List of Articles Hami Tourajizadeh

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  1 - Longitudinal and Lateral Vibration Analysis of Cables in a Cable Robot Using Finite Element Method
  Hami Tourajizadeh Mahdi Yousefzadeh Moharram Korayem
  In this paper, vibrational response of a variable-length cable in longitudinal, lateral and torsional directions is analysed in a cable robot using FE method. The flexibility of cables has remarkable effect on positioning of the end-effector in cable robots. Also consid More

  In this paper, vibrational response of a variable-length cable in longitudinal, lateral and torsional directions is analysed in a cable robot using FE method. The flexibility of cables has remarkable effect on positioning of the end-effector in cable robots. Also considering the fact that the length of the cables are time dependent in a dynamic cable structure like robocrane, the numerical approaches are preferable compared to analytic solutions. To do so, the cable is divided into finite elements in which the virtual work equation and Galerkin method can be implemented for the equations. Considering the stiffness matrix, the characteristic equations and Eigen values of each element can be defined. A simulation study is done in the ANSIS on a planar robocrane with 2-DOF and also for a spatial case with 6-DOF that is controlled by the aid of six variable-length flexible cables in the space for two different types of solid and flexible end-effectors. Whole the cable robot flexibility is analyzed simultaneously instead of separation calculation of each cable. Not only all of the 3-D vibrating behaviour of the whole structure is studied in this paper but also the lengths of the cables are considered as variable. The vibrating response of mode shapes, amplitude and frequencies are extracted and analysed, and the results are compared for two case of solid and flexible end-effector which shows the effect of the flexibility in the position of the end-effector and the tension of the cables in different situations. Manuscript profile
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  2 - Modeling and Optimal Control of a Sport Utility Cable Suspended Robot
  Hami Tourajizadeh Moharam Habibnejad Korayem Mahdi Yousefzadeh
  A new mechanism is presented in this paper for simulating the athlete performance and training the sportsman’s exercises, using a closed loop six degrees of freedom (DOFs) cable suspended robot. This robot cancels the necessity of presence of a sport coach for training More

  A new mechanism is presented in this paper for simulating the athlete performance and training the sportsman’s exercises, using a closed loop six degrees of freedom (DOFs) cable suspended robot. This robot cancels the necessity of presence of a sport coach for training the sportsman. Using the proposed robot, it is possible to program the robot for training the athlete limb (arm, leg and etc.) within a predefined trajectory corresponding to his special sport performance. The limb of the sportsman which is involved in the game and should be trained could be attached to the end-effector of the cable robot. Since in many sports a large environmental space needs to be covered by the athlete movement, ordinary robots are not capable to be employed for this application while cable robots are applicable since a large dynamic workspace can be covered by them. Moreover, training the sportsman limb requires a precise movement of the mentioned end-effector on a predefined trajectory. This importance could not be satisfied without using a proper closed loop controlling system since a variable external disturbing force applies on the end-effector as a result of the weight of the sportsman limb and its dynamic movement. Studio cams and automatic brancard for carrying the damaged sportsman out of the field are also of other applications of the presented closed loop cable robot. So required dynamic and control formulation of the end-effector of the cable robot is derived for handling the athlete limb on a predefined trajectory in a closed loop way. Simulation on using the MATLAB confirms the possibility of the mentioned claim for simulating the sportsman training. Finally the efficiency of the proposed mechanism in training the athletes’ limb is also proved by conducting experimental test on Iran University of Science and Technology (IUST) cable robot (ICaSbot). Manuscript profile
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  3 - Design, Modeling and Adaptive Force Control of a New Mobile Manipulator with Backlash Disturbances
  Hami Tourajizadeh Samira Afshari
  In this paper a new model of the mobile robot is designed and modelled equipped by a manipulator which can perform an operational task. Also an adaptive force controller is designed and implemented on the robot to provide the capability of the operational task of the ro More

  In this paper a new model of the mobile robot is designed and modelled equipped by a manipulator which can perform an operational task. Also an adaptive force controller is designed and implemented on the robot to provide the capability of the operational task of the robot. Kinematic and kinetic modelling of the robot is developed and a new force control method is proposed for controlling the manipulator of the mobile robot by which the external disturbances caused by its operational performance can be controlled. Therefore, in this paper, a new mobile robot is designed which is suitable for operational tasks like firing and its related modelling is presented. Afterwards, an adaptive force controller is designed and implemented in order to neutralize the destructive effect of the mentioned backlash disturbance. By conducting some analytic and comparative simulation scenarios, the correctness of modelling and efficiency of the designed force controller is verified and it is shown that the proposed closed loop mobile manipulator can successfully accomplish a firing operation in a large workspace of a mobile robot with good accuracy. Manuscript profile
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  4 - A New Optimal Method for Calculating the Null Space of a Robot using NOC Algorithm; Application on Parallel 3PRS Robot
  Hami Tourajizadeh oveas gholami
  In this paper, a new optimal method for modelling of a 3PRS robot is proposed according to NOC algorithm. An optimal method of selecting the generalized coordinate is presented and a new algorithm of extracting the null space of over and under constrained robots is prop More

  In this paper, a new optimal method for modelling of a 3PRS robot is proposed according to NOC algorithm. An optimal method of selecting the generalized coordinate is presented and a new algorithm of extracting the null space of over and under constrained robots is proposed through which a lower amount of mathematical calculations is required. In this method, using the principal of derivatives of implicit functions, the null space of constraint matrix will be extracted. Afterwards the null space matrix is calculated with orthogonal columns. The proposed method is implemented on a 3PRS robot which is an under constrained robot. This robot is a kind of parallel spatial robot with 6 DOFs which can be controlled using 3 active prismatic joints and 3 passive rotary ones. This robot similar to other parallel robots has heavy, complicated and nonlinear model which needs heavy and time consuming mathematical calculations. The proposed strategy of extracting the null space of the robot, extremely and heavily decreases the volume of required mathematical calculations for modelling the robot and consequently decreases the inevitable consumed time of processing and numerical errors and increases the accuracy of simulations. Manuscript profile
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  5 - Design, Modeling and Manufacturing a New Robotic Gripper with High Load Bearing Capability and Robust Control of its Mechanical Arm
  vahid Boomeri Hami Tourajizadeh
  10.30495/admt.2021.1872367.1131
  In this paper, a new robotic gripper is proposed and modeled which is able to bear a high amount of load and it can be used as the claws of climbing robots. As the climbing robots are usually heavy and their configuration should be kept in height against the gravity, fi More

  In this paper, a new robotic gripper is proposed and modeled which is able to bear a high amount of load and it can be used as the claws of climbing robots. As the climbing robots are usually heavy and their configuration should be kept in height against the gravity, firm grippers with no slippage possibility should be designed in order to guarantee the stability. The proposed new gripper is essentially required for the grip-based climbing robots which are heavy and are supposed to accomplish a specific operational task while they are grasping the pipe-shaped structures. The kinematic and quasi-static modeling of the proposed gripper is extracted and its related parameters are optimized to provide the maximum gripping force and the minimum slippage probability. Since these robust grippers are usually actuated by high torque motors, the reaction effect of the actuators force on the arm of the robot model is investigated here as a new study. Hence, the corresponding mechanical arm is also controlled, using a robust nonlinear controller to neutralize the destructive effect of extreme reaction forces or torques from the gripper motors to the robot arm during its mission. Thus, a robust controller is designed and implemented on the arm joint to cover the required positioning accuracy of the arm movement during the climbing motion. Afterward, the applicability of the proposed gripper and also the efficiency of the designed controller is verified by the aid of some analytic and comparative simulation scenarios performed in MATLAB-SIMULINK and MSC-ADAMS simulation. It is shown that the proposed gripper together with its related controlling algorithm for the arm can successfully provide a proper climbing mechanism for these kinds of robots which are supposed to climb through the structures and perform a special manipulating task. Manuscript profile
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  6 - Modelling and Control of Mutation Dynamics of the Cancer Cells Employing Chemotherapy
  Hami Tourajizadeh zahra zarandi zakie farbodi ehsan sadeghi
  10.30486/admt.2021.1920220.1240
  In this paper, the analytic model of the mutation dynamics related to the cancer cells which is under the control of chemotherapy is developed and its corresponding metastasis is controlled using chemotherapy method. The progress of a cancer tumours is contributed to tw More

  In this paper, the analytic model of the mutation dynamics related to the cancer cells which is under the control of chemotherapy is developed and its corresponding metastasis is controlled using chemotherapy method. The progress of a cancer tumours is contributed to two main factors including metastasis and mutation. It is observed that controlling the metastasis dynamic without considering the mutation phenomenon is doomed to fail. In this paper, the mathematical model of the cancer dynamic is improved considering the mutation of the stem cells and the effect of chemotherapy injection as the corresponding controlling signal is investigated in the extracted state space. Controlling the cancer growth and its mutation process is accomplished here using PID controller and State Feedback Control (SVFC) method. It is shown that by the aid of the proposed model of this paper, not only the number of the cancer cells can be converted to zero, but also the mutation process can be blocked since the feedback of the mutated cells are also engaged in the state space of the system. Verification of the model is conducted by the aid of simulation in the MATLAB and comparing the results with previous studies. Manuscript profile