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robotic-systems
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Total 45 records
A biologically plausible learning method for neurorobotic systems
, Article 2009 4th International IEEE/EMBS Conference on Neural Engineering, NER '09, Antalya, 29 April 2009 through 2 May 2009 ; 2009 , Pages 128-131 ; 9781424420735 (ISBN) ; Vosoughi Vahdat, B ; National Institutes of Health, NIH; National Institute of Neurological Disorders and Stroke, NINDS; National Science Foundation, NSF ; Sharif University of Technology
2009
Abstract
This paper introduces an incremental local learning algorithm inspired by learning in neurobiological systems. This algorithm has no training phase and learns the world during operation, in a lifetime manner. It is a semi-supervised algorithm which combines soft competitive learning in input space and linear regression with recursive update in output space. This method is also robust to negative interference and compromises bias-variance dilemma. These qualities make the learning method a good nonlinear function approximator having possible applications in neuro-robotic systems. Some simulations illustrate the effectiveness of the proposed algorithm in function approximation, time-series...
Decentralized impedance control of nonredundant multi-manipulator systems
, Article 2008 IEEE International Conference on Networking, Sensing and Control, ICNSC, Sanya, 6 April 2008 through 8 April 2008 ; 2008 , Pages 206-211 ; 9781424416851 (ISBN) ; Ghaffarkhah, A ; Sharif University of Technology
2008
Abstract
In this paper, we propose a decentralized control scheme for combined motion/force control of nonredundant multi-manipulator robotic systems, cooperatively grasping a rigid body in a prespecifled position/force trajectory. The proposed control scheme uses the impedance method for modeling the internal force exerted by the end effectors to the object. The precise mathematical analysis of the overall dynamical system and the proposed controller are presented and the stability of the overall system is studied. The proposed controller, then, is applied to a cooperative system composed of two PUMA560 manipulators and the simulation results are presented to verify the proposed control scheme
Facility location optimization via multi-agent robotic systems
, Article 2008 IEEE International Conference on Networking, Sensing and Control, ICNSC, Sanya, 6 April 2008 through 8 April 2008 ; 2008 , Pages 287-292 ; 9781424416851 (ISBN) ; Sayyaadi, H ; Sharif University of Technology
2008
Abstract
A facility location problem deals with locating the best place for a group of facilities, among distinct demand points, minimizing a certain locational optimization function. In this paper, distributed, asynchronous, and scalable algorithms are presented for solving a facility location problem known as continuous n-median problem (generalized Fermat-Weber problem) via multi-agent robotic systems. The algorithms are discussed both in continuous and discrete time domain, and their validity is proved. It is also shown that the solution of this facility location problem is the set of points that are the geometric medians of their corresponding Voronoi cells
Automated Lip-Reading robotic system based on convolutional neural network and long short-term memory
, Article 13th International Conference on Social Robotics, ICSR 2021, 10 November 2021 through 13 November 2021 ; Volume 13086 LNAI , 2021 , Pages 73-84 ; 03029743 (ISSN) ; 9783030905248 (ISBN) ; Taheri, A ; Mohammadzade, H ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In Iranian Sign Language (ISL), alongside the movement of fingers/arms, the dynamic movement of lips is also essential to perform/recognize a sign completely and correctly. In a follow up of our previous studies in empowering the RASA social robot to interact with individuals with hearing problems via sign language, we have proposed two automated lip-reading systems based on DNN architectures, a CNN-LSTM and a 3D-CNN, on the robotic system to recognize OuluVS2 database words. In the first network, CNN was used to extract static features, and LSTM was used to model temporal dynamics. In the second one, a 3D-CNN network was used to extract appropriate visual and temporal features from the...
Introducing shell formation and a thermodynamics-inspired concept for swarm robotic systems
, Article Robotics and Autonomous Systems ; Volume 148 , 2022 ; 09218890 (ISSN) ; Alasty, A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In this article, a new formation for swarm robotic systems is introduced. This formation, which is made up of a portion of swarm members and encircles the whole swarm, is called the shell formation. In this regard, an effective algorithm for developing the shell formation in swarm robotic systems is established. The interaction mechanism among swarm agents is based on the method of artificial potential fields and the local rule of the nearest neighbor. Subsequently, inspired by the thermodynamic science and based on the introduced shell formation, the thermodynamic concept of pressure is generalized to swarm robotic systems. Finally, the efficacy of the introduced shell formation in solving...
Modelling and Control of Swarm Robotic Systems with Multiple Ground and Aerial Clusters under an Imperfect Network
, Ph.D. Dissertation Sharif University of Technology ; Alasty, Aria (Supervisor)
Abstract
In this study, an effective collective control strategy is presented for the decentralized behavior control of a heterogeneous multi–cluster swarm robotic system composed of a group of quadrotors as aerial agents, and a group of two–wheeled mobile robots as ground agents. In this regard, first of all, a new element for swarm robotic systems is introduced. This element, which is made up of a portion of swarm members and encircles the whole swarm, is called the shell element. An algorithm for developing the shell element in swarm robotic systems composed of agents moving in the two–dimensional space is established. Subsequently, inspired by the thermodynamic science and based on the introduced...
Swarm aggregation using emotional learning based intelligent controller
, Article 2009 6th International Symposium on Mechatronics and its Applications ; 2009 , Article number 5164827 ; ISBN: 9781424434817 ; Vatankhah, R ; Alasty, A ; Vossoughi, G ; Sharif University of Technology
Abstract
In this paper, we consider a control strategy of multi-robot systems, or simply, swarms, based on emotional control technique. First, we briefly discuss a "kinematic" swarm model in n-dimensional space introduced in an earlier paper. In that model, motion of every swarm member is governed by predefined inter-individual interactions. Limitations of every member's field of view are also considered in that model. After that, we consider a general model for vehicle dynamics of each swarm member, and use emotional control theory to force their motion to obey the dynamics of the kinematic model. Based on the kinematic model, stability (cohesion) analysis is performed and coordination controller.is...
Adaptive impedance control of UAVs interacting with environment using a robot manipulator
, Article 2014 2nd RSI/ISM International Conference on Robotics and Mechatronics, ICRoM 2014 ; Oct , 2014 , p. 636-641 ; Sharifi, M ; Sharif University of Technology
Abstract
In this paper, a nonlinear adaptive impedance controller is proposed for UAVs equipped with a robot manipulator that interacts with environment. In this adaptive controller, by considering the nonlinear dynamics model of the UAV plus the robot manipulator in Cartesian coordinates, all of model parameters are considered to be completely uncertain and their estimation is updated using an adaptation law. The objective of the proposed adaptive controller is the control of manipulator's end-effector impedance in Cartesian coordinates to have a stable physical interaction. The adjustable Cartesian impedance is a desired dynamical relationship between the end-effector motion in Cartesian...
Use of PSO in parameter estimation of robot dynamics; part one: No need for parameterization
, Article 2012 16th International Conference on System Theory, Control and Computing, ICSTCC 2012 - Joint Conference Proceedings ; 2012 ; 9786068348483 (ISBN) ; Namvar, M ; Sharif University of Technology
2012
Abstract
Offline procedures for estimating parameters of robot dynamics are practically based on the parameterized inverse dynamic model. In this paper, we present a novel approach to parameter estimation of robot dynamics which removes the necessity of parameterization (i.e. finding the minimum number of parameters from which the dynamics can be calculated through a linear model with respect to these parameters). This offline approach is based on a simple and powerful swarm intelligence tool: the particle swarm optimization (PSO). In this paper, we discuss and validate the method through simulated experiments. In "Part Two" we analyze our method in terms of robustness and compare it to robust...
Design and development of an effective low-cost robotic cameraman for laparoscopic surgery: RoboLens
, Article Scientia Iranica ; Volume 18, Issue 1 B , 2011 , Pages 59-71 ; 10263098 (ISSN) ; Farahmand, F ; Meghdari, A ; Karimian, F ; Sharif University of Technology
2011
Abstract
A robotic system was designed and developed to perform the camera handling task during laparoscopic surgery. The system employs an effective low cost mechanism, with a minimum number of actuated DOFs, enabling spherical movement around a remote centre of motion positioned at the the insertion point of the laparoscopic stem. Kinematic analysis showed a high manipulability measure for the system, with the left/right movements directly governed by rotation of the first rotary actuator, and zoom and up/down movements by the simultaneous motions of the linear and second rotary actuators. A prototype of the robot was developed for practical use in an operating room environment. Hands-free operator...
Adaptive characterisation of a human hand model during intercations with a telemanipulation system
, Article International Conference on Robotics and Mechatronics, ICROM 2015, 7 October 2015 through 9 October 2015 ; 2015 , Pages 688-693 ; 9781467372343 (ISBN) ; Sadeghnejad, S ; Farahmand, F ; Vosoughi, G ; Sharif University of Technology
2015
Abstract
Proper modeling of the human arm dynamic, as it interacts with telemanipulation and haptic systems, is important in enhancing the transparency of these systems. In this article, we introduced an adaptive identifier to estimate the impedance characteristic of a human operator as it interacts with a single translational degree of freedom mechanism. The five parameter model, including an extra spring and damper for a better approximation of the dynamic behavior of human arm, has been used. Since the impedance characteristic of human arm differs from one individual to another, it is important to estimate these parameters for each individual and update the controller to enhance the transparency...
Nonlinear robust adaptive Cartesian impedance control of UAVs equipped with a robot manipulator
, Article Advanced Robotics ; Volume 29, Issue 3 , Feb , 2015 , Pages 171-186 ; 01691864 (ISSN) ; Sayyaadi, H ; Sharif University of Technology
Robotics Society of Japan
2015
Abstract
In this paper, a new nonlinear robust adaptive impedance controller is addressed for Unmanned Aerial Vehicles (UAVs) equipped with a robot manipulator that physically interacts with environment. A UAV equipped with a robot manipulator is a novel system that can perform different tasks instead of human being in dangerous and/or inaccessible environments. The objective of the proposed robust adaptive controller is control of the UAV and its robotic manipulators end-effector impedance in Cartesian space in order to have a stable physical interaction with environment. The proposed controller is robust against parametric uncertainties in the nonlinear dynamics model of the UAV and the robot...
Hardware in the loop simulation and analysis of a model of fish robotic system
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 5 , 2010 , Pages 203-210 ; 9780791849194 (ISBN) ; Vosoughi, G. R ; Farshchi, M ; Nemati, A ; Sharif University of Technology
2010
Abstract
In the present study, an adaptive sliding mode control method was employed to control a fish robotic system using hardware in the loop methodology. Up to now, few researches have focused on autonomous control of fish robot in dynamic environments which may be the result of difficulties in modeling of hydrodynamic effects on fish robot. Therefore, following the introduction of the nonlinear model for the robot, elongated body theory, suggested by Lighthill, was used to analyze fish movements. Then, kinematics control to track desired trajectories was designed for under-actuated model of robot. Adaptive sliding mode controller, capable of adapting according to changes and uncertainties, was...
Adaptive control of robot manipulators including actuator dynamics and without joint torque measurement
, Article 2010 IEEE International Conference on Robotics and Automation, ICRA 2010, Anchorage, AK, 3 May 2010 through 7 May 2010 ; 2010 , Pages 4639-4644 ; 10504729 (ISSN) ; 9781424450381 (ISBN) ; Namvar, M ; Sharif University of Technology
2010
Abstract
Ignoring actuator dynamics in control of rigid manipulators can in practice result in performance degradation or loss of system stability. However, consideration of actuator dynamics usually requires measurement of robot joint torques. This paper addresses motion tracking control of an n-DOF rigid robot by taking into account its actuator dynamics. Joint torque measurement is avoided by using an adaptive observer. The backstepping technique is adopted to develop a dynamically smooth adaptive nonlinear controller dealing with uncertainties in manipulator and actuator dynamics. Semi-global convergence of motion tracking errors as well as torque estimation error are proven without any...
Motion tracking in robotic manipulators in presence of delay in measurements
, Article Proceedings - IEEE International Conference on Robotics and Automation, 3 May 2010 through 7 May 2010, Anchorage, AK ; 2010 , Pages 3884-3889 ; 10504729 (ISSN) ; 9781424450381 (ISBN) ; Namvar, M ; Sharif University of Technology
2010
Abstract
Time-delay in sensor measurements can be a frequent cause of instability and performance degradation in a robotic system. In this paper, motion tracking of rigid manipulators in presence of constant and known delay in sensors is investigated. By using non-minimal model of a manipulator, a dynamically smooth controller based on the Linear Matrix Inequality (LMI) approach is proposed which guarantees asymptotic tracking of desired joint angles and velocities in presence of delayed measurements. For a given controller the maximum amount of delay that preserves system stability is computed by solving an LMI optimization and also by numerical simulations, and the results are compared. Finally, a...
Modified branching process for the reliability analysis of complex systems: multiple-robot systems
, Article Communications in Statistics - Theory and Methods ; 2017 , Pages 1-12 ; 03610926 (ISSN) ; Akhavan Niaki, S. T ; Sharif University of Technology
Abstract
Current design practice is usually to produce a safety system which meets a target level of performance that is deemed acceptable by the regulators. Safety systems are designed to prevent or alleviate the consequences of potentially hazardous events. In many modern industries the failure of such systems can lead to whole system breakdown. In reliability analysis of complex systems involving multiple components, it is assumed that the components have different failure rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed generating function (GF) and the recursive algorithm to obtain reliability of systems consisting of a...
Tele-echography of moving organs using an Impedance-controlled telerobotic system
, Article Mechatronics ; Volume 45 , 2017 , Pages 1339-1351 ; 09574158 (ISSN) ; Salarieh, H ; Behzadipour, S ; Tavakoli, M ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
A novel impedance-controlled teleoperation system is developed for robot-assisted tele-echography of moving organs such as heart, chest and breast during their natural motions (beating and/or breathing). The procedure of devising the two impedance models for the master and slave robots is developed such that (a) the slave robot holding the ultrasound (US) probe follows the master trajectory but complies with the oscillatory interaction force of the moving organ, and (b) the sonographer receives feedback from the non-oscillatory portion of the slave-organ interaction force via the master robot similar to the haptic feedback received in echography of a stationary organ. These goals are...
Glimpse-gaze deep vision for modular rapidly deployable decision support agent in smart jungle
, Article 2018 6th Iranian Joint Congress on Fuzzy and Intelligent Systems ; Volume 2018-January , 2018 , Pages 75-78 ; 9781538628362 (ISBN) ; Majidi, B ; Manzuri, M. T ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Visual interpretation of complex visual patterns in non-urban environments is necessary for many applications in smart rural community management, smart farming and smart jungles. In this paper, the Glimpse-Gaze framework for deep learning based visual interpretation of complex rural and jungle environment scenes is proposed. The proposed framework is used for decision support and navigation by a multi-agent robotic system singularly referred to as MOdular RApidly Deployable Decision Support Agent (MORAD DSA). A set of deep con-volutional neural networks are trained for fast and accurate interpretation of jungle scenes. Transfer learning and auxiliary pretraining on salient regions of the...
Modified branching process for the reliability analysis of complex systems: Multiple-robot systems
, Article Communications in Statistics - Theory and Methods ; Volume 47, Issue 7 , 2018 , Pages 1641-1652 ; 03610926 (ISSN) ; Akhavan Niaki, S. T ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
Current design practice is usually to produce a safety system which meets a target level of performance that is deemed acceptable by the regulators. Safety systems are designed to prevent or alleviate the consequences of potentially hazardous events. In many modern industries the failure of such systems can lead to whole system breakdown. In reliability analysis of complex systems involving multiple components, it is assumed that the components have different failure rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed generating function (GF) and the recursive algorithm to obtain reliability of systems consisting of a...
Swarm aggregation using emotional learning based intelligent controller
, Article 2009 6th International Symposium on Mechatronics and its Applications, ISMA 2009, Sharjah, 23 March 2009 through 26 March 2009 ; 2009 ; 9781424434817 (ISBN) ; Vatankhah, R ; Alasty, A ; Vossoughi, G ; Sharif University of Technology
2009
Abstract
In this paper, we consider a control strategy of multi-robot systems, or simply, swarms, based on emotional control technique. First, we briefly discuss a "kinematic" swarm model in n-dimensional space introduced in an earlier paper. In that model, motion of every swarm member is governed by predefined inter-individual interactions. Limitations of every member's field of view are also considered in that model. After that, we consider a general model for vehicle dynamics of each swarm member, and use emotional control theory to force their motion to obey the dynamics of the kinematic model. Based on the kinematic model, stability (cohesion) analysis is performed and coordination controller is...