Integral Sliding Mode Control Technique Research Articles

Secure control for remote networked stochastic systems via integral sliding mode

This paper deals with the secure control problem for a class of networked stochastic systems with false data injection attacks via an integral sliding mode control technique. The networked control system is with a hierarchical structure, and the main controller and a remote controller are considered to realize the secure control against false data injection attacks on the network between a main controller and the plant. A mode-shared event-triggering controller is designed as the main controller, by utilizing a time delay approach. An input–output model based on a two-term approximation is applied to cope with the formulated time-varying delay. Then, the scaled small gain theory is employed to analyze the stability of the resulting system. Sufficient conditions on ensuring the desired system performance are derived and then the controller parameters are synthesized. Moreover, an elaborated sliding mode control law is proposed for the desired secure control action. Finally, two simulation examples are permitted to verify the effectiveness of the theoretical derivations.

Model-free low-power observer based robust trajectory tracking control of UAV quadrotor with unknown disturbances

PurposeThe purpose of this paper is to design an output-feedback algorithm based on low-power observer (LPO), robust chattering-free controller and nonlinear disturbance observer (DO) to achieve trajectory tracking of quadrotor in the Cartesian plane.Design/methodology/approachTo achieve trajectory tracking control, firstly the decoupled rotational and translational model of quadrotor are modified by introducing backstepped state-space variables. In the second step, robust integral sliding mode control is designed based on the proportional-integral-derivative (PID) technique. In the third step, a DO is constructed. In next step, the measurable outputs, i.e. rotational and translational state variables, are used to design the LPO. Finally, in the control algorithm all state variables and its rates are replaced with its estimates obtained using the state-observer.FindingsThe finding includes output-feedback control (OFC) algorithm designed by using a LPO. A modified backstepping model for rotational and rotational systems is developed prior to the design of integral sliding mode control based on PID technique. Unlike traditional high-gain observers (HGO), this paper used the LPO for state estimation of quadrotor systems to solve the problem of peaking phenomenon in HGO. Furthermore, a nonlinear DO is designed such that it attenuates disturbance with unknown magnitude and frequency. Moreover, a chattering reduction criterion has been introduced to solve the inherited chattering issue of controllers based on sliding mode technique.Practical implicationsThis paper presents input and output data-driven model-free control algorithm. That is, only input and output of the quadrotor model are required to achieve the trajectory tracking control. Therefore, for practical implementation, the number of on-board sensor is reduced.Originality/valueAlthough extensive research has been done for designing OFC algorithms for quadrotor, LPO has never been implemented for the rotational and translational state estimations of quadrotor. Furthermore, the mathematical model of rotational and translational systems is modified by using backstepped variables followed by the controller designed using PID and integral sliding mode control technique. Moreover, a DO is developed for attenuation of disturbance with unknown bound, magnitude and frequency.

Trajectory tracking guidance of interceptor via prescribed performance integral sliding mode with neural network disturbance observer

This paper investigates interception missiles’ trajectory tracking guidance problem under wind field and external disturbances in the boost phase. Indeed, the velocity control in such trajectory tracking guidance systems of missiles is challenging. As our contribution, the velocity control channel is designed to deal with the intractable velocity problem and improve tracking accuracy. The global prescribed performance function, which guarantees the tracking error within the set range and the global convergence of the tracking guidance system, is first proposed based on the traditional PPF. Then, a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid singularities. Meanwhile, an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem. A back propagation neural network (BPNN) extended state observer (BPNNESO) is employed in the inner loop to identify disturbances. The obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors, convergence times, and overshoots.

Robust optimal sliding mode control for the deployment of Coulomb spacecraft formation flying

Inter-spacecraft electrostatic force (Coulomb force) is desirable for close formation flying control because of its propellant-less and free contaminate characteristics attributed to the propellant exhaust emission. This paper presents robust optimal sliding mode control to deal with the problem of thruster saturation in tracking the formation trajectory for Coulomb spacecraft formation flying. The robust controller design is based on optimal control theory as a linear quadratic system, and it is augmented with an integral sliding mode control technique. The stability of the closed-loop system is guaranteed using the second Lyapunov method. The developed controller outperforms the existing ones, because it has a higher degree of fine-tuning to cope with the uncertainty. Numerical simulations are employed to confirm the efficiency of the developed controller.

Robust Global Synchronization of a Hyperchaotic System with Wide Parameter Space via Integral Sliding Mode Control Technique

The inherent property of invariance to structural and parametric uncertainties in sliding mode control makes it an attractive control strategy for chaotic dynamics control. This property can effectively constrain the chaotic property of sensitive dependence on initial conditions. In this paper, the trajectories of two identical four-dimensional hyperchaotic systems with fully-known parameters are globally synchronized using the integral sliding mode control technique. Based on the exponential reaching law and the Lyapunov stability principle, the problem of synchronizing the trajectories of the two systems was reduced to the control objective of asymptotically stabilizing the synchronization error state dynamics of the coupled systems in the sense of Lyapunov. To verify the effectiveness of the control laws, the model was numerically tested on a hyperchaotic system with a wide parameter space in a master-slave configuration. The parameters of the hyperchaotic system were subsequently varied to evolve a topologically non-equivalent hyperchaotic system that was identically coupled. In both cases, the modeled ISM control laws globally synchronized the dynamics of the coupled systems after transient times, which sufficiently proved the invariance property of the ISMC. This study offers an elegant technique for the modeling of an ISMC for hyperchaotic coupling systems. As an open problem, this synchronization technique holds promises for applications in robot motion control, chaos-based secure communication system design, and other sensitive nonlinear system control.

Energy based sliding mode control of Brushless Double-fed Induction Generator

In this paper, a novel robust control scheme for a Brushless Double-fed Induction Generator is presented. The mathematical model for the electrical machine is developed, based on the Hamiltonian energy function, including the mathematical description for a wind turbine. Furthermore, in order to add robustness and taking into account the energy properties of the system, the Integral Sliding Mode control technique is proposed, to guarantee the rejection of the system perturbations. Then, a passive state feedback control law is applied, to stabilize the closed-loop system. The proposed combination is able to reject the system perturbations and stabilize the system in the desired operation point.

Fault-tolerant control via integral sliding mode output feedback for unmanned marine vehicles

In this article, the fault-tolerant control problem against thruster faults is investigated for unmanned marine vehicles. The main approach is, for the first time, based on integral sliding mode control technique where only measurable outputs of unmanned marine vehicles are used. By using matrix full-rank decomposition and adaptive mechanism, an output integral sliding surface is constructed and an integral sliding mode controller with a full-order compensator is designed to attenuate the oscillation amplitudes of the yaw angle and yaw velocity error in the presence of thruster faults and ocean external disturbances. Through a typical floating production ship, the effectiveness of the proposed method is verified in the simulation example.

Design of Robust Fault-Tolerant Control for Target Tracking System With Input Delay and Sensor Fault

This paper presents a robust fault-tolerant control scheme that provides reliable tracking and effective disturbance rejection for a low-cost tracking system. As the controlled apparatus, a 2-axis gimbaled mechanism is involved in a networked control system, and an unreliable sensor brings sensor drift into the system. Besides, external disturbances heavily affect the system in practical applications. Representation of the faulty gimbal system with its constraints and disturbances is firstly introduced. Then, the design of the fault-tolerant controller is detailed, which consists of two components: (1) an unknown input observer that estimates the fault and effect of disturbances and network delay simultaneously, and (2) a robust control law, using the observer estimations, designed based on the combination of the super-twisting algorithm, backstepping procedure, and integral sliding mode control technique. Subsequently, simulations and experiments are conducted, in which the performance of the proposed control system is compared to those from the previous studies. The results show the superiority and reliability of the proposed control system.

MPPT Based PMSG Wind Turbine System Using Sliding Model Control (SMC) and Artificial Neural Network (ANN) Based Regression Analysis

In view of the recent development and phenomenal growth in the field of electrical/power engineering, various new enhanced and sophisticated power control techniques have emerged which have got the enormous capabilities to produce the desired power in the most efficient and effective manner. This paper presents the permanent magnet synchronous generator (PMSG) connected to the wind turbine to extract the maximum power using the integral sliding mode control technique and artificial neural network (ANN). The real power produced by the generator is directly dependent on the internal characteristic of the wind turbine like TSR (tip speed ratio), Power Coefficient, etc. To extract the maximum power from the wind turbine, it has been depicted that ANN a is more efficient and reliable form than the sliding mode control technique.

Microscopic chaos control of chemical reactor system using nonlinear active plus proportional integral sliding mode control technique

This paper puts forward the microscopic chaos control in the deterministic dynamics of the chemical reactor system. First, the dynamic behavior of the chemical reactor system is explored for some of the parameters and chaotic behavior is investigated. Phase plane, bifurcation plots and Lyapunov exponents are presented to verify the chaotic behavior. Second, nonlinear active plus proportional integral sliding mode control (NA-PISMC) is proposed to control microscopic chaos in the chemical reactor system. A proportional integral switching surface is proposed to achieve the stability condition of the error dynamics and controller is designed by using the relevant variables of the chemical system. Unlike the open loop and open plus closed loop control techniques, the design of proposed controller does not require the parameter perturbation. The required stability condition is derived based on Lyapunov stability theory. Simulation is done in MATLAB environment. Numerical simulation results are presented in order to show the effective performances of the proposed controller design. Simulation results correspond that the objectives of chaos existence and chaos control are achieved successfully.

Finite-time consensus of high-order heterogeneous multi-agent systems with mismatched disturbances and nonlinear dynamics

In this study, we investigate the finite-time consensus problem for a general class of high-order nonlinear heterogeneous multi-agent systems, for which not only the unknown nonlinear dynamics, mismatched disturbances but also the system orders are not required to be identical. We propose two families of consensus algorithms, and the output consensus can be achieved with them in a finite time even with nonlinear dynamics and mismatched disturbances. The Lipschitz-like condition generally required in the literature is removed in this paper. The integral sliding-mode control technique is used to construct the first family of consensus algorithms, which may cause chattering problem for the existence of high-frequency switching terms. To overcome the chattering phenomenon, a new variable-gain finite-time observer is developed to construct the second family of continuous algorithms based on a different assumption. It is shown that some existing consensus protocols can be broadened in several directions through the framework of this study; moreover, the output feedback finite-time consensus can also be solved.

Decentralized Adaptive Double Integral Sliding Mode Controller for Multi-Area Power Systems

Most of the existing results for load frequency control of multi-area interconnected power systems can only be obtained when the norm of the aggregated uncertainties is bounded by a positive constant. This condition is difficult to achieve in real multi-area interconnected power systems. In this paper, a new load frequency control (LFC) for multi-area interconnected power systems is developed based on a decentralised adaptive double integral sliding mode control technique where the above limitation is eliminated. First, an adaptive gain tuning law is adopted to estimate the unknown upper bound of the aggregated uncertainties. Second, a double integral sliding surface based adaptive sliding mode controller is proposed to improve the transient performance of the closed loop system. Simulation results show that the proposed control law results in shortening the frequency’s transient response, avoiding the overshoot, rejecting disturbance better, maintaining required control quality in the wider operating range, and being more robust to uncertainties as compared to some existing control methods.

Sliding mode predictive control of linear uncertain systems with delays

In this paper, a continuous control strategy for robust stabilization of a class of uncertain multivariable linear systems with delays in both the state and control variables is proposed. A predictor is designed to compensate the delay effect in the control input, and then an integral sliding mode control technique along with super-twisting algorithm is applied to compensate partially the effect of the perturbation term. Finally, a nominal delay-free part of the control input is designed to stabilize the sliding mode dynamics. The proposed control scheme is extended to the class of systems modeled in Regular form. For this class of perturbed systems with delay in the state, a transformation to the systems with the delay-free state is proposed. The stability conditions of the closed-loop uncertain system are derived, and the results obtained in this work are compared against previous works. To show the effectiveness of the proposed method, simulation results are presented.

An adaptive integral sliding mode control approach for piezoelectric nano-manipulation with optimal transient performance

This paper presents a control framework supporting high precision tracking of a piezoelectric nano-manipulating system with guaranteed transient performance, where a modified dynamic model describing the hysteresis behavior is also proposed. To achieve the desired optimal transient performance, a dynamic hysteresis compensation based control approach is developed by employing robust adaptive integral sliding mode control technique to accommodate both hysteresis nonlinearities and model uncertainties. An adaptive law is designed to estimate the gain of the integral sliding mode controller such that the chattering behavior is alleviated and the upper bound of uncertainties is no longer required a priori. In particular, it can be proved that the tracking error converges to zero in a finite time. The proposed control architecture is applied to a PZT actuated nano-manipulating stage, where real time implementations demonstrate excellent tracking performance with tracking error around 4.6‰for multi-frequency trajectory tracking experiments. Comparisons with existing results are also given, where significant improvements are achieved in various tracking scenarios.

Fault-Tolerant Cooperative Tracking Control via Integral Sliding Mode Control Technique

In this paper, we aim to deal with the cooperative tracking problem for a group of nonlinear systems with actuator faults and external disturbance/model uncertainty. The faults in the actuator are allowed to be in arbitrary forms such as actuator degradation, amplification, or even total failure. Moreover, the disturbance/model uncertainty under consideration is of Lipschitz type by assuming that the derivative of disturbance/model uncertainty is uniformly bounded. Then, provided that the actuator has sufficient healthy components when the faults happen, we employ the integral sliding mode technique to design the controller that can tolerate the actuator faults, meanwhile the external disturbance can also be rejected. The controller design is separated into two steps. First, a nominal controller is designed such that the estimated disturbance/model uncertainty from disturbance observer is completely rejected and the desired performance is guaranteed. Second, by the integral sliding mode control technique, a compensating controller is designed such that the matched estimation error of actuator faults and the external disturbance/model uncertainty can be compensated. The designed controller, formed by the sum of the nominal controller and compensating controller, finally proves to guarantee practical synchronization of nonlinear systems. Simulations demonstrate the effectiveness of our theoretical findings.

Robust Predictor-Based Control of Uncertain Linear Systems with Delay via Integral Sliding Mode Control

In this paper, a continuous control strategy for robust stabilization of a class of uncertain multivariable linear systems with delays in both the state and control variables is proposed. A predictor is designed to compensate the delay effect in control input, and then an integral sliding mode control technique along with super-twisting algorithm is applied to compensate partially the effect of the perturbation term. Finally, a nominal delay-free part of the control input is designed to stabilize the sliding mode dynamics. The method is extended to the class of systems modeled in Regular form, it is proposed a transformation for the systems with delay in state then results in a system delay-free in state. Conditions for the stability of the closed-loop uncertain system are derived. Simulation results are presented and compared against previous works.

Adaptive output feedback integral sliding mode attitude tracking control of spacecraft without unwinding

This article studies an output feedback attitude tracking control problem for rigid spacecraft in the presence of parameter uncertainties and external disturbances. First, an anti-unwinding attitude control law is designed using the integral sliding mode control technique to achieve accurate tracking responses and robustness against inertia uncertainties and external disturbances. Next, the derived control law is combined with a suitable tuning law to relax the knowledge about the bounds of uncertainties and disturbances. The stability results are rigorously proved using the Lyapunov stability theory. In addition, a new finite-time sliding mode observer is developed to estimate the first time derivative of attitude. A new adaptive output feedback attitude controller is designed based on the estimated results, and angular velocity measurements are not required in the design process. A Lyapunov-based analysis is provided to demonstrate the uniformly ultimately bounded stability of the observer errors. Numerical simulations are given to illustrate the effectiveness of the proposed control method.

Robust control for uncertain linear delay systems via sliding mode control

SummaryIn this paper, a novel discontinuous control strategy for robust stabilization of a class of uncertain multivariable linear time‐delay systems with delays in both the state and control variables is proposed. Two predictors are first designed to compensate the delay effect in the control input, and then an integral sliding mode control technique is applied to compensate partially the effect of the perturbation term. Finally, a nominal delay‐free component of the full control input is designed to stabilize the sliding mode dynamics. Conditions for the stability of the closed‐loop perturbed system are then derived. The proposed framework is then extended to the class of systems modeled in regular form. Some examples illustrate the feasibility of the proposed scheme. Copyright © 2017 John Wiley & Sons, Ltd.

Decentralized control for harmonic drive–based modular and reconfigurable robots with uncertain environment contact

In this article, a decentralized control strategy is presented for harmonic drive–based modular and reconfigurable robots with uncertain environment contact. Unlike conventional methods that rely on robot–environment contact model or force/torque sensing, this article addresses the problem of controlling modular and reconfigurable robots in contact with uncertain environment using only encoder data of each joint module. By employing a control-oriented harmonic drive model, the dynamic model of modular and reconfigurable robot is formulated as a synthesis of interconnected subsystems, in which the interconnected joint couplings are with small magnitudes. Based on the integral sliding mode control technique and the adaptive super-twisting algorithm, the decentralized controller is designed to compensate model uncertainty in which the up-bound is unknown. The stability of the modular and reconfigurable robot system is proved using Lyapunov theory. Finally, simulations are conducted for 2-degree-of-freedom modular and reconfigurable robots with different configurations under the situations of dynamic contact and collision to investigate the advantage of the proposed approach.

Distributed adaptive control for vehicular platoon with unknown dead‐zone inputs and velocity/acceleration disturbances

SummaryThis paper is focused on designing a distributed adaptive control scheme for a vehicular platoon with unknown bounded velocity/acceleration disturbances and unknown nonlinear dead‐zone inputs. Our aim is to design distributed adaptive controllers based on integral sliding mode control techniques that guarantee practical exponential convergence (i.e., exponential stability of an arbitrarily small neighborhood of zero) of the spacing errors and the string stability of the whole vehicular platoon. The contributions of this paper are that: (i) based on a modified constant time headway policy, the whole vehicular platoon is guaranteed to have string stability despite dead zone inputs; (ii) adaptive compensation terms are constructed to compensate for the time‐variant effects caused by unknown bounded velocity/acceleration disturbances, and unknown dead zone inputs; (iii) an efficient numerical method for avoiding the singularity problem of the control law is also proposed. Numerical simulation results show the validity and advantages of the proposed method are significantly higher traffic density and string stability. Copyright © 2016 John Wiley & Sons, Ltd.