Showing papers in "Journal of The Franklin Institute-engineering and Applied Mathematics in 2013"
TL;DR: An overview on the existing works on fault detection and diagnosis (FDD) and fault-tolerant control (FTC) for unmanned rotorcraft systems and techniques developed recently at the Networked Autonomous Vehicles Lab of Concordia University are presented.
Abstract: As the first part, this paper presents an overview on the existing works on fault detection and diagnosis (FDD) and fault-tolerant control (FTC) for unmanned rotorcraft systems. Considered faults include actuator and sensor faults for single and multi-rotor systems. As the second part, several FDD and FTC techniques developed recently at the Networked Autonomous Vehicles Lab of Concordia University are detailed along with experimental application to a unique and newly developed quadrotor helicopter testbed.
216 citations
TL;DR: It is shown, that direct voltage control for a boost converter results in unstable zero dynamics and chattering suppression based on harmonic cancellation principle along with switching frequency control is demonstrated.
Abstract: Sliding mode control algorithms for buck and boost power converters are surveyed in the paper. Current and voltage controls are demonstrated for the both cases. It is shown, that direct voltage control for a boost converter results in unstable zero dynamics. Chattering suppression based on harmonic cancellation principle along with switching frequency control is demonstrated.
198 citations
TL;DR: An investigation for the flow and radiation heat transfer of a nanofluid over a stretching sheet with velocity slip and temperature jump in porous medium with very good agreement to validate the present results.
Abstract: In this paper, we present an investigation for the flow and radiation heat transfer of a nanofluid over a stretching sheet with velocity slip and temperature jump in porous medium. The Brownian motion and thermophoresis are taken into account according to Rosseland’s approximation. The governing coupled partial differential equations are non-dimensionalized and solved both numerically and analytically by local similarity method. The effects of involved parameters (velocity slip, temperature jump, thermal radiation, Prandtl number, Lewis number, Brownian motion, thermophoresis) on velocity, temperature and concentration profiles are presented graphically and analyzed. Moreover, the numerical results are compared with the analytical solutions obtained by Homotopy analysis method with very good agreement to validate the present results.
196 citations
TL;DR: Simulation results show that the proposed controller is robust with respect to uncertainties on the mechanical parameters that characterize the model and secures global convergence.
Abstract: In the last three decades, the need for increased flight safety and aircraft reliability has been and will continue to be an important issue in commercial aviation industry. All pilots undergo widespread training to help them to be able to react to unexpected difficulties that may occur during a flight in uncertain conditions. Furthermore, advanced fault-tolerant control (FTC) systems are designed to help pilots overcome abnormal situations that previously might have resulted in catastrophic events.
116 citations
TL;DR: The main purpose of this paper is to design an event-based fault detection filter such that, for all unknown input, communication delay and nonlinear perturbation, the error between the residual signal and the fault signal is made as small as possible.
Abstract: This paper is concerned with the event-based fault detection for the networked systems with communication delay and nonlinear perturbation. We propose an event-triggered scheme, which has some advantages over existing ones. The sensor data is transmitted only when the specified event condition involving the sampled measurements of the plant is violated. An event-based fault detection model is firstly constructed by taking the effect of event-triggered scheme and the network transmission delay into consideration. The main purpose of this paper is to design an event-based fault detection filter such that, for all unknown input, communication delay and nonlinear perturbation, the error between the residual signal and the fault signal is made as small as possible. Sufficient conditions for the existence of the desired fault detection filter are established in terms of linear matrix inequalities. Based on these conditions, the explicit expression is given for the designed fault detection filter parameters. A numerical example is employed to illustrate the advantage of the introduced event-triggered scheme and the effectiveness of the proposed method.
109 citations
TL;DR: The basic idea is to develop the conjugate gradients squared (CGS) and bi-conjugate gradient stabilized (Bi-CGSTAB) methods for obtaining matrix iterative methods for solving the Sylvester-transpose and periodicSylvester matrix equations.
Abstract: The problem of solving matrix equations has many applications in control and system theory. This paper is concerned with the iterative solutions of the Sylvester-transpose matrix equation ∑ i = 1 k ( A i XB i + C i X T D i ) = E , and the periodic Sylvester matrix equation A ^ j X ^ j B ^ j + C ^ j X ^ j + 1 D ^ j = E ^ j for j = 1 , 2 , … , λ . The basic idea is to develop the conjugate gradients squared (CGS) and bi-conjugate gradient stabilized (Bi-CGSTAB) methods for obtaining matrix iterative methods for solving the Sylvester-transpose and periodic Sylvester matrix equations. Numerical test results are given to compare matrix iterative methods with other well-known methods.
109 citations
TL;DR: A sufficient condition is obtained to guarantee the consensus of heterogeneous multi-agent systems in terms of linear matrix inequality (LMI).
Abstract: This paper investigates the consensus problem for a set of discrete-time heterogeneous multi-agent systems composed of two kinds of agents differed by their dynamics. The consensus control is designed based on the event-triggered communication scheme, which can lead to a significant reduction of the information communication burden in the multi-agent network. Meanwhile, only the communication between the agent and its local neighbors is needed, therefore, the designed control is essentially distributed. Based on the Lyapunov functional method and the Kronecker product technique, a sufficient condition is obtained to guarantee the consensus of heterogeneous multi-agent systems in terms of linear matrix inequality (LMI). Simulation results illustrate the effectiveness of the developed theory in the last.
106 citations
TL;DR: Sufficient conditions ensuring the finite-time boundedness, H ∞ finite- time boundedness and finite- Time-Finite-time state feedback stabilization are developed for the given system for the first time.
Abstract: This paper is concerned with the problem of robust finite-time H ∞ control for Markovian jump systems with partially known transition probabilities Sufficient conditions ensuring the finite-time boundedness, H ∞ finite-time boundedness and finite-time H ∞ state feedback stabilization are, respectively, developed for the given system for the first time A robust finite-time H ∞ state feedback controller is also designed, which guarantees the H ∞ finite-time boundedness of the closed-loop system Seeking computational convenience, all the conditions are cast in the format of linear matrix inequalities Finally a numerical example is provided to demonstrate the effectiveness of the main results
105 citations
TL;DR: Based on the proposed stability criteria, a sufficient condition for designing feedback gains of time-delayed controllers which guarantee the stability of the concerned system is presented and the effectiveness to enhance the feasible region of the proposed criteria is demonstrated.
Abstract: This paper is concerned with the stability and stabilization problems for discrete-time systems with interval time-varying delays. By construction of an augmented Lyapunov–Krasovskii functional and utilization of zero equalities, improved delay-dependent criteria for asymptotic stability of the systems are derived in terms of linear matrix inequalities (LMIs). Based on the proposed stability criteria, a sufficient condition for designing feedback gains of time-delayed controllers which guarantee the stability of the concerned system is presented. Through three numerical examples, the effectiveness to enhance the feasible region of the proposed criteria is demonstrated.
102 citations
TL;DR: The stability criterion for such a class of uncertain MJSs is derived in terms of linear matrix inequalities (LMIs), which is more general than the existing ones and can be applicable to more practical situations.
Abstract: This paper is concerned with exploring stability analysis for a class of Markovian jump systems (MJSs) with generally uncertain transition rates (GUTRs). In the GUTR model, each transition rate can be completely unknown or only its estimate value is known. This new uncertain model is more general than the existing ones and can be applicable to more practical situations. The stability criterion for such a class of uncertain MJSs is derived in terms of linear matrix inequalities (LMIs). Finally, a numerical example is given to illustrate the effectiveness and applicability of the proposed method.
97 citations
TL;DR: The mean square stability of the closed loop multi-agent systems is analyzed based on the Lyapunov functional method and the Kronecker product technique and sufficient conditions are obtained to guarantee the consensus in terms of linear matrix inequalities (LMIs).
Abstract: In this paper, we investigate the consensus problem of a set of discrete-time heterogeneous multi-agent systems with random communication delays represented by a Markov chain, where the multi-agent systems are composed of two kinds of agents differed by their dynamics. First, distributed consensus control is designed by employing the event-triggered communication technique, which can lead to a significant reduction of the information communication burden in the multi-agent network. Then, the mean square stability of the closed loop multi-agent systems is analyzed based on the Lyapunov functional method and the Kronecker product technique. Sufficient conditions are obtained to guarantee the consensus in terms of linear matrix inequalities (LMIs). Finally, a simulation example is given to illustrate the effectiveness of the developed theory.
TL;DR: The result shows how the packet dropouts probability of a communication channel may fundamentally constrain a control system's tracking ability.
Abstract: The optimal tracking problem for single-input–single-output (SISO) networked control system over a communication channel with packet dropouts is studied in this paper. The tracking performance is measured by the energy of the error signal between the output of the plant and the reference signal. It is shown that the optimal tracking performance is constrained by nonminimum phase zeros, unstable poles, the characteristics of the reference signal and packet dropout probability, and the optimal controller is obtained. It is also shown that when the communication constraint does not exist, the optimal tracking performance reduces to the existing normal tracking performance of the control system without a communication channel. The result shows how the packet dropouts probability of a communication channel may fundamentally constrain a control system's tracking ability. Some typical examples and simulations are given to illustrate the theoretical results.
TL;DR: Two new schemes of sensor fault estimation for a class of nonlinear systems are proposed and investigated and it is demonstrated that the proposed schemes can successfully estimate sensor faults even in the presence of system uncertainties.
Abstract: The present paper proposes two new schemes of sensor fault estimation for a class of nonlinear systems and investigates their performances by applying these to satellite control systems. Both of the schemes essentially transform the original system into two subsystems (subsystems 1 and 2), where subsystem-1 includes the effects of system uncertainties, but is free from sensor faults and subsystem-2 has sensor faults but without any uncertainties. Sensor faults in subsystem-2 are treated as actuator faults by using integral observer based approach. The effects of system uncertainties in subsystem-1 can be completely eliminated by a sliding mode observer (SMO). In the first scheme, the sensor faults present in subsystem-2 are estimated with arbitrary accuracy using a SMO. In the second scheme, the sensor faults are estimated by designing an adaptive observer (AO). The sufficient condition of stability of the proposed schemes has been derived and expressed as a linear matrix inequality (LMI) optimization problem and the design parameters of the observers are determined by using LMI techniques. The effectiveness of the schemes in estimating sensor faults is illustrated by considering an example of a satellite control system. The results of the simulation demonstrate that the proposed schemes can successfully estimate sensor faults even in the presence of system uncertainties.
TL;DR: Sufficient conditions for the existence-uniqueness and global asymptotic stability of the equilibrium point are derived by using fixed point theorems, Lyapunov–Krasovskii functional and model transformation technique, and the stability criterion is given in terms of a linear matrix inequality (LMI), which can be efficiently solved via standard numerical software.
Abstract: In this paper, a class of nonlinear differential systems with leakage time-varying delay is considered. Sufficient conditions for the existence-uniqueness and global asymptotic stability of the equilibrium point are derived by using fixed point theorems, Lyapunov–Krasovskii functional and model transformation technique. The stability criterion that depends on the upper bounds of the leakage time-varying delay and its derivative is given in terms of a linear matrix inequality (LMI), which can be efficiently solved via standard numerical software. Even for the case of leakage constant delay, the criterion is shown to be less conservative than a recent publication. Finally, two numerical examples are provided to demonstrate the less conservatism and effectiveness of the proposed results.
TL;DR: Improved results with less computational burden and conservatism have been obtained in the sense of Filippov solutions of the delay-dependent exponential passivity problem of the memristor-based recurrent neural networks.
Abstract: This paper investigates the delay-dependent exponential passivity problem of the memristor-based recurrent neural networks (RNNs). Based on the knowledge of memristor and recurrent neural network, the model of the memristor-based RNNs is established. Taking into account of the information of the neuron activation functions and the involved time-varying delays, several improved results with less computational burden and conservatism have been obtained in the sense of Filippov solutions. A numerical example is presented to show the effectiveness of the obtained results.
TL;DR: Based on multiple Lyapunov-like functions method, some sufficient conditions are provided for FTSB of switched linear system and the corresponding sliding motion problem is also considered.
Abstract: In this paper, finite-time stabilization and boundedness (FTSB) problems are investigated. Unlike the existing approach based on time-dependent switching strategy, in which the switching instants must be given in advance, largest region function strategy, i.e., state-dependent switching strategy, is adopted to design the switching signal. Based on multiple Lyapunov-like functions method, some sufficient conditions are provided for FTSB of switched linear system and the corresponding sliding motion problem is also considered. Finally, two examples are given to verify the efficiency of the proposed methods.
TL;DR: The simulation on a closed-loop satellite control system with time-varying or constant actuator faults in the form of additive and multiplicative unknown dynamics demonstrates the effectiveness of the proposed robust fault diagnosis strategy.
Abstract: In this paper, a robust actuator fault diagnosis scheme is investigated for satellite attitude control systems subject to model uncertainties, space disturbance torques and gyro drifts. A nonlinear unknown input observer is designed to detect the occurrence of any actuator fault. Subsequently, a bank of adaptive unknown input observers activated by the detection results are designed to isolate which actuator is faulty and then estimate of the fault parameter. Fault isolation is achieved based on the well known generalized observer strategy. The simulation on a closed-loop satellite control system with time-varying or constant actuator faults in the form of additive and multiplicative unknown dynamics demonstrates the effectiveness of the proposed robust fault diagnosis strategy.
TL;DR: A novel group consensus protocol, called hybrid protocol, is proposed to solve the couple-group average-consensus problem and the convergence analysis is presented and the algebraic criterions are established.
Abstract: This paper investigates a group consensus problem with discontinuous information transmissions among different groups of dynamic agents. In the group consensus problem, the agents reach more than one consistent state asymptotically. We consider that the communication topology of these agents, represented by a network, is undirected. Then a novel group consensus protocol, called hybrid protocol, is proposed to solve the couple-group average-consensus problem. The convergence analysis is presented and the algebraic criterions are established. Furthermore, the multi-group consensus is discussed as an extension of the couple-group consensus. By similar techniques, some analysis results are presented. The analysis tools developed in this paper are based on algebraic graph theory, matrix theory, and control theory. Finally, the simulations are provided to demonstrate the effectiveness of the proposed theoretical results.
TL;DR: A new notion of effective value of transmission packets (EVTP) is proposed in this paper to better study the phenomenon of packet disordering and a sufficient criterion for robust stability of NCSs is presented.
Abstract: The article is concerned with the design of H ∞ controller for networked control systems (NCSs) with both time delay and packet disordering. Analyzing and establishing the relation between time delay and packet disordering, the NCS with both time delay and packet disordering is transformed into the model with multi-step time delays. Given the time delays, we can easily obtain the action time of the control signals without calculating the disorder number. Moreover, a new notion of effective value of transmission packets (EVTP) is proposed in this paper to better study the phenomenon of packet disordering. The bigger the EVTP, the better the NCS will be stabilized, that is, the less negative influence is resulted from packet disordering. By Lyapunov functional method and linear matrix inequality approach, a sufficient criterion for robust stability of NCSs is presented. Finally, numerical examples and simulations are used to illustrate the effectiveness and validity of the proposed method.
TL;DR: In this paper, the stability of networked control systems (NCSs) with communication constraints at both channels is investigated and a necessary and sufficient condition of the exponential mean-square stability for the NCSs is derived.
Abstract: In this paper, the stability of networked control systems (NCSs) with communication constraints at both channels is investigated. A Conventional Round-Robin Scheduling (CRRS) is applied to deal with the communication constraints issue for its simple structure. Furthermore, a Dynamic Round-Robin Scheduling (DRRS), which can preserve the controllability and the detectability of the systems, is considered. For the unreliable communication channels, two independent homogeneous Markov chains are selected to model the packet dropouts phenomenon in the sensor-to-controller (S/C) channel and the controller-to-actuator (C/A) channel. According to the periodic property of the Round-Robin Scheduling (RRS), an auxiliary system with augmented Markov chain is established by the lifting technique to facilitate the stability analysis of the closed-loop system. A necessary and sufficient condition of the exponential mean-square stability for the NCSs is derived. Two illustrative examples are shown to demonstrate the effectiveness of the proposed stability analysis method.
TL;DR: A continuous stabilizator is designed for stabilizing the states of stochastic BAM neural networks in finite time based on the finite-time stability theorem of Stochastic nonlinear systems.
Abstract: This paper is concerned with the finite-time stabilization for a class of stochastic BAM neural networks with parameter uncertainties. Compared with the previous references, a continuous stabilizator is designed for stabilizing the states of stochastic BAM neural networks in finite time. Based on the finite-time stability theorem of stochastic nonlinear systems, several sufficient conditions are proposed for guaranteeing the finite-time stability of the controlled neural networks in probability. Meanwhile, the gains of the finite-time controller could be designed by solving some linear matrix inequalities. Furthermore, for the stochastic BAM neural networks with uncertain parameters, the problem of robust finite-time stabilization could also be ensured as well. Finally, two numerical examples are given to illustrate the effectiveness of the obtained theoretical results.
TL;DR: An improved delay-dependent stability criterion is derived for neutral stochastic delay systems using the martingale theory and the model transformation method and the free-weighting-matrix method.
Abstract: This paper is concerned with the problem of stability analysis for neutral stochastic delay systems. Firstly, expectations of stochastic cross terms containing the Ito integral are investigated by the martingale theory. Based on this, an improved delay-dependent stability criterion is derived for neutral stochastic delay systems. In the derivation process, the mathematical development avoids bounding stochastic cross terms, and neither the model transformation method nor free-weighting-matrix method is used. Thus the method leads to a simple criterion and shows less conservatism. Finally, two examples are provided to demonstrate the effectiveness and reduced conservatism of the proposed conditions.
TL;DR: Not only linear matrix inequality conditions for the system dynamics but also average dwell-time of switching signal is given to guarantee finite-time boundedness of discrete-time switched linear systems.
Abstract: In this paper, finite-time boundedness and finite-time l2 gain analysis for a class of discrete-time switched linear systems are investigated. Not only linear matrix inequality conditions for the system dynamics but also average dwell-time of switching signal is given to guarantee finite-time boundedness of discrete-time switched linear systems. Moreover, sufficient conditions which guarantee finite-time boundedness of discrete-time switched linear systems with a finite-time l2 gain are also presented. Detail proofs are given by using multiple Lyapunov-like functions. A numerical example is employed to verify the efficiency of the proposed method.
TL;DR: An effective feedback control with an updated law is designed to finite-time synchronization between two chaotic neural networks to identify all the unknown parameters for two coupled neural networks with time delay.
Abstract: This work presents an approach for finite-time synchronization to identify all the unknown parameters for two coupled neural networks with time delay. Based on the finite-time stability theory, an effective feedback control with an updated law is designed to finite-time synchronization between two chaotic neural networks. Since finite-time topology identification means the suboptimum in the identification time, the results of this paper are important. Finally, an illustrative example is given to show the effectiveness of the main results.
TL;DR: It is shown that, for such systems, the exponential stability with given decay rate is closely related to the bound of the delay, and sufficient conditions for the existence of static output feedback controllers are established in terms of linear programming (LP) problems.
Abstract: This paper investigates the problem of exponential stability analysis and static output feedback stabilization for discrete-time and continuous-time positive systems with bounded time-varying delays. Based on the relationship between the solution to the system with time-varying delay and that to the corresponding system with constant delay under specific conditions, the equivalence between the α - exponential stability of such two types of systems is established. Then some necessary conditions and sufficient conditions are provided for α - exponential stability of positive systems with bounded time-varying delays. It is shown that, for such systems, the exponential stability with given decay rate is closely related to the bound of the delay. Then by using the singular value decomposition approach, sufficient conditions for the existence of static output feedback controllers are established in terms of linear programming (LP) problems. Some illustrative examples are given to show the correctness of the obtained theoretical results.
TL;DR: By constructing some one-homogeneous codes over F p [ u ] / 〈 u m 〉, this work obtains a class of optimal p-ary one-Hamming weight linear codes from one-Homogeneous weight linear Codes p p m − 1 n.
Abstract: We characterize the structures and properties of one-homogeneous weight linear codes C k 1 , … , k m over F p [ u ] / 〈 u m 〉 of type 1 k 1 p k 2 ⋯ ( p m − 1 ) k m with one unique nonzero weight w0. We introduce a distance-preserving Gray map from ( F p [ u ] / 〈 u m 〉 ) n to F p p m − 1 n . By the Gray map, we obtain a class of optimal p-ary one-Hamming weight linear codes from one-homogeneous weight linear codes over F p [ u ] / 〈 u m 〉 . We conclude by constructing some one-homogeneous codes over F p [ u ] / 〈 u m 〉 .
TL;DR: The design results included in the paper clearly show the improvement of the proposed PSO technique over earlier reported results.
Abstract: In this paper, a new particle swarm optimization (PSO) based method is proposed for the design of a two-channel linear phase quadrature mirror filter (QMF) bank in frequency domain. The origional particle swarm optimization technique is modified by introducing the concept of Scout Bee from Artificial Bee Colony (ABC) technique for designing a low pass prototype filter having ideal filter characteristics in the passband and stopband regions, and its magnitude response at quadrature frequency is 0.707. The design problem is formulated as a linear combination of passband error and residual stop band energy of the low pass filter, and the square error of the overall transfer function of the QMF bank at the quadrature frequency π/2, in the transition band. The design results included in the paper clearly show the improvement of the proposed PSO technique over earlier reported results.
TL;DR: In this paper, the authors derive structure theorems for cyclic codes over the ring of the Golden code and use them to characterize the lengths of self dual F 4 -cyclic codes.
Abstract: The ring in the title is perhaps the first noncommutative ring to have been used as alphabet for block codes. The original motivation was the construction of some quaternionic modular lattices from codes. The new application is the construction of space time codes obtained by concatenation from the Golden code. In this paper, we derive structure theorems for cyclic codes over that ring, and use them to characterize the lengths where self dual cyclic codes exist. These codes in turn give rise to formally self dual F 4 - codes .
TL;DR: By using Lyapunov–like Krasovskii approach, the relationship between the average dwell-time of the switched nonlinear singular time-delay system and the exponential decay rate of differential and algebraic states is given.
Abstract: We address exponential stability of switched nonlinear singular systems with time-delay in which delay is time varying and presents in the states. For switched nonlinear singular time-delay systems with average dwell-time switching signals, we provide sufficient conditions, in terms of linear matrix inequalities (LMIs) to guarantee the exponential stability of such systems. By using Lyapunov–like Krasovskii approach, the relationship between the average dwell-time of the switched nonlinear singular time-delay system and the exponential decay rate of differential and algebraic states is given. A numerical example is also included to illustrate the effectiveness of the results proposed in this paper.
TL;DR: A novel, type-2 fuzzy wavelet neural network (type-2 FWNN) structure that combines the advantages of type- 2 fuzzy systems and wavelet Neural networks for identification and control of nonlinear uncertain systems is proposed.
Abstract: This paper proposes a novel, type-2 fuzzy wavelet neural network (type-2 FWNN) structure that combines the advantages of type-2 fuzzy systems and wavelet neural networks for identification and control of nonlinear uncertain systems. The proposed network is constructed on the base of a set of fuzzy rules that includes type-2 fuzzy sets in the antecedent part and wavelet functions in the consequent part. For structure identification, a fuzzy clustering algorithm is implemented to generate the rules automatically and for parameter identification the gradient learning algorithm is used. The effectiveness of the proposed system is evaluated for identification and control problems of time-invariant and time-varying systems. The results obtained are compared with those obtained by the use of type-1 FWNN based systems and other similar studies.