Papers by Rambod Rastegari
IAES International Journal of Robotics and Automation (IJRA), 2016
We examined mechanism design and kinematic simulation of a new six degrees of freedom (DOF) robot... more We examined mechanism design and kinematic simulation of a new six degrees of freedom (DOF) robotic arm with rotational joints and a linkage motion mechanism. In the design, a parallel linkage mechanism, accompanied by an additional set of bevel gears, was used to create the desired motion for all six links along with transfer of all actuators to the robot’s base to reduce the mass of most of the arms. These changes resulted in reduction of the torque required for joints 1, 2, and 3. Using this parallel mechanism ensures dependence to motion links and creates a special case for the control of the robot and more rigidity against unwanted movement. Initially, we examined mechanism design methods for a parallel linkage mechanism and considered methods for application in an operational robot. In the next step, we determined the kinematic relationships that were established between the robot’s actuators and joints spaces due to the use of this mechanism. Then, we developed an example of ...
Modares Mechanical Engineering, Jul 10, 2017
European Journal of Emergency Medicine, Apr 21, 2021
To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which on... more To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which one or more manipulators are mounted on a thruster-equipped base, have been proposed. Unlike fixed-based manipulators, the robotic arms of SFFR are dynamically coupled with each other and the free-flying-base, hence the control problem becomes more challenging. In this paper, the Multiple Impedance Control (MIC) is developed to manipulate space objects by multiple arms of SFFR. The MIC law is based on the concept of designated impedances and enforces them at various system levels, i.e., the free-flying base, all cooperating manipulators, and the manipulated object itself. The object may include an internal angular momentum source, as is the case in most satellite manipulation tasks. The disturbance rejection characteristic of this algorithm is also studied. The result of this analysis reveals that the effect of disturbances substantially reduces through appropriate tuning of the controller...
دییامن هدافتسا لیذ ترابع زا هلاقم نیا هب عاجرا یارب : Please cite this article using: R. Rastegar... more دییامن هدافتسا لیذ ترابع زا هلاقم نیا هب عاجرا یارب : Please cite this article using: R. Rastegari, Kh. Alipour, Deriving equations of motion of a wheeled mobile robot and its control using extended multiple impedance strategy, Modares Mechanical Engineering, Vol. 17, No. 5, pp. 394-404, 2017 (in Persian) تلاداعم جارختسا کي تکرح خرچ تابر یژتارتسا زا هدافتسا اب نآ لرتنک و راد سناذپما هناگذنچ هتفاي ميمعت
Wheeled mobile manipulators utilize both the locomotion capabilities of the wheeled platform and ... more Wheeled mobile manipulators utilize both the locomotion capabilities of the wheeled platform and manipulation capacity of the arm. While the modelling and control of such systems have previously been studied, most of them have considered robots with rigid suspension and their wheels are subject to pure rolling conditions. To relax the aforementioned limiting assumptions, this research addresses modelling and control of a mobile manipulator with flexible suspension while considers the frictional effects. To this end, the Newton-Euler approach is employed and the modelling process is elaborated. To control the system, a two degree-of-freedom policy is suggested at two levels. In the first level, the Multiple Impedance Control (MIC) algorithm is modified and then is effectively utilized. Next, in the second level, the wheels actuating torques are adjusted such that the required forces/torques of the platform resulted from the first level be realized. The obtained simulation results sup...
2017 Artificial Intelligence and Robotics (IRANOPEN), 2017
Hyper redundant robots due to the highly degrees of freedom (DOFs) are very efficient to utilize ... more Hyper redundant robots due to the highly degrees of freedom (DOFs) are very efficient to utilize in inaccessible environments. In this paper, using ball screw mechanism for the sections of robot as a novel movement method is proposed. Based on the situation locating of the actuators, the robot can be assumed as a serial hyper redundant robot. The robot modeled as 3 sections that result 6 DOFs in SOLIDWORKS and its equations brought in MAPLE software based on the denavit-hartenberg (D-H) parameters. The equations worked in a general form that can be promoted for N DOFs.
Object grasping by robot fingers with purely rolling constraints is one of the most interesting i... more Object grasping by robot fingers with purely rolling constraints is one of the most interesting issues under consideration by many researchers. In earlier studies, the main goal was the manipulation of object under purely rolling constraints to reach the final stable configuration. In this paper, in addition to deriving kinematic and dynamic equations of the system dual fingers robot and grasping semi-circular object located on a moving hand on the plane with rigid hemi-spherical fingertips under pure rolling constrained, we investigate object manipulation on desired path maintaining dynamics stability. Modified multiple impedance control is used for object manipulation and robot fingers by considering the required reforms in this control law. In this method multiple impedance control is performed by applying the desired behavior of the entire system, including moving base, fingers and object, and dynamics stability condition is satisfied. In this way power adjustment and that these...
International Journal of Robotics and Automation (IJRA), 2016
We examined mechanism design and kinematic simulation of a new six degrees of freedom (DOF) robot... more We examined mechanism design and kinematic simulation of a new six degrees of freedom (DOF) robotic arm with rotational joints and a linkage motion mechanism. In the design, a parallel linkage mechanism, accompanied by an additional set of bevel gears, was used to create the desired motion for all six links along with transfer of all actuators to the robot's base to reduce the mass of most of the arms. These changes resulted in reduction of the torque required for joints 1, 2, and 3. Using this parallel mechanism ensures dependence to motion links and creates a special case for the control of the robot and more rigidity against unwanted movement. Initially, we examined mechanism design methods for a parallel linkage mechanism and considered methods for application in an operational robot. In the next step, we determined the kinematic relationships that were established between the robot's actuators and joints spaces due to the use of this mechanism. Then, we developed an exa...
Journal of the Brazilian Society of Mechanical Sciences and Engineering
The purpose of the present study was to estimate storage and loss moduli of an electromagnetic rh... more The purpose of the present study was to estimate storage and loss moduli of an electromagnetic rheological (EMR) fluid in frequencies higher than 100 rad/s. In rotational rheometers, the maximum applicable frequency by the rheometer is 100 rad/s. On the other hand, the required frequency range in various applications of EMR is much higher than this frequency. Therefore, it is necessary to determine rheological properties of smart fluids in frequencies higher than 100 rad/s. The used smart fluid is a magneto-rheological (MR) fluid with the commercial name of MRHCCS4-A. First, using a rotational rheometer, storage and loss moduli in frequencies lower than 100 rad/s were measured. Then, Fredholm integral equations of the first kind and Tikhonov regularization were employed to estimate the relaxation spectrum values. Here, three optimization methods, including imperialist competitive algorithm, genetic algorithm, and particle swarm optimization, have been used. Finally, available analytic correlations were used to estimate the storage and loss moduli in frequencies higher than 100 rad/s. To validate the optimization methods, the numerical results of storage and loss moduli (for frequencies lower than 100 rad/s) were compared with the ones of rheology test. Good agreement between numerical and test results was noticed.
2015 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2015
Proceedings. 2000 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2000) (Cat. No.00CH37113), 2000
ABSTRACT
IEEE/RSJ International Conference on Intelligent Robots and System, 2002
To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which on... more To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which one or more manipulators are mounted on a thruster-equipped base, have been proposed. Unlike fixedbased manipulators, the robotic arms of SFFR are dynamically coupled with each other and the freeflying-base, hence the control problem becomes more challenging. In this paper, the Multiple Impedance Control (MIC) is developed to manipulate space objects by multiple arms of SFFR. The MIC law is based on the concept of designated impedances and enforces them at various system levels, i.e., the free-flying base, all cooperating manipulators, and the manipulated object itself. The object may include an internal angular momentum source, as is the case in most satellite manipulation tasks. The disturbance rejection characteristic of this algorithm is also studied. The result of this analysis reveals that the effect of disturbances substantially reduces through 2 appropriate tuning of the controller mass matrix gain. A system of three manipulators mounted on a free-flying base is simulated in which force and torque disturbances are exerted at several points. The system dynamics is developed symbolically and the controlled system is simulated. The simulation results reveal the merits of the MIC algorithm in terms of smooth performance, i.e.
2006 IEEE International Conference on Control Applications, 2006
ABSTRACT
The multiple impedance control (MIC) is a model-based algorithm for cooperative object manipulati... more The multiple impedance control (MIC) is a model-based algorithm for cooperative object manipulation. Computation of the system dynamics even if perfectly known, may require considerable process time at each step for implementing the control law. The non-model-based multiple impedance control (NMIC) has been recently proposed for fixed base robots to eliminate the need to system dynamic model in implementation of the MIC algorithm. In this paper, the NMIC law is extended to coordinated object manipulation by a space free flying robot (SFFR) that consists a moving spacecraft and a number of manipulators mounted on it. To improve the precise tracking characteristics of the manipulated object and the SFFR, the butter-worth filter is also exploited. Next, the proposed NMIC law is applied on a SFFR with 20 DOF that manipulates an object on a desired path that deliberately includes impacts due to contact with an obstacle. The obtained results show good tracking performance that reveal the ...
Robotics and Autonomous Systems, 2006
Multiple Impedance Control (MIC) is an algorithm that enforces designated impedance at various le... more Multiple Impedance Control (MIC) is an algorithm that enforces designated impedance at various levels, i.e. on the manipulated object, all cooperating manipulators, and the moving platform of a robotic system. In this paper, a force tracking strategy inspired by a human control system is added to the MIC algorithm and the general formulation is revised to fulfill a desired force tracking strategy for object manipulation tasks. The stability analysis of the MIC algorithm based on the Liapunov Direct Method, besides error analysis, shows that a good tracking of cooperative manipulators and the manipulated object is guaranteed. Next, using MAPLE and MATLAB tools, a system of three manipulators mounted on a space free-flying robot is simulated. The task is moving an object based on given trajectories which come across an obstacle, to examine the performance of the developed control law. The results show that, even in the presence of both external disturbances and an impact due to collision with the obstacle, the response of the MIC algorithm is smooth. Moreover, based on the embedded force tracking strategy, the contact force is confined to follow a desired trajectory. Also, it is shown that decreasing the values of the controller mass matrix elements results in reducing both the object position and force tracking error.
Journal of Guidance Control and Dynamics, Sep 1, 2005
To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which on... more To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which one or more manipulators are mounted on a thruster-equipped base, have been proposed. Unlike fixedbased manipulators, the robotic arms of SFFR are dynamically coupled with each other and the freeflying-base, hence the control problem becomes more challenging. In this paper, the Multiple Impedance Control (MIC) is developed to manipulate space objects by multiple arms of SFFR. The MIC law is based on the concept of ...
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Papers by Rambod Rastegari