Linna Zhou

Bio: Linna Zhou is an academic researcher from China University of Mining and Technology. The author has contributed to research in topics: Control theory & Computer science. The author has an hindex of 15, co-authored 47 publications receiving 517 citations. Previous affiliations of Linna Zhou include Chinese Ministry of Education & Northeastern University (China).

Disturbance Observer-Based Integral Sliding Mode Control for Singularly Perturbed Systems With Mismatched Disturbances

Abstract: This paper presents a disturbance observer-based integral sliding mode control (ISMC) for singularly perturbed systems (SPSs) with mismatched disturbances. First, a linear state feedback control law for the slow subsystem of the SPS is designed, and the fast subsystem is established. Second, a disturbance observer and an ISMC incorporating the disturbance estimate are constructed. The gain of ISMC is obtained by applying the ${H_\infty }$ control theory, and the resulting ISMC can effectively attenuate the mismatched disturbances. Finally, the proposed method is applied to an electric system, which illustrates the effectiveness and feasibility. The proposed design methods are based on the reduced-order subsystems and thus free of the high dimensionality and possible numerical ill-conditioned problems.

Positive Realness and Absolute Stability Problem of Descriptor Systems

Abstract: This paper considers a class of nonlinear descriptor systems described by a linear time-invariant descriptor system with feedback-connected sector-constrained nonlinearities. First, we discuss the positive realness problem of descriptor systems and present a new version of positive real lemma. Second, we define the notion of strongly absolute stability (SAB) which is equivalent to the linear part is regular and impulsive-free and the overall feedback system is exponential stable and a SAB criteria in frequency domain is derived. Then, we address the problem of designing a state feedback controller such that the closed-loop feedback-connected system is SAB. To achieve this, we give a linear matrix inequality (LMI)-based SAB criteria, and the above problem is converted into an LMI feasibility problem. Finally, some numerical examples are given to illustrate our approach

An Adaptive-Gain Sliding Mode Observer for Sensorless Control of Permanent Magnet Linear Synchronous Motors

Abstract: In this paper, a novel adaptive-gain sliding mode observer (SMO) is designed for sensorless control of permanent magnet linear synchronous motors (PMLSMs). By the proposed adaptive-gain algorithm, the gain can dynamically adapt to a changing operation condition of the PMLSMs and reach an appropriate value in finite time. Stability of the SMO is proved by using Lyapunov stability theory. Compared with the traditional SMO, the adaptive-gain SMO can improve the control precision, especially when the operation condition is not invariant. Simulation results are given to show the advantages of the proposed method.

Stability Analysis and Design for Nonlinear Singular Systems

Abstract: Practical stability analysis and synthesis for nonlinear singular systems .- 3 Strongly absolute stability analysis for Lur'e singular .- 4 Input-to-state stability analysis and design for Lur'e singular systems .- 5 Observer design for nonlinear singular systems .- 6 Absolute stability of Lur'e singularly perturbed systems .- 7 Multi-objective control for T-S fuzzy singularly perturbed systems. 4 Input-to-state stability analysis and design for Lur'e singular systems .- 5 Observer design for nonlinear singular systems .- 6 Absolute stability of Lur'e singularly perturbed systems .- 7 Multi-objective control for T-S fuzzy singularly perturbed systems.

Practical stability of descriptor systems with time delays in terms of two measurements

Abstract: This paper introduces the concepts of practical stability for descriptor systems with time delays in terms of two measurements. Some results of practical stability parallel to Lyapunov stability theorems are given. Based on Lyapunov functions and the comparison principle, a criterion, by which the problem of a descriptor system with time delay is reduced to that of a standard state-space system without time delays, is derived. Finally, the application of the results obtained is demonstrated through an analysis of a class of linear time-invariant descriptor systems with time delay.

Numerical solution of initial value problems in differential - algebraic equations

Abstract: During the last decade, a big progress has been achieved in the analysis and numerical treatment of Initial Value Problems (IVPs) in Differential Algebraic Equations (DAEs) and Ordinary Differential Equations (ODEs). In spite of the rich variety of results available in the literature, there are still many specific problems that require special attention. Two of such, which are considered in this work, are the optimization of order of accuracy and reduction of cost of functional evaluations of Explicit Runge - Kutta (ERK) methods. Traditionally, the maximum attainable order p of an s-stage ERK method for advancing the solution of an IVP is such that p(s) 4 In 1999, Goeken presented an s-stage ERK Method of order p(s)=s +1,s>2. However, this work focuses on the design of a new approximation algorithm that reduces the cost of functional evaluations and yet increases the attainable order higher U n and Jonhson [94]; and the classical ERK methods. The order p of the new scheme called Multiderivative Explicit Runge-Kutta (MERK) Methods is such that p(s) 2. The stability, convergence and implementation for the optimization of IVPs in DAEs and ODEs systems are also considered.

Fault tolerant control for singular systems with actuator saturation and nonlinear perturbationFault tolerant control for singular systems with actuator saturation and nonlinear perturbation.

Abstract: In this paper, the problem of robust fault tolerant control for a class of singular systems subject to both time-varying state-dependent nonlinear perturbation and actuator saturation is investigated. A sufficient condition for the existence of a fixed-gain controller is first proposed which guarantees the regularity, impulse-free and stability of the closed-loop system under all possible faults. An optimization problem with LMI constraints is formulated to determine the largest contractively invariant ellipsoid. An adaptive fault tolerant controller is then developed to compensate for the failure effects on the system by estimating the fault and updating the design parameter matrices online. Both of these two controllers are in the form of a saturation avoidance feedback with the advantage of relatively small actuator capacities compared with the high gain counterpart. An example is included to illustrate the proposed procedures and their effectiveness.

Network-Based Quantized Control for Fuzzy Singularly Perturbed Semi-Markov Jump Systems and its Application

Abstract: This paper deals with the quantized control problem for nonlinear semi-Markov jump systems subject to singular perturbation under a network-based framework. The nonlinearity of the system is well solved by applying Takagi–Sugeno (T-S) fuzzy theory. The semi-Markov jump process with the memory matrix of transition probability is introduced, for which the obtained results are more reasonable and less limiting. In addition, the packet dropouts governed by a Bernoulli variable and the signal quantization associated with a logarithmic quantizer are deeply studied. The major goal is to devise a fuzzy controller, which not only assures the mean-square $\bar { \sigma }$ -error stability of the corresponding system but also allows a higher upper bound of the singularly perturbed parameter. Sufficient conditions are developed to make sure that the applicable controller could be found. The further examination to demonstrate the feasibility of the presented method is given by designing a controller of a series DC motor model.

Extended Dissipative Control for Singularly Perturbed PDT Switched Systems and its Application

Abstract: In this paper, a class of discrete-time singularly perturbed switched systems $\left ({\text {SPSSs}}\right) $ with persistent dwell-time $\left ({\text {PDT}}\right)$ switching law is firstly proposed. Using the slow-state feedback control method, sufficient conditions to ensure the global uniform exponential stability of the closed-loop PDT SPSSs are derived. Based on the aforementioned conditions, the analyses of the extended dissipative performance of the closed-loop PDT SPSSs and a preferable decoupling method deriving the mode-dependent controller gains are given for the first time. Finally, the potential practicability of the method is verified by a purely numerical example and a tunnel diode circuit model, and a convex optimization method calculating the upper bound of the singular perturbation parameter is provided.

$H_{\infty}$ State Estimation for Discrete-Time Nonlinear Singularly Perturbed Complex Networks Under the Round-Robin Protocol

Abstract: This paper investigates the $H_{\infty }$ state estimation problem for a class of discrete-time nonlinear singularly perturbed complex networks (SPCNs) under the Round-Robin (RR) protocol. A discrete-time nonlinear SPCN model is first devised on two time scales with their discrepancies reflected by a singular perturbation parameter (SPP). The network measurement outputs are transmitted via a communication network where the data transmissions are scheduled by the RR protocol with hope to avoid the undesired data collision. The error dynamics of the state estimation is governed by a switched system with a periodic switching parameter. A novel Lyapunov function is constructed that is dependent on both the transmission order and the SPP. By establishing a key lemma specifically tackling the SPP, sufficient conditions are obtained such that, for any SPP less than or equal to a predefined upper bound, the error dynamics of the state estimation is asymptotically stable and satisfies a prescribed $H_{\infty }$ performance requirement. Furthermore, the explicit parameterization of the desired state estimator is given by means of the solution to a set of matrix inequalities, and the upper bound of the SPP is then evaluated in the feasibility of these matrix inequalities. Moreover, the corresponding results for linear discrete-time SPCNs are derived as corollaries. A numerical example is given to illustrate the effectiveness of the proposed state estimator design scheme.