Integral Sliding Mode Control Law Research Articles

Recurrent neural network based adaptive integral sliding mode power maximization control for wind power systems

An adaptive integral sliding mode controller is proposed to maximize wind power extraction by maintaining the optimum rotation speed of wind turbine. In the proposed controller, an integral sliding mode control law is designed to track the optimum turbine rotation speed based on a recurrent neural network (RNN) that is used to identify the uncertain wind turbine dynamics. An online update algorithm is then derived to update the weights of the RNN in real time and hence to facilitate the maximum power extraction control. The stability of the overall control system is guaranteed in the sense of Lyapunov stability theory. Comparative experimental results demonstrate that the proposed controller outperforms a conventional control method in tracking the optimum turbine rotation speed and extracting the maximum wind power despite system uncertainties and high nonlinearities.

Chaos control of a four-dimensional fundamental power system using pole placement-based proportional integral sliding mode control

In this paper, the problem of chaos control for a four-dimensional fundamental power system (FDFPS) model is investigated. Pole placement-based proportional integral sliding mode control (PISMC) is designed to control the chaos present in the system. Proportional integral sliding mode control law is derived by placing the poles at appropriate location to control the chaotic behaviour in four-dimensional fundamental power systems. The sufficient condition is derived for the asymptotic stability of the sliding manifold using Lyapunov stability theory. The proposed controller reduces the chattering, simplifies the design of power system stabiliser. Further the proposed pole placement-based PISMC is compared with conventional SMC approach. MATLAB is used for simulation. Simulation results show the effectiveness of proposed PISMC scheme.

Adaptive Dynamic Programming based Integral Sliding Mode Control Law for Continuous-Time Systems: A Design for Inverted Pendulum Systems

Adaptive Dynamic Programming based Integral Sliding Mode Control Law for Continuous-Time Systems: A Design for Inverted Pendulum Systems

Chaos control of a four-dimensional fundamental power system using pole placement-based proportional integral sliding mode control

In this paper, the problem of chaos control for a four-dimensional fundamental power system (FDFPS) model is investigated. Pole placement-based proportional integral sliding mode control (PISMC) is designed to control the chaos present in the system. Proportional integral sliding mode control law is derived by placing the poles at appropriate location to control the chaotic behaviour in four-dimensional fundamental power systems. The sufficient condition is derived for the asymptotic stability of the sliding manifold using Lyapunov stability theory. The proposed controller reduces the chattering, simplifies the design of power system stabiliser. Further the proposed pole placement-based PISMC is compared with conventional SMC approach. MATLAB is used for simulation. Simulation results show the effectiveness of proposed PISMC scheme.

Compound control for autonomous docking to a three-axis tumbling target

This paper investigates the coupled position and attitude control problem of an on-orbit servicing spacecraft autonomous docking to a three-axis freely tumbling target in space. A compound control law is presented to guarantee that the docking port of servicing spacecraft is always directing towards the docking port of tumbling target, which is accomplished through the combination of the coupled relative position tracking and relative attitude control. For the purpose of avoiding collision between the two spacecraft, a two-phased approach for the terminal approaching the tumbling target is proposed. Also, the compound control is composed of a nonlinear feedback control law and an integral sliding mode control law. The nonlinear feedback control law is mainly used to track the system command and the integral sliding mode control law is mainly used to deal with the external disturbances and system uncertainties to enhance the robustness of the control system. Furthermore, the control saturation problem is considered. In addition, the characteristic of integral sliding mode under the control constraint and measurement noise is also analyzed. Finally, several numerical simulations are performed to verify the effectiveness and robustness of the compound control law for autonomous docking to a three-axis freely tumbling target.

A robust control approach for MEMS capacitive micromachined ultrasonic transducer

An optimal composite nonlinear feedback control method with integral sliding mode is presented in this paper. The controller extends the travel range of the micro-electromechanical system capacitive micromachined ultrasonic transducer (CMUT). Moreover, enhanced transient response and precise tracking performance is achieved. It is known that CMUT is inherently unstable which results in pull-in phenomenon and it is very sensitive to small perturbations, so one of the major problems is to stabilize the CMUT beyond the pull-in limit with the external disturbances. In addition, the input saturation problem is significant to CMUT. Based on that, a robust control scheme is derived using composite nonlinear feedback control law combined with integral sliding mode control law. Then all the tuning parameters for the proposed control method are converted into a minimization problem and solved by particle swarm optimization algorithm automatically. We verified the effectiveness through extending the travel range of the CMUT gap by three control methods which are proportional integral derivative, composite nonlinear feedback and the method we proposed. The stability and small range tracking performance with three control methods is compared on the pull-in position of CMUT. The simulations show that the proposed control method has desired tracking performance and robustness to external disturbance with input saturation.

An Adaptive LPV Integral Sliding Mode FTC of Dissimilar Redundant Actuation System for Civil Aircraft

This paper addresses three major issues in dissimilar redundant actuation system when operates in active/active mode. The first one is to reduce the effect of force fighting. The second one is to obtain precise tracking performance of the control surface. The third one is to induce fault tolerance in the presence of faults in hydraulic actuator. The proposed strategy is to design LPV integral sliding mode controller for each actuator in a dissimilar actuation system. The nonlinear dynamics of each actuator is first transformed into LPV form and employed tensor product model transformation to convert into polytopic LPV form. The integral sliding mode FTC is designed based on the LPV model of actuators. To induce the fault tolerance, the nonlinear injection term of proposed integral sliding mode control law is made adaptive subject to the severity of the fault. In order to verify the robustness of the proposed scheme, an external disturbance acting as an airload is applied at the control surface input. Finally, the proposed strategy is applied on the nonlinear model of system to validate the dominant performance as compared to existing methods in the literature. In the simulations, three types of faults in hydraulic actuator are considered and the performance of closed loop system is analyzed.

Smooth integral sliding mode controller for the position control of Stewart platform

This paper proposes the application of a new algorithm for the position control of a Stewart platform. The conventional integral sliding mode controller is a combination of nominal control and discontinuous feedback control hence the overall control is discontinuous in nature. The discontinuity in the feedback control is undesirable for practical applications due to chattering which causes the wear and tear of the mechanical actuators. In this paper the existing integral sliding mode control law for systems with matched disturbances is modified by replacing the discontinuous part by a continuous modified twisting control. This proposed controller is continuous in nature due to the combinations of two continuous controls. The desired position of the platform has been achieved using the proposed controller even in the presence of matched disturbances. The effectiveness of the proposed controller has been proved with the simulation results.

Quantized Feedback Control Design of Nonlinear Large-Scale Systems via Decentralized Adaptive Integral Sliding Mode Control

A novel decentralized adaptive integral sliding mode control law is proposed for a class of nonlinear uncertain large-scale systems subject to quantization mismatch between quantizer sensitivity parameters. Firstly, by applying linear matrix inequality techniques, integral-type sliding surface functions are derived for ensuring the stability of the whole sliding mode dynamics and obtaining the prescribed boundedL2gain performance. Secondly, the decentralized adaptive sliding mode control law is developed to ensure the reachability of the sliding manifolds in the presence of quantization mismatch, interconnected model uncertainties, and external disturbances. Finally, an example is shown to verify the validity of theoretical results.

Tensor Product Model Transformation Based Adaptive Integral-Sliding Mode Controller: Equivalent Control Method

This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model.

LMI-based adaptive fuzzy integral sliding mode control of mismatched uncertain systems

LMI-based adaptive fuzzy integral sliding mode control of mismatched uncertain systems Integral sliding mode design is considered for a class of uncertain systems in the presence of mismatched uncertainties in both state and input matrices, as well as norm-bounded nonlinearities and external disturbances. A sufficient condition for the robust stability of the sliding manifold is derived by means of linear matrix inequalities. The initial existence of the sliding mode is guaranteed by the proposed control law. The improvement of the proposed control scheme performances, such as chattering elimination and estimation of norm bounds of uncertainties, is then considered with the application of an adaptive fuzzy integral sliding mode control law. The validity and efficiency of the proposed approaches are investigated through a sixth order uncertain mechanical system.

Integral sliding mode control of time-delay systems with mismatching uncertainties

A linear matrix inequality (LMI)-based sliding surface design method for integral sliding mode control of uncertain time-delay systems with mismatching uncertainties is proposed. The uncertain time-delay system under consideration may have mismatching norm bounded uncertainties in the state matrix as well as the input matrix. A sufficient condition for the existence of a sliding surface is given to guarantee asymptotic stability of the full order sliding mode dynamics. An LMI characterization of the sliding surface is given, together with an integral sliding mode control law guaranteeing the existence of a sliding mode from the initial time. Finally, a simulation is given to show the effectiveness of the proposed method.

LMI-Based Sliding Surface Design for Integral Sliding Mode Control of Mismatched Uncertain Systems

We propose a linear matrix inequality (LMI)-based sliding surface design method for integral sliding-mode control of mismatched uncertain systems. The uncertain system under consideration may have mismatched norm bounded uncertainties in the state matrix as well as the input matrix. We give a sufficient condition for the existence of a sliding surface guaranteeing asymptotic stability of the full order sliding mode dynamics. We also give an LMI characterization of the sliding surface, together with an integral sliding mode control law guaranteeing the existence of a sliding mode from the initial time. Additionally, we give an LMI condition of sliding surfaces guaranteeing the alpha-stability constraint. Finally, we give a simulation result to show the effectiveness of our method