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.

A novel nonlinear controller is proposed to track active and reactive power for a Brushless Doubly-Fed Induction Generator (BDFIG) wind turbine. Due to nonlinear DYNAMICs and the presence of parametric uncertainties and perturbations in this system, SLIDING MODE control is employed. To generate a smooth control signal, DYNAMIC SLIDING MODE method is used. Uncertainties bound is not required in the suggested algorithm, since the adaptive gain in the controller relation is used in this study. Convergence of the SLIDING variable to zero and adaptive gain to the uncertainty bound are verified using Lyapunov stability theorem. The proposed controller is evaluated in a comprehensive simulation on the BDFIG MODEl. Moreover, output performance of the proposed control algorithm is compared to the conventional and second-order SLIDING MODE and proportional-integral-derivative (PID) controllers.

Two phenomena can produce chattering: switching of input control signal and the large amplitude of this switching (switching gain). To remove the switching of input control signal, DYNAMIC SLIDING MODE control (DSMC) is used. In DSMC switching is removed due to the integrator which is placed before the plant. However, in DSMC the augmented system (system plus the integrator) is one dimension bigger than the actual system and then, the plant MODEl should be completely known. To overcome this difficulty, a fuzzy system is employed to identify the unknown nonlinear function of the plant MODEl and then, a robust adaptive law is developed to train the parameters of this fuzzy system. The other problem is that the switching gain may be chosen unnecessary large to cope on the unknown uncertainty. To solve this problem, another fuzzy system is proposed which does not need the upper bound of the uncertainty. Moreover, to have a suitable small enough switching gain an adaptive procedure is applied to increase and decrease the switching gain according to the system circumstances. Then, chattering is removed using the DSMC with a small adaptive switching gain (ASG). As a case study, nonlinear chaotic Duffing-Holmes system is selected.

This paper investigates a new scheme in the design of a DYNAMIC observer for generator torque estimation in the wind turbine. Using a DYNAMIC SLIDING MODE observer design that has never been used for a wind turbine, we increase the Lipschitz constant, which is equivalent to increase the operation range and increasing the observer's robustness to the nonlinear term. Design innovation is the use of DYNAMIC gain in the design of the SMO and guarantee of asymptotic stability condition by optimal control problem. The additional degree of freedom proposed by this DYNAMIC formula is used to cope with the nonlinearity. Finally, using the real wind profile, the design procedure is implemented on the 100 kW wind turbine of the Sun and Air Research Institute and the results are also evaluated with the wind turbine simulator software FAST. Also, as the second contribution of this paper, by adding process noise and measurement noise to the turbine, the superiority of the proposed algorithm over others is investigated.

Tracking guidance commands for a time-varying aerospace launch vehicle during the atmospheric flight is considered in this paper. Hence, the DYNAMIC terminal SLIDING MODE control law is constructed for this purpose and DYNAMIC SLIDING MODE control is utilized.The terminal SLIDING manifold causes the DYNAMIC SLIDING MODE to converge asymptotically to zero in finite-time. The actuator and rate gyro DYNAMICs are included in the MODEl of launch vehicle. DYNAMIC SLIDING MODE control accommodates unmatched disturbances, while the terminal SLIDING MODE control is used to accelerate the system to reach the DYNAMIC SLIDING manifold. Finally, the effectiveness of the proposed control is demonstrated in the presence of unmatched disturbances and is compared with the DYNAMIC SLIDING MODE.

In this paper, DYNAMIC SLIDING MODE control (DSMC) of nonlinear systems using neural networks is proposed. In DSMC, the chattering is removed due to the integrator placed before the input control signal of the plant. However, in DSMC, the augmented system has higher order than the actual system, i. e. the states number of the augmented system is higher than the actual system and then to control of such a system, we must know and identify the new states, or the plant MODEl should be completely known. To solve this problem, we suggest two online neural networks to identify and to obtain a MODEl for the unknown nonlinear system. In the first approach, the neural network training law is based on the available system states and the bound of the observer error is not proved to converge to zero. The advantage of the second training law is only using the system’ s output and the observer error converges to zero based on the Lyapunov stability theorem. To verify these approaches, Duffing-Holmes chaotic systems (DHC) are used.

In this paper, a new approach has been presented for DYNAMIC control of active suspension vehicle system subject to the road disturbances. The active suspension system (ASS) which has been considered in this paper is operated by a hydraulic actuator. The input of this hydraulic actuator is a servo valve. In other words, both mechanical equation of system (related to hydraulic actuator) and its electrical equation (related to servo valve) are considered. Therefore, the equations are complicated and only the input current of servo valve is accessible as the input control signal. The proposed approach is based on DYNAMIC SLIDING MODE control (DSMC).In DSMC chattering is removed due to the integrator which is placed before the input control signal of the plant. However, in DSMC the augmented system (the system plus the integrator) is one dimension bigger than the actual system and then, control of the plant is more complicated. But, its advantage is that the input control signal is obtained from a DYNAMIC system or a low pass filter, while the robust performance (invariance property) of the system is reserved even in the presence of disturbance. Another advantage of proposed approach is that the desired output force of the hydraulic actuator is obtained by the controller.

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 proposes a control strategy for a cable-suspended robot based on SLIDING MODE approach (SMC) which is faced to external disturbances and parametric uncertainties. This control algorithm is based on Lyapunov technique which is able to provide the stability of the end-effecter during tracking a desired path with an acceptable precision. The main contribution of the paper is to calculate the DYNAMIC Load Carrying Capacity (DLCC) of a spatial cable robot while tracking a desired trajectory based on SMC algorithm. In finale, the efficiency of the proposed method is illustrated by performing some simulation studies on the ICaSbot (IUST Cable Suspended Robot) which supports 6 DOFs using six cables. Simulation and experimental results confirm the validity of the authors’ claim corresponding to the accurate tracking capability of the proposed control, its robustness and its capability toward DLCC calculation.