This article aims to control the group flight of unmanned helicopters. After presenting the dynamic equations using the Newton-Euler METHOD, the dynamic inversion control has been applied to control the position and attitude of helicopters. generalized predictive control was also used to control the position and attitude of the helicopter. And the results of the simulation of these two controllers were compared, which showed the better performance of the predictive control. Therefore, in the design of the formation control, the independent control of the helicopters was done using the predictive control METHOD. To control the formation, the METHOD based on the leader-follower MODEl has been used, An integral SLIDING MODE controller is also used to control the dynamics of the formation error. The results of the simulation showed the success of the tracking by increasing the number of helicopters and the linear and spiral paths in the control commands.

This article investigates the problem of simultaneous attitude and vibration control of a flexible spacecraft to perform high precision attitude maneuvers and reduce vibrations caused by the flexible panel excitations in the presence of external disturbances, system uncertainties, and actuator faults. Adaptive integral SLIDING MODE control is used in conjunction with an attitude actuator fault iterative learning observer (based on SLIDING MODE) to develop an active fault tolerant algorithm considering rigid-flexible body dynamic interactions. The discontinuous structure of fault-tolerant control led to discontinuous commands in the control signal, resulting in chattering. This issue was resolved by introducing an adaptive rule for the SLIDING surface. Furthermore, the utilization of the sign function in the iterative learning observer for estimating actuator faults has not only enhanced its robustness to external disturbances through a straightforward design, but has also led to a decrease in computing workload. The strain rate feedback control algorithm has been employed with the use of piezoelectric sensor/actuator patches to minimize residual vibrations caused by rigid-flexible body dynamic interactions and the effect of attitude actuator faults. Lyapunov's law ensures finite-time overall system stability even with fully coupled rigid-flexible nonlinear dynamics. Numerical simulations demonstrate the performance and advantages of the proposed system compared to other conventional approaches.

This paper considers the work entitled “ Dynamic SLIDING MODE Control Design for Nonlinear Systems Using SLIDING MODE Observer” that is published in Tabriz Journal of Electrical Engineering where the authors try to design a SLIDING MODE control design with SLIDING MODE observer for a class of nonlinear systems. In this paper, we first give a brief overview of the proposed approach of aforementioned paper to the observer design. For the convergence of the estimation error, there is a proposition that we will discuss the validity of its proof. Finally, with a change in dynamic error equations of observer, its stability is proven.

In this paper, a new adaptive control METHOD is proposed for direct matrix converters. The proposed METHOD uses interval type-2 fuzzy logic integrated with SLIDING MODE control. Employing the SLIDING MODE control in matrix converters leads to an efficient choice of switching combinations and a reliable reference tracking. The main problem of the SLIDING MODE control is the chattering phenomenon that degrades the controller performance through injecting high-frequency variations in the controller variables. The proposed METHOD incorporates the interval type-2 fuzzy with the SLIDING MODE control to mitigate the chattering problem. The SLIDING MODE switch surface can be adjusted adaptively according to the system state and the proposed fuzzy compensation based on the Lyapunov stability theorem, so that the control system has the characteristics of low chattering effect and appropriate operation quality. Comprehensive evaluations of the waveforms are conducted for the new matrix converter through various simulations. Simulation results verify the effectiveness of the proposed adaptive control METHOD for matrix converter in various conditions, and its superiority in chattering suppression in comparison to the conventional SLIDING MODE control and the boundary layer METHOD.

In this paper, at first, a new MODEl will be attained for unified power flow controller (UPFC) using state space equation of bilinear systems. Then, a complete novel METHOD of designing UPFC controllers will be represented by the use of variant structure systems. In this METHOD, input signals of UPFC are designed through SLIDING MODE controller. In order to design these kinds of controllers, at first, control rules are obtained by the use of designing four different slide levels and then setting their derivatives (which express dynamics of the flows of axes d and q, in serial and parallel transformers) to zero. In fact, applying the outputs of this controller to UPFC is equal to bring the flows of axes d and q to the reference value in both UPFC. In the other hand, internal dynamics (DC capacitor voltage) will be stabilized in UPFC by means of PI controller. The stability of the system is obtained through Lyapunov function.

In the present paper, the improved SLIDING MODE control algorithm are presented. This strategy is based on the combination of SLIDING MODE control and Bang-Bang control theory. The Bang-Bang theory can switch abruptly between the on and off situation, this property can improve the performance of SLIDING MODE control strategy. Also, three thresholds used to decrease the time of using the control system and optimizing the responses of structure.

In this paper, a dynamic SLIDING MODE controller with fractional order SLIDING surface based on backstepping algorithm is designed and presented for controlling performance of a micro-electro-mechanical triaxial gyroscope. To compensate uncertainties and incoming disturbances to the system, a SLIDING MODE controller is used. In order to increase the degree of freedom and further robustness of the controller, the SLIDING surface is selected as fractional order form. Using dynamic SLIDING MODE controller in addition to the increasing the performance of controller, cause to reduce the chattering phenomenon in the input control signal. Using the backstepping approach as a very powerful design tool for nonlinear systems, makes the designed controller more robust against incoming disturbances to the system. Asymptotic stability of the closed loop system will be proven by Lyapunov stability theorem. At the end of the design, in order to efficacious reduce the chattering phenomenon in the control signal, fuzzy control theory for control the boundary layer and also adaptive METHOD for online estimating the upper bound of uncertainty are used. In order to evaluate performance of the designed controller, this controller is compared with two other SLIDING MODE controllers. Simulation results show that the proposed controller have a much less chattering phenomenon in control signal, increasing system stability, reducing the rise time and better tracking.

In this paper, according to flight devices categories, advantages and features of quadrotors and its performances are investigated. Then, the main challenges in quadrotors control and stability in the presence of obstacles have been considered in such a way that the system crosses the maximum number of obstacles in the best distance and time. For this purpose, the equations of motion of the system are derived and a controller for command tracking is designed without obstacles based on SLIDING MODE METHOD. The simulation results of the controller performances are given in the paper. Following this trajectory planning for crossing the system from the obstacles in alternative positions is presented and the quadrotor with the designed control system is simulated using the designed trajectory. The preference of the proposed trajectory planning is that the system can cross the number of obstacles in alternative positions in minimum time and using fewer sensors. Because of the independently shape of designing METHOD and alternative initial velocity, the proposed METHOD is applicable for piecewise trajectories. As a result of considering the drag force, the proposed approach is more successful in the various problems.