In this paper, distributed adaptive robust controller is investigated to solve the leader-follower consensus problem for a multi-agent system consisting of several single-link robot arms. In this approach, each arm is considered as an agent. The dynamical model of each arm contains known and unknown non-linear terms. Unknown terms may be due to parameter uncertainty or simplification of the model. Furthermore, external disturbances are considered in the dynamical equations of each agent. Moreover, the input signal amplitude for each agent should be limited, which is due to the upper bound of the saturation function of the input. In this paper, in order to eliminate the effect of uncertain terms, the adaptive robust approach is used in the design of control laws. In this regard, the upper bounds of uncertain terms are obtained through adaptive laws, which dramatically reduce conservatism. Furthermore, the distributed control laws are designed in such a way that all the agents reach consensus in spite of the uncertain terms and input saturation constraint. The basis of the approach proposed in this paper is based on adaptive sliding mode techniques. For this purpose, suitable sliding surfaces are proposed and distributed adaptive sliding mode controllers are designed. Finally, simulations are presented to confirm the results of theories.

In this paper an uncertain multi objective closed-loop supply chain is developed. The first objective function is maximizing the total profit. The second objective function is minimizing the use of row materials. In the other word, the second objective function is maximizing the amount of remanufacturing and recycling. Genetic algorithm is used for optimization; and for finding the pareto optimal line, Epsilon-constraint method is used. Finally a numerical example is solved with proposed approach and performance of the model is evaluated in different sizes. The results show that this approach is effective and useful for managerial decisions.

Constrain is the condition of driven by necessity. The principle of constraint determines the duties of the person constrained. In jurisprudence, it includes a range of activities from cleanness to blood compensation. However, jurisprudents have discussed it mainly with regard to those that can be eaten and drunk, and presented three different interpretations: fear of losing one"s life; fear in general, including fear of losing one"s life, or one"s limb, etc.; and fear of things not related to oneself but to others. The roots of constraint are compulsion, precautionary concealment, loss and necessity. The present article deals with a kind of constraint whose source is necessiy. The Qur"an has explicitly excused the person constrained from duties provided that the oppressor shows no inclination to sin. Tradition says that "there is so unlawful act that God Almighty has not made it permissible under constraint." The intellect also knows it permissible to give up necessary duties and to do the unlawful acts under constraint. Finally, the writer presents the conditions under which the application of the principle of constrain is made permissible.

A computational approach is presented to obtain the optimal path of the end-effector for the 10 DOF bipedal robot to increase its load carrying capacity for a given task from point to point. The synthesizing optimal trajectories problem of a robot is formulated as a problem of trajectory optimization. An Iterative Linear Programming method (ILP) is developed for finding a numerical solution for this nonlinear trajectory. This method is used for determining the maximum dynamic load carrying capacity of bipedal robot walking subjected to torque actuators, stability and jerk limits constraints. First, the Lagrangian dynamic equation should be written to be suitable for the load dynamics which together with kinematic equations are substantial for determining the optimal trajectory. After that, a representation of the state space of the dynamic equations is introduced also the linearized dynamic equations are needed to obtain the numerical solution of the trajectory optimization followed by formulation for the optimal trajectory problem with a maximum load. Finally, the method of ILP and the computational aspect is applied to solve the problem of trajectory synthesis and determine the dynamic load carrying capacity (DLCC) to the bipedal robot for each of the linear and circular path. By implementing on an experimental biped robot, the simulation results were validated.

Changing the trajectory of a projectile can be accomplished by unbalancing the pressure distribution on the body surface and this usually is achieved by surface spreading techniques. The major drawbacks of such techniques are high drag force; fins aerodynamic heating and high time response. To overcome these difficulties, recently application of plasma actuators has been evaluated numerically and experimentally. It is known that the time response of a projectile to control commands is a key factor to its CEP. In the present paper, unsteady flow around a supersonic projectile was calculated using Fluent software and its time response to a control command was analyzed. In this investigation, it is shown that using plasma actuator in comparison with aerodynamic fins can reduce the time response of a projectile about one order of magnitude. This reduction in time response can improve the performance of a projectile significantly.

An actuator is a device that converts input energy into mechanical energy. According to various types of input energy, various actuators have been advanced. Displacement in the electromagnetic, hydraulic and pneumatic actuators achieve by moving a piston via electromagnetic force or pressure, however the piezoelectric actuator (piezoceramic plates) displace directly. Therefore, accuracy and speed in the piezoelectric device are higher than other types of actuators. In the present work, the high-field electromechanical response of high-quality (1−x)(Bi 0.5Na0.5)TiO3–x(Bi0.5K0.5)TiO3 samples abbreviated to BNKTx with x = 0.18, 0.20, 0.22 and 0.24 ceramic materials across its MPB was investigated. The piezoelectrics and actuation characteristics were characterized. Ourresults indicate that x = 0.20, indeed, constitutes the best choice for the MPB composition in the system. Maximum of remanent polarization (37.5 mC cm-2) was obtained for x=0.20. High-field electromechanical responses were also obtained for BNKT0.20 samples. This material exhibited giant field induced strains of 0.13% under 1 kV mm -1 at room temperature.

In this paper, the thermal buckling analysis of a circular plate made of FGM materials with actuator/actuator piezoelectric layers based on neutral plane, classical plate theory and first order shear deformation plate theory is investigated. Reddy's model is assumed for material properties of FGM plate. Plate under the thermal loading, nonlinear temperature rise through the thickness and clamped edges is considered. Equilibrium and stability equations are drived using the calculus of variations and applying Euler equations. The obtained results are compared with the numerical values of the critical buckling temperature based on the theories mentioned above, and good agreement is observed between them.

The concept of design is associated with the notion of constraint as a limiting factor, and the search for the constraint in the design process is essential in design research. This study applies the ontological method to define the domain and scope of constraints, their classes and subclasses, and how to apply them. We concluded that there are two types of constraints in design: inside the designer’, s mind or internal constraint and outside it or external constraint. Each of these is classified into two subclasses: internal constraints can be divided into deduced and subject constraints, and external constraints are categorised into imposed and intrinsic constraints. In the end, we proposed a model that shows that designers can identify, choose, manage, and even generate constraints in the design process to facilitate the restructuring of the design problem, which helps them solve the design problem.