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In this study, the control problem of a knee rehabilitation robot is examined. The main drawback of rehabilitation facilities, such as continuous passive motion, is the lack of feedback from the interaction force between the robot and patient leg. This means that if during the exercises, an unvoluntary motion by patient is generated, the increased interaction force can then damage the patient leg. The interaction force is increased because the robot tries to hold the patient leg along the prescribed reference path. In the current paper, to realize the compliant behavior of the robot, the concept of admittance along with two control methods including adaptive model reference and integral backstepping will be utilized. Adopting admittance control method, the robot will deviate the prescribed path so that the interaction force can be decreased. The obtained simulation results reveal the good performance of the robot even in the presence of noisy sensory data. Additionally, it has been shown that the proposed combined admittance and backstepping controller has better performance, in terms of tracking error and decrease of interaction force, as compared with the model adaptive reference model.

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The tractor-trailer system is a wheeled mobile robot (WMR), including one wheeled unit named tractor that is equipped with actuators and one or some wheeled units named trailer that are connected to each other with a passive joint. As a special case, in this paper, the system locomotion is by tractor, and trailer is completely passive. In this paper, we develop the kinematic model of tractor-trailer; so the inputs of system are supposed to be tractor angular velocity and trailer linear velocity. Because of pure rolling condition between wheel and ground surface, we encounter a nonholonomic system. In this paper Model Predictive Control (MPC) is used in control designing of Tractor-Trailer for the first time and the goal is trajectory tracking of trailer position. First, the kinematic equations of tractor-trailer are developed. Then a feasible reference geometrical path is considered. After linearizing the system equations around reference path and using MPC that is an optimal control based method, a tracking controller is designed that minimizes a predefined cost function. Considering actuator saturation in system inputs, we solve a constrained optimization problem using numerical methods. The controller designed in this paper, will be compared against classic controller PID and its better performance is presented. Finally, the effectiveness and robustness of controller against disturbances and parameter uncertainties is proved using MATLAB results.

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Human ankle-foot gait is the result of a complex interaction between nerves and muscles. A significant number of prosthetic ankle-foots (passive, semi-active, active) have been designed to restore an identical function of a real limb. Excluding passive and semi-active prosthesis who couldn’t generate any positive work, one of the biggest challenges in creating these prostheses is providing the needed power and energy during movement. Supplying this power and energy, requires a high-torque and high-power actuator having high weight, thereby causing a dramatic increase in the weight and size of that prostheses. In this paper, a combination of an active actuator (an electrical motor) and an passive stimulus (a spring) is utilized, which decrease the needed power and energy, and in addition to walking mode can also support running mode up to 2.5m/s. Accordingly, The first stage of this article includes mechanical modeling of the ankle and evaluation of efficiency and power consumption in all presented models. Then the structure of Series Elastic Actuator differed with the previous structures is selected as the best combination.  In this opted structure, power and energy consumption is dramatically declined up to 58% and 26% in walking mode and 64% and 57% in running mode. Consequently, a lighter motor and battery can supply the required power, so the prosthesis chr('39')s weight is subtracted.

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Sports simulation mechanisms practically have a lot of appeal and application to implement virtual reality environments. Cycling simulator has a more special place in sports and urban transportation due to the popularity of cycling activities. In this paper, the design and construction of a new motion generating mechanism for an interactive cycling simulator is presented. First, by using the references, the range of velocity and acceleration that the user should experience while cycling has been extracted, and by analyzing other cycling simulators, the required degrees of freedom and its range have been determined. Then, a new motion generating mechanism with two degrees of freedom is designed. Genetic algorithm has been used for dimensional optimization of the mechanism parameters. Kinematics and dynamic equations of the mechanism have been extracted. According to the dynamic model of the mechanism, a controller has been designed using the feedback linearization method and the performance have been investigated. Finally, the designed motion generating mechanism has been constructed and the position control has been implemented on the platform.

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The purpose of this study is to provide a paradigmatic and systematic model for developing Iran’s science diplomacy, based on capabilities of the Imam Sadiq University and prioritizing its strategies. This study is based on data-driven management strategy and according to systematic approach of Strauss and Corbin wants in order to obtain paradigmatic model of the Science Diplomacy development and by using IPA methodology, has prioritized its strategies. For this purpose, 18 professors, experts and professionals of science diplomacy at the Imam Sadiq(AS) University have been identified and interviewed. At the next stage, by processing data and concepts, Level 1 and Level 2 concepts of the paradigmatic model have been obtained. At the next step, the strategies were prioritized using the opinions of 15 persons priorly selected as the sample. According to taken steps, it has become clear that moving towards the development of science diplomacy at the Imam Sadiq(AS) University due to its dynamic capabilities needs special qualifications and factors and special delicacies in its designs and plans. Some of results of implementing the science diplomacy at the Human Sciences Universities are as follows: enhancing the capabilities of the university, strengthening the international position of the Islamic Republic of Iran, dealing with the dysfunctions of the science diplomacy at the Human Sciences Universities and fulfilling the mission of the Islamic Republic of Iran towards the poor people of Muslim world. The "university internationalization" strategy also has the highest priority among the proposed strategies.