Loading...
Search for:
beigzadeh--b---borhan
0.1 seconds
Total 3079 records
PRI (Palm Rotation Indicator): a metric for postural stability in dynamic nonprehensile manipulation [electronic resource]
, Article Journal of MECHANIKA ; 2012, Vol. 18, No. 4, pp. 461-466 ; Meghdar, Ali ; Sohrabpour, Saeed ; Sharif University of Technology
Abstract
In this study, we discuss the postural stability of a nonprehensile manipulation problem, which deals with multibody objects. As a metric for postural stability, we define PRI. Then, the system is posturally stable, if PRI is inside the convex hull of the object-manipulator contact surface. We then discuss that dynamic biped locomotion is a special case of dynamic nonprehensile manipulation in all aspects; we prove that ZMP (zero-moment point) and FRI (zoot rotation indicator) are special cases of PRI (palm rotation indicator). Simulations and experiments corresponding to simple examples support the results
Application of Fourier Transform Infrared (FTIR) Spectroscopy of Biofluids in Disease Diagnosis
, M.Sc. Thesis Sharif University of Technology ; Nejat, Hossein (Supervisor) ; Meghdari, Ali (Supervisor) ; Beigzadeh, Borhan (Co-Advisor)
Abstract
The ability to diagnose a disease rapidly, non-invasively, with high confidence level and low cost can be of great importance in many ways such as 'detection and on-time conduction of remedial strategies. Hence It can reduce fatality rate and costs in the hygiene field. Currently some pathological diagnosis methods are not suitable considering their precision and costs and in addition to that, most of them are single-function and are developed for diagnosis of a particular disease and don't perform well in the case of multiple disease factors. Many diseases are caused by metabolic disorders and thus direct study of metabolic factors can provide us with a lot of evidence on the disease. One...
Passive dynamic object manipulation: preliminary definition and examples
, Article Acta Automatica Sinica ; Volume 36, Issue 12, December 2010, Pages 1711–1719 ; Meghdari, A. (Ali) ; Sohrabpour, S ; Sharif University of Technology
Abstract
In this work, we introduce a category of dynamic manipulation processes, namely passive dynamic object manipulation, according to which an object is manipulated passively. Specifically, we study passive dynamic manipulation here. We define the main concept, discuss the challenges, and talk about the future directions. Like other passive robotic systems, there are no actuators in these systems. The object follows a path and travels along it under the effect of its own weight, as well as the interaction force applied by each manipulator on it. We select some simple examples to show the concept. For each example, dynamic equations of motion are derived and the stability of the process is taken...
Adaptive online prediction of operator position in teleoperation with unknown time-varying delay: simulation and experiments
, Article Neural Computing and Applications ; 2020 ; Yazdankhoo, B ; Beigzadeh, B ; Meghdari, A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2020
Abstract
One of the most important problems in teleoperation systems is time delay and packet loss in the communication channel, which can affect transparency and stability. One way to overcome the time delay effects in a teleoperation system is to predict the master-side motion. In this way, when data is received in the slave side, it will be considered as the current position of the master robot and, thus, complete transparency could be achieved. The majority of the previous works regarding operator position prediction have considered known and constant time delay in the system; however, in the real applications, time delay is unknown and variable. In this paper, an adaptive online prediction...
Adaptive online prediction of operator position in teleoperation with unknown time-varying delay: simulation and experiments
, Article Neural Computing and Applications ; Volume 33, Issue 13 , 2021 , Pages 7575-7592 ; 09410643 (ISSN) ; Yazdankhoo, B ; Beigzadeh, B ; Meghdari, A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
One of the most important problems in teleoperation systems is time delay and packet loss in the communication channel, which can affect transparency and stability. One way to overcome the time delay effects in a teleoperation system is to predict the master-side motion. In this way, when data is received in the slave side, it will be considered as the current position of the master robot and, thus, complete transparency could be achieved. The majority of the previous works regarding operator position prediction have considered known and constant time delay in the system; however, in the real applications, time delay is unknown and variable. In this paper, an adaptive online prediction...
Dealing with biped locomotion as a dynamic object manipulation problem: Manipulating of body using legs
, Article ASME International Mechanical Engineering Congress and Exposition, IMECE 2007, Seattle, WA, 11 November 2007 through 15 November 2007 ; Volume 9 PART B , 2008 , Pages 1209-1216 ; 0791843033 (ISBN); 9780791843031 (ISBN) ; Meghdari, A ; Beigzadeh, Y ; Sharif University of Technology
2008
Abstract
In this paper, we try to show that it is possible to deal with biped locomotion as a dynamic object manipulation problem. We show that during locomotion, a biped locomotion can be seen as manipulating of upper part of biped robot using a leg, which now plays the role of a manipulator. So the whole locomotion process can be seen as a dynamic manipulation of an object (upper part of a biped robot) using a numerous series of manipulators each of which placed in a proper place where the object tends to land, so it catches the object and throws it to the next point which another manipulator waits for catching it. The authors in the previous works have explored the problem of dynamic manipulation...
Dynamic manipulation of objects using multiple manipulators
, Article ASME International Mechanical Engineering Congress and Exposition, IMECE 2007, Seattle, WA, 11 November 2007 through 15 November 2007 ; Volume 9 PART B , 2008 , Pages 1201-1208 ; 0791843033 (ISBN); 9780791843031 (ISBN) ; Meghdari, A ; Beigzadeh, Y ; Sharif University of Technology
2008
Abstract
In this study, we explore the possibility of dynamic object manipulation of objects using a series of manipulators. Here, two three-active-link manipulators have been considered and the generality of the idea to a series of manipulator is developed easily. So without any gripper, and in an unstable grasp manner, we try to throw an object by a manipulator and catch It with another. Also we can consider the impacts generated in the moment of throwing and catching objects, as some disturbance and therefore we damp it. Finally we deal with the whole manipulation process as a system with some noise and disturbance and try to demonstrate its stability. All results have been validated with the aid...
Improvement of operator position prediction in teleoperation systems with time delay: Simulation and experimental studies on Phantom Omni devices
, Article Jordan Journal of Mechanical and Industrial Engineering ; Volume 13, Issue 3 , 2019 , Pages 197-205 ; 19956665 (ISSN) ; Nikpour, M ; Beigzadeh, B ; Meghdari, A ; Sharif University of Technology
Hashemite University
2019
Abstract
An online operator position prediction approach based on artificial neural network for teleoperation systems is proposed in this paper, which predicts future position of operator's hand based on current available data. The neural network gathers inputs for some time at the beginning of the operation, then is trained, and is finally exploited through the rest of the operation. Superiority of the proposed approach can be investigated from two aspects. Firstly, no limiting assumption is required in this approach in contrast with the proposed methods in the literature. Secondly, unknown operator intention can be dealt with in real time if it is not too sudden and unpredictable. Two different...
Dynamic modeling of geometrically nonlinear electrostatically actuated microbeams (Corotational Finite Element formulation and analysis)
, Article Journal of Physics: Conference Series ; Volume 34, Issue 1 , 2006 , Pages 606-613 ; 17426588 (ISSN) ; Ahmadian, M. T ; Sharif University of Technology
Institute of Physics Publishing
2006
Abstract
In this paper, a complete nonlinear finite element model for coupled-domain MEMS devices with electrostatic actuation and squeeze film effect is developed. For this purpose, a corotational finite element formulation for the dynamic analysis of planer Euler beams is employed. In this method, the internal nodal forces due to deformation and intrinsic residual stresses, the inertial nodal forces, and the damping effect of squeezed air film are systematically derived by consistent linearization of the fully geometrically nonlinear beam theory using d′Alamber and virtual work principles. An incremental-iterative method based on the Newmark direct integration procedure and the Newton-Raphson...
Forced Nonlinear Vibrational Analysis of Micro Rotating Shaft Based on Non Classical Continuum Theories
, M.Sc. Thesis Sharif University of Technology ; Asghari, Mohsen (Supervisor)
Abstract
The analysis of nonlinear forced vibration of micro-rotors (rotating micro-shafts with disks) is carried out under loads of mass eccentricity distribution and in the presence of internal damping. For the analysis, the non-classical continuum theories of couple stress and strain gradient are employed. Vibrational behavior of micro-rotors is extremely sensitive due to the very high rotational speed, which is at the order of several millions per minute speed. The considered nonlinearity is of geometrical type due to the mid-plane stretching. First, the governing equations of motion of micro-rotors are derived by utilizing the Hamilton principle. In the next step, the Galerkin and multiple scale...
Dynamics of multi layer microplates considering nonlinear squeeze film damping
, Article 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006, Chicago, IL, 5 November 2006 through 10 November 2006 ; 2006 ; 1096665X (ISSN); 0791837904 (ISBN); 9780791837900 (ISBN) ; Moghimi Zand, M ; Borhan, H ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2006
Abstract
This paper presents a model to analyze pull-in phenomenon and dynamics of multi layer microplates using coupled finite element and finite difference methods. Firstorder shear deformation theory is used to model dynamical system using finite element method, while Finite difference method is applied to solve the nonlinear Reynolds equation of squeeze film damping. Using this model, Pull-in analysis of single layer and multi layer microplates are studied. The results of pull-in analysis are in good agreement with literature. Validating our model by pull-in results, an algorithm is presented to study dynamics of microplates. These simulations have many applications in designing multi layer...
Passive dynamic object manipulation: A framework for passive walking systems
, Article Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics ; Volume 227, Issue 2 , 2013 , Pages 185-198 ; 14644193 (ISSN) ; Meghdari, A ; Sohrabpour, S ; Sharif University of Technology
2013
Abstract
In this study, we deal with passive dynamic object manipulation. During passive dynamic object manipulation, a passive object is manipulated using passive manipulators. Like other passive robotic systems, there are no actuators in these systems. The object follows a path and travels along it under the effect of its own weight, as well as, the interaction force applied by each manipulator on it. The objects are not necessarily rigid, but we manipulate passive multibody objects as well as rigid ones. Thus, for a passive walking system, we assume that the passive walker is a multibody object and is manipulated by the ground (zero degree-of-freedom manipulator). As an example, we show that a...
Manipulation of multibody active objects using simple passive manipulators
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 12 November 2010 through 18 November 2010, Vancouver, BC ; Volume 8, Issue PARTS A AND B , 2010 , Pages 597-603 ; 9780791844458 (ISBN) ; Meghdari, A ; Sohrabpour, S ; Sharif University of Technology
2010
Abstract
In this paper, we study passivity in dynamic manipulation of active objects. Active object is a concept covering a variety of objects, which are not rigid and need to be controlled during manipulation process. In this work, we use multi-link mechanisms with sufficient actuators to be controlled as object and a series of simple 1-DoF passive manipulators to perform such a process. Control of the object, dynamic and motion planning of the system, and stability in presence of impact are significant issues in this study
Passive dynamic object manipulation: preliminary definition and examples
, Article Zidonghua Xuebao/Acta Automatica Sinica ; Volume 36, Issue 12 , 2010 , Pages 1711-1719 ; 02544156 (ISSN) ; Meghdari, A ; Sohrabpour, S ; Sharif University of Technology
2010
Abstract
In this work, we introduce a category of dynamic manipulation processes, namely passive dynamic object manipulation, according to which an object is manipulated passively. Specifically, we study passive dynamic manipulation here. We define the main concept, discuss the challenges, and talk about the future directions. Like other passive robotic systems, there are no actuators in these systems. The object follows a path and travels along it under the effect of its own weight, as well as the interaction force applied by each manipulator on it. We select some simple examples to show the concept. For each example, dynamic equations of motion are derived and the stability of the process is taken...
Control and manipulation of multibody objects
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 3 , 2010 , Pages 579-584 ; 9780791849170 (ISBN) ; Meghdari, A ; Sohrabpour, S ; Sharif University of Technology
2010
Abstract
In this work, we study a kind of manipulation process during which we deal with active objects. An active object is a concept covering a variety of objects that are not rigid and need to be controlled during the manipulation process. Here, we use a multi-link mechanism with active motors (actuator) as the object and a series of simple planar manipulators to perform the manipulation process. Dynamic, control, motion planning, and stability at the presence of impact are the most important challenges in this work
Two dimensional dynamic manipulation of a disc using two manipulators
, Article 2006 IEEE International Conference on Mechatronics and Automation, ICMA 2006, Luoyang, 25 June 2006 through 28 June 2006 ; Volume 2006 , 2006 , Pages 1191-1196 ; 1424404665 (ISBN); 9781424404667 (ISBN) ; Nili Ahmadabadi, M ; Meghdari, A ; Sharif University of Technology
2006
Abstract
In this paper, we analyze a Dynamic Object Manipulation (DOM) problem; throwing upward and catching a disc using two planar manipulators. The manipulators control the disc xy position dynamically and use its angular movement as a free parameter. We use a simple model for the system. Each manipulator has three links and three active joints. In addition, the disc has considerable radius and mass. Therefore, we design a simple mechanism in the palm to damp a portion of the impact. © 2006 IEEE
Kinematical and dynamic analysis of biped robots' locomotion using dynamic object manipulation approach
, Article 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006, Torino, 4 July 2006 through 7 July 2006 ; Volume 2006 , 2006 ; 0791837793 (ISBN); 9780791837795 (ISBN) ; Nili Ahmadabadi, M ; Meghdari, A ; Sharif University of Technology
2006
Abstract
In this paper, we try to interpret "Duality of Dynamic Locomotion and Dynamic Object Manipulation". Since our main goal in this paper is to offer the duality concept and to validate it with a case study, we deal with the problem in a simple and abstract system. As a case study, we describe the duality between the problem of 2D dynamic object manipulation of a sphere using two planar manipulators and 2D dynamic locomotion of lower part of a biped robot. Having obtained the equations of dynamic object manipulation, we change the boundary conditions of the problem in such a way that both radius and mass of sphere object tend to infinity. Simultaneously, both of size and mass of manipulators'...
A dynamic object manipulation approach to dynamic biped locomotion
, Article Robotics and Autonomous Systems ; Volume 56, Issue 7 , 31 July , 2008 , Pages 570-582 ; 09218890 (ISSN) ; Nili Ahmadabadi, M ; Meghdari, A ; Akbarimajd, A ; Sharif University of Technology
2008
Abstract
In this paper, we aim at an integrated approach to Dynamic Biped Walking (DBW) and Dynamic Object Manipulation (DOM) at an abstract level. To this end, we offer a unified and abstract concept with a dual interpretation as a DOM and as a DBW system. We validate the proposed approach by using a set of simulations on an illustrative case study and show how it can be used in modeling as well as design of planning and control algorithms for DOM and DBW systems. In the case study, we describe the proposed approach and show its dual interpretation by identifying the relations between 2D dynamic object manipulation of a disc using two planar manipulators and 2D dynamic object locomotion of lower...
On Correlation of Dynamic Biped Locomotion and Dynamic Object Manipulation
, Ph.D. Dissertation Sharif University of Technology ; Meghdari, Ali (Supervisor) ; Sohrabpour, Saeed (Supervisor)
Abstract
Dynamic Object Manipulation (DOM) and Dynamic Biped Locomotion (DBL) are certainly two major categories in robotics, which attract much attention of scientists. Their (hybrid) nonlinear dynamics usually make them challenging subjects to deal with. Such systems are often used as benchmarks to test new nonlinear control approaches or stability analyses. However, there is not a unified approach to both systems. Although it seems that DOM and DBL systems are completely different at first view, we deeply believe that essential similarities exist between these two robotic fields. In this dissertation, we study the correlation of DOM and DBL while addressing passive, underactuated, and fully...
Prediction of in-plane elastic properties of graphene in the framework of first strain gradient theory
, Article Meccanica ; Volume 54, Issue 1-2 , 2019 , Pages 299-310 ; 00256455 (ISSN) ; Mehralian, F ; Dehghani Firouz Abadi, R ; Borhan Panah, M. R ; Rahmanian, M ; Sharif University of Technology
Springer Netherlands
2019
Abstract
In the present study, the in-plane elastic stiffness coefficients of graphene within the framework of first strain gradient theory are calculated on the basis of an accurate molecular mechanics model. To this end, a Wigner–Seitz primitive cell is adopted. Additionally, the first strain gradient theory for graphene with trigonal crystal system is formulated and the relation between elastic stiffness coefficients and molecular mechanics parameters are calculated. Thus, the ongoing research challenge on providing the accurate mechanical properties of graphene is addressed herein. Using results obtained, the in-plane free vibration of graphene is studied and a detailed numerical investigation is...