Integral Sliding Mode Technique Research Articles

Signal synchronization transmission within uncertain quantum network based on the differential–integral sliding mode technique

Signal synchronization transmission within uncertain quantum network based on the differential–integral sliding mode technique

Observer-based adaptive ISMC for connected vehicles against cyber-attacks

This paper concentrates on decentralized variable structure adaptive integral sliding mode control (ISMC) for connected vehicles (CV) against cyber-attacks. First of all, a novel vehicle leader-follower model is established by jointly considering the cyber-attacks which involve replay attack and DoS attack simultaneously. Secondly, a decentralized control scheme is designed on the basis of the variable structure observer and adaptive integral sliding mode technique. The Lyapunov-Razumikhin method is adopted such that the state estimation error of CV system is asymptotically converged to zero, which can overcome the replay attack, DoS attack, and measurement delays, then a corrective signal is designed for the deception attack to eliminate the influence of deception attack on the CV system. Furthermore, the robust asymptotic stability of CV system is guaranteed by exploiting the emerging technique of robust control for time-delay systems. Meanwhile, the string stability of CV is guaranteed, even under the condition of heterogeneous vehicles. Finally, extensive simulations are conducted to verify the theoretical analysis and demonstrate the effectiveness and superiority of the proposed method.

Adaptive Super-Twisting Cooperative Guidance Law with Fixed-Time Convergence

For the guidance problem of multiple missiles cooperatively intercepting a maneuvering target, fixed-time cooperative guidance law is proposed with impact angle constraints. First, fixed-time consensus, integral sliding mode technique, and adaptive super-twisting algorithm are implemented to construct cooperative guidance law along the line-of-sight (LOS) direction. Second, based on fixed-time convergence observer and terminal sliding mode control, one fixed-time guidance law along the normal direction of LOS is designed to ensure that the missiles attack the target with expected angles. Finally, simulation results are carried out to demonstrate the effectiveness of the proposed fixed-time cooperative guidance law.

Fault-Tolerant Control of Linear Systems with Unmatched Uncertainties Based on Integral Sliding Mode Technique

This paper proposes a novel fault-tolerant control method based on the integral sliding mode technique for unmatched uncertain linear systems with external perturbations. Differently from the existing works, the uncertainties under consideration have an unmatched norm-bounded form in the system and input matrix. Based on linear matrix inequalities, the existence conditions of the sliding mode surface are presented. The unknown fault information is then estimated by some adaptive laws. On the grounds of that, an integral sliding mode controller is also obtained to guarantee the disturbance attenuation and fault tolerance for linear uncertain systems with unmatched uncertainties and actuator faults from the initial time. Finally, the comparative simulation results verify the effectiveness of our presented scheme.

Trajectory Tracking of Robotic Arm Based on Power Regulation of Actuator Using Neural Averaged Subgradient Control

This study aims to present the design of robust control based on the integral sliding mode control version of the averaged sub-gradient for a robotic manipulator considering the dynamics of the direct current motor device driven by a power converter electrical system. The control action is sequentially operated, developing a class of back-stepping approaches, including the perturbed dynamics of the actuator. The proposed control strategy for solving the end-effector trajectory tracking problem in each stage implements the averaged subgradient-version of the integral sliding mode technique aided with an adaptive approximation of the robotic arm dynamics using an artificial neural network with differential evolution. The main result of this study shows that the minimization of the proposed functional leads to the optimal tracking regime. A numerical example proves the effectiveness of the suggested robust dynamic controller. The proposed controller exhibits a better tracking of the reference trajectory than the state feedback version.

Indirect Acceleration Tracking of Robotic Arm by Power Regulation of Actuator Using Averaged Subgradient Control

The purpose of this study is to present the design of robust control based on the integral sliding mode control version of the averaged subgradient for a robotic manipulator considering the dynamics of the direct current motor, which is driven by a power converter electrical device. The control action is sequentially developed in the subsystems of the complete model, realizing the so-called backstepping (or cascade) approach, including the perturbed dynamics of the actuator. The proposed control strategy for solving the trajectory tracking problem in each stage implements the averaged subgradient-version of the integral sliding mode technique. The controller design solution is treated as optimizing a suitable convex (not obligatory strongly convex) cost functional, depending on the tracking error and reaching its minimal value at the origin of the error tracking space. The main result of this study shows that the minimization of the proposed functional leads to the optimal tracking regime in the presence of significant uncertainties in the mathematical model of the power converter. A numerical example proves the effectiveness of the suggested robust dynamic controller. The comparison between the obtained trajectory tracking results and the outcomes produced by standard proportional integral derivative (PID) controllers is presented. The proposed controller exhibits a better tracking of the reference trajectory than the PID version, showing a smaller mean square estimation for the tracking error.

Extended state observer-based integral line-of-sight guidance law for path following of underactuated unmanned surface vehicles with uncertainties and ocean currents

This article focuses on the problem of path following for underactuated unmanned surface vehicles (USVs) considering model uncertainties and time-varying ocean currents. An extended state observer (ESO)-based integral line-of-sight (ILOS) with an integral sliding mode adaptive fuzzy control scheme is proposed as the main control framework. First, a novel ESO is employed to estimate the surge and sway velocities based on the kinetic model, which are difficult to measure directly. Then, the adaptive ILOS guidance law is proposed, in which the integral vector is incorporated into the adaptive method to estimate the current velocities. Meanwhile, an improved fuzzy algorithm is introduced to optimize the look-ahead distance. Second, the controller is extended to deal with the USV yaw and surge velocity signal tracking using the integral sliding mode technique. The uncertainties of the USV are approximated via the adaptive fuzzy method, and an auxiliary dynamic system is presented to solve the problem of actuator saturation. Then, it is proved that all of the error signals in the closed-loop control system are uniformly ultimately bounded. Finally, a comparative simulation substantiates the availability and superiority of the proposed method for ESO-based ILOS path following of USV.

Improved Adaptive Integral-Sliding-Mode Fault-Tolerant Control for Hypersonic Vehicle With Actuator Fault

In this paper, the problem of attitude control for hypersonic vehicle in the present of actuator fault and unknown uncertainties including modeling uncertainties, aerodynamic parameters uncertainties is investigated based on integral sliding mode technique. A fault-tolerant control (FTC) law is proposed consisting of three parts, an improved integral sliding mode(ISM) equivalent control law, a power reaching law and a new adaptive compensation control law. The proposed FTC possesses triple advantages. Firstly, when sliding mode is established, the proposed equivalent controller will offer faster convergence speed via introducing a switching condition into the conventional ISM control. Secondly, the adaptive compensation control law is presented considering both the unknown uncertainty and the unexpected actuator fault including additive fault and multiplicative fault. Finally, the boundness of bounded unknown uncertainty is no longer needed in advance. Simulation results show the effectiveness and the superiority of the proposed fault-tolerant controller on fast convergence speed and expected attitude tracking performance.

Robust admissible consensus of singular multi‐agent systems using sliding mode approach

AbstractThe admissible consensus problem of singular multi‐agent systems (SMASs) with mismatched norm‐bounded parametric uncertainties and unknown norm‐bounded disturbances is investigated by an integral sliding mode technique. Under a directed spanning tree network of the state transmission graph, the error states are defined. Then a linear matrix inequality (LMI)‐based sufficient condition is presented to guarantee regularity, free impulse, quadratic stability and H∞ performance of the sliding mode dynamics of the error states. Next, an integral sliding manifold parameter is designed to decrease the order of the LMI caused by the parametric uncertainties, and matrix inversion formulas and inequality techniques are applied to reduce the conservativeness of the LMI. Finally, the control laws, relying on the error states, the property of the state transmission graph and the upper norm bound of disturbances, are presented to ensure the state trajectories of the resulting closed‐loop system to achieve robust admissible consensus with H∞ performance. A simulation example is provided to show the effectiveness of the proposed method.

Robust nonovershooting tracking control for fractional‐order systems

SummaryA robust tracking control is proposed for the fractional‐order systems (FOSs) to achieve a tracking response with no overshoot, even in the presence of a class of disturbances. The control proposed makes use of a newly designed integral sliding mode technique for FOSs, which is capable of rejecting the bounded disturbances acting through the input channel. The proposed integral sliding mode control design has two components: a nominal control component and a discontinuous control component. The overshoot in the system response is avoided by the nominal control designed with the use of Moore's eigenstructure assignment algorithm. The sliding mode technique is used for the design of discontinuous part of the control that imparts the desired robustness properties.

Finite‐time disturbance observer based integral sliding mode control for attitude stabilisation under actuator failure

This work develops a novel disturbance observer and integral sliding mode technique based fault tolerant attitude control scheme for spacecraft, which is subject to external disturbance torques and actuator failures. More specifically, a simple and novel finite-time disturbance observer is first designed to reconstruct the synthetic uncertainty deriving from actuator failures and disturbances, by which the synthetic uncertainty is also compensated or restricted. Then, an integral sliding mode based finite-time fault tolerant attitude stabilisation controller incorporating with an adjusting law is investigated to ensure the closed-loop attitude control system converge to the stable region in finite time. And also the finite-time stability of the closed-loop attitude control system driven by the proposed attitude control scheme is analysed and proved utilising Lyapunov methodology. Finally, a simulation example for a rigid spacecraft model is carried out to verify the effectiveness and superiority of the proposed attitude control approach.

Integrated Fault Estimation and Fault-Tolerant Tracking Control for Lipschitz Nonlinear Multiagent Systems.

An integrated fault estimation (FE) and fault-tolerant tracking control (FTTC) strategy is developed for Lipschitz nonlinear multiagent systems subject to actuator faults, external disturbance, and uncertainties. First, for each agent, a corresponding unknown input observer with reduced/full order is constructed to obtain the FE. Then, a state/output feedback FTTC strategy is proposed based on the integral sliding-mode technique and adaptive super-twisting algorithm. The observer and controller gains are obtained simultaneously via H∞ optimization with a linear matrix inequality formulation. Finally, the comparison simulations are provided to demonstrate the effectiveness of the proposed algorithm.

Robust non‐overshooting tracking using continuous control for linear multivariable systems

A robust continuous control for tracking a step reference signal without any overshoot and arbitrarily small rise time is proposed for a linear multivariable system. Integral sliding mode technique with the super-twisting sliding mode is used to make the control robust against the matched disturbances with bounded derivatives. Moore's eigenstructure assignment is used to compute nominal control part of the integral sliding mode technique which makes the system output to track the step reference with arbitrarily small rise time and without any overshoot under some mild assumptions. The efficacy of the proposed control is validated using simulation results on benchmark quadruple tank model.

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.

Observer‐based adaptive control of uncertain stochastic singular systems via integral sliding mode technique

This study is concerned with the problem of adaptive sliding mode control (SMC) for uncertain stochastic singular systems. A novel integral-type sliding surface function is first introduced based on a particular observer design, which incorporates both the state estimations and the outputs to achieve prescribed specifications. The analysis of mean-square asymptotic admissibility of the underlying sliding mode dynamics with H ∞ disturbance attenuation level for the closed-loop systems is performed to exploit a new condition via linear matrix inequality technique. Then, the reachability of the predesigned sliding surface is ensured within finite-time almost surely by utilising a novel adaptive SMC law. Two examples are provided to demonstrate the validity and potential of the proposed method.

Fault‐tolerant control with control allocation for linear time varying systems: an output integral sliding mode approach

A fault-tolerant control scheme with a fixed control allocation strategy for linear time varying systems is proposed. The effects of the faults in the critical control channels are compensated theoretically exactly and the remaining effects are minimised by using an output integral sliding mode technique. Both aspects are achieved right after the initial time by using only output information. This approach allows dealing with total failures in some actuators under the assumption of redundancy. The effectiveness of the proposed scheme considering time varying faults is validated by computer simulations.

Adaptive neural dynamic surface sliding mode control for uncertain nonlinear systems with unknown input saturation

In this article, an adaptive neural dynamic surface sliding mode control scheme is proposed for uncertain nonlinear systems with unknown input saturation. The non-smooth input saturation nonlinearity is firstly approximated by a smooth non-affine function, which can be further transformed into an affine form according to the mean value theorem. Then, one simple sigmoid neural network is employed to approximate the uncertain nonlinearity including the input saturation, and the approximation error is estimated using an adaptive learning law. Virtual controls are designed in each step by combing the dynamic surface control and integral sliding mode technique, and thus the problem of complexity explosion inherent in the conventional backstepping method is avoided. With the proposed control scheme, no prior knowledge is required on the bound of input saturation, and comparative simulations are given to illustrate the effectiveness and superior performance.

Finite time attitude tracking control of an autonomous airship

The problem of station-keeping attitude tracking control for an autonomous airship with system uncertainties and external disturbances is investigated. Adaptive laws are applied to estimate the upper bounds of uncertainties and disturbances, and a nonlinear finite time control scheme is proposed by combing input/output feedback linearization with integral sliding mode technique. Different from the existing works on attitude control of airship, the developed controller can guarantee the yaw, pitch and roll angle trajectories track the desired attitude in finite time in spite of uncertain system uncertainties and external disturbances. Simulation results are provided to illustrate the attitude tracking performance.

Robustification of time varying linear quadratic optimal control based on output integral sliding modes

A hierarchical observer for an uncertain linear time-varying system is designed generalising the output integral sliding-mode approach. The observer is based on a step by step reconstruction of the output and its derivatives, to reconstruct the state theoretically exactly right after the initial time, eliminating completely the effects of the uncertainties/perturbations. The observed state is used in linear quadratic control with an output integral sliding-mode technique, allowing the uncertain system to behave as a nominal (uncertainties/perturbations free) one. The proposed approach is tested by computer simulations.

Sliding mode identification and control for linear uncertain stochastic systems

This article presents the integral sliding mode technique applied to identify disturbances and robustify the optimal linear quadratic Gaussian controller for linear uncertain stochastic systems, which is compared to the conventional sliding mode approach. The obtained identifier/controller provides a method for estimating uncertainty values and ensures robustness of the system against matched uncertainties, starting from the initial time instant. Numerical simulations illustrating the obtained results are given for the inverted pendulum.