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    How to synchronize and register an optical-inertial tracking system

    , Article Applied Mechanics and Materials ; Volume 332 , 2013 , Pages 130-136 ; 16609336 (ISSN) ; 9783037857335 (ISBN) Soroush, A ; Akbar, M ; Farahmand, F ; Sharif University of Technology
    2013
    Abstract
    Multi-sensor tracking is widely used for augmentation of tracking accuracy using data fusion. A basic requirement for such applications is the real time temporal synchronization and spatial registration of two sensory data. In this study a new method for time and space coordination of two tracking sensor measurements has been presented. For spatial registration we used a body coordinate system and then applied the effect of the level arm. The time synchronization was done based on least mean square (LMS) error method. This method was implemented to synchronize the position and orientation of an object using Inertial (1IMU) and Optical (Optotrak) tracking systems. The results of synchronized... 

    Design and implementation of an improved real-time tracking system for navigation surgery by fusion of optical and inertial tracking methods

    , Article Applied Mechanics and Materials ; Volume 186 , 2012 , Pages 273-279 ; 16609336 (ISSN) ; 9783037854440 (ISBN) Soroush, A ; Farahmand, F ; Salarieh, H ; Sharif University of Technology
    2012
    Abstract
    The fusion of the optical and inertial tracking systems seems an attractive solution to solve the shadowing problem of the optical tracking systems, and remove the time integration troubles of the inertial sensors. We developed a fusion algorithm for this purpose, based on the Kalman filter, and examined its efficacy to improve the position and orientation data, obtained by each individual system. Experimental results indicated that the proposed fusion algorithm could effectively estimate the 2 seconds missing data of the optical tracker  

    Orbit Determination of Satellite in LEO Using Satellite Transmitted Signals

    , M.Sc. Thesis Sharif University of Technology Roghanizad, Ebrahim (Author) ; Pourtakdoust, Hossein (Supervisor)
    Abstract
    One of the most important pillars of independence in the space programs of any country is to have the capability of tracking and orbit determination of its own satellites. Hence, in this project, based on the practical approach, a radio-tracking system has been designed domestically for Iran. In this one-way radio-tracking system, the pseudo-noise code, which in fact has the role of spreading frequency spectrum in the satellite digital communications, is employed as the periodic ranging signal. Furthermore, the Doppler effect on the carrier-wave frequency provides the range rate of the satellite. Thus, it has been shown that from the satellite waves, which are emitted omnidirectionally for... 

    Dynamic based cost functions for TF/TA flights

    , Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 48, Issue 1 , 2012 , Pages 44-63 ; 00189251 (ISSN) Malaek, S. M ; Kosari, A. R ; Sharif University of Technology
    Abstract
    In this work we present a systematic approach to incorporating the dynamic capabilities of an aircraft via suitable cost functions while planning for terrain following-terrain avoidance trajectories. We further show that use of nondimensional parameters related to the dynamics of an aircraft within the cost function provides a better understanding of how they could affect the resulting trajectories. Different case studies for arbitrary three-dimensional flights show that the current approach provides more realistic trajectories and so helps alleviate the design process of relevant controllers as well as tracking systems over the desired terrain. We further introduce two new parameters of... 

    A Hough based data association algorithm for target tracking

    , Article International Radar Symposium, IRS 2011 - Proceedings, 7 September 2011 through 9 September 2011 ; September , 2011 , Pages 623-628 ; 9783927535282 (ISBN) Mahdavi, A ; Moqiseh, A ; Nayebi, M. M ; Sharif University of Technology
    2011
    Abstract
    A new approach for tracking targets in TWS systems is introduced which is based on Hough transform. The main idea is to take target's velocity and course of motion as the main tracking quantities and calculate other kinematic parameters of the target from these two main parameters. The main criteria for associating targets to tracks in Data Association (DA) step is co linearity of targets with the history of track and Hough transform is the main tool in this step. Computer simulation results are presented to compare the performance of the suggested algorithm with the conventional tracking systems  

    A new haptic interaction with a visual tracker: implementation and stability analysis

    , Article International Journal of Intelligent Robotics and Applications ; Volume 5, Issue 1 , 2021 , Pages 37-48 ; 23665971 (ISSN) Mashayekhi, A ; Nahvi, A ; Meghdari, A ; Mohtasham Shad, H ; Sharif University of Technology
    Springer  2021
    Abstract
    In this paper, a new haptic interaction is presented where the operator is in contact with the haptic device (HD) only when she/he is in contact with the virtual environment (VE). This is in contrast with traditional haptic systems, where the operator is always in contact with the HD, even if she/he is out of the VE. In this haptic interaction, a visual tracking system is used to track the operator’s finger. When the finger is out of the VE, the HD tracks the finger so that the stylus of the HD keeps a constant distance of about 2 cm from the finger. When the finger gets close to the VE, the stylus slows down and stops upon reaching the VE; it then waits until the operator touches the stylus... 

    A receding horizon control of a cooperative multi target tracking system

    , Article Proceedings of 2011 2nd International Conference on Instrumentation Control and Automation, ICA 2011 ; 2011 , Pages 109-112 ; 9781457714603 (ISBN) Pari, E. M ; Haeri, M ; Sharif University of Technology
    Abstract
    In this paper the problem of cooperative tracking of multiple targets for multi-agent systems is investigated. Defining problem of target tracking as gathering maximum rewards associated with the targets, an optimization-based algorithm is presented. A cooperative receding horizon controller for reaching moving targets is proposed. Agents are controlled by adjusting their headings toward the moving targets. A notable advantage of the proposed approach is the estimations of target's motion and planning the agent's heading based on them. Simulation results are provided to verify the efficiency of the proposed method  

    A novel vehicle tracking method with occlusion handling using longest common substring of chain-codes

    , Article 2009 14th International CSI Computer Conference, CSICC 2009, Tehran, 20 October 2009 through 21 October 2009 ; 2009 , Pages 176-181 ; 9781424442621 (ISBN) Shabani Nia, E. S ; Kasaei, S ; Sharif University of Technology
    Abstract
    Vehicle tracking is an essential requirement of any vision based Intelligent Transportation System for extracting different traffic parameters, efficiently. Handling inter-object occlusion is the most challenging part of tracking as a process of finding and following interested objects in a sequence of video frames. In this paper we present a system, based on code-book background model for motion segmentation and Kalman filter for tracking with a new approach for occlusion. This approach separates occluded vehicles based on longest common substring of chain codes. We use this tracking system to estimate some traffic parameters. Experimental results show the efficiency of the method. ©2009... 

    Human arm motion tracking by inertial/magnetic sensors using unscented Kalman filter and relative motion constraint

    , Article Journal of Intelligent and Robotic Systems: Theory and Applications ; Volume 90, Issue 1-2 , May , 2018 , Pages 161-170 ; 09210296 (ISSN) Atrsaei, A ; Salarieh, H ; Alasty, A ; Abediny, M ; Sharif University of Technology
    Springer Netherlands  2018
    Abstract
    Human motion tracking has many applications in biomedical and industrial services. Low-cost inertial/magnetic sensors are widely used in human motion capture systems to obtain the orientation of the human body segments. In this paper, we have presented a quaternion-based unscented Kalman filter algorithm to fuse inertial/magnetic sensors measurements for tracking human arm movements. In order to have a better estimation of the orientation of the forearm and the upper arm, a constraint equation was developed based on the relative velocity of the elbow joint with respect to the inertial sensors attached to the forearm and the upper arm. Also to compensate for fast body motions, we adapted the... 

    Intelligent landing of autonomous aerial vehicles using fuzzy logic control

    , Article 2009 IEEE Aerospace Conference, Big Sky, MT, 7 March 2009 through 14 March 2009 ; 2009 ; 1095323X (ISSN); 9781424426225 (ISBN) Saghafi, F ; Pouya, S ; Khansari Zadeh, M ; Sharif University of Technology
    2009
    Abstract
    In this paper a fuzzy controller is developed for automatic landing of fixed wing Unmanned Aerial Vehicles (UAVs). It is assumed that the vehicle has a built in vision system which provides the runway relative position and orientation to be used in the designed tracking system. The stability of the controller was analyzed through vector field diagrams, and the system performance is tested through a complete 6DOF computer simulation. The results show a satisfactory performance of the controller all through the automatic landing phase. ©2009 IEEE  

    Manufacture and Experimental Study of the Desalination System and Atmospheric Water Generator with Evacuated Tube Collector

    , M.Sc. Thesis Sharif University of Technology Akbarpour, Gholamhossein (Author) ; Shafii, Mohammad Behshad (Supervisor)
    Abstract
    This research aims to design and build a device that Using solar energy and can be used as water heaters and water desalination and water from the soluble hygroscopic. For this purpose, a combination of evacuated tube collector with parabolic through collector with sun tracking mechanism is used. sun tracking mechanism is polar and works with optical sensor. in this research we have designed new setup with evacuated tube collector for direct desalination and water heater. in this method heat pipes have been omitted from setup that cause high performance in heat transfer from evacuated tube collector to water and is minimized losses. 15w air compressor used to increased rate of evaporation ... 

    Robust regulation and tracking system design for multivariable control of the tape transport mechanism

    , Article Microsystem Technologies ; Vol. 18, Issue. 5 , 2012 , pp. 557-573 ; ISSN: 09467076 Moradi, H ; Bakhtiari-Nejad, F ; Alasty, A ; Sharif University of Technology
    Abstract
    Tape mechanisms must be able to transport the tape with a constant velocity for achieving high rate of data transfer. In this paper, a multivariable model of tape transport mechanism including the take-up and supply reel servos for tape tension control and capstan servo for speed control is considered. To achieve desired performance,pole-placement approach based on general canonical control form (GCCF) is used. Instead of using expensive tension sensors, an observer is designed. A regulator system is developed for disturbance rejection; and a modified integral control is designed for perfect tracking of desired setpoints in tape speed and tensions. Since the real dynamic model associates... 

    Robust regulation and tracking system design for multivariable control of the tape transport mechanism

    , Article Microsystem Technologies ; Volume 18, Issue 5 , 2012 , Pages 557-573 ; 09467076 (ISSN) Moradi, H ; Bakhtiari Nejad, F ; Alasty, A ; Sharif University of Technology
    2012
    Abstract
    Tape mechanisms must be able to transport the tape with a constant velocity for achieving high rate of data transfer. In this paper, a multivariable model of tape transport mechanism including the take-up and supply reel servos for tape tension control and capstan servo for speed control is considered. To achieve desired performance,pole-placement approach based on general canonical control form (GCCF) is used. Instead of using expensive tension sensors, an observer is designed. A regulator system is developed for disturbance rejection; and a modified integral control is designed for perfect tracking of desired setpoints in tape speed and tensions. Since the real dynamic model associates... 

    Regulator and tracking system design for a single-rod hydraulic actuator via pole-placement approach

    , Article ASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011, 11 November 2011 through 17 November 2011 ; Volume 7, Issue PARTS A AND B , November , 2011 , Pages 173-181 ; 9780791854938 (ISBN) Moradi, H ; Hajikolaei, K. H ; Bakhtiari Nejad, F ; Sharif University of Technology
    2011
    Abstract
    Due to the nonlinear dynamics of hydraulic systems, applying high performance closed-loop controllers is complicated. In this paper, a single-rod hydraulic actuator is considered in which load displacement (for positioning purposes) is controlled via manipulation of the input voltage to the servo-valve. Dynamics of the servo-valve is described by first and second order transfer functions (named as Models 1 and 2). Through linearization of the system around its operating points, dynamics of the hydraulic actuator is represented in the state space. A full-order observer is designed for on-line states estimation. Then, feedback control system is designed for both regulation and tracking... 

    Human arm motion tracking by inertial/magnetic sensors using unscented kalman filter and relative motion constraint

    , Article Journal of Intelligent and Robotic Systems: Theory and Applications ; 2017 , Pages 1-10 ; 09210296 (ISSN) Atrsaei, A ; Salarieh, H ; Alasty, A ; Abediny, M ; Sharif University of Technology
    Abstract
    Human motion tracking has many applications in biomedical and industrial services. Low-cost inertial/magnetic sensors are widely used in human motion capture systems to obtain the orientation of the human body segments. In this paper, we have presented a quaternion-based unscented Kalman filter algorithm to fuse inertial/magnetic sensors measurements for tracking human arm movements. In order to have a better estimation of the orientation of the forearm and the upper arm, a constraint equation was developed based on the relative velocity of the elbow joint with respect to the inertial sensors attached to the forearm and the upper arm. Also to compensate for fast body motions, we adapted the... 

    Particle filtering-based low-elevation target tracking with multipath interference over the ocean surface

    , Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 56, Issue 4 , 2020 , Pages 3044-3054 Shi, X ; Taheri, A ; Cecen, T ; Celik, N ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    Abstract
    As radar signals propagate above the ocean surface to determine the trajectory of a target, the signals that are reflected directly from the target arrive at the receiver along with indirect signals reflected from the ocean surface. These unwanted signals must be properly filtered; otherwise, their interference may mislead the signal receiver and significantly degrade the tracking performance of the radar. To this end, we propose a low-elevation target tracking mechanism considering the specular and diffuse reflection effects of multipath propagation over the ocean surface simultaneously. The proposed mechanism consists of a state-space model and a particle filtering algorithm and promises... 

    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) Chak, Y. C ; 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...