Event-triggered Sliding Mode Control Research Articles

Event-triggered sliding mode control for trajectory tracking of robotic system with signal quantization

Event-triggered sliding mode control for trajectory tracking of robotic system with signal quantization

Event-triggered sliding mode control for singular discrete-time fuzzy Markov jump networked systems

In this present paper, the event-triggered sliding mode control (SMC) issue for a type of singular networked Markov jump systems with partly unknown transition probabilities (TPs) is mainly investigated, and it is modeled by discrete-time Takagi–Sugeno fuzzy systems. To save network resources, a mode-dependent event-triggered scheme (ETS) is applied to improve transmission efficiency. Subsequently, a common sliding surface is designed, which can effectively reduce the impact of the jumping process. Therein, the stochastic admissibility criterion for the system with [Formula: see text] performance [Formula: see text] is derived in the sense of partly unknown TPs. Moreover, a novel SMC law that guarantees the reachability of the quasi-sliding mode is given in view of the reaching condition. Finally, the validity of the presented theorems is demonstrated by a numerical example.

Event-triggered sliding mode control for uncertain systems with multiple disturbances

A new event-triggered sliding mode anti-disturbance (ETSMAD) control scheme is presented for the uncertain linear systems encountered by multiple disturbances containing the modelled unmeasurable disturbances and unmodelled disturbances. On the sliding mode reaching stage and sliding stage, different event-triggered programmes are developed to reduce the communication transmission load between the system and controller. The SM control law based on the ET programme is established to achieve the compensation and suppression of the modelled unmeasurable disturbances and unmodelled disturbances, respectively. Meanwhile, the criteria are formed to ensure the robustness of the system. The efficiency of the established ETSMAD control strategy is confirmed by a turbofan system example.

Time-varying formation for MSVs with input and prescribed performance constraints by fixed-time event-triggered sliding mode control

This work develops a new fixed-time sliding mode time-varying formation control strategy for multiple surface vessels (MSVs) to improve the control performance, ensure the navigation safety and reduce the communication burden. At first, a fixed-time adaptive radial basis function neural network (FxRBFNN) observer is designed to provide the estimations for external environmental disturbances and model parameters uncertainties. Then, observer-based fixed-time distributed time-varying formation event-triggered control law is proposed based on the novel fixed-time auxiliary dynamic system (FxADS), the proposed prescribed performance function, the designed fixed-time nonsingular terminal sliding mode (FxNTSM) manifold and the proposed uniform exact differentiator. Finally, the system stability is proved by Lyapunov theory. The salient features as follows. First, to enhance the convergence performance for time-varying formation control method, a novel hyperbolic cosecant prescribed performance function (PPF) is introduced. Second, a novel FxADS is proposed to confront input constraints. Third, the proposed scheme is combined with a relative threshold event-triggered strategy to reduce the unnecessary updates of actuators under the premise of ensuring the control performance. Fourth, to avoid the proposed formation control law including adjacent vessel accelerations, this work proposed an improved uniform exact differentiator to identify them. Numerical simulations confirm that the proposed scheme has superior control performance.

Event-triggered sliding mode control of linear repetitive processes and its application in metal rolling process

Event-triggered sliding mode control of linear repetitive processes and its application in metal rolling process

Memory Event-triggered Sliding Mode Control for UAV Formation Under Communication Delay and Wake Interferences

Memory Event-triggered Sliding Mode Control for UAV Formation Under Communication Delay and Wake Interferences

Event-triggered sliding mode control for a cableless microsatellite with input delay and quantization

This paper proposes a solution to the attitude control problem for a cableless microsatellite with input delay and quantized communication using event-triggered sliding mode control theory. The aim is to reduce the communication burden. The attitude dynamic is developed based on the unit quaternion, taking into account the inertial uncertainties, external disturbance uncertainties, and input delay. Based on the developed model, a sliding mode controller with input delay compensation and quantized input is proposed to ensure that the closed-loop system is uniformly ultimately bounded stable. The hybrid quantizer signal, based on the compensated event-triggered sliding mode controller, is updated only at an inconsecutive discrete instant. Thus, the communication burden can be significantly reduced, and the impact of input delay on the system can be effectively suppressed. The method's stability and effectiveness are ultimately confirmed through numerical simulation.

Tracking scheme of airborne star tracker based on event-triggered sliding mode control with known input delay

The airborne star tracker is crucial in aircraft navigation systems, with its tracking performance directly impacting navigation accuracy. Under airborne conditions, the performance of its tracking control will be compromised by various disturbances. Moreover, the limitation in computational resources is another issue that must be addressed. Assuming that the existing studies on this application did not consider these two aspects of the effects simultaneously, this study proposes a novel event-triggered sliding mode control (ET-SMC) scheme considering the known input time delay for star tracking control to address these two issues. First, an extended state observer (ESO) is presented to estimate the disturbance generated by airborne conditions. Second, the ET-SMC scheme further enhances the robustness and improves resource utilization, thus easing the processor burden. An ET mechanism related to the disturbance estimation triggering error in the ESO is introduced to ensure that the system input is only updated when necessary. A novel, easy-to-implement sliding gain is also proposed to increase system adaptability and reduce inherent chattering. The reachability of the sliding surface and the existence of a practical sliding mode of the system are ensured based on the Lyapunov theory. The ultimate upper bound of system states considering the known input time delay is also proven, thereby confirming the stability of the proposed design. The exclusion of Zeno behavior validates the feasibility of the proposed ESO-based ET-SMC. Finally, the effectiveness of the proposed method is verified using comparative simulations and target-tracking experiments. The experimental results demonstrate that the proposed method excels in robustness, disturbance attenuation, high tracking accuracy, and computational resource efficiency. These enhancements are anticipated to result in a more stable tracking performance for the star tracker, thereby contributing to precise aircraft navigation.

Event-triggered sliding mode control for networked control systems with actuator faults: Application to gas turbine system

This paper presents an event-triggered sliding mode fault-tolerant control method for networked control systems with actuator faults and external disturbance. First, an event-triggered scheme in the networked control systems is proposed to reduce the number of data transmission. In addition, considering the event-triggering, a sliding mode surface based on the system structure is constructed. Besides, to obtain the controller parameters that meet the [Formula: see text] performance, the bounded real lemma in the form of linear matrix inequality is obtained using the Lyapunov functional. In addition, a sliding mode fault-tolerant control is designed to guarantee that the system can still run stably under the condition of faults and disturbances. Finally, the simulation results of gas turbine system are given to verify the feasibility of the theoretical method.

Event-Triggered Sliding Mode Control for 2D FMII Systems Under Bounded Direction Round-Robin Protocol

Event-Triggered Sliding Mode Control for 2D FMII Systems Under Bounded Direction Round-Robin Protocol

Continuous and Periodic Event-Triggered Sliding-Mode Control for Path Following of Underactuated Surface Vehicles.

This article develops continuous and periodic event-triggered sliding-mode control (SMC) algorithms for path following of underactuated surface vehicles (USVs). Based on the SMC technology, a continuous path-following control law is designed. The upper bounds of quasi-sliding modes for path following of USVs are established for the first time. Subsequently, both continuous and periodic event-triggered mechanisms are considered and added into the proposed continuous SMC scheme. It is demonstrated that with appropriate selecting of control parameters, the use of hyperbolic tangent functions does not affect the boundary layer of quasi-sliding mode caused by event-triggered mechanisms. The proposed continuous and periodic event-triggered SMC strategies can make the sliding variables reach the quasi-sliding modes and stay in there. Moreover, energy consumption can be reduced. Stability analysis shows that the USV can follow a reference path by using the designed method. The simulation results show the effectiveness of the proposed control methods.

Dissipativity-Based Event-Triggered Sliding Mode Control of Discrete-Time 2-D Systems

This paper focuses on dissipativity analysis and dissipativity-based sliding mode control (SMC) of discrete-time two-dimensional (2-D) systems described by Roesser model. First, dissipativity is introduced for 2-D systems. Aimed at the characteristics of Roesser model, the horizontal and vertical sliding surface functions are constructed for the addressed 2-D systems, respectively. Then sufficient conditions are proposed to guarantee the asymptotic stability and the pre-specified dissipativity for the resultant reduced-order 2-D sliding mode dynamics. Next, the SMC law is developed such that the system trajectories are driven into the quasi-sliding mode band in a finite region and maintained there all the time. In order to achieve a better resource utilisation, the event-triggered strategy is further incorporated in the design of SMC law. The event-triggered rule is also established to implement the event-triggered SMC scheme for 2-D systems. In the meantime, the corresponding quasi-sliding mode band is obtained. Finally, one verification example is given to show the effectiveness of the proposed SMC design method.

Fixed-time event-triggered sliding mode cooperative path-following control with prescribed performance for USVs based on lumped disturbance observer

In order to solve the problem of Unmanned Surface Vehicles being unable to accurately cooperative path-following under the parameter uncertainties, actuator faults, and external disturbances, this paper mainly combines the fixed-time and sliding mode theory to design the control strategy. Firstly, a fixed-time disturbance observer is adopted to estimate composite disturbances. Then, a fixed-time heading-surge guidance law that satisfies the fixed-time stability of the position error system is designed, and the synchronization of the formation on the full paths is realized by the fixed-time path parameter consensus. On this basis, a fixed-time dynamic event-triggered sliding mode controller with prescribed performance is proposed to ensure that the velocity error system is stable in fixed time and the tracking error is strictly within the specified range. Due to the application of fixed-time theory in cooperative path-following, the whole closed-loop system is proved to be fixed-time stable. Moreover, the dynamic event-triggered mechanism is introduced to reduce the energy consumption. Finally, the effectiveness and superiority of the proposed control method are verified by simulations.

Event-triggered sliding mode control for 2-D Roesser model with mismatched disturbance

This paper is concerned with designing two-dimensional event generators and sliding mode controllers for discrete-time two-dimensional systems described by the celebrated Roesser model with external mismatched disturbance. First of all, aimed at the characteristics of the Roesser model, the horizontal and vertical disturbance observers and sliding surface functions are established for the addressed two-dimensional systems, respectively. Then based on the disturbance estimation and rejection technique, a modified reaching law and its corresponding sliding mode controller are designed to achieve the system robustness and disturbance attenuation. To reduce the resource usage, the event-triggered strategy is further incorporated in the design of sliding mode control law. Moreover, the stability of the sliding-mode dynamics is analyzed by resorting to the Lyapunov stability theory. Finally, a simulation example is presented to verify the effectiveness of the proposed method.

Event-Triggered SMC for Networked Markov Jumping Systems With Channel Fading and Applications: Genetic Algorithm.

The event-triggered sliding-mode control (SMC) for discrete-time networked Markov jumping systems (MJSs) with channel fading is investigated by means of a genetic algorithm. In order to reduce resource consumption in the transmission process, an event-triggered protocol is adopted for networked MJSs. A key feature is that the signal transmission is inevitably affected by fading phenomenon due to delay, random noise, and amplitude attenuation in a networked environment. With the aid of a common sliding surface, an event-triggered SMC law is designed by adjusting the system network mode. Under the framework of stochastic Lyapunov stability, sufficient conditions are constructed to ensure the mean-square stability of the closed-loop networked MJSs, and the sliding region is reached around the specified sliding surface. Moreover, based on the iteration optimizing accessibility of objective function, an effective SMC approach under genetic algorithm is proposed to minimize the convergence region around the sliding surface. Finally, the effectiveness of the proposed method is proved by the F-404 aircraft model.

Asynchronous event-triggered linear sliding mode control for T-S fuzzy singular systems

This paper investigates an asynchronous event-triggered linear sliding mode control (SMC) problem for T-S fuzzy singular systems with external disturbances. The generalized regular form of T-S fuzzy singular systems is presented to obtain the reduced-order sliding motion, which removes the constraints that all the subsystems share the same input matrix. Based on the generalized regular form, the singular matrix and the state variables are used to design the triggering function, which fully employs the characteristics of singular systems compared with the related results. Furthermore, an asynchronous event-triggered SMC (ETSMC) law is designed to guarantee the existence of the practical sliding mode, and the controller gains can be obtained via the admissibility analysis of the reduced-order sliding motion. Based on the designed singular-matrix-dependent event triggering mechanism and the asynchronous ETSMC law, the positive lower bound of the inter execution time can be guaranteed. Finally, two simulation examples are presented to verify the effectiveness of the obtained results, and some comparison results with the relevant methods are presented to illustrate the advantages of the proposed method.

An event-triggered sliding mode control mechanism to exponential consensus of fractional-order descriptor nonlinear multi-agent systems

The problem of leader-following exponential consensus is addressed for fractional-order descriptor nonlinear multi-agent systems by designing an event-triggered sliding mode control strategy. Such an exponential consensus is achieved by defining a suitable sliding surface and a controller under the Mittag–Leffler stability of fractional-order systems. Due to the memory nature of the fractional-order calculus operator, a new condition is established to avoid Zeno behaviors happening, which is different from existing event-triggered schemes. Finally, to illustrate the effectiveness and feasibility of the proposed method, two examples are provided.

Event-Triggered Sliding-Mode Control for Fuzzy Semi-Markovian Jump Systems With Dead Zone Input and Application to Circuit Systems

This paper investigates event-triggered sliding mode control (SMC) for fuzzy semi-Markovian jump systems (S-MJSs) subject to limited communication capacity, in which we consider the network-induced transmission delay, dead-zone input and partially unknown transition rates of jumping mode in a whole framework. First, an event-triggered mechanism(ETM) is employed in the sensor-to-controller channel to save network resources efficiently. Then, a novel integral sliding surface is obtained with the aid of the event-triggered state information, and some new sufficient conditions on the stochastic stability of the overall closed-loop system are given in the sense of partially unknown transition rates via stochastic stability theory and matrix inequality method. Furthermore, a mode-depended sliding mode controller is designed to guarantee the reachability of the sliding surface in finite time by using the Lyapunov stability theory. Finally, a TD circuit model is provided to illustrate the validity of the proposed control scheme.

Stochastic Synchronization of Semi-Markovian Switching Cyber-Physical Impulsive Complex Networks via Dynamic Event-Triggered SMC

In this paper, a novel dynamic event-triggered sliding mode control (SMC) scheme is developed to investigate the stochastic synchronization of semi-Markovian switching cyber-physical complex network (SSCCN) with impulsive effects. First of all, the mode-dependent average dwell time (MDADT) and the transition probability (TP) are introduced to express the semi-Markovian switching signal, which makes the proposed model more applicable than other systems where only the average dwell time (ADT) switching is provided. Moreover, to prevent system uncertainty and unnecessary data transmission, a new dynamic event-triggered mechanism is incorporated into the design of SMC. In most of the existing event-triggered SMC strategies, the continuity of sliding mode surfaces for SSCCN is lost due to intermittent impulsive effects and stochastic switching in the system. Considering this problem, a piecewise mode-independent integral sliding function is put forward that takes into account the dynamic properties of the impulses through the proposed dynamic event-triggered mechanism. It can not only obtain the continuous trajectories of the impulsive networked system, but also significantly reduce the number of event triggers. Some rigorous analytical techniques have been developed to obtain the sufficient conditions required to ensure both the mean square synchronization (MSS) and almost sure synchronization (ASS) of SSCCN. Finally, some numerical examples are presented to demonstrate the effectiveness of the theoretical analysis.

Leader–follower sliding mode formation control of fractional-order multi-agent systems: A dynamic event-triggered mechanism

This paper examines the concept of the leader–follower formation for fractional-order multi-agent systems (FO-MASs) by utilizing dynamic event-triggered sliding mode control (SMC) method. Firstly, a dynamic event-triggered mechanism (DETM) is designed relying on the combined measurement vector, in which an auxiliary variable is introduced to dynamically adjust the threshold for each fractional-order agent system. Unlike most existing event-triggered communication mechanisms, whose threshold parameters are always fixed, the threshold parameters in our designed event-triggered conditions can be dynamically adjusted according to the fractional-order dynamic rule. Numerical results show that the proposed DETM can achieve a better system performance in reducing the sampling frequency and the expected formation performance. Secondly, the leader–follower formation control problem is transformed into checking the asymptotic stability problem of the closed-loop system. In addition, due to the memorability of fractional calculus operators, a distinctive condition is established to avoid the occurrence of Zeno behaviors reported in existing dynamic event-triggered schemes. Finally, a simulation example is presented to illustrate the effectiveness and feasibility of the dynamic event-triggered SMC method proposed in this paper.