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Showing papers on "Sliding mode control published in 2016"


Journal ArticleDOI
TL;DR: This study gives the mathematic model of a quadrotor unmanned aerial vehicle (UAV) and then proposes a robust nonlinear controller which combines the sliding-mode control technique and the backstepping control technique, which is designed to achieve Cartesian position trajectory tracking capability.
Abstract: This study gives the mathematic model of a quadrotor unmanned aerial vehicle (UAV) and then proposes a robust nonlinear controller which combines the sliding-mode control technique and the backstepping control technique. To achieve Cartesian position trajectory tracking capability, the construction of the controller can be divided into two stages: a regular SMC controller for attitude subsystem (inner loop) is first developed to guarantee fast convergence rapidity of Euler angles and the backstepping technique is applied to the position loop until desired attitudes are obtained and then the ultimate control laws. The stability of the closed-loop system is guaranteed by stabilizing each of the subsystems step by step and the robustness of the controller against model uncertainty and external disturbances is investigated. In addition, an adaptive observer-based fault estimation scheme is also considered for taking off mode. Simulations are conducted to demonstrate the effectiveness of the designed robust nonlinear controller and the fault estimation scheme.

501 citations


Journal ArticleDOI
TL;DR: An integral sliding mode surface and observer-based adaptive sliding mode controller is designed such that the MJSs are insensitive to all admissible uncertainties and satisfy the reaching condition and the stochastic stability of the closed-loop system can be guaranteed.

474 citations


Journal ArticleDOI
TL;DR: It is shown that when STC is implemented based on super-twisting observer (STO), then it is not possible to achieve second-order sliding mode (SOSM) using continuous control on the chosen sliding surface, so two methodologies are proposed to circumvent the problem.
Abstract: In this paper, an output feedback stabilization of perturbed double-integrator systems using super-twisting control (STC) is studied. It is shown that when STC is implemented based on super-twisting observer (STO), then it is not possible to achieve second-order sliding mode (SOSM) using continuous control on the chosen sliding surface. Two methodologies are proposed to circumvent the above-mentioned problem. In the first method, control input is discontinuous, which may not be desirable for practical systems. In the second method, continuous STC is proposed based on higher order sliding mode observer (HOSMO) that achieves SOSM on the chosen sliding surface. For simplicity, we are considering here only the perturbed double integrator, which can be generalized for an arbitrary-order systems. Numerical simulations and experimental validation are also presented to show the effectiveness of the proposed method.

378 citations


Journal ArticleDOI
TL;DR: A new adaptive sliding-mode control scheme that uses the time-delay estimation (TDE) technique, then applies the scheme to robot manipulators and shows that the tracking errors of the proposed ASMC scheme are guaranteed to be uniformly ultimately bounded (UUB) with arbitrarily small bound.
Abstract: This paper presents a new adaptive sliding-mode control (ASMC) scheme that uses the time-delay estimation (TDE) technique, then applies the scheme to robot manipulators. The proposed ASMC uses a new adaptive law to achieve good tracking performance with small chattering effect. The new adaptive law considers an arbitrarily small vicinity of the sliding manifold, in which the derivatives of the adaptive gains are inversely proportional to the sliding variables. Such an adaptive law provides remarkably fast adaptation and chattering reduction near the sliding manifold. To yield the desirable closed-loop poles and simplify a complicated system model by adapting feedback compensation, the proposed ASMC scheme works together with a pole-placement control (PPC) and a TDE technique. It is shown that the tracking errors of the proposed ASMC scheme are guaranteed to be uniformly ultimately bounded (UUB) with arbitrarily small bound. The practical effectiveness and the fast adaptation of the proposed ASMC are illustrated in simulations and experiments with robot manipulators, and compared with those of an existing ASMC.

366 citations


Journal ArticleDOI
14 Apr 2016
TL;DR: Interval type-2 Takagi-Sugeno (T-S) fuzzy model is employed to represent uncertain nonlinear systems and a novel sliding mode controller is designed to guarantee that the closed-loop system is uniformly ultimately bounded.
Abstract: This paper is concerned with the adaptive sliding mode control problem of uncertain nonlinear systems. Interval type-2 Takagi–Sugeno (T–S) fuzzy model is employed to represent uncertain nonlinear systems. The input matrices of the nonlinear systems are allowed to be different for the sliding mode controller design. The uncertain parameters are described by the lower and upper membership functions. An integral sliding mode surface is designed for analysis of sliding motion. Based on the sliding mode surface, a novel sliding mode controller is designed to guarantee that the closed-loop system is uniformly ultimately bounded. Some simulation results are given to illustrate the effectiveness of the presented control scheme.

279 citations


Journal ArticleDOI
TL;DR: The objective is to alter the modulation gains associated with these schemes in such a way that they are as small as possible to mitigate chattering effects, but large enough to ensure that sliding can be maintained in the presence of bounded and derivative bounded uncertainties.

279 citations



Journal ArticleDOI
TL;DR: It is shown that the newly proposed non-smooth control-based DSMC can guarantee the same level of accuracy for the sliding mode motion as that of an equivalent control- based DSMC.

250 citations


Journal ArticleDOI
TL;DR: The proposed integrated design approach using FE and fault compensation within the control system in which the design is achieved by integrating together the FE and FTC controller modules is illustrated through studying the control of an uncertain model of a DC motor.

237 citations


Journal ArticleDOI
TL;DR: This technical note discusses to what extent the high order sliding mode control may serve as an alternative to the conventional sliding Mode control.
Abstract: This technical note discusses to what extent the high order sliding mode control may serve as an alternative to the conventional sliding mode control. Definition of sliding mode order, relative degree, chattering attenuation, filtering, and implementation complexity constitute the scope of the discussion.

231 citations


Journal ArticleDOI
TL;DR: A new adaptive sliding mode controller based on system output is presented to guarantee that the closed-loop system is uniformly ultimately bounded.
Abstract: In this paper, a novel adaptive sliding mode controller is designed for Takagi–Sugeno (T–S) fuzzy systems with actuator saturation and system uncertainty. By the delta operator approach, the discrete-time nonlinear system is described by a T–S fuzzy model with unmeasurable state. By singular value decomposition of system input matrix, a reduced-order system is obtained for the design of sliding mode surface. A new adaptive sliding mode controller based on system output is presented to guarantee that the closed-loop system is uniformly ultimately bounded. Four examples are provided to illustrate the effectiveness and applicability of the proposed control scheme.

Journal ArticleDOI
TL;DR: The disturbance observer is proposed to generate the disturbance estimate, which can be incorporated in the controller to counteract the disturbance, and two approaches are proposed to design the controller and disturbance rejection gains.
Abstract: This paper develops the disturbance observer-based integral sliding-mode control approach for continuous-time linear systems with mismatched disturbances or uncertainties. The disturbance observer is proposed to generate the disturbance estimate, which can be incorporated in the controller to counteract the disturbance. With the help of the proposed disturbance observer, both the memoryless and memory-based integral sliding surfaces and integral sliding-mode controllers are developed, respectively, and two approaches, i.e., $H_\infty$ control and steady-state output-based approaches, are proposed to design the controller and disturbance rejection gains. Finally, the effectiveness and applicability of the proposed technique are illustrated by a numerical example and a real-time experiment.

Journal ArticleDOI
TL;DR: The proposed control strategy modifies reaching law (RL) of the sliding mode technique to reduce chattering issue and to improve total harmonic distortion property compared to conventional RL SMC.
Abstract: This paper proposes a sliding-mode control (SMC)-based scheme for the variable-speed direct-driven wind energy conversion systems (WECS) equipped with a permanent magnet synchronous generator connected to the grid. In this paper, diode rectifier, boost converter, neutral point clamped inverter, and L filter are used as the interface between the wind turbine and grid. This topology has abundant features such as simplicity for low- and medium-power wind turbine applications. It is also less costly than back-to-back two-level converters in medium-power applications. The SMC approach demonstrates great performance in complicated nonlinear systems control such as WECS. The proposed control strategy modifies reaching law (RL) of the sliding mode technique to reduce chattering issue and to improve total harmonic distortion property compared to conventional RL SMC. The effectiveness of the proposed control strategy is explored by simulation study on a 4-kW wind turbine, and then verified by experimental tests for a 2-kW setup.

Journal ArticleDOI
TL;DR: In this paper, a guidance problem for impact time control applicable to salvo attacks is considered based on the sliding mode control, and a positive continuous nonlinear function of the lead angle is introduced to the guidance command, which makes the Lyapunov stability negative semidefinite.
Abstract: A guidance problem for impact time control applicable to salvo attacks is considered based on the sliding mode control. To prevent the singularity of the guidance command, a positive continuous nonlinear function of the lead angle is introduced to the guidance command, which makes the Lyapunov stability negative-semidefinite. This issue is also resolved by the additional component of the guidance command, which makes the sliding mode be the only attractor still without the singularity. The capturability analysis is presented regardless of the initial launching conditions of missiles, which can guarantee a wide range of the capture region. The proposed guidance law is easily extended to a nonmaneuvering target using the predicted interception point. Simulation results confirm the effectiveness of the proposed guidance against a nonmaneuvering target as well as a stationary target with absence and presence of measurement noise.

Journal ArticleDOI
TL;DR: A model-free–based terminal sliding-mode control strategy to control the attitude and position of a quadrotor whose model includes parameter variations, uncertainties, and external disturbances is developed.
Abstract: In this paper, a model-free–based terminal sliding-mode control (MFTSMC) strategy is developed to control the attitude and position of a quadrotor whose model includes parameter variations, uncertainties, and external disturbances. The proposed MFTSMC combines a model-free control approach with a sliding-mode technique and makes possible to eliminate the tracking error in a finite time. To demonstrate the performance and effectiveness of the proposed MFTSMC, numerical simulation results have been obtained and compared with corresponding results for PID, backstepping and sliding-mode controls.

Journal ArticleDOI
TL;DR: Simulation and experimental results are presented to validate the proposed constrained state feedback speed control algorithm in comparison to nonconstrained state feedback control and cascade control structure, respectively.
Abstract: This paper presents constrained state feedback speed control of a permanent-magnet synchronous motor (PMSM). Based on classical control theory, nonlinear state-space model of PMSM is developed. A simple linearization procedure is employed to design a linear state feedback controller (SFC). Digital redesign of a SFC is carried out to achieve discrete form suitable for implementation in a DSP. Model predictive approach is used to a posteriori constraint introduction into control system. It overcomes limitations of motion control system with nonconstrained SFC resulting in low dynamic properties. The novel concept utilizes machine voltage equation model to calculate the boundary values of control signals which provide permissible values of the future state variables. Secondary control objectives such as zero $d$ -axis current are included. Simulation and experimental results are presented to validate the proposed constrained state feedback control algorithm in comparison to nonconstrained state feedback control and cascade control structure, respectively.

Journal ArticleDOI
TL;DR: A sliding-mode control methodology based on the adaptive dynamic programming (ADP) method is designed, so that the closed-loop system with time-varying disturbances is stable and the nearly optimal performance of the sliding- mode dynamics can be guaranteed.
Abstract: This paper is concerned with the problem of integral sliding-mode control for a class of nonlinear systems with input disturbances and unknown nonlinear terms through the adaptive actor–critic (AC) control method. The main objective is to design a sliding-mode control methodology based on the adaptive dynamic programming (ADP) method, so that the closed-loop system with time-varying disturbances is stable and the nearly optimal performance of the sliding-mode dynamics can be guaranteed. In the first step, a neural network (NN)-based observer and a disturbance observer are designed to approximate the unknown nonlinear terms and estimate the input disturbances, respectively. Based on the NN approximations and disturbance estimations, the discontinuous part of the sliding-mode control is constructed to eliminate the effect of the disturbances and attain the expected equivalent sliding-mode dynamics. Then, the ADP method with AC structure is presented to learn the optimal control for the sliding-mode dynamics online. Reconstructed tuning laws are developed to guarantee the stability of the sliding-mode dynamics and the convergence of the weights of critic and actor NNs. Finally, the simulation results are presented to illustrate the effectiveness of the proposed method.

Journal ArticleDOI
TL;DR: The event-based sliding-mode control (ESMC) is designed for each linear subsystem of the global fuzzy model first, and the conditions for “fuzzily” amalgamated ESMC are discussed to stabilize theglobal fuzzy model.
Abstract: This paper studies the aperiodic sampled-data control for the sliding-mode control (SMC) scheme of fuzzy systems with communication-induced delays via the event-triggered method. In practice, it is impossible to update control in continuous manner; thus, an event-based control technique has become popular with the advantage that the control task is executed only if it is triggered by an event. In this paper, the event-based sliding-mode control (ESMC) is designed for each linear subsystem of the global fuzzy model first. Then, the conditions for “fuzzily” amalgamated ESMC are discussed to stabilize the global fuzzy model. This ensures that the SMC is executed only when necessary. Furthermore, the results are extended to the fuzzy systems with communication-induced delays. Finally, case studies are carried out to demonstrate the effectiveness of the derived results.

Journal ArticleDOI
TL;DR: In this article, a fault-tolerant output tracking control for the flexible air-breathing hypersonic vehicle (AHV) subject to parametric uncertainties, external disturbances, and actuator constraints is presented.
Abstract: This paper deals with fault-tolerant output tracking control for the flexible air-breathing hypersonic vehicle (AHV) subject to parametric uncertainties, external disturbances, and actuator constraints. By regarding the flexible dynamics as equivalent disturbances, the vehicle model can be split into three functional subsystems, namely, horizontal translation subsystem, vertical translation subsystem, and rotation subsystem. Then, for each subsystem, a disturbance observer is utilized to estimate the lumped effect of model uncertainties, external disturbances, and actuator faults, while a novel auxiliary system combined with the command prefilter is constructed to handle the physical constraints on actuators. Furthermore, sliding mode control is employed to design control commands for the three subsystems, sequentially. The proposed controller modifies the reference trajectories dynamically when one or more actuators become constrained, and can steer the AHV to the desired trim finally. Simulation results are provided to demonstrate the effectiveness of the designed controller.

Journal ArticleDOI
TL;DR: In this article, an adaptive fuzzy gain-scheduling sliding mode control (AFGS-SMC) approach is proposed for attitude regulation of UAVs with parametric uncertainties and external disturbances.

Journal ArticleDOI
TL;DR: A robust sliding-mode observer (RSMO) for state-of-charge (SOC) estimation of a lithium-polymer battery (LiPB) in electric vehicles (EVs) is presented and a radial basis function (RBF) neural network is employed to adaptively learn an upper bound of system uncertainty.
Abstract: This paper presents a robust sliding-mode observer (RSMO) for state-of-charge (SOC) estimation of a lithium-polymer battery (LiPB) in electric vehicles (EVs). A radial basis function (RBF) neural network (NN) is employed to adaptively learn an upper bound of system uncertainty. The switching gain of the RSMO is adjusted based on the learned upper bound to achieve asymptotic error convergence of the SOC estimation. A battery equivalent circuit model (BECM) is constructed for battery modeling, and its BECM is identified in real time by using a forgetting-factor recursive least squares (FFRLS) algorithm. The experiments under the discharge current profiles based on EV driving cycles are conducted on the LiPB to validate the effectiveness and accuracy of the proposed framework for the SOC estimation.

Journal ArticleDOI
TL;DR: In this paper, a trajectory tracking control scheme is proposed for underactuated autonomous underwater vehicles (AUVs), which is designed using the sliding mode control technique in order to be robust against bounded disturbances.
Abstract: This paper deals with the control of underactuated autonomous underwater vehicles (AUVs). AUVs are needed in many applications such as the exploration of oceans, scientific and military missions, etc. There are many challenges in the control of AUVs due to the complexity of the AUV model, the unmodelled dynamics, the uncertainties and the environmental disturbances. A trajectory tracking control scheme is proposed in this paper; this control scheme is designed using the sliding mode control technique in order to be robust against bounded disturbances. The control performance of an example AUV, using the proposed method, is evaluated through computer simulations. These simulation studies, which consider different reference trajectories, show that the proposed control scheme is robust under bounded disturbances.

Journal ArticleDOI
TL;DR: In this article, the maximum hands-off control is defined as the minimum support (or sparsest) per unit time among all control objectives that achieve control objectives, and the equivalence between the maximum handoff control and the optimal control under a uniqueness assumption called normality is shown.
Abstract: In this paper, we propose a paradigm of control, called a maximum hands-off control. A hands-off control is defined as a control that has a short support per unit time. The maximum hands-off control is the minimum support (or sparsest) per unit time among all controls that achieve control objectives. For finite horizon continuous-time control, we show the equivalence between the maximum hands-off control and $L^{1}$ -optimal control under a uniqueness assumption called normality. This result rationalizes the use of $L^{1}$ optimality in computing a maximum hands-off control. The same result is obtained for discrete-time hands-off control. We also propose an $L^{1}/L^{2}$ -optimal control to obtain a smooth hands-off control. Furthermore, we give a self-triggered feedback control algorithm for linear time-invariant systems, which achieves a given sparsity rate and practical stability in the case of plant disturbances. An example is included to illustrate the effectiveness of the proposed control.

Journal ArticleDOI
Bing Xiao1, Shen Yin1
TL;DR: This paper addresses a difficult problem of velocity-free uncertain attenuation control for a class of nonlinear systems with external disturbance and multiple actuator faults by proposing a sliding-mode observer (SMO) to reconstruct the full states.
Abstract: This paper addresses a difficult problem of velocity-free uncertain attenuation control for a class of nonlinear systems with external disturbance and multiple actuator faults. With only the output measurement available for feedback, a sliding-mode observer (SMO) is proposed to reconstruct the full states. The reconstructed signal can approximate the true value to any accuracy. An adaptive version of the observer is further presented to handle a class of structured uncertainties in the system. Together with the system output feedback, the reconstructed state is used to synthesize a velocity-free controller. All states in the closed-loop system are guaranteed to be uniformly ultimately bounded (UUB). System uncertainty and external disturbances are attenuated. Actuator fault is accommodated. An example with application the approach to satellite attitude stabilization maneuver is presented to verify the effectiveness of the proposed scheme.

Journal ArticleDOI
TL;DR: In this paper, a load frequency control (LFC) strategy based on sliding mode control (SMC) theory and disturbance observer is proposed for the single area power system in order to reduce the frequency deviation caused by the unmatched parameter uncertainties such as the renewable source and different load disturbance.

Journal ArticleDOI
TL;DR: This paper addresses the problem of robust stabilisation for a class of nonlinear systems subject to external disturbances using sliding mode control (SMC) by event-triggering scheme and shows that with delay steady-state bound of the system is increased than that of the case without delay.
Abstract: Event-triggering strategy is one of the real-time control implementation techniques which aims at achieving minimum resource utilisation while ensuring the satisfactory performance of the closed-loop system. In this paper, we address the problem of robust stabilisation for a class of nonlinear systems subject to external disturbances using sliding mode control (SMC) by event-triggering scheme. An event-triggering scheme is developed for SMC to ensure the sliding trajectory remains confined in the vicinity of sliding manifold. The event-triggered SMC brings the sliding mode in the system and thus the steady-state trajectories of the system also remain bounded within a predesigned region in the presence of disturbances. The design of event parameters is also given considering the practical constraints on control execution. We show that the next triggering instant is larger than its immediate past triggering instant by a given positive constant. The analysis is also presented with taking delay into a...

Journal ArticleDOI
TL;DR: A data-driven model-free adaptive sliding mode control (MFASMC) approach based on a novel transformation and linearization of the robotic exoskeleton dynamics and a discrete time sliding mode with exponential reaching law that can maneuver the roboticExoskeleton tracking on its desired velocity tightly even when the dynamic parameter of the exos skeleton is time-varying irregularly and uncertainly.

Journal ArticleDOI
TL;DR: Simulation and experimental results show that the proposed SMC strategy exhibits an excellent performance in achieving the required control objectives such as fast dynamic response, robustness, sinusoidal grid current with low total harmonic distortion, and simplicity in a practical implementation.
Abstract: This paper presents a sliding-mode control (SMC) strategy for single-phase grid-connected $\mbox{LCL}$ -filtered voltage source inverters (VSIs) with double-band hysteresis scheme. The proposed SMC is simpler than the existing SMC methods devised for grid-connected VSIs since its sliding-surface function requires the sensing of capacitor voltage and grid current only. In addition, a double-band hysteresis scheme which ensures the switching of a transistor in the VSI during a half cycle while it remains either on or off in the other half cycle of the fundamental period is used to mitigate the switching frequency. Furthermore, the analytical expressions for the instantaneous and average switching frequencies are derived. The theoretical considerations and analytical results are verified through computer simulations and experimental results obtained from a 3.3-kW system. Simulation and experimental results show that the proposed SMC strategy exhibits an excellent performance in achieving the required control objectives such as fast dynamic response, robustness, sinusoidal grid current with low total harmonic distortion, and simplicity in a practical implementation.

Journal ArticleDOI
TL;DR: A novel robust fractional-order sliding mode (FOSM) controller for maximum power point tracking (MPPT) control of doubly fed induction generator (DFIG)-based wind energy conversion system is proposed.
Abstract: Wind power plants have nonlinear dynamics and contain many uncertainties such as unknown nonlinear disturbances and parameter uncertainties. Thus, it is a difficult task to design a robust reliable controller for this system. This paper proposes a novel robust fractional-order sliding mode (FOSM) controller for maximum power point tracking (MPPT) control of doubly fed induction generator (DFIG)-based wind energy conversion system. In order to enhance the robustness of the control system, uncertainties and disturbances are estimated using a fractional order uncertainty estimator. In the proposed method a continuous control strategy is developed to achieve the chattering free fractional order sliding-mode control, and also no knowledge of the uncertainties and disturbances or their bound is assumed. The boundedness and convergence properties of the closed-loop signals are proven using Lyapunov׳s stability theory. Simulation results in the presence of various uncertainties were carried out to evaluate the effectiveness and robustness of the proposed control scheme.

Journal ArticleDOI
TL;DR: In this article, a piezoelectric actuated compliant micro gripper was designed to get a large jaw motion stroke, and a three-stage flexure-based amplification composed of the homothetic bridge and leverage mechanisms was developed and the key structure parameters were optimized.
Abstract: The design and control of a novel piezoelectric actuated compliant microgripper is studied in this paper to achieve fast, precise, and robust micro grasping operations. First, the microgripper mechanism was designed to get a large jaw motion stroke. A three-stage flexure-based amplification composed of the homothetic bridge and leverage mechanisms was developed and the key structure parameters were optimized. The microgripper was manufactured using the wire electro discharge machining technique. Finite element analysis and experimental tests were carried out to examine the performance of the microgripper mechanism. The results show that the developed microgripper has a large amplification factor of 22.6. Dynamic modeling was conducted using experimental system identification, and the displacement and force transfer functions were obtained. The position/force switching control strategy was utilized to realize both precision position tracking and force regulation. The controller composed of an incremental proportional-integral-derivative control and a discrete sliding mode control with exponential reaching law was designed based on the dynamic models. Experiments were performed to investigate the control performance during micro grasping process, and the results show that the developed compliant microgripper exhibits good performance, and fast and robust grasping operations can be realized using the developed microgripper and controller.