scispace - formally typeset
Search or ask a question

Showing papers on "Sliding mode control published in 2021"


Journal ArticleDOI
TL;DR: The aim of this work is to design an appropriate SMC law based on an adaptive event-triggered communication scheme such that the resulting closed-loop system could realize stochastic stability and reduce communication burden.
Abstract: In this article, the sliding mode control (SMC) design is studied for a class of stochastic switching systems subject to semi-Markov process via an adaptive event-triggered mechanism. Network-induced communication constraints, semi-Markov switching parameters, and uncertain parameters are considered in a unified framework for the SMC design. Due to the constraint of measuring transducers, the system states always appear with unmeasurable characteristic. Compared with the traditional event-triggered mechanism, the adaptive event-triggered mechanism can effectively reduce the number of triggering than the static event-triggered mechanism. During the data transmission of network communication systems, network-induced delays are characterized from the event trigger to the zero-order holder. The aim of this work is to design an appropriate SMC law based on an adaptive event-triggered communication scheme such that the resulting closed-loop system could realize stochastic stability and reduce communication burden. By introducing the stochastic semi-Markov Lyapunov functional, sojourn-time-dependent sufficient conditions are established for stochastic stability. Then, a suitable SMC law is designed such that the system state can be driven onto the specified sliding surface in a finite-time region. Finally, the simulation study on boost converter circuit model (BCCM) illustrates the effectiveness of the theoretical findings.

237 citations


Journal ArticleDOI
TL;DR: In the framework of the networked control systems (NCSs), the components are connected with each other over a shared band-limited network as mentioned in this paper, and the merits of NCSs include easy extensibility, resource availability, and low power consumption.
Abstract: In the framework of the networked control systems (NCSs), the components are connected with each other over a shared band-limited network. The merits of NCSs include easy extensibility, resource sh...

217 citations


Journal ArticleDOI
TL;DR: To process the measurement output and schedule the transmission sequence for eliminating the communication burden, a logarithmic quantizer and a weighted try-once-discard protocol are synthesized, which can further improve the network bandwidth utilization in networked control systems.
Abstract: In this paper, the sliding mode control issue is investigated for a class of discrete-time Takagi-Sugeno fuzzy networked singularly perturbed systems via an observer-based technique. Moreover, to process the measurement output and schedule the transmission sequence for eliminating the communication burden, a logarithmic quantizer and a weighted try-once-discard protocol are synthesized, which can further improve the network bandwidth utilization in networked control systems. Based on the fuzzy observer states, a novel fuzzy sliding surface is established with taking the singularly perturbed parameter into consideration properly, and we endeavor to synthesize a fuzzy observer-based sliding mode control law such that the reachability of the prescribed sliding surface could be guaranteed. In addition, by virtue of the convex optimization theory and Lyapunov approach, sufficient conditions are developed to guarantee the asymptotic stability of the sliding mode dynamics as well as the error system with an expected $H_{\infty }$ performance. Finally, a verification example is presented to illustrate the feasibility and effectiveness of the proposed method.

194 citations


Journal ArticleDOI
TL;DR: This paper aims to improve the performance of the permanent magnet synchronous motor speed regulation system by combining a novel disturbance observer (DOB) with the super-twisting sliding mode (STSM) technique, and the gain of the composite sliding mode controller can be significantly reduced.
Abstract: This paper aims to improve the performance of the permanent magnet synchronous motor (PMSM) speed regulation system by combining a novel disturbance observer (DOB) with the super-twisting sliding mode (STSM) technique. First, a STSM controller is constructed to eliminate the adverse effects of the lumped disturbance in the PMSM speed regulation system. A novel DOB is introduced to estimate and compensate the lumped unknown disturbance, which constitutes a composite controller with a feedforward compensation term and a state-feedback control. As a result, the gain of the composite sliding mode controller can be significantly reduced, which will improve the performance of the closed-loop PMSM speed regulation system. The validity and robustness of the proposed composite control scheme are fully verified by simulation and experimental results.

120 citations


Journal ArticleDOI
Bo Xu1, Lei Zhang1, Wei Ji1
26 May 2021
TL;DR: A compound control method using improved non-singular fast terminal sliding mode controller (NFTSMC) and disturbance observer compensation techniques are developed and shows that the proposed control method has better suppression of chattering effect, fast dynamic response and disturbance rejection ability.
Abstract: For the purpose of shortening response time and improved anti-disturbance performance of the permanent magnet synchronous motor (PMSM) drives, a compound control method using improved non-singular fast terminal sliding mode controller (NFTSMC) and disturbance observer compensation techniques are developed. First, in order to overcome the contradiction between fast response and heavy chattering of the conventional NFTSMC, a new sliding mode reaching law (NSMRL) is proposed for the improved NFTSMC. The NSMRL, which allows chattering reduction on control output while maintaining high tracking performance of the controller, can dynamically adapt to the variations of the controlled system. Second, to further improve the anti-disturbance performance of the PMSM control system, the sliding mode disturbance observer (SMDO) is introduced to estimate the load disturbance and add to the output of the improved NFTSMC for a feed-forward compensation item. Finally, both the simulation and experimental results applied to PMSM drives show that the proposed control method has better suppression of chattering effect, fast dynamic response, and disturbance rejection ability.

118 citations


Journal ArticleDOI
01 Jan 2021
TL;DR: An overview of the state of the art of the terminal sliding mode control (TSMC) theory and its applications can be found in this paper, where key technical issues and future challenges are discussed.
Abstract: Sliding mode control (SMC) has been a very popular control technology due to its simplicity and robustness against uncertainties and disturbances since its inception more than 60 years ago. Its very foundation of stability and stabilization is built on the principle of the Lyapunov theory which ascertains asymptotic stability. In the 1990s, a novel class of SMC, called the terminal sliding mode control (TSMC), was proposed which has been studied and applied extensively, giving rise to a robust control with tunable finite-time convergence delivering fast response, high precision, and strong robustness. In recent years, interest in this particular control technology has been increasing. This paper provides an overview of the state of the art of the TSMC theory and its applications, and postulates key technical issues and future challenges.

118 citations


Journal ArticleDOI
TL;DR: A flexible lateral control scheme is considered for the developed wheel-legged robot, which consists of a cubature Kalman algorithm to evaluate the centroid slip angle and the yaw rate and a fuzzy compensation and preview angle-enhanced sliding model controller to improve the tracking accuracy and robustness.
Abstract: Accurate path tracking and stability are the main challenges of lateral motion control in mobile robots, especially under the situation with complex road conditions. The interaction force between robots and the external environment may cause interference, which should be considered to guarantee its path tracking performance in dynamic and uncertain environments. In this article, a flexible lateral control scheme is considered for the developed wheel-legged robot, which consists of a cubature Kalman algorithm to evaluate the centroid slip angle and the yaw rate. Furthermore, a fuzzy compensation and preview angle-enhanced sliding model controller to improve the tracking accuracy and robustness. Finally, some simulations and experimental demonstrations using the four-wheel-legged robot (BIT-NAZA) are carried out to illustrate the effectiveness and robustness, and the proposed method has achieved satisfactory results in high-precision trajectory tracking and stability control of the mobile robot.

116 citations


Journal ArticleDOI
TL;DR: An observer-based adaptive control strategy for nonlinear stochastic Markovian jump systems with uncertain time-varying delay is proposed, and an interesting result reveals that the stability for the dynamics with type of uncertain transition rates may cover the completely known type.
Abstract: In this article, the issue of sliding mode control for nonlinear stochastic Markovian jump systems with uncertain time-varying delay is investigated. Considering the system state measurements and the state-dependent disturbances are not available for feedback purposes, an observer-based adaptive control strategy is proposed. Based on the decomposition of the input matrices, the state-space representation of the system is turned into a regular form with the aid of T–S fuzzy models first. Then, a fuzzy observer system is constructed, which could be transformed into two lower order subsystems. By choosing a common linear switching surface, on which it also obtains linear sliding mode dynamics in a simple form. Further, an adaptive controller is synthesized relying on the bounded system delay information to ensure the estimated states driven on the predefined sliding surface and remain the sliding motion. Also, the stochastic stability analysis of the sliding mode dynamics is undertaken with two types of transition rates, and an interesting result reveals that the stability for the dynamics with type of uncertain transition rates may cover the completely known type. Finally, a single-link robot arm model is provided to verify the validity of the proposed method.

112 citations


Journal ArticleDOI
TL;DR: Experiments demonstrate the superior property of stronger robustness and fewer chattering effects of the proposed method compared to existing disturbance observers and adaptive recursive terminal sliding mode (ARTSM) controller.

104 citations


Journal ArticleDOI
TL;DR: This article proposes a fault-tolerant compensation control approach against nonlinearity, simultaneous additive, and multiplicative actuator faults in Markov jump systems using the fuzzy logic system (FLS) to approximate the nonlinear functions, which have no available knowledge.
Abstract: This article proposes a fault-tolerant compensation control approach against nonlinearity, simultaneous additive, and multiplicative actuator faults in Markov jump systems. In this article, we first exploit the fuzzy logic system (FLS) to approximate the nonlinear functions, which have no available knowledge. Then, by utilizing the adaptive backstepping technique, a FLS-based adaptive fault-tolerant compensation controller is proposed, which can completely compensate for the adverse effects, arising from the additive actuator faults, the multiplicative actuator faults, and the mismatched nonlinearity simultaneously. The stability of the closed-loop system can be guaranteed by the proposed FLS-based adaptive controller with the adaptation laws. The novelty of this article lies in the fact that the additive and multiplicative actuator faults, and mismatched nonlinearity are considered simultaneously. Besides, the renown sliding mode control approach has limitations to deal with the FTC problem considered in this article because the considered nonlinearity is a mismatched one. The proposed control approach can cope with the challenging case. Finally, a practical wheeled mobile manipulator system is used to demonstrate the effectiveness and validity of the proposed approach.

98 citations


Journal ArticleDOI
TL;DR: This article addresses the investigation of sliding-mode control (SMC) for slow-sampling singularly perturbed systems (SPSs) with Markov jump parameters and the applicability of the SMC strategy is verified by a numerical example and a practical electric circuit model.
Abstract: This article addresses the investigation of sliding-mode control (SMC) for slow-sampling singularly perturbed systems (SPSs) with Markov jump parameters. As a new attempt, the SMC strategy is considered in the study of discrete-time Markov jump SPSs. Subsequently, in order to design a sliding-mode controller to ensure the stability of the proposed system, a novel integral sliding surface is constructed, and an SMC law is synthesized to ensure the reachability of the sliding surface. Through the utilization of Lyapunov stability and SMC theory, sufficient conditions are derived to ensure the state trajectories of the system are driven to a predefined sliding surface and the closed-loop sliding mode dynamics are stochastically stable. Finally, the applicability of the proposed SMC strategy is verified by a numerical example and a practical electric circuit model.

Journal ArticleDOI
TL;DR: The presented scheme can realized better tracking property and estimate the unknown model more accurately, thus obtaining better control effects than that without adding fractional order control.
Abstract: This article proposes a fractional order nonsingular terminal super-twisting sliding mode control (FONT-STSMC) method for a micro gyroscope with unknown uncertainty based on the double-loop fuzzy neural network (DLFNN). First, the advantages of nonsingular terminal sliding control are adopted, a nonlinear function is used to design the sliding hyper plane, then the tracking error in the system could converge to zero in a specified finite time. Second, fractional order control can increase the order of differential and integral, which greatly improves the flexibility of control method. The fractional-order controller has some advantages that integer-order systems cannot achieve, thus obtaining better control effects than that without adding fractional order control. Furthermore, the chattering problem of control input can be effectively solved by using the super-twisting algorithm, which makes the control input smoother. Finally, the unknown model of the micro gyroscope is estimated by using the DLFNN. Because the DLFNN can adjust the base width, the center vector and the feedback gain of the inner and outer layers adaptively, the accurate approximation of the unknown model can be achieved, and the robustness and accuracy can be enhanced. The simulation results and the comparisons with conventional neural sliding mode control prove the presented scheme can realized better tracking property and estimate the unknown model more accurately.

Journal ArticleDOI
TL;DR: Hardware-in-the-loop experimental results show that the supertwisting SOSM control algorithm with the NDOB technique can achieve better tracking performance and suppress the chattering phenomenon.
Abstract: In this article, we aim to investigate the path following control problem for four-wheel-independent-drive electric vehicles with consideration of modeling errors and complex driving scenarios. In order to guarantee operational safety and robustness, a supertwisting second-order sliding mode (SOSM) control strategy is employed to suppress the heavy chattering issue existing in the traditional sliding mode control (SMC). To degrade the lumped disturbance, a nonlinear disturbance observer (NDOB) technique is proposed to estimate the disturbance and compensate the modeling error. Then, a composite control strategy, which combines the SMC algorithm and NDOB technique is proposed based on stability analysis of the corresponding closed-loop system. Finally, hardware-in-the-loop experimental results show that the supertwisting SOSM control algorithm with the NDOB technique can achieve better tracking performance and suppress the chattering phenomenon.

Journal ArticleDOI
TL;DR: It is proved that the system responses can be made reaching the designed sliding-mode surface in finite and fixed time, and then stay on it, and it also illustrates that the inevitable external disturbances can be rejected by the designed slide-mode control.
Abstract: This paper proposes a unified framework to design sliding-mode control for stabilization of delayed memristive neural networks (DMNNs) with external disturbances. Under the presented framework, finite-time stabilization, and fixed-time stabilization of the controlled DMNNs can be, respectively, obtained by choosing different values for a specific control parameter. It is proved that the system responses can be made reaching the designed sliding-mode surface in finite and fixed time, and then stay on it. Moreover, it also illustrates that the inevitable external disturbances can be rejected by the designed sliding-mode control. Finally, the efficiency and superiority of the obtained main results are verified by comparisons with related works and numerical simulations.

Journal ArticleDOI
TL;DR: The development of SMC based technique with integration of intelligent control in the field of control engineering has been surveyed by considering numerous applications.
Abstract: In recent development in the control area, advanced control schemes are well established for the systems under the influence of parametric uncertainties due to modelling error, nonlinearities, and the external disturbances. Among the different robust control schemes sliding mode control (SMC) has made attention for the control engineer due to its merits. SMC has grown rapidly as a control in comparison with other robust control strategies due to its distinguish features like insensitive to matched uncertainties, reduced order sliding mode equations, zero error convergence of closed loop system and it offers a nonlinear control. The objective of this paper is to present the literature review of SMC development in an era of control technology. The development of SMC based technique with integration of intelligent control in the field of control engineering has been surveyed by considering numerous applications.

Journal ArticleDOI
TL;DR: In this article, a fault tolerant control strategy for dynamic positioning of unmanned marine vehicles using the quantized feedback sliding mode control technique is proposed, which is based on switching mechanism to compensate for thruster faults effects.
Abstract: This paper proposes a novel fault tolerant control strategy for dynamic positioning of unmanned marine vehicles using the quantized feedback sliding mode control technique. Due to the complex ocean environment, the unmanned marine vehicles are modeled as the Takagi-Sugeno fuzzy system with unknown membership functions. When the membership functions are not available, traditional sliding mode control technique becomes infeasible. To tackle this difficulty, a novel quantized sliding mode control strategy based on switching mechanism is designed to compensate for thruster faults effects. In addition, the phenomenon of time-varying delay leads to conservativeness of the existing dynamic quantization parameter adjustment strategy. Then a larger quantization parameter adjustment range, by taking time delay and fault factor into account, is given. Combining the novel sliding mode controller design and the improved dynamic quantization parameter adjustment strategy, the dynamic positioning of unmanned marine vehicles with thruster faults and quantization can be maintained. Finally, the effectiveness of the proposed method is verified through the simulation comparison results.

Journal ArticleDOI
TL;DR: A new dynamic model, which involves parameters uncertainties, nonlinearities, and Lévy noises, is proposed, and an adaptive sliding mode controller is built to study the stability of such a complex model.
Abstract: In this paper, the exponential stability in mean square for Markovian jumping systems (MJSs) is discussed. A new dynamic model, which involves parameters uncertainties, nonlinearities, and Levy noises, is proposed. Moreover, an adaptive sliding mode controller is built to study the stability of such a complex model. First, an integral-type sliding mode surface (SMS) is established to obtain the sliding mode motion dynamics of MJSs. By the generalized Ito formula and the Lyapunov stability theory, some sufficient conditions are obtained to make sure the exponential stability in mean square for the sliding mode motion dynamics. Second, an adaptive sliding mode control law is provided to assure the reachability of the specified SMS. Furthermore, corresponding parameters of the sliding mode controller and the SMS can be got by solving the convex optimization problem. Finally, the validity of the stability results obtained is illustrated by a numerical simulation and a practical simulation.

Journal ArticleDOI
TL;DR: This paper studies a new coupled fractional-order sliding mode control (CFSMC) and obstacle avoidance scheme, which has superior capacities of providing more control flexibilities and achieving high-accuracy.
Abstract: Recently, four-wheeled steerable mobile robots (FSMR) have attracted increasing attention in industrial fields, however the collision-free trajectory tracking control is still challenging in dynamic environments. This paper studies a new coupled fractional-order sliding mode control (CFSMC) and obstacle avoidance scheme, which has superior capacities of providing more control flexibilities and achieving high-accuracy. Instead of exploring traditional integer-order solutions, novel fractional-order sliding surfaces are proposed to handle the nonlinear interconnected states in a coupled structure. To accomplish non-oscillating avoidance of both stationary and moving entities within an uncertain workspace, a modified near-time-optimal potential function is subsequently presented with improved efficiency and reduced collision-resolving distances. By utilizing fuzzy rules, proper adaption gains of the reaching laws are designed to degenerate the effect of undesired chattering. The asymptotic stability and convergence can be guaranteed for the resultant closed-loop system. Three experiments are implemented on a real-time FSMR system. The results validate the reliability of the presented CFSMC scheme in terms of significantly mitigated following errors, faster disturbance rejection and smooth transition as compared to conventional methods.

Journal ArticleDOI
TL;DR: In this article, a quantized sliding-mode control (SMC) design methodology for nonlinear stochastic switching systems subject to semi-Markovian switching parameters, T-S fuzzy strategy, uncertainty, signal quantization, and nonlinearity is proposed.
Abstract: This article is concerned with the issue of quantized sliding-mode control (SMC) design methodology for nonlinear stochastic switching systems subject to semi-Markovian switching parameters, T-S fuzzy strategy, uncertainty, signal quantization, and nonlinearity. Compared with the previous literature, the quantized control input is first considered in studying T-S fuzzy stochastic switching systems with a semi-Markovian process. A mode-independent sliding surface is adopted to avoid the potential repetitive jumping effects. Then, by means of the Lyapunov function, stochastic stability criteria are proposed to be dependent of sojourn time for the corresponding sliding-mode dynamics. Furthermore, the fuzzy-model-based SMC law is proposed to ensure the finite-time reachability of the sliding-mode dynamics. Finally, an application example of a modified series dc motor model is provided to demonstrate the effectiveness of the theoretical findings.

Journal ArticleDOI
TL;DR: This paper aims to devise an asynchronous event-triggered sliding mode control law so as to guarantee the trajectories of the resulting closed-loop system can be forced onto the predefined sliding surface in a finite-time interval.
Abstract: In this paper, the finite-time sliding mode control issue is studied for a series of semi-Markov jump systems subject to actuator faults, where an asynchronous control method is adopted to overcome the non-synchronous phenomenon between the system mode and controller mode. Additionally, the event-triggered protocol, which determines whether the transmission of data should be performed according to the threshold condition, is introduced to alleviate the burden of data transmission in the communication channel. This paper aims to devise an asynchronous event-triggered sliding mode control law so as to guarantee the trajectories of the resulting closed-loop system can be forced onto the predefined sliding surface in a finite-time interval. Thence, by means of the mode-dependent Lyapunov functions and the finite-time theory, sufficient conditions are derived to assure that the closed-loop system is mean-square finite-time bounded in both reaching and sliding motion phases. Eventually, a numerical example and a tunnel diode circuit model are presented to illustrate the availability and practicability of the proposed approach.

Journal ArticleDOI
TL;DR: A simulation result and a practical example related to the Chua’s circuit are given to show the validity of the SMC strategy.
Abstract: This paper studies the $ {H}_{ {\infty }}$ sliding mode control (SMC) problem for a class of discrete-time conic-type nonlinear systems with time-delays and uncertainties. The nonlinear terms satisfy the conic-type constraint condition that lies in a know hyper-sphere with an uncertain center. By choosing a proper Lyapunov candidate, sufficient conditions are derived to ensure the asymptotic stability of the sliding mode dynamics while achieving a prescribed $ {H}_{ {\infty }}$ disturbance attenuation level and finally converted into a minimization problem. The controller is constructed to guarantee the discrete-time reach condition and maintain the states on the prespecified sliding surface. A simulation result and a practical example related to the Chua’s circuit are given at last to show the validity of our SMC strategy.

Journal ArticleDOI
TL;DR: Wang et al. as discussed by the authors proposed a two-hidden-layer recurrent neural network (THLRNN) for a single-phase shunt active power filter to approximate the unknown nonlinearities.
Abstract: In this article, a fractional-order sliding-mode control scheme based on a two-hidden-layer recurrent neural network (THLRNN) is proposed for a single-phase shunt active power filter. Considering the shortcomings of traditional neural networks (NNs) that the approximation accuracy is not high and weight and center vector of NNs are unchangeable, a new THLRNN structure which contains two hidden layers to make the network have more powerful fitting ability, is designed to approximate the unknown nonlinearities. A fractional-order term is added to a sliding-mode controller to have more adjustable space and better optimization space. Simulation and experimental studies prove that the proposed THLRNN strategy can accomplish the current compensation well with acceptable current tracking error, and have satisfactory compensation property and robustness compared with a traditional neural sliding controller.

Journal ArticleDOI
TL;DR: A new strategy for robust fault-tolerant control of robot manipulators using an adaptive fuzzy integral sliding-mode control (ISMC) and a disturbance observer (DO) is developed.
Abstract: This article develops a new strategy for robust fault-tolerant control (FTC) of robot manipulators using an adaptive fuzzy integral sliding-mode control (ISMC) and a disturbance observer (DO). First, an ISMC is developed for the FTC system. The major features of the approach are discussed. Then, to enhance the performance of the system, a fuzzy logic system approximation and a DO are introduced to approximate the unknown nonlinear terms, which include the model uncertainty and fault components, and to estimate the compounded disturbance and then are integrated into the ISMC. Next, a switching term based on an adaptive two-layer supertwisting algorithm is designed to compensate the disturbance estimated error and guarantee stability and convergence of the whole system. The nominal controller of the ISMC is reconstructed using a backstepping control technique to achieve the stability for the nominal system based on the Lyapunov criterion. The computer simulation results demonstrate the effectiveness of the proposed approach.

Journal ArticleDOI
TL;DR: In this article, an adaptive neural sliding mode control with ESO for uncertain nonlinear systems is proposed to improve the stability of the control system, which has superior tracking performance and anti-interference ability.
Abstract: An adaptive neural sliding mode control with ESO for uncertain nonlinear systems is proposed to improve the stability of the control system. Any control system inevitably exists uncertain disturbances and nonlinearities which severely affect the control performance and stability. Neural network can be utilized to approximate the uncertain nonlinearities. Nevertheless, it produces approximate errors, which will become more difficult to deal with as the order of the system increases. Moreover, these errors and uncertain disturbances will result in a consequence that the control system can be unable to converge quickly, and has to deal with a lot of calculations. Therefore, in order to perfect the performance and stability of the control system, this paper combines sliding mode control and ESO, and designs an adaptive neural control method. The simulation results illustrate that the improved system has superior tracking performance and anti-interference ability.

Journal ArticleDOI
TL;DR: In this paper, a backstepping global fast terminal sliding mode control for trajectory tracking control of industrial robotic manipulators is proposed to improve the dynamic performance and fast convergence of Sliding Mode Control (SMC) and Terminal SMC (TSMC).
Abstract: We propose a backstepping global fast terminal sliding mode control for trajectory tracking control of industrial robotic manipulators in this article. An integral of the global fast terminal sliding mode surface is firstly suggested to improve the dynamic performance and fast convergence of Sliding Mode Control (SMC) and Terminal SMC (TSMC), which also obtains a finite-time convergence. A controller is then developed from the proposed sliding surface using the backstepping control method and High-Order SMC (HOSMC) to ensure the global stability of the control system. Thanks to this proposed method, the controller provides small position and velocity control errors with less oscillation, smooth control torque, and convergence of the control errors in the short time. The stability and convergence also are guaranteed with Lyapunov theory. Finally, computer simulation verifies the effectiveness of the designed controller.

Journal ArticleDOI
TL;DR: In this article, an asynchronous observer-based sliding mode control (SMC) strategy is developed to guarantee the reachability of the predetermined sliding surface in a limited time, and a sufficient condition is established for the mean-square stability of the overall closed-loop systems and the desired controller is designed.
Abstract: The brief studies the asynchronous observer-based sliding mode control (SMC) for Markov jump systems (MJSs) with actuator failures. Considering the phenomena of unmeasurable states and the case that the controller/observer to be devised have different modes from the original systems, a hidden Markov model (HMM) is used to construct an asynchronous observer and the corresponding sliding surface is designed. Then, the asynchronous SMC strategy is developed to guarantee the reachability of the predetermined sliding surface in a limited time. A sufficient condition is established for the mean-square stability of the overall closed-loop systems and the desired controller is designed. Moreover, when the conditional probabilities describing the mode asynchronism are only partially known for the HMM in the systems, the related results are also given. Finally, simulation results show the usefulness of the developed techniques.

Journal ArticleDOI
Juntao Fei1, Zhe Wang1, Xiao Liang1, Zhilin Feng1, Yuncan Xue1 
TL;DR: In this article, an approximation-based adaptive fractional sliding mode control scheme is proposed, where a double loop recurrent fuzzy neural network (DLRFNN) is employed to approximate system uncertainties and disturbance.
Abstract: In this paper, an approximation-based adaptive fractional sliding mode control scheme is proposed, where a double loop recurrent fuzzy neural network (DLRFNN) is employed to approximate system uncertainties and disturbance. A fractional order term is incorporated into sliding surface that could add an extra degree of freedom, and combine the advantages of fractional calculus and sliding mode control. A new four-layer FNN is studied, which has two feedback loops (internal feedback loop and external feedback loop) to capture the weights and output signal calculated in the previous step, and use it as a feedback signal for the next step. On the one hand, the proposed DLRFNN structure combines the fuzzy system to process uncertain information with the neural network to learn from the process. On the other hand, both the internal state information and output signal are acquired and stored so that better approximation performance is obtained compared to regular FNN system. Furthermore, the adaptive law of DLRFNN parameters is derived, which can automatically update free parameters with bound. Finally, the effectiveness of the proposed adaptive fractional SMC using DLRFNN strategy is identified by simulations analysis with different fractional orders, whereby tracking errors are uniformly ultimately bounded. The proposed adaptive fractional SMC using DLRFNN strategy can achieve remarkably superior tracking performance in terms of high-precision and fast-response by comprehensive comparisons.

Journal ArticleDOI
TL;DR: In this article, a fuzzy double hidden layer recurrent neural network (FDHLRNN) controller for a class of nonlinear systems using a terminal sliding-mode control (TSMC) is proposed.
Abstract: This study designs a fuzzy double hidden layer recurrent neural network (FDHLRNN) controller for a class of nonlinear systems using a terminal sliding-mode control (TSMC). The proposed FDHLRNN is a fully regulated network, which can be simply considered as a combination of a fuzzy neural network (FNN) and a radial basis function neural network (RBF NN) to improve the accuracy of a nonlinear approximation, so it has the advantages of these two neural networks. The main advantage of the proposed new FDHLRNN is that the output values of the FNN and DHLRNN are considered at the same time, and the outer layer feedback is added to increase the dynamic approximation ability. FDHLRNN was designed to approximate the nonlinear sliding-mode equivalent control term to reduce the switching gain. To ensure the best approximation capability and control performance, the proposed FDHLRNN using TSMC is applied for the second-order nonlinear model. Two simulation examples are implemented to verify that the proposed FDHLRNN has faster convergence speed and the FDHLRNN with TSMC has good dynamic property and robustness, and a hardware experimental study with an active power filter proves the feasibility of the method.

Journal ArticleDOI
17 May 2021
TL;DR: The simulation and experimental results both show the effectiveness of the proposed MPCC scheme, and the steady-state performance of MPCC is greatly improved compared with traditional MPCC.
Abstract: As an efficient control strategy, model predictive current control (MPCC) has rapid response and simple calculation. This article proposes an improved MPCC scheme for permanent-magnet synchronous hub motor (PMSHM) drives. The mentioned control scheme uses the parameter values at the last moment to obtain the back electromotive force (EMF) and utilizes the obtained back EMF to obtain the predicted current value at the next moment. In the actual application of the motor, to enhance the robustness of the control system, a sliding mode controller is used to replace the conventional proportional-integral (PI) speed loop, and a finite position phase-locked loop based on the dichotomy is added to achieve sensorless speed control and provide an accurate rotor position angle. To improve the steady-state performance, the method of duty cycle is introduced, and the null vector and the actual vector are used together in the same control cycle. The simulation and experimental results both show the effectiveness of the proposed MPCC scheme, and the steady-state performance of MPCC is greatly improved compared with traditional MPCC.

Journal ArticleDOI
TL;DR: A quantized sliding mode controller and a dynamic quantization parameter adjustment strategy are developed to suppress oscillation amplitudes of the yAW velocity error and the yaw angle in the presence of thruster faults.
Abstract: This paper investigates quantized sliding mode control of unmanned marine vehicles (UMVs) with thruster faults and nonlinearities. We give a unified model to accommodate different types of thruster faults (e.g., partial, total, time-varying stuck, hard-over, and bias faults) in a common framework, which is significant because existing methods can only address them separately in a fault-specific manner. To eliminate the quantization effect induced by the communication channel by which the UMV outputs (e.g., position and velocity) and the control inputs are transmitted to and from the remote control station, a new dynamic uniform quantizer with an adjustable range of sensitivity is given. Via flexible choice of parameters, the adjustment range can fall within that of the existing results in the fault-free case. A quantized sliding mode controller and a dynamic quantization parameter adjustment strategy are then developed to suppress oscillation amplitudes of the yaw velocity error and the yaw angle in the presence of thruster faults. Simulation studies have verified the effectiveness of the proposed method.