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29th AAAI Conference on Artificial Intelligence, AAAI 2015

作者： Mousavi, Amin Araabi, Babak Nadjar Ahmadabadi, Majid Nili Robotics and AI Lab Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Iran School of Cognitive Science Tehran Iran

ISBN: (纸本)9781577357209

This article discusses the notion of context transfer in reinforcement learning tasks. Context transfer, as defined in this article, implies knowledge transfer between tasks that share the same environment's dynamics and reward function, but have different state and action spaces. For example, we have a working mobile robot in an environment. At some point, we decide to upgrade its sensors and/or actuators. Any change in these modules will result in a different description of the agent- environment model, and the trained knowledge is no longer applicable. We consider the tasks of the old and new robots, as the source and target tasks, respectively. The Markov decision process (MDP) of these tasks, under certain conditions, are called Q-transferable tasks, and the problem of knowledge transfer between them is called context transfer. We investigate the relation of the MDPs of these tasks. Copyright © 2015, Association for the Advancement of Artificial Intelligence (***). All rights reserved.

关键词： Markov processes

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The effect of finite duration inputs on the dynamics of a system： Proposing a new approach for cancer treatment

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International Journal of Biomathematics 2015年第3期8卷 155-173页

作者： Mostafa Nazari Ali Ghaffari Center of Excellence in Robotics and Control K. N. Toosi University of Technology Pardis St. Tehran 19697 64499 Iran Mechanical Engineering DepartmentK. N. Toosi University of TechnologyPardis St. Tehran 19697 64499 Iran

In this paper, a principal question regarding the effect of inputs on the characteristics of dynamic systems is discussed. Whether an input implemented only for a limited duration, can change the characteristics of a dynamic system such that the behavior of the free system, after eliminating the input, differs from that before acting the input？ In this paper, it is shown that a limited time acted input is not able to change the dynamical properties of a system after its elimination. Regarding the proposed approach, a novel finite duration treatment method is developed for a tumor-immune system. The vaccine therapy is used to change the parameters of the system and the chemotherapy is applied for pushing the system to the domain of attraction of the healthy state. For optimal chemotherapy, an optimal control is used based on state-dependent Riccati equation （SDRE）. It is shown that, in spite of eliminating the treatment （therapeutic inputs）, the system approaches to healthy state conditions. The present analysis suggests that a proper treatment method must change the dynamics of the cancer instead of only reducing the population of cancer cells.

关键词： Cancer stability changeable dynamic properties system.

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An Adaptive Sliding Mode Observer for Linear Systems under Malicious Attack

An Adaptive Sliding Mode Observer for Linear Systems under M...

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IEEE International Conference on Systems, Man, and Cybernetics

作者： Niloofar Jahanshahi Nader Meskin Farzaneh Abdollahi Wassim M. Haddad Center of Excellence on Control and Robotics Department of Electrical Engineering Amirkabir University of Technology (Tehran Polytechnic) Iran Department of Electrical Engineering Qatar university Doha Qatar Department of Electrical Engineering Amirkabir University of Technology Tehran 15914 Iran Department of Aerospace Engineering Georgia Institute of Technology Atlanta United States

ISBN: (纸本)9781509018987

Recent years have witnessed extensive research activities in the development of control law architectures for cyber-physical systems consisting of sensing, computing and communication modules working together to control physical systems. One of the main challenges in cyber-physical systems is the vulnerability to adversarial attacks. As the important module in cyber physical systems, sensor measurements are prone to malicious attacks due to the use of open computation and communication architectures. This paper proposes an adaptive sliding mode observer for state estimation of systems subjected to adversarial attacks. The novelty of the method considered here lies in the use of the equivalent control concept to explicitly reconstruct attack signals and consequently the system state. A design procedure is described and simulation results are presented to demonstrate the effectiveness of the proposed approach.

关键词： Attack reconstruction Adaptive sliding mode observers Cyber-physical systems Equivalent control

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Output Synchronization of Multi-agent Systems with Nonlinear Non-minimum Phase Dynamics

Output Synchronization of Multi-agent Systems with Nonlinear...

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American control Conference

作者： Foroogh Shamsi H. A. Talebi Farzaneh Abdollahi Center of Excellence on Control and Robotics Department of Electrical Engineering Amirkabir University of Technology Tehran 15914 Iran

ISBN: (纸本)9781479917730

This paper deals with output synchronization problem in nonlinear multi-agent systems. The main contribution of the paper is to guarantee output synchronization in the network while the dynamics of agents exhibit non-minimum phase behavior. To achieve this goal, a control signal is presented for each agent consisting of two terms. The first term is a linear function of each agent states employed in order to overcome the non-minimum phase dynamics of the multiagent system, whereas the second term is a function of the output of neighboring agents which provides coupling among agents and guarantees output synchronization in the network. A numerical example is presented to verify the effectiveness of the proposed approach.

关键词： Agents synchronized network Output dynamics PHASE BEHAVIOR linear function

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Nonlinear Bilateral Teleoperation with Flexible-Link Slave Manipulator

Nonlinear Bilateral Teleoperation with Flexible-Link Slave M...

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RSI/ISM International Conference on robotics and Mechatronics

作者： A. Rashidinejad S. K. Y. Nikravesh H. A. Talebi The Center of Excellence on Control and Robotics Department of Electrical Engineering Amirkabir University of Technology Tehran 15914 Iran

ISBN: (纸本)9781467372350

This paper addresses bilateral control of a nonlinear teleoperation system with flexible-link slave manipulator. For this purpose, due to the non-minimum phase behavior of flexible-link manipulators, tip position tracking of the slave manipulator is performed based on the output redefinition method. Moreover, to compensate the uncertainties, a robustifying term is considered in the controller. However, disturbances exerted on the master robot are estimated via a nonlinear disturbance observer. Then, the master force controller is designed based on the estimated value and environmental force feedback from the slave part.

关键词： Bilateral teleoperation flexible-link manipulator output redefinition stability uncertainty

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Mechanical Design, Fabrication, Kinematics and Dynamics Modeling, Multiple Impedance control of a Wrist Rehabilitation Robot

Mechanical Design, Fabrication, Kinematics and Dynamics Mode...

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RSI/ISM International Conference on robotics and Mechatronics

作者： Mohammad Reza Sajadi Ali Nasr S. Ali A. Moosavian Hassan Zohoor Center of Excellence in Mechatronics University of Tabriz Tabriz Iran t Center of Excellence in Robotics and Control ARAS Lab. K.N. Toosi University of Technology Tehran Iran Center of Excellence in Robotics and Control ARAS Lab. K.N. Toosi University of Technology Tehran Iran Center of Excellence in Design Robotics and Automation Sharif Univ. of Tech. Tehran Iran

ISBN: (纸本)9781467372350

Rehabilitation is the best approach for patients who suffer physical disability of their upper-limbs. Maintaining the intensity of exercise during treatment is the main factor that makes the robots suitable for rehabilitation since robots do not get tired and do the exercises with constant intensity under supervision of the doctor. Two main categories of rehabilitation robots are End-Effector based robots and wearable robots. According to the fact that most problems occur in need of rehabilitation for hand wrist area, in this paper a wearable rehabilitation robot has been developed for the wrist. Nowadays, wearable robots attract more attention than the other group. Wearable robots are categorized into three types: Exoskeleton robots, Prosthetic robots and Orthotic robot. In this paper, a new structure for an Orthotic wearable robot is developed for human wrist rehabilitation. This structure has an automatic base that makes the robot suitable for both hands. This robot has three degrees of freedom that is similar to human wrist joint. In the remaining of the paper, Conceptual design, mechanical design, kinematics and dynamic analysis of the robot as well as multiple impedance control are presented.

关键词： Wrist Rehabilitation Robot Design and Fabrication Robot Kinematics and Dynamics Modeling Multiple Impedance control

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Balance Recovery of a Quadruped Robot

Balance Recovery of a Quadruped Robot

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RSI/ISM International Conference on robotics and Mechatronics

作者： Mahdi Khorram S. Ali A. Moosavian Center of Excellence in Robotics and Control Advanced Robotics and Automated Systems Lab Dept of Mech Eng K. N. Toosi Univ of Tech Tehran Iran Center of Excellence in Robotics and Control Advanced Robotics and Automated Systems Lab Dept of Mech Eng K. N. Toosi Univ of Tech Tehran Iran

ISBN: (纸本)9781467372350

Maintaining the balance or stability of legged robots in natural terrains is a challenging problem. Besides the inherent unstable characteristics of legged robots, the sources of instability are the irregularities of the ground surface and also the external pushes. In this paper, a push recovery framework for restoring the robot balance against external unknown disturbances will be demonstrated. It is assumed that the magnitude of exerted pushes is not large enough to use a reactive stepping strategy. In the comparison with previous methods, which a simplified model such as point mass model is used as the model of the robot for studying the push recovery problem, the whole body dynamic model will be utilized in present work. This enhances the capability of the robot to exploit all of the DOFs to recover its balance. To do so, an explicit dynamic model of a quadruped robot will be derived. The balance controller is based on the computation of the appropriate acceleration of the main body. It is calculated to return the robot to its desired position after the perturbation. This acceleration should be chosen under the stability and friction conditions. To calculate main body acceleration, an optimization problem is defined so that the stability, friction condition considered as its constraints. The simulation results show the effectiveness of the proposed algorithm. The robot can restore its balance against the large disturbance solely through the adjustment of the position and orientation of main body.

关键词： Push recovery Quadruped robots dynamics stability friction constraints

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A fuzzy controller for visual comfort inside a meeting-room 23

A fuzzy controller for visual comfort inside a meeting-room

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23rd Mediterranean Conference on control and Automation, MED 2015

作者： Rodriguez, J.M. Castilla, M. Alvarez, J.D. Rodriguez, F. Berenguel, M. University of Almería Agrifood Campus of International Excellence CeiA3 CIESOL Joint Center University of Almería CIEMAT Automatic Control Robotics and Mechatronics Research Group Ctra. Sacramento s/n La-Cañada04120 Spain

ISBN: (纸本)9781479999361

In general, human beings receive most part of information through eyesight. Therefore, light is an essential element which allows people to distinguish the shape, colour and perspective of the environment around them. Moreover, energy efficiency in buildings is a problem that is being widely analysed since energy consumption inside them represents approximately 40% of total world energy consumption. In addition, illumination supposes around 20% of total energy consumption in houses and between 40% and 70% in shops and offices. This paper presents a fuzzy logic controller which allows maintaining visual comfort inside a meeting-room through an efficient use of both natural and artificial lights. In order to probe the effectiveness of the proposed control system, suitable real results obtained in a meeting-room of the CIESOL bioclimatic building are included and commented. © 2015 IEEE.

关键词： Energy utilization

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Modified Jacobian Transpose control of a Quadruped Robot

Modified Jacobian Transpose Control of a Quadruped Robot

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RSI/ISM International Conference on robotics and Mechatronics

作者： Mahdi Khorram S. Ali A. Moosavian Center of Excellence in Robotics and Control Advanced Robotics and Automated Systems Lab Dept of Mech Eng K. N. Toosi Univ of Tech Tehran Iran

ISBN: (纸本)9781467372350

Quadruped robots have many advantages over other robots. Their excellent potentials to traverse different terrains are one of main advantages which distinguish these robots from wheeled mobile robot. In this article, the gait planning problem and also the design of an appropriate controller for a quadruped robot will be investigated. To this end, an explicit dynamics model of an 18-DOF quadruped robot will be derived. Then, a constraint elimination method is proposed to cancel the contact forces from dynamics equations and also express the dynamics equations in terms of the independent variables of the motion. In the walking gait, these DOFs are the position and the orientation of main body and also the joint angles of the swing leg. A stable COG trajectory generation algorithm based on the ZMP approach will be proposed. The path of swing legs is planned to prevent any impact between the swing legs and the ground. To apply the generated path on the robot, Modified Transpose Jacobian (MTJ) controller is used. This controller is based on the feedback linearization approach. It uses the command controller in the previous time step to increase the controller performance. The simulation is conducted to evaluate the performance of the gait planning algorithm and also the controller. Obtained results verify the merits of the proposed algorithms.

关键词： Quadruped robots Walking gait stable gait planning control MTJ Algorithm

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CPG-Based Gait Planning Of a quadruped robot for Crossing Obstacles

CPG-Based Gait Planning Of a quadruped robot for Crossing Ob...

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RSI/ISM International Conference on robotics and Mechatronics

作者： Farhad Asadi Mahdi Khorram S. Ali A. Moosavian Center of Excellence in Robotics and Control Advanced Robotics & Automated Systems (ARAS) Lab Department of Mechanical Engineering K. N. Toosi University of Technology Tehran Iran

ISBN: (纸本)9781467372350

ability of quadruped robots for adjusting posture for crossing natural obstacles is an important issue. These robots should change their footholds to avoid any obstacles. In this paper, a gait planning algorithm based on Cartesian CPG-based controller for a quadruped robot in order to cross different planar obstacles will be developed. In proposed approach, the rhythmic patterns in central pattern generator are modulated by feedback signals which encode foothold positions in respect to the planar obstacles. By using these feedback signals the frequency of oscillation will be adjusted so that desired gait avoids the obstacles. The obtained gait results in the swing and stance sequences and also step length for each foot. Then, the trajectory of the swing legs in Cartesian space will be computed based on the CPG output data. So, the desired ZMP (Zero moment Point) trajectory will be obtained by using the footholds. Then, COG trajectory will be obtained by using a preview controller on the basis of the desired ZMP trajectory. Finally, proposed algorithm will be tested for crossing planar obstacles in different size and distance. Obtained results show the effectiveness of the proposed approach in crossing obstacles with different size and distance to each other.

关键词： central pattern generation gait planning Quadruped robots obstacle-crossing phase resetting

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