This paper considers the guaranteed cost control problem for a class of uncertain linear systems with both state and input delays. By representing the time-delay system in the descriptor system form and using a recent...This paper considers the guaranteed cost control problem for a class of uncertain linear systems with both state and input delays. By representing the time-delay system in the descriptor system form and using a recent result on bounding of cross products of vectors, we obtain new delay-dependent sufficient conditions for the existence of the guaranteed cost controller in terms of linear matrix inequalities. Two examples are presented which show the effectiveness of our approach.展开更多
The problem of designing a non-fragile delay-dependent H∞ state-feedback controller was investigated for a linear time-delay system with uncertainties in state and control input. First, a recently derived integral in...The problem of designing a non-fragile delay-dependent H∞ state-feedback controller was investigated for a linear time-delay system with uncertainties in state and control input. First, a recently derived integral inequality method and Lyapunov-Krasovskii stability theory were used to derive new delay-dependent bounded real lemmas for a non-fragile state-feedback controller containing additive or multiplicative uncertainties. They ensure that the closed-loop system is internally stable and has a given H∞ disturbance attenuation level. Then, methods of designing a non-fragile H∞ state feedback controller were presented. No parameters need to be tuned and can be easily determined by solving linear matrix inequalities. Finally, the validity of the proposed methods was demonstrated by a numerical example with the asymptotically stable curves of system state and controller output under the initial condition of x(0)=1 0 -1]T and h=0.8 time-delay boundary.展开更多
This note deals with the problem of stabilization/stability for neutral systems with nonlinear perturbations. A new stabilization/stability scheme is presented. Using improved Lyapunov functionals, less conservative s...This note deals with the problem of stabilization/stability for neutral systems with nonlinear perturbations. A new stabilization/stability scheme is presented. Using improved Lyapunov functionals, less conservative stabilization/stability conditions are derived for such systems based on linear matrix inequalities （LMI）. Numerical examples are provided to show that the proposed results significantly improve the allowed upper bounds of the delay size over some existing ones in the literature.展开更多
This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our propose...This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our proposed delay-dependent coupled LMIs criterion lies in that: ( 1 ) it can optimize one of multiple time delays with others selected properly, and at the same time, the feedback-gain and observer-gain can be obtained, respectively. (2) it is less conservative than the existing delay-independent ones in the literature. Algorithm to solve the coupled LMIs is also given. Numerical examples illustrate the effectiveness of our method. Keywords Delay-dependent criterion - Time-delay system - Multiple time-delay - Observer-based controller - Linear matrixinequality (LMI)展开更多
This paper discribes a one-dimensional flow model to explain the basic mechanism of coal-gas outbursts.A break-start criterion of coal,as the elementary outburst criterion,is given approximately.In this ideal model,th...This paper discribes a one-dimensional flow model to explain the basic mechanism of coal-gas outbursts.A break-start criterion of coal,as the elementary outburst criterion,is given approximately.In this ideal model,the tectonic pressure before excavation,as a load on coal body,affects the break-start and then the flow field.The flow field is decoupled with the stress field,so that the gas seepage through unbroken coal body,break-start and consequent two-phase flow,and pure gas flow can be analysed independently of the stress field. The tunnelling,an external disturbance that makes the seepage intensify relatively,is an essential factor for initiating outburst.Under steady tunnelling,seepage ought to tend to be steadily progressive.From its asymptotic solution initiation criterion is obtained.This is described by three conditions,possibility condi- tion—tectonic pressure condition,incubation condition—tunnelling or gas condition and triggering condi- tion—seepage velocity condition.展开更多
In this correspondence paper, an equivalent stability criterion with minimal number of linear matrix inequality （LMI） variables is presented for a delay-dependent stability criterion reported recently in the Interna...In this correspondence paper, an equivalent stability criterion with minimal number of linear matrix inequality （LMI） variables is presented for a delay-dependent stability criterion reported recently in the International Journal of Automation and Computing for a class of linear discrete-time systems with additive time delays. The reported stability criterion for the additive timedelay systems has more number of matrix variables in the LMI and, hence, demand additional computational burden. The proposed equivalent stability criterion, unlike the reported one, does not involve free-weighing matrices and encompass only the matrix variables that are associated in the Lyapunov-Krasovskii functional, making the criterion mathematically less complex and computationally more effective.展开更多
动力装置性能试飞科目中,经常需要飞机稳定平飞,获取稳态飞行数据。但在稳态飞行过程中,由于种种原因,总会出现一些异常值。这些异常值应当被标记,有助于工程师对数据的有效性进行进一步判断。本文主要介绍了用于标记稳态飞行异常值的AE...动力装置性能试飞科目中,经常需要飞机稳定平飞,获取稳态飞行数据。但在稳态飞行过程中,由于种种原因,总会出现一些异常值。这些异常值应当被标记,有助于工程师对数据的有效性进行进一步判断。本文主要介绍了用于标记稳态飞行异常值的AEDC(Arnold Engineering Development Center)方法,将AEDC方法与莱茵达准则、肖维勒准则对比,并通过小样本的算例验证,证明AEDC方法对样本数并不敏感,能识别异常点,对稳态数据标记实用且有效。展开更多
基金This work was supported by the National Natural Science Foundation of China (No. 10461001).
文摘This paper considers the guaranteed cost control problem for a class of uncertain linear systems with both state and input delays. By representing the time-delay system in the descriptor system form and using a recent result on bounding of cross products of vectors, we obtain new delay-dependent sufficient conditions for the existence of the guaranteed cost controller in terms of linear matrix inequalities. Two examples are presented which show the effectiveness of our approach.
基金Project(60574014) supported by the National Natural Science Foundation of ChinaProject(20050533015) supported by the Doctor Subject Foundation of ChinaProject(60425310) supported by the National Science Foundation for Distinguished Youth Scholars, China
文摘The problem of designing a non-fragile delay-dependent H∞ state-feedback controller was investigated for a linear time-delay system with uncertainties in state and control input. First, a recently derived integral inequality method and Lyapunov-Krasovskii stability theory were used to derive new delay-dependent bounded real lemmas for a non-fragile state-feedback controller containing additive or multiplicative uncertainties. They ensure that the closed-loop system is internally stable and has a given H∞ disturbance attenuation level. Then, methods of designing a non-fragile H∞ state feedback controller were presented. No parameters need to be tuned and can be easily determined by solving linear matrix inequalities. Finally, the validity of the proposed methods was demonstrated by a numerical example with the asymptotically stable curves of system state and controller output under the initial condition of x(0)=1 0 -1]T and h=0.8 time-delay boundary.
基金This work was supported by the National Natural Science Foundation of China(No.10571036).
文摘This note deals with the problem of stabilization/stability for neutral systems with nonlinear perturbations. A new stabilization/stability scheme is presented. Using improved Lyapunov functionals, less conservative stabilization/stability conditions are derived for such systems based on linear matrix inequalities （LMI）. Numerical examples are provided to show that the proposed results significantly improve the allowed upper bounds of the delay size over some existing ones in the literature.
文摘This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our proposed delay-dependent coupled LMIs criterion lies in that: ( 1 ) it can optimize one of multiple time delays with others selected properly, and at the same time, the feedback-gain and observer-gain can be obtained, respectively. (2) it is less conservative than the existing delay-independent ones in the literature. Algorithm to solve the coupled LMIs is also given. Numerical examples illustrate the effectiveness of our method. Keywords Delay-dependent criterion - Time-delay system - Multiple time-delay - Observer-based controller - Linear matrixinequality (LMI)
基金The project supported by the National Natural Science Foundation of China
文摘This paper discribes a one-dimensional flow model to explain the basic mechanism of coal-gas outbursts.A break-start criterion of coal,as the elementary outburst criterion,is given approximately.In this ideal model,the tectonic pressure before excavation,as a load on coal body,affects the break-start and then the flow field.The flow field is decoupled with the stress field,so that the gas seepage through unbroken coal body,break-start and consequent two-phase flow,and pure gas flow can be analysed independently of the stress field. The tunnelling,an external disturbance that makes the seepage intensify relatively,is an essential factor for initiating outburst.Under steady tunnelling,seepage ought to tend to be steadily progressive.From its asymptotic solution initiation criterion is obtained.This is described by three conditions,possibility condi- tion—tectonic pressure condition,incubation condition—tunnelling or gas condition and triggering condi- tion—seepage velocity condition.
文摘In this correspondence paper, an equivalent stability criterion with minimal number of linear matrix inequality （LMI） variables is presented for a delay-dependent stability criterion reported recently in the International Journal of Automation and Computing for a class of linear discrete-time systems with additive time delays. The reported stability criterion for the additive timedelay systems has more number of matrix variables in the LMI and, hence, demand additional computational burden. The proposed equivalent stability criterion, unlike the reported one, does not involve free-weighing matrices and encompass only the matrix variables that are associated in the Lyapunov-Krasovskii functional, making the criterion mathematically less complex and computationally more effective.
文摘动力装置性能试飞科目中,经常需要飞机稳定平飞,获取稳态飞行数据。但在稳态飞行过程中,由于种种原因,总会出现一些异常值。这些异常值应当被标记,有助于工程师对数据的有效性进行进一步判断。本文主要介绍了用于标记稳态飞行异常值的AEDC(Arnold Engineering Development Center)方法,将AEDC方法与莱茵达准则、肖维勒准则对比,并通过小样本的算例验证,证明AEDC方法对样本数并不敏感,能识别异常点,对稳态数据标记实用且有效。
