The determination of the optimal locations of controllers in active or semi active structural control has received very little attention. The optimal PLACEMENT, compared with the non optimal case, provides control performance with a fewer number of controllers and smaller control force. In this research, the effect of the locations of the controllers on the control force and control performance was studied. This project uses the ‘POLE-Assignment’ method for the purpose of determining control forces, and for considering the semi active state. In the semi active control state system, the control force is determined by specifying a value to produce this state. During this study, two optimization methods have been used for active control. In the first method, all cases are studied to find the optimal case. Then several evaluation criteria have been used to find an optimal case. The second method is based on defining a performance index related to each story. In this method, with a series of repeatable operations, stories with a maximum index have been selected as optimum. The numerical examples show that the results of the first and second method are somewhat different. In addition, the findings of this study indicate that the number of controllers can be reduced in most cases. General results have been obtained for the optimal PLACEMENT of controllers in common structures.

In this paper the control algorithm for controlled civil structures subjected to earthquake excitation isthoroughly investigated. The structural control consists of monitoring and analyzing the incomingexcitation signal and the response of structure, applying the control algorithm for the calculation of therequired control action, and, finally, implementing this action to the structure. The objective of this work isthe control of structures by means of the POLE PLACEMENT algorithm, in order to improve their responseagainst earthquake actions. The POLE PLACEMENT or POLE assignment algorithm is a well-known, classicalcontrol algorithm that estimates the feedback matrix so that the system will have POLEs (eigenvalues) thatare pre-decided by the designer. Successful application of the algorithm requires judicious PLACEMENT of theclosed-loop eigenvalues from the part of the designer. The POLE PLACEMENT algorithm was widely applied tocontrol mechanical systems. In this paper, a modification in the mathematical background of the algorithmin order to be suitable for civil fixed structures is primarily presented. The proposed approach isdemonstrated by numerical simulations for the control of both single and multi-degree of freedom systemssubjected to seismic actions. Numerical results have shown that the control algorithm is efficient inreducing the response of building structures, with small amount of required control forces.

In this paper, a gain-scheduled three-loop autopilot is designed for the pursuit system that can satisfy the mixed H2=H1 performance and time-domain constraints. The gain-scheduled autopilot problem was  rst converted into a state-feedback control problem for Linear Parameter Varying (LPV) systems and then, a control method was proposed using the Linear Matrix Inequality (LMI) approaches. The new approaches could satisfy the mixed H2=H1 performance and regional POLE PLACEMENT constraints and ensure no constraints on system matrices. The  nal gain-scheduled autopilot which can promise greater stability and performance for the entire parameter range was calculated using the interpolation of the  nite number of  xed controllers. Simulation results showed the e ciency of the proposed method in designing the three-loop autopilot.

Efficient distribution of service requests between fog and cloud nodes considering user mobility and fog nodes’ overload is an important issue of fog computing. This paper proposes a heuristic method for task PLACEMENT considering the mobility of users, aiming to serve a higher number of requested services and minimize their response time. This method introduces a formula to overload prediction based on the entry-exit ratio of users and the estimated time required to perform current requests that are waiting in the queue of a fog node. Then, it provides a solution to avoid the predicted overloading of fog nodes by sending all delay-tolerant requests in the overloaded fog node’s queue to the cloud to reduce the time required for servicing delay-sensitive requests and to increase their acceptance rate. In addition, to prevent requests from being rejected when the mobile user leaves the coverage area of the current fog node, the requests in the current fog node’s queue will be transferred to the destination fog node. Simulation results indicate that the proposed method is effective in avoiding the overloading of the fog nodes and outperforms the existing methods in terms of response time and acceptance rate.

This paper presents implementation of position control for planar cable-driven parallel robots using Visual servoing. The main contribution of this paper contains three objectives. First, a method is used toward kinematic modeling of the robot using four-bar linkage kinematic concept, which could be used in online control approaches for real-time purposes due to decreasing of the unknown parameters and computation time. Second, in order to track the position of End-Effector, an online image processing procedure is developed and implemented. Finally, as the third contribution, two different controllers in classic and modern approaches are applied in order to validate the model with plant and obtain the most promising controller. As classic controller, POLE PLACEMENT approach is suggested and results demonstrate weaknesses in modeling the uncertainties although they represent acceptable performance. Due to the latter incapability, sliding mode controller is utilized and experimental tests represent effectiveness of this method. Result of the latter procedure is an inimitable operation on the desired task, however, it suffers from chattering effect. Moreover, results of these controllers confirm accommodation between the model and robot. The whole procedure imposed could be applied for any kind of cable-driven parallel robot.

In this paper, first a new algorithm for POLE assignment of closed-loop multi-variable controllable systems in a prescribed region of the z-plane is presented. Then, robust state feedback controllers are designed by implementing a neural fuzzy system for the PLACEMENT of closed-loop POLEs of a controllable system in a prescribed region in the left-hand side of z-plane. A new method based on the parameterizations of condition number function of a closed-loop system whose POLEs are varied in a prescribed region by neural fuzzy system is also designed.

Liquid transport by unmanned aerial vehicles is a necessary task in autonomous firefighting and field spraying missions. On the other hand, transient and residual sloshing of the liquid during and after the movement can cause instability, increase position error and control effort, and create danger or damage if the liquid is flammable. Therefore, in this study, control of a liquid carrier quadrotor has been studied and a controller has been presented that, unlike previous studies, can provide stability in point-to-point transmission without the need to measure or estimate liquid states. For this purpose, a controller is first designed by linearizing the equations of motion of the system and assuming the liquid is rigid via POLE PLACEMENT. On the other hand, in order for the behavior of the system to be similar to the behavior of the design model and to maintain the stability of the system, the liquid sloshing must be reduced as much as possible. Therefore, a command smoother based on the natural frequencies of the liquid sloshing modes is used. The ability of the proposed control system has been investigated, validated, and compared with a similar study by simulation. Also, the simulation results show that the implementation of the designed command smoother can significantly reduce the amplitude of liquid sloshing, the deviation of the system states from the equilibrium state, and the control effort.

Interest in applying flying robots especially quadcopters for civil purposes has dramatically grown in the last decade. In fact, since quadcopters are capable of vertical takeoff and landing (VTOL), they can be widely employed for nearly any aerial task where a human presence is hazardous or response time is critical. This paper is concerned with a tracking control design of a quadrotor via POLE PLACEMENT Technique based on presence of a diffeomorphism. To this end, after dynamic modeling of the flying robot using Newton-Euler equations, the state space form of the acquired final model as well as the signal controls are presented. Since the main objective of this work is to track the smooth reference signals, the differential equations described the dynamics of the system, based on our proposed approach, should be transformed from the state space into input-output space. So, the output controllability of the system, as well as the presence of a diffeomorphism between two state spaces are considered, respectively. Finally, a tracking control design via POLE PLACEMENT Technique, in the presence and absence of uncertainty, is proposed.