Radio interferometry is one of the techniques used for determining azimuth and elevation look angles of a satellite. In this paper we introduce three structures based on interferometry for determining the view angles of satellites .The estimated angles are combined with range measurement for orbital positioning of geostationary (GEO) satellites. In the proposed interferometry structures, to acquire the required angular accuracy, the distance...
Control tuning of a اeart motion tracking system in off-pump heart surgery
, Article 5th RSI International Conference on Robotics and Mechatronics, IcRoM 2017, 25 October 2017 through 27 October 2017 ; 2018 , Pages 445-450 ; 9781538657034 (ISBN) ; Behzadipour, S ; Sharif University of Technology
Elsevier
2018
Abstract
Design, implementation and experimental evaluation of a classic PID, and a modern Generalized Predictive Control (GPC) for an off-pump heart tracking system were carried out. Following the design and simulation analysis of the controllers, experimental evaluation was conducted on the slave robot of SINA tele-operational surgical system. Results revealed that considering the volatile high-frequency/speed pattern of heart motion, the agility of the controlled system is the most influential factor on its performance. With this in mind, unlike the Ziegler-Nichols-based tuned PID with emphasis on steady-state condition, the PID control with more transient behavior showed a superior performance....
Positioning and tracking control of an amphibious single wheel robot
, Article 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE 2008, Boston, MA, 31 October 2008 through 6 November 2008 ; Volume 11 , 2009 , Pages 545-551 ; 9780791848722 (ISBN) ; Alizadeh, D ; Sharif University of Technology
2009
Abstract
Amphibious single wheel robot consists of a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The spinning flywheel acts as a gyroscope to stabilize the robot and also can be tilted to achieve steering. In this paper, the kinematics of a single wheel robot in water, Gyrover, is analyzed and then a simple mechanism for driving it is proposed. In previous studies, Lagrange approach is used for hydrodynamic modeling of the robot. A nonlinear position controller is designed to bring the robot to any desired position. Based on the designed controller, a tracking controller is augmented to the robot. For simplicity the added mass effect has been...
On-line orbit and albedo estimation using a strong tracking algorithm via satellite surface temperature data
, Article IEEE Transactions on Aerospace and Electronic Systems ; 9 December , 2020 ; Kiani, M ; Pourtakdoust, S. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
The Earth albedo factor (EAF) is a major required parameter for the thermal analysis of low Earth orbit (LEO) satellites. Satellites receive variable albedo radiation as they orbit around the Earth that is heavily dependent on the Earth's local terrain as well as the instantaneous cloud coverage. However, for satellite thermal balancing and control analysis, a constant mean EAF is usually taken based on the orbital parameters that could potentially introduce erroneous results. Recent advances in temperature-based orbit estimation (TBOE) algorithms have revealed a significant sensitivity concerning EAF giving rise to the idea of its on-line estimation for added accuracy. In this sense, a...
Object modeling for multicamera correspondence using fuzzy region color adjacency graphs
, Article 13th International Computer Society of Iran Computer Conference on Advances in Computer Science and Engineering, CSICC 2008, Kish Island, 9 March 2008 through 11 March 2008 ; Volume 6 CCIS , 2008 , Pages 637-644 ; 18650929 (ISSN); 3540899847 (ISBN); 9783540899846 (ISBN) ; Kasaei, S ; Sharif University of Technology
2008
Abstract
In this paper, a novel moving object modeling suitable for multicamera correspondence is introduced. Taking into consideration the color and motion features of foreground objects in each independent video stream, our method segments the existing moving objects and constructs a graph-based structure to maintain the relational information of each segment. Using such graph structures reduces our correspondence problem to a subgraph optimal isomorphism problem. The proposed method is robust against various resolutions and orientations of objects at each view. Our system uses the fuzzy logic to employ a human-like color perception in its decision making stage in order to handle color inconstancy...
Adaptive fuzzy Jacobian control of spacecraft combined attitude and Sun tracking system
, Article Aircraft Engineering and Aerospace Technology ; Volume 93, Issue 1 , 2021 , Pages 1-14 ; 17488842 (ISSN) ; Varatharajoo, R ; Assadian, N ; Sharif University of Technology
Emerald Group Holdings Ltd
2021
Abstract
Purpose: The paper aims to address the combined attitude control and Sun tracking problem in a flexible spacecraft in the presence of external and internal disturbances. The attitude stabilization of a flexible satellite is generally a challenging control problem, because of the facts that satellite kinematic and dynamic equations are inherently nonlinear, the rigid–flexible coupling dynamical effect, as well as the uncertainty that arises from the effect of actuator anomalies. Design/methodology/approach: To deal with these issues in the combined attitude and Sun tracking system, a novel control scheme is proposed based on the adaptive fuzzy Jacobian approach. The augmented spacecraft model...