Teleoperation systems have attracted more attention in processes that human operator’s availability is difficult. In this paper, using retarded functions, teleoperation systems have been modeled as a special case of Network Control Systems (NCS) with nonuniform sampling and network delays. It is assumed that slave and master robots are linear and continues-time systems and input-delay approach is used for the stability analysis. Using the proposed Lyapunov function, the sufficient conditions for the stability of discrete network-based teleoperation system is proposed. It will be represented that the proposed conditions are less conservative than previous recent researches. Also an upper bound of sampling time for discrete control signals is computed in a manner that does not disturb the stability conditions. To meet this condition the problem is defined as the convex optimization program and is represented by the LMI terms. In the simulation part, the behavior of the teleoperation system under the nonuniform sampling is represented and the effect of sampling time on the trade-off between the stability and transparency has been studied.

Abstract - - Abstract - - Abstract - This paper proposes a master-slave approach to simultaneously control two drones with the aim of carrying an object toward a goal. The proposed method utilizes the Double Deep Q-Learning (DDQN) technique to train a master agent to be able to carry an object toward a goal with the help of a slave agent. This procedure is implemented such that the master agent gathers the observations and specifies the actions to be made by itself and the slave agent. Indeed, the slave agent just applies a predefined action and does not process any input for producing the output. This manner of learning, leads to a unified convergence to an optimal solution compared to the situation in which each agent is trained separately. To verify the functionality of the proposed method, the algorithm is examined in the webots simulation environment. The simulations show that the introduced method has a good performance when controlling the drones to reach to the goal. The introduced method, other than algorithmic benefits which leads to a faster convergence of the model, suggests some reduction in the processing demand. The reason is that the learning procedure is guided by one of the agents and consequently only one of the agents is responsible for doing the calculations that lead to choosing the action. In this scenario, the slave agent does not require any processing resources for choosing the action and just simply applies a predefined action dictated by the master agent.

Abstract - - Abstract - - Abstract - This paper proposes a master-slave approach to simultaneously control two drones with the aim of carrying an object toward a goal. The proposed method utilizes the Double Deep Q-Learning (DDQN) technique to train a master agent to be able to carry an object toward a goal with the help of a slave agent. This procedure is implemented such that the master agent gathers the observations and specifies the actions to be made by itself and the slave agent. Indeed, the slave agent just applies a predefined action and does not process any input for producing the output. This manner of learning, leads to a unified convergence to an optimal solution compared to the situation in which each agent is trained separately. To verify the functionality of the proposed method, the algorithm is examined in the webots simulation environment. The simulations show that the introduced method has a good performance when controlling the drones to reach to the goal. The introduced method, other than algorithmic benefits which leads to a faster convergence of the model, suggests some reduction in the processing demand. The reason is that the learning procedure is guided by one of the agents and consequently only one of the agents is responsible for doing the calculations that lead to choosing the action. In this scenario, the slave agent does not require any processing resources for choosing the action and just simply applies a predefined action dictated by the master agent.

In this paper the phase of two Duffing-Vanderpol oscillators with different initial conditions are synchronized using an alternative force added to the slave system. The master and slave systems are solved using Adomian’s decomposition methodphas and the solutions and their phase differences are plotted to show the effectiveness of the method.

Jacques Lacan, influenced by Freidrich Hegel, registered dialectic of Master and Slave into psychoanalytic discourses. Sigmund Freud's psychoanalysis, commonly known, is considered the science that examines the impact of unconscious actions, searching for signs of disease. Over time, psychoanalysis has been concerned with various sciences such as philosophy. One subject of dialectic of master and slave is linked with the analyst raised earlier by Hegel. The current paper aims to examine this theory through analysis of the relationships between four pair characters presented in Asghar Farhadi's film, About Elly (2009), using a qualitative research method. The data were collected by the film's observation and library sources, then its content was analyzed based on interpretive phenomenological analysis with a psychoanalytical approach mainly inspired by Freudian school. The first mode of such master-slavery contradictory is formed by Sepideh-Amir relationship, in which both of them are in struggle for power. The second mode is formed by Nazi-Manouchehr relationship, in which Nazi (female) is Master and Manouchehr (male) is in Slave status. The third mode is formed by Shohreh-Peyman relationship, in which the female figure confirms power of the other, as she is a slave, but at the same time she pretends to be the master herself. Finally, the last mode is formed by Elly-Ahmad relationship, in which both sides have tendency to be slave. The findings show that the master-slave dialectic, present in Iranian patriarchic society, is represented in defensive psychological processes of characters in Farhadi's film.

We propose a new impedance control algorithm for delayed linear bilateral teleoperation systems. In the presented control strategy, with regard to a preferred impedance model for the master and slave robots, a special dynamic feature at the human and the master robot along with the slave robot and environment interface is proposed. In addition, external forces signals including operator and remote environmental forces are used in the controller to attain desired impedance model. A force estimation scheme is presented to remove measurement of external forces. Then, the desired impedance model is located into an appropriate sliding-mode control scheme to compensate the parameters uncertainties emerged by external force estimation errors. Then, the absolute stability criterion is used to investigate the stability of the closed-loop teleoperation system along with transparency. Consequently, the control strategy is implemented on 1-DOF robotic system as the master and slave robots. Simulation results verify the effectiveness of the presented impedance controller by using estimated external forces.

In this paper, a new method for nonlinear teleoperation system with uncertainty in dynamical parameters and gravitational acceleration is introduced. This system can be used in space teleoperation where the slave robot works on uncertain height with unknown gravitational acceleration. Also the proposed method can be used when the master and slave robot work on different latitude. In the adaptive controller which is used in this paper, the gradient descent method is used to update parameters. In the proposed method, the bound of unknown parameters is not used in the controller. The proposed method cannot estimate the parameters of the master and slave robots and the unknown gravitational acceleration but can cause a proper functioning of the system. To verify the efficiency of the proposed method, it is applied on 2-DOF planar robots with constant delays in the transmission channel.

The so-called Islamic State (ISIS/ISIL) used the hadith mentioning that “ the slave-girl will give birth to her master” to justify its renewal of sexual slavery. This hadith is talking about signs before the end of the world, so it could be interpreted by the same Temple theology technique that has been used in the biblical book of Revelation, which is also about the end of the world. “ Temple theology” refers to the fact that many obscure and bizarre texts symbolically describe the rituals and politics of the Temple in Jerusalem. Thus, it will be argued that the whole hadith is talking about events that happened prior to the destruction of the Second Temple in Jerusalem in 70 CE (the Temple symbolized the world, so the end of the world refers to this incident). In particular, it will be shown that slave-girl refers to the Virgin Mary giving birth to Christ. The hadith is then linked to the start date of the building the Dome of the Rock in 688 CE, which is the year 999/1000 according to the “ Seleucid Era” calendar, implying a nearness to a symbolic end of the world. As such, the “ Islamic State” has no Islamic basis to use sexual slavery. As an appendix, the Dabiq hadith concerning the conquest of Constantinople is briefly discussed with reference to the possibility that Constantinople did fall to the Muslims before another symbolic end of the world, the year 7000 according to the Byzantine Calendar.

The possibility of transferring the sense and force of the user on the driver side to the follower robot has always been discussed in master/slave systems. It has gained special importance in recent research. In the present study, the control torque of the slave side is adjusted by transferring the user's force (with the haptic handle) from the master side to the slave robot. The proposed system is a four-channel approach where the position signal and force signal are transmitted to the slave on the master's side, and reciprocally, the position signal and the contact force of the environment on the slave reach the master's side. The input-to-state stability for the master-slave system is investigated with the proposed approach. The approach of this research, unlike the approach of many previous studies, does not require the acceleration of the joints to parameterize the robot's dynamics or control it. In this method, the amount of force/torque of the user's hand of the master robot will be directly involved in the control command of the slave robot. In this article, in addition to the four-channel system, a three-channel system is proposed. Both systems, in addition to following the path, can follow the user's will on the master's side when encountering unexpected obstacles and stopping joints. In addition to software simulation, experimental implementation has been done on a leader-follower system with haptic robots, which confirms the correctness of the proposed approach.