Robust Reliable Control Research Articles

Input–output finite-time stabilisation for periodic piecewise polynomial systems with nonlinear actuator faults: an observer-based approach

This paper is concerned with the input–output finite-time (IO-FT) stabilisation problem for a class of continuous-time periodic piecewise polynomial systems (PPPSs) with immeasurable states and external disturbances via state estimation-based robust reliable controller. Firstly, to reflect the actuality, a parameter uncertainty that exhibits the random nature and the actuator faults with nonlinear character are considered in the addressed PPPSs and the control scheme, respectively. In detail, the randomness of uncertain parameters is portrayed by the stochastic variable and it is presumed to pursue the Bernoulli distributions. Secondly, to estimate the immeasurable states of PPPSs, a periodic piecewise polynomial observer is designed depending on the output of PPPSs. The main intent of this article is to devise a state estimation-based robust reliable controller to ascertain the IO-FT stabilisation of the PPPSs. Moreover, by bridging the Lyapunov stability theory, linear matrix inequality technique and IO-FT stability theory, the required IO-FT stabilisation conditions in the frame of linear matrix inequality are procured for the system under consideration. Eventually, simulation results of the addressed PPPSs are shown in line with the proposed analytical findings, revealing the competence, inherent capability and utility of the devised control protocol.

Robust Observer-based Control of Nonlinear Multi-Omnidirectional Wheeled Robot Systems via High Order Sliding-mode Consensus Protocol

This paper presents a novel observer-based controller for a class of nonlinear multi-agent robot models using the high order sliding mode consensus protocol. In many applications, demand for autonomous vehicles is growing; omnidirectional wheeled robots are suggested to meet this demand. They are flexible, fast, and autonomous, able to find the best direction and can move on an optional path at any time. Multi-agent omnidirectional wheeled robot (MOWR) systems consist of several similar or different robots and there are multiple different interactions between their agents, thus the MOWR systems have complex dynamics. Hence, designing a robust reliable controller for the nonlinear MOWR operations is considered an important obstacles in the science of the control design. A high order sliding mode is selected in this work that is a suitable technique for implementing a robust controller for nonlinear complex dynamics models. Furthermore, the proposed method ensures all signals involved in the multi-agent system (MAS) are uniformly ultimately bounded and the system is robust against the external disturbances and uncertainties. Theoretical analysis of candidate Lyapunov functions has been presented to depict the stability of the overall MAS, the convergence of observer and tracking error to zero, and the reduction of the chattering phenomena. In order to illustrate the promising performance of the methodology, the observer is applied to two nonlinear dynamic omnidirectional wheeled robots. The results display the meritorious performance of the scheme.

Extended dissipative analysis for T–S fuzzy semi-Markov jump systems with sampled-data input and actuator fault

This paper is concerned with reliable robust sampled-data control for T–S fuzzy semi-Markov jump systems (SMJSs) with time-varying delay. The asynchronous model is established, which makes the fuzzy sampled-data controller share the premise variable of the fuzzy plant with the fuzzy system. By adjusting the free weight matrix in the concept of extended dissipative, H∞, L2−L∞, passive and Q,S,R-dissipative performance are solved in a unified framework. A novel mode-dependent Lyapunov–Krasovskii functional (LKF) is constructed, which fully utilizes the characteristics of the real sampled period. Based on Lyapunov stability theory, Newton–Leibniz condition and new integral inequality techniques, some less conservative sufficient conditions are obtained to guarantee the close-loop system is stochastically stable and extended dissipative. Based on sampled-data approach, a robust reliable controller can be developed by solving the linear matrix inequalities (LMIs). The advantage and effectiveness of the proposed design method can be illustrated by the numerical example.

Extended dissipative analysis for T–S fuzzy system with sampled-data input and actuator fault

This paper is concerned with reliable robust sampled-data control for T–S fuzzy system with time-varying delay. By adjusting the free weight matrix in the concept of extended dissipative, , , passive and -dissipative performance are solved in a unified framework. A novel mode-dependent Lyapunov–Krasovskii functional (LKF) is constructed, which fully utilises the characteristics of the real sampling period. Based on Lyapunov stability theory, Newton–Leibniz condition and new integral inequality techniques, some less conservative sufficient conditions are obtained to guarantee the close-loop system is asymptotically stable and extended dissipative. Based on sampled-data approach, a robust reliable controller can be developed by solving the linear matrix inequalities (LMIs). The advantage and effectiveness of the proposed design method can be illustrated by several numerical examples.

Finite-time reliable stabilization of uncertain semi-Markovian jump systems with input saturation

Abstract In this study, we concentrate on the design problem of robust reliable control for uncertain semi-Markovian jump systems with input saturation over a specified finite interval of time. To exhibit the reality, a delay function that varies with respect to time and a more practical actuator fault model are included in the addressed system and the control design, respectively. By coupling the linear matrix inequality technique and the Lyapunov stability method with the finite-time theory, the required finite-time stabilization conditions are established to the system under consideration. The proposed reliable control gain matrices can be subsequently acquired by solving the aforementioned conditions with the support of existing convex optimization algorithms. To testify the correctness of the developed theoretical results and display the effectiveness of the proposed control design, an academic example is presented.

Robust reliable fault tolerant control of islanded microgrids using augmented backstepping control

This study proposes a novel fault tolerant voltage control method considering actuator faults and disturbances by using the backstepping control augmented by a new differentiator for islanded microgrids (MGs). Existing voltage control methods are designed based on the ideal condition that the distributed generations' actuators work healthily with the assumption of the absence of faults and disturbances, whereas MGs are exposed to the actuator faults including partial loss of effectiveness and biased faults. The proposed controller robustly regulates the MG voltages irrespective of the actuator faults. In contrast to existing methods, the controller has considered both actuator faults and loads with harmonic/interharmonic currents, which does not need to know the exact model of faults and frequency of harmonic and interharmonic of MG loads. This feature enables the MG to work properly, even at the lowest level, instead of the system completely collapsing. Therefore, it improves the reliability of the MG system. The MATLAB/SimPowerSystems toolbox has verified the validity of the proposed fault tolerant control method. Compared with effective methods, both the theoretical and simulation results show that the proposed method has better, robust, resilient, acceptable, and desirable performance, with respect to the unknown faults, actuator faults, non-linear loads, and disturbances.

Reliable Robust Control for Semi-Markovian Jump Sampled-data Systems Based on a Dissipativity Unified Framework

This paper is concerned with the reliable robust control for semi-Markovian jump sampled-data systems. A mode-dependent Lyapunov-Krasovskii function (LKF) which fully capture the available characteristics of real sampling period is constructed. Based on the LKF approach, Newton-Leibniz condition and convex combination method, less conservative sufficient conditions are presented, which ensure that the closed-loop systems are robust asymptotically stable and extended-dissipativity. Then, actuator failures are taken into consideration, the desired sampled-data controller can be obtained by solving the linear matrix inequalities (LMIs). Finally, two numerical examples are given to illustrate the effectiveness of the proposed method.

Finite-time reliable attitude tracking control design for nonlinear quadrotor model with actuator faults

This paper is focused on a finite-time reliable control design for nonlinear quadrotor attitude dynamic model against the actuator faults and external disturbances. By the utilization of an appropriate Lyapunov–Krasovskii functional, a finite-time performance analysis criterion is derived to obtain the robust reliable tracking control design for quadrotor dynamic model. Then, a fault-tolerant tracking control is designed such that the attitude of the quadrotor is reliable in the sense that it is finite-time bounded and satisfies the suggested mixed $$H_\infty $$ and passivity performance index under given constraints. Also, the finite-time fault-tolerant controller gain is derived by solving the obtained linear matrix inequalities based on the convex optimization technique. Finally, simulation results are provided to verify the effectiveness and robustness of the proposed control design law.

Adaptive Reliable H∞ Control of Uncertain Affine Nonlinear Systems

For general input affine nonlinear systems, robust reliable control designs are commonly available that compensate the actuator faults in pure outage mode. In this paper, a more general and complex problem is considered and an adaptive reliable H∞ controller is designed for a class of uncertain input affine nonlinear systems in the presence of actuators fault. The key element of the work is the introduction of a novel adaptive mechanism that estimates the faults which are modeled as an outage or loss of effectiveness and stabilizes the overall system. Incorporating with the parameter projection algorithm and the solution of Hamilton-Jacobi-Inequality (HJI), the proposed method combines adaptive reliable control and robust H∞ control techniques. A numerical approach is developed based on the Taylor series expansion for solving the HJI. Various simulation examples are given to illustrate the effectiveness of the proposed adaptive reliable H∞ control scheme over the conventional H∞ control and reliable H∞ control method.

Design of robust reliable control for T-S fuzzy Markovian jumping delayed neutral type neural networks with probabilistic actuator faults and leakage delays: An event-triggered communication scheme

This study examines the problem of robust reliable control for Takagi-Sugeno (T-S) fuzzy Markovian jumping delayed neural networks with probabilistic actuator faults and leakage terms. An event-triggered communication scheme. First, the randomly occurring actuator faults and their failures rates are governed by two sets of unrelated random variables satisfying certain probabilistic failures of every actuator, new type of distribution based event triggered fault model is proposed, which utilize the effect of transmission delay. Second, Takagi-Sugeno (T-S) fuzzy model is adopted for the neural networks and the randomness of actuators failures is modeled in a Markov jump model framework. Third, to guarantee the considered closed-loop system is exponential mean square stable with a prescribed reliable control performance, a Markov jump event-triggered scheme is designed in this paper, which is the main purpose of our study. Fourth, by constructing appropriate Lyapunov-Krasovskii functional, employing Newton-Leibniz formulation and integral inequalities, several delay-dependent criteria for the solvability of the addressed problem are derived. The obtained stability criteria are stated in terms of linear matrix inequalities (LMIs), which can be checked numerically using the effective LMI toolbox in MATLAB. Finally, numerical examples are given to illustrate the effectiveness and reduced conservatism of the proposed results over the existing ones, among them one example was supported by real-life application of the benchmark problem.

Robust reliable control of uncertain nonlinear stochastic systems subject to actuator fault

This paper addresses the issue of robust reliable stabilization for a class of uncertain nonlinear stochastic systems with both discrete and distributed time-varying delays and possible occurrence of actuator faults. By constructing a new Lyapunov functional and using linear matrix inequality technique, a new set of sufficient conditions is established for the stochastic stability of the uncertain nonlinear stochastic systems. Then, sufficient conditions are obtained for the solvability of the robust stabilization problem via robust reliable controller. More precisely, the derived control law guarantees the robust stabilization of nonlinear stochastic systems in the presence of known actuator failure matrix and uncertainties. Further, the results are extended to study the stabilization of stochastic systems with unknown actuator failure matrix. Moreover, the obtained criteria are formulated in terms of LMIs and also the reliable controller can be designed in terms of the solutions to certain linear matrix inequalities. Finally, numerical examples with simulation result are presented to demonstrate the validity and less conservatism of the obtained results.

Reliable Robust Control for the System with Input Saturation Based on Gain Scheduling

In this paper, a reliable robust discrete gain scheduling controller is designed based on the linear matrix inequalities (LMIs) and gain scheduling technology for the systems with the input saturation, system uncertainty, external disturbance and actuator failures. By the designed discrete gain scheduling controller, we can use a series of nesting ellipsoid invariant sets to strengthen the disturbance attenuation ability as strong as possible. It means that the innermost invariant ellipsoid set needs to be minimized to strengthen the disturbance attenuation ability. The dynamic performance of the closed-loop system is improved by introducing a parameter. By the Lyapunov approach, the existing conditions for the admissible controller can be formulated in the form of LMIs. The numerical simulation illustrates the effectiveness of the proposed method.

Robust reliable dissipative control of nonlinear networked control systems

This article focuses on the robust reliable dissipative control issue for a class of switched discrete‐time nonlinear networked control systems with external energy bounded disturbances. In particular, nonlinearities are modeled in a probabilistic way according to Bernoulli distributed white sequence with known conditional probability. A Lyapunov–Krasovskii functional is proposed based on which sufficient conditions for the existence of the reliable dissipative controller are derived in terms of linear matrix inequalities (LMIs) which ensures exponentially stability as well as dissipative performance of the resulting closed‐loop system. The explicit expression of the desired controller gains can be obtained by solving the established LMIs. Finally, a numerical example is presented to demonstrate the effectiveness and applicability of the proposed design strategy. © 2016 Wiley Periodicals, Inc. Complexity 21: 427–437, 2016

Research on Gait Planning of Quadruped Search Robot Based on Non-fragile Reliable Control Strategy with the D-stability

The problem of gait planning for the quadruped search robot is described as an uncertainty discrete system. According to the basic gait elements of the quadruped search robot, the periodic gait of the robot is analyzed on the basis of gait timing diagram. The non-fragile control theory is proposed for gait planning control of quadruped search robot. A non-fragile reliable adaptive controller is designed for adaptive gait transition with the D-stability, which makes the gait planning to be regular, causal and D-stable. The condition of controller is given based on robust control theory, which include theorem 1 and theorem 2. And the approaches of designing the controller are given in terms of linear matrix inequalities. The results given by linear matrix inequalities indicate that the proposed non-fragile reliable robust controller is correct and effective.

Robust fractional order sliding mode control of doubly-fed induction generator (DFIG)-based wind turbines

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.

Robust reliable control in vibration suppression of sandwich circular plates

The wide real life applications of circular plates under dynamic loading such as laminate saw blades and accurate slitting narrow industrial cutters require special attention to smart structural design that optimally handles the dynamic behavior of these configurations. The purpose of this paper is to investigate the vibration regulation of a sandwich circular plate using a non-fragile robust control strategy. A new dynamic modeling of the piezolaminated structure is proposed based on satisfying the Maxwell static electricity equation and on assuring the full coupling effects of the piezoelectric layers on the host structure. The Eigen functions are chosen optimally such that the boundary conditions for the piezoelectric sensor/actuator are satisfied without additional complexities. In order to reach to the desired performance in vibration attenuation, a robust controller is designed by considering the uncertainties that exist in the system matrices and controller itself. The proposed controller is obtained by solving a system of linear matrix inequalities (LMIs) that are based on the Bounded Real Lemma (BRL). Simulations show that the controller is capable of suppressing the vibration in existence of both the structured uncertainty in the system matrices and the feedback controller gain.

Reliable Dissipative Sampled-Data Control for Uncertain Systems With Nonlinear Fault Input

This paper investigates the robust reliable β-dissipative control for uncertain dynamical systems with mixed actuator faults via sampled-data approach. In particular, a more general reliable controller containing both linear and nonlinear parts is constructed for the considered system. Then, by applying the input delay approach, the sampling measurement of the digital control signal is transformed into time-varying delayed one. The aim of this paper is to design state feedback sampled-data controller to guarantee that the resulting closed-loop system to be strictly (Q, S, R)-β-dissipative. By constructing appropriate Lyapunov function and employing a delay decomposition approach, a new set of delay-dependent sufficient stabilization criteria is obtained in terms of linear matrix inequalities (LMIs). Moreover, the obtained LMIs are dependent, not only upon upper bound of time delay but also depend on the dissipative margin β and the actuator fault matrix. As special cases, H∞ and passivity control performances can be deduced from the proposed dissipative control result. Finally, numerical simulation is provided based on a flight control model to verify the effectiveness and applicability of the proposed control scheme.

Robust reliable sampled-data control for switched systems with application to flight control

abstractThis paper addresses the robust reliable stabilisation problem for a class of uncertain switched systems with random delays and norm bounded uncertainties. The main aim of this paper is to obtain the reliable robust sampled-data control design which involves random time delay with an appropriate gain control matrix for achieving the robust exponential stabilisation for uncertain switched system against actuator failures. In particular, the involved delays are assumed to be randomly time-varying which obeys certain mutually uncorrelated Bernoulli distributed white noise sequences. By constructing an appropriate Lyapunov–Krasovskii functional (LKF) and employing an average-dwell time approach, a new set of criteria is derived for ensuring the robust exponential stability of the closed-loop switched system. More precisely, the Schur complement and Jensen's integral inequality are used in derivation of stabilisation criteria. By considering the relationship among the random time-varying delay and its lower and upper bounds, a new set of sufficient condition is established for the existence of reliable robust sampled-data control in terms of solution to linear matrix inequalities (LMIs). Finally, an illustrative example based on the F-18 aircraft model is provided to show the effectiveness of the proposed design procedures.

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.

Robust reliable feedback controller design against actuator faults for linear parameter‐varying systems in finite‐frequency domain

This study addresses the finite-frequency robust feedback controller design problem against actuator faults for linear parameter-varying systems. First, a general model of actuator faults is presented. Then, sufficient conditions for the existence of the state-feedback controller are obtained by using generalised Kalman–Yakubovich–Popov lemma and projection lemma, which guarantee that the closed-loop system satisfies robustness performance in a finite-frequency domain and is stable for both faults free and actuator faults. In addition, by introducing a state feedback gain, the non-convexity conditions of the output-feedback gain are derived. An iterative linear matrix inequality algorithm is proposed in this study to get the solution. The performances of the proposed reliable controller schemes are illustrated by two examples.