rose babaie

This paper presents the design and implementation of a nonlinear control algorithm for quadrotor helicopters which have become increasingly important by virtue of their high degrees of manoeuvres ability to hover. This algorithm is based on the incremental sliding mode controller (ISMC) technique, whereby the robustness is ensured presence of unknown time-varying wind disturbances for a quadrotor. Foremost, the first-level sliding surface is described, and then one of the left variables is utilized to construct the next sliding surfaces and this process continues till the last sliding surface is constructed. In addition the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. The suggested algorithm is verified in studies in the execution of various maneuvers subject to forcible wind disturbance while performing accurate attitude and position tracking by running an extensive numerical simulation.

n this paper, to overcome the problem of hovering a quadrotor system, under aerodynamic effects, an optimal recursive backstepping controller is designed. One of the main achievements of this study is to propose a nonlinear efficient observer based on extended kalman bucy filter (EKBF) to estimate the unmeasured states of the system. Our control method is robust against perturbations and ensures the stability of the system by using Lyapanv theory. In order to improve the system response, the controller coefficients are also optimized by using the genetic algorithm. Finally, simulation results are included to show that the performance of the quadrotor UAV with the proposed controller and observer is quite satisfactory. The results demonstrate better robustness against the aerodynamic effects in comparison with previous works.

In this paper, using the State Dependent Riccati Equation (SDRE) method, we propose a Robust Optimal Integral Sliding Mode Controller (ROISMC) to guarantee an optimal control law for a quadrotor which has become increasingly important by virtue of its high degrees of manoeuvres ability in presence of unknown time-varying external disturbances and actuator fault. The robustness of the controller is ensured by an Integral Sliding Mode Controller (ISMC). Subsequently, based on Luenberger linear state estimator, the control algorithm is reformed and the actuator’s faults are detected. Moreover, design of the controller is based on Lyapunov method which can provide the stability of all system states during the tracking of the desired trajectory. The stability of suggested algorithm is verified via the execution of sudden maneuvers subjected to forcible wind disturbance and actuator faults while performing accurate attitude and position tracking by running an extensive numerical simulatio...

This paper investigates the problem of controlling a team of quadrotors that cooperatively transport a common payload. The main contribution of this study is to propose a cooperative control algorithm based on a decentralized algorithm. This strategy is comprised of two main steps: the first one is calculating the basic control vectors for each quadrotor using Moore-Penrose theory aiming at cooperative transport of an object and the second one is combining these vectors with individual control vectors, which are obtained from a closed-loop non-linear robust controller. In this regard, a nonlinear robust controller is designed based on Second Order Sliding Mode (SOSMC) approach using Extended Kalman-Bucy Filter (EKBF) to estimate the unmeasured states which is capable of facing external disturbances. The distinctive features of this approach include robustness against model uncertainties along with high flexibility in designing the control parameters to have an optimal solution for the nonlinear dynamics of the system. Design of the controller is based on Lyapunov method which can provide the stability of the end-effecter during the tracking of the desired trajectory. Finally, simulation results are given to illustrate the effectiveness of the proposed method for the cooperative quadrotors to transport a common payload in various maneuvers. 147 1-Introduction The cooperative control of multiple vehicle systems despite its wide range of practical applications requires tackling important theoretical and practical challenges which have attracted many researchers in recent years. Formation control problems for multiple vehicle systems can be categorized with applications to unmanned aerial vehicles (UAVs), autonomous underwater vehicles, cooperative transport, mobile robots, cooperative role assignment and cooperative search. In this paper, we seek to drive a control algorithm for cooperation between quadrotors that allow the robots to control their position and angles to grasp and transport a common payload in various maneuvers. The controller is designed to move the object by two or more quadrotors. To make a framework for interplay between a group of quadrotors and payload, many control schemes have been extensively used to solve the problems of creating formation control for UAVs. Some of them have focused on centralized and leader-follower approach to access interaction between cooperative quadrotors and payload [1-7]. Although these methods have acceptable results on small robotic systems but suffer from several disadvantages including high computational complexity of centralized methods in large-scale systems and possibility of disappearing the group formation in leader-follower strategy due to not receiving the position of leader by the followers. In this regard, there is a plethora of research in cooperative multi-robot controller design based on decentralized control methods which can solve a significant number of problems in cooperative control strategies and benefit also from the advantages such as decreased number of sensors and fast performance. In [8], the problem of cooperation by a team of ground robots is addressed under quasi-static assumptions based on decentralize controllers considering a unique solution to robot and object motion. Also, transporting a payload by aerial manipulation using cables based on decentralized control is studied in [9,10]. In other research, cooperative aerial towing-based decentralized mechanism is studied [11]. The authors of [12] employ bilinear matrix inequalities to present optimal solutions for decentralized nonlinear multi-agent systems. Despite the numerous advantages of decentralized methods, there are still some critical issues related to the performance of the control system in presence of disturbances and uncertainties. On the other hand, some of the most popular control schemes for uncertain nonlinear systems are based on discontinuous schemes; in particular, sliding mode controllers (SMC) have shown robustness against uncertainties and matched disturbances [13-18]. Moreover, the finite-time convergence of SMC as well as their simplicity have made them suitable for a large variety of applications such as designing a robust formation control scheme. A high order sliding mode concept can effectively reduce the chattering while keeping the invariant characteristics in the sliding mode. Some successful implementations of high order (second order) SMC schemes in UAVs have been reported in [19,20]. Also, in [21] a robust second order sliding mode controller was proposed for the attitude stabilization of a four-rotor helicopter. This controller was able to overcome the chattering phenomena in classical sliding mode control while preserving the invariance property of sliding mode. In [22], using an equivalent

In this paper, using the State Dependent Riccati Equation (SDRE) method, we propose a Robust Optimal Integral Sliding Mode Controller (ROISMC) to guarantee an optimal control law for a quadrotor which has become increasingly important by virtue of its high degrees of manoeuvres ability in presence of unknown time-varying external disturbances and actuator fault. The robustness of the controller is ensured by an Integral Sliding Mode Controller (ISMC). Subsequently, based on Luenberger linear state estimator, the control algorithm is reformed and the actuator's faults are detected. Moreover, design of the controller is based on Lyapunov method which can provide the stability of all system states during the tracking of the desired trajectory. The stability of suggested algorithm is verified via the execution of sudden maneuvers subjected to forcible wind disturbance and actuator faults while performing accurate attitude and position tracking by running an extensive numerical simulation. It is comprehended that the proposed optimal robust method can achieve much better tracking capability compared with conventional sliding mode controller.

n this paper, to overcome the problem of hovering a quadrotor system, under aerodynamic effects, an optimal recursive backstepping controller is designed. One of the main achievements of this study is to propose a nonlinear efficient observer based on extended kalman bucy filter (EKBF) to estimate the unmeasured states of the system. Our control method is robust against perturbations and ensures the stability of the system by using Lyapanv theory. In order to improve the system response, the controller coefficients are also optimized by using the genetic algorithm. Finally, simulation results are included to show that the performance of the quadrotor UAV with the proposed controller and observer is quite satisfactory. The results demonstrate better robustness against the aerodynamic effects in comparison with previous works.