event triggered fuzzy h control for a class of nonlinear networked control systems using the deviation bounds of asynchronous normalized membership functions this paper is concerned with the event triggered h control for a nonlinear networked control system a new event triggered transmission scheme is first proposed to reduce the network bandwidth utilization under this scheme the nonlinear networked control system is formulated as a takagi sugeno fuzzy threshold error dependent system with asynchronous normalized membership functions then by using the deviation bounds of asynchronous normalized membership functions some sufficient conditions on the existence of the parameters of the event triggered transmission scheme and the fuzzy controller are derived such that the takagi sugeno fuzzy threshold error dependent system with asynchronous normalized membership functions is asymptotically stable with a prescribed h attenuation level it is shown that the proposed design method can reduce the conservativeness of some existing results finally two examples are given to demonstrate the effectiveness of the proposed design method and the event triggered transmission scheme

lmi based stability analysis for fuzzy model based control systems using artificial t s fuzzy model this paper investigates the stability of fuzzy model based fmb control systems an alternative stability analysis approach using an artificial fuzzy system based on the lyapunov stability theory is proposed to facilitate the stability analysis the continuous membership functions of the takagi sugeno t s fuzzy model are represented by the staircase ones with the nice property of the staircase membership functions it turns the set of infinite number of linear matrix inequality lmi based stability conditions into a finite one furthermore the staircase membership functions carrying system information can be brought to the stability conditions to relax the stability conditions the stability of the original fmb control systems is guaranteed by the satisfaction of the lmi based stability conditions the proposed stability analysis is applied to the fmb control systems of which the t s fuzzy model and fuzzy controller do not share the same premise membership functions and thus is able to enhance the design flexibility of the fuzzy controller a simulation example is given to illustrate the merits of the proposed approach

robust reliable control design for networked control system with sampling communication in this article the problem of robust exponential stability and reliable stabilisation for a class of continuous time networked control systems ncss with a sample data controller and unknown time varying sampling rate is considered the analysis is based on average dwell time lyapunov krasovskii functional and linear matrix inequality lmi technique the delay dependent criteria are developed for ensuring the robust exponential stability of the considered ncss the obtained conditions are formulated in terms of lmis that can easily be solved by using standard software packages furthermore the result is extended to study the robust stabilisation for ncs with parameter uncertainties a state feedback controller is constructed in terms of the solution to a set of lmis which guarantee the robust exponential stabilisation of ncs and the controller finally numerical examples are presented to illustrate the effectiveness of the obtained results

stabilization of networked stochastic time delay fuzzy systems with data dropout this paper deals with the problem of stabilization for networked stochastic systems with transmitted data dropout the plant in the networked control system ncs under consideration is a discrete stochastic time delay nonlinear system represented by a takagi sugeno fuzzy model exponential stability criteria of the ncs are developed by using a common quadratic lyapunov function and a fuzzy lyapunov function respectively a stabilization controller with convergence rate constraint can be designed by solving a set of linear matrix inequalities that is numerically feasible with commercially available software three numerical examples are presented to demonstrate the effectiveness of the proposed methods

event triggered h stabilization for networked stochastic systems with multiplicative noise and network induced delays this paper is concerned with event triggered h stabilization in the mean square sense for networked stochastic system with multiplicative noise and network induced delays firstly a new discrete event triggered transmission protocol dettp is proposed to reduce the utilization rate of communication bandwidth the main features of the proposed protocol involve three aspects 1 it allows the presence of external disturbances and multiplicative noise 2 it is more general than some existing event triggered transmission schemes in the deterministic setting and 3 the minimum inter event time is implicity defined and is naturally given by the sampling period chosen for the plant secondly under the dettp a new closed loop stochastic networked control system model is established remarkably to facilitate theoretical analysis the resultant event based stochastic networked control system is further transformed into a system with two successive delay components in the state considering the effects of network induced delays multiplicative noise and dettp in a unified framework by using stochastic system theory sufficient conditions on the existence of the desired event based h state feedback controller are derived such that the resultant event based stochastic networked control system is exponentially stable in the mean square sense with a prescribed h performance while reducing the number of sampled state transmission along the feedback link as much as possible thirdly a co design algorithm for determining the parameters of the dettp and the state feedback controller gain matrix are also proposed finally two practical examples are given to illustrate the effectiveness and advantage of the proposed method over some existing results in the literature

event triggered networked h control of discrete time nonlinear singular systems this paper is concerned with h controller design for a class of discrete time nonlinear singular system which is controlled over a communication network the network induced delay is considered and its distribution characteristic is described by a bernoulli stochastic variable a novel event triggered control scheme is proposed in order to save the limited network communication bandwidth based on the lyapunov kravoskii stability theory a delay distribution dependent criterion is derived which guarantees the closed loop networked discrete time nonlinear singular system is regular causal and stable with a certain h performance index a co design method for the h controller and the event triggered scheme is presented by using the singular value decomposition technology an numerical example is given to illustrate the effectiveness of the proposed method

fuzzy model based piecewise mathscr h _ infty static output feedback controller design for networked nonlinear systems this paper investigates the problem of robust h output feedback control for a class of nonlinear systems under unreliable communication links the nonlinear plant is represented by a takagi sugeno t s uncertain fuzzy model and the communication links between the plant and controller are assumed to be imperfect i e data packet dropouts occur intermittently which is often the case in a network environment stochastic variables that satisfy the bernoulli random binary distribution are adopted to characterize the data missing phenomenon and the attention is focused on the design of a piecewise static output feedback sof controller such that the closed loop system is stochastically stable with a guaranteed h performance based on a piecewise lyapunov function combined with some novel convexifying techniques the solutions to the problem are formulated in the form of linear matrix inequalities lmis finally simulation examples are also provided to illustrate the effectiveness of the proposed approaches

sampled data h fuzzy filtering for nonlinear systems with missing measurements in this paper a sampled data h fuzzy filtering problem is considered for nonlinear systems with missing measurements the nonlinear sampled data system and missing measurements are assumed to be represented by a takagisugeno ts fuzzy system and an independent identically distributed bernoulli random process respectively based on the fuzzy system the h fuzzy filtering problem is formulated to design the sampled data fuzzy filter by using the exponential mean square stability definition the stability condition with an h performance is guaranteed for the fuzzy system with the sampled data fuzzy filter and its sufficient condition is converted into the linear matrix inequality lmi format finally an example is provided to verify the effectiveness of the proposed fuzzy filtering technique

on collapse of wave maps abstract we derive the universal collapse law of degree 1 equivariant wave maps solutions of the sigma model from the 2 1 minkowski space time to the 2 sphere to this end we introduce a nonlinear transformation from original variables to blowup ones our formal derivations are confirmed by numerical simulations

communication delay distribution dependent networked control for a class of t s fuzzy systems this paper investigates a robust networked control for a class of takagi sugeno t s fuzzy systems the controller design specifically takes probabilistic interval distribution of the communication delay into account a general framework of networked control is first proposed the two main features are 1 the zero order hold can choose the latest control input signal when the packets received are out of order and 2 as the result of 1 the models of the all kinds of uncertainties in networked signal transfer including network induced delay and data packet dropout are under a unified framework next if the probability distribution of communication delay is known or specified in a design process sufficient stability conditions for networked t s fuzzy systems are derived which are based on the lyapunov theory following this a stabilizing controller design method is developed which shows that the solvability of the design depends not only on the upper and lower bounds of the delay but on its probability distribution as well finally a numerical example is used to show the application of the theoretical results obtained in this paper

event triggered fuzzy adaptive compensation control for uncertain stochastic nonlinear systems with given transient specification and actuator failures abstract in this paper an event triggered fuzzy adaptive compensation controller is constructed for uncertain stochastic nonlinear systems with given transient specification and actuator failures the main characteristics of the systems are that they take into account the effect of actuator failures and given transient specification system communication resource limitation simultaneously it is still an arduous task and challenge to design for uncertain stochastic nonlinear system specially to stabilize the uncertain nonlinear stochastic systems the fuzzy logic systems are used to approximate the unknown functions an event triggered control mechanism is established to save the system communication resource and a transformed system control mechanism is developed to satisfy the given transient specification all the time in normal mode or faulty mode based on the lyapunov approach it is proved that all the signals of the closed loop system are bounded and the tracking error is limited to a given transient specification the simulation results illustrates the effectiveness of the proposed control approach

network based h control for t s fuzzy systems with an adaptive event triggered communication scheme abstract this paper extends the prior work of discrete event triggered communication for networked t s fuzzy systems where the next communication instant is determined by an event triggered communication scheme with a constant threshold and the premises of t s fuzzy systems and parallel distribution compensation pdc fuzzy control rules are synchronous firstly an adaptive event triggered communication scheme for ncss is presented which relaxes the assumption of the prior work that the threshold of event triggered communication scheme is a preselected constant secondly an asynchronous premise re construct method for networked t s fuzzy systems is proposed which relaxes the assumption of the prior work that the premises of the plant and the pdc control rules are synchronous we show that the number of transmitted packets generated by the proposed scheme is smaller than those generated by some existing ones while ensuring the desired control performance simulations show the effectiveness of the proposed method

sampled data fuzzy stabilization of nonlinear systems under nonuniform sampling this paper investigates the sampled data fuzzy stabilization problem for a class of nonlinear systems that is exactly modeled in takagi sugeno fuzzy form at least locally a new method for designing parallel distribution compensation fuzzy controller is proposed which just requires that the nonlinear function is locally lipschitz by considering the sample and hold behavior of the system and using jensen s integral inequality an inequality constrain condition is derived from the locally lipschitz property further by defining a time dependent lyapunov krasovskii functional term a new technique instead of the use of s procedure is developed and stabilization conditions for state feedback and observer based output feedback under nonuniform sampling are obtained compared with the existing ones the new design method not only avoids the difficulty of finding exact upper bounds of asynchronous errors of mismatch membership functions but contains less conservatism and less numerical complexity as well finally some illustrative examples are given to show the effectiveness of the proposed design method and the significant improvement over the existing results

to transmit or not to transmit a discrete event triggered communication scheme for networked takagi sugeno fuzzy systems this paper first proposes a discrete event triggered communication scheme for a class of networked takagi sugeno t s fuzzy systems this scheme has two main features 1 whether or not the sampled state should be transmitted is determined by the current sampled state and the error between the current sampled state and the latest transmitted state compared with those in a periodic time triggered communication scheme the communication bandwidth utilization is considerably reduced while preserving the desired control performance and 2 it is a discrete event triggered communication scheme due to the fact that the triggered conditions are only measured and checked at a constant sampling period compared with a continuous event triggered communication scheme the special hardware for continuous measurement and computation is no longer needed second a networked t s fuzzy model is delicately constructed which not only considers nonuniform time scales in the networked t s fuzzy model and the parallel distributed compensation fuzzy control rules but includes the aforementioned state error as well third a stability criterion and a stabilization criterion about the networked t s fuzzy system are derived respectively the stability criterion and stabilization criterion can provide a tradeoff to balance the required communication resource and the desired performance lowering the desired performance allows the network to allocate more limited bandwidth to other nodes in need finally a numerical example is given to show the effectiveness of the proposed method

stabilization and separation principle of networked control systems using the t s fuzzy model approach this paper is concerned with the stabilization problem for a class of discrete time networked control systems ncss with bounded time delays and packet losses the controlled plant is represented by a takagi sugeno fuzzy model and both the state feedback control and output feedback control cases are considered by guaranteeing the decrement of lyapunov functional at each control signal updating step a less conservative stability condition for the state feedback ncss is derived and the corresponding stabilizing controller design method is also presented under an observer based framework the output feedback stabilization problem is further studied where the main contribution is the development of the separation principle for ncss illustrative examples are provided to show the advantage and effectiveness of the developed results

robust h control for nonlinear systems over network a piecewise analysis method a piecewise analysis method pam is proposed to investigate the h performance analysis and h control design for nonlinear networked control systems nncss which are presented in the form of t s fuzzy model with time varying input delay different from the existing method in dealing with the time varying delay the whole variation interval of the delay is divided into two subintervals with equal length respecting for the delay belonging each subinterval new criteria on h performance analysis of the nncss are obtained by checking the variation of the derivative of the lyapunov functional in the two subintervals then criteria for the h controller design are obtained by using the convexity properties of the matrix inequality and some other new analysis techniques which are shown in terms of nonlinear matrix inequalities and can be solved by using a cone complementarity liberalization method as application of the derived results h controller design is carried out for the nonlinear mass spring system discussion shows that the proposed method is less conservative than the existing references

validation of first order diffraction theory for the traveltimes and amplitudes of propagating waves ultrasonic measurements of acoustic wavefields scattered by single spheres placed in a homogenous background medium water are presented the dimensions of the spheres are comparable to the wavelength and the wavelength and represent both positive rubber and negative teflon velocity anomalies with respect to the background medium the sensitivity of the recorded wavefield to scattering in terms of traveltime delay and amplitude variation is investigated the results validate a linear first order diffraction theory for wavefields propagating in heterogeneous media with anomaly contrasts on the order of 15 the diffraction theory is compared further with the exact results known from literature for scattering from an elastic sphere formulated in terms of legendre polynomials to investigate the 2d case the first order scattering theory is tested against 2d elastic finite difference calculations as the presented theory involves a volume integral it is applicable to any geometric shape and the scattering object does not need to be spherical or any other specific symmetrical shape furthermore it can be implemented easily in seismic data inversion schemes which is illustrated with examples from seismic crosswell tomography and a reflection experiment

sampled data robust h control for t s fuzzy systems with time delay and uncertainties abstract this paper investigates sampled data robust h control for t s fuzzy systems with time delay and uncertainties by introducing the free weighting matrices to deal with the integral items and converting the coupling time varying matrix inequalities into a group of decoupling matrix inequalities an innovative delay dependent stabilization criterion is first presented then a sampled data h controller is designed to stabilize the t s fuzzy system to achieve the prescribed disturbance attenuation level which is dependent on both the size of state delay and upper bound of allowable sampling period since 1 the sawtooth structure of delay is fully considered 2 neither model transformation nor bounding techniques are employed in deriving the delay dependent results and 3 none of the integral items are arbitrarily ignored and magnified the less conservative results can be expected a practical application example is given to demonstrate the effectiveness of the proposed methods

a novel observer based output feedback controller design for discrete time fuzzy systems this paper addresses the problem of observer based output feedback controller designs for discrete time t s fuzzy systems based on a relaxed approach in which the fuzzy lyapunov functions are used different from the existing two step method a single step linear matrix inequality method is provided for the observer based controller design it is shown that the controller and observer parameters can be obtained by solving a set of strict linear matrix inequalities that are numerically feasible with commercially available software the new design method not only overcomes the drawback induced by the two step approach but also provides less conservative results over some existing results finally the effectiveness of the proposed approach is demonstrated by an example

event triggered fuzzy control for nonlinear networked control systems abstract this paper investigates the problem of event triggered et dynamic output feedback controller dofc design for nonlinear networked control systems ncss in the framework of interval type 2 it2 fuzzy systems the parameter uncertainties in the nonlinear plant can be captured effectively by utilizing the membership functions with upper and lower bounds to reduce the utilization of limited network bandwidth an et communication mechanism is applied a novel type of dofc subject to parameter uncertainties et communication mechanism and transmission delay is proposed where the membership functions are different from those of the fuzzy models consequently the closed loop system is with mismatched membership functions which hampers the stability analysis and controller design to promote the stability analysis and achieve a better control performance the information of membership functions and slack matrices are utilized for obtaining the main results finally a simulation example is employed to demonstrate the effectiveness of the proposed mechanism

on switched regulator design of uncertain nonlinear systems using takagi sugeno fuzzy models this paper is concerned with the design of state feedback switched controllers for a class of uncertain nonlinear plants described by takagi sugeno t s fuzzy models the proposed methodology eliminates the need to find the membership function expressions to implement the control law which is relevant in cases where the membership function depends on uncertain parameters the design of the switched controllers is based on a minimum type lyapunov function and the minimization of the time derivative of this lyapunov function the conditions of the new stability criterion are represented by a kind of bilinear matrix inequalities bmis that has been solved by the path following method a numerical example and the nonlinear control design of a magnetic levitator with uncertainties illustrate the procedure

stabilization of networked control systems with a logic zoh the technical note is concerned with the stabilization problem of networked control systems a general framework is proposed firstly where the zero order hold has the logical capability of choosing the newest control input packet the continuous time process is discretized as a system with input delays then a sufficient condition for testing the stability of the discretized system and two sufficient conditions for designing a stabilizing controller are established based upon the lyapunov theory finally numerical examples and simulations are used to illustrate the developed theory

co design of event generator and filtering for a class of t s fuzzy systems with stochastic sensor faults this paper is firstly concerned with reliable h filter design for a class of t s fuzzy systems with stochastic sensor faults under an event triggered scheme 1 a t s fuzzy model is used to approximate the nonlinear dynamics of the plant a set of stochastic variables are used to describe the sensor failure 2 an event triggered scheme which has some advantages over some existing ones is introduced to the networked control systems under the event triggered scheme the sensor data are transmitted only when the sampled measurements of the plant violate the specified event condition then an event based filter design model for t s fuzzy systems is constructed by taking the effect of event triggered scheme and the sensor faults into consideration sufficient conditions for the existence of the desired filter are established in terms of linear matrix inequalities and the explicit expression is given for the designed filter parameters a numerical example is provided to illustrate the design method