The coupling between the Lyapunov variables and system matrices makes the problem of mixed H2/H∞flight tracking controller design non-convex.With the aid of enhanced linear matrix inequality(LMI)approach,the non-conv...The coupling between the Lyapunov variables and system matrices makes the problem of mixed H2/H∞flight tracking controller design non-convex.With the aid of enhanced linear matrix inequality(LMI)approach,the non-convex optimization problem is transformed into convex LMI representations.The proposed coupling is eliminated by introducing slack variables.Moreover,a necessary and sufficient condition is derived for the mixed H2/H∞flight tracking controller which not only stabilizes the controlled system but also satisfies the mixed H2/H∞performance index in normal case and fault cases.The new enhanced LMI representations provide additional degrees of freedom to solve the non-convex optimization problem,and reduce the conservativeness of the controller design.Simulation results of the aero-data model in a research environment(ADMIRE)model show the advantages of the enhanced LMI approach.展开更多
This paper is concerned with the mixed H2/H∞ control with linear continuous time system and time delay. To deal with this, we presents a Stackelberg strategy by treating the control input and the disturbance as leade...This paper is concerned with the mixed H2/H∞ control with linear continuous time system and time delay. To deal with this, we presents a Stackelberg strategy by treating the control input and the disturbance as leader and follower, respectively. The leader＇s control strategy minimizes the cost function which is in H2 norm and the follower＇s control strategy maximizes the cost function which is in H∞ norm. The main technique of this paper is deal with the noncausal relationship of the variables caused by time delay in the control input by introducing two costates to capture the future information and one state to capture the past information. Through theory analyzing, the Stackelberg strategy exists uniquely. Moreover, with the assistance of the extended state space expression, the explicit expression of the strategy is obtained.展开更多
Autophagy is an evolutionarily conserved lysosome-mediated catabolic process（Klionsky,2007）.Autophagy is believed to be essential for cell survival,especially when cells were exposed to stresses,such as nutrient sta...Autophagy is an evolutionarily conserved lysosome-mediated catabolic process（Klionsky,2007）.Autophagy is believed to be essential for cell survival,especially when cells were exposed to stresses,such as nutrient starvation.展开更多
This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncerta...This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncertain system in terms of linear matrix inequalities (LMIs). A solution to the robust H2 estimation problem is then derived in terms of two LMIs. As compared to the existing results, our result on robust H2 estimation is more general. In addition, explicit search of appropriate scaling parameters is not needed as the optimization is convex in the scaling parameters. The LMI approach is also extended to solve the robust H2 control problem which has been difficult for the traditional Riccati equation approach since no separation principle has been known for uncertain systems. The design approach is demonstrated through a simple example.展开更多
This paper presents an improved method for H-two control with regional stability constraints for the closedloop system. The controller is given by the convex combination of a set of fixed gains. Both continuous and di...This paper presents an improved method for H-two control with regional stability constraints for the closedloop system. The controller is given by the convex combination of a set of fixed gains. Both continuous and discrete-time systems in a known polytopic domain are investigated. New LMI-based sufficient conditions for the existence of parameterdependent Lyapunov functions are proposed. Numerical examples are given to show the proposed conditions provide useful and less conservative results for the problems of H-two control with regional stability constraints.展开更多
文摘The coupling between the Lyapunov variables and system matrices makes the problem of mixed H2/H∞flight tracking controller design non-convex.With the aid of enhanced linear matrix inequality(LMI)approach,the non-convex optimization problem is transformed into convex LMI representations.The proposed coupling is eliminated by introducing slack variables.Moreover,a necessary and sufficient condition is derived for the mixed H2/H∞flight tracking controller which not only stabilizes the controlled system but also satisfies the mixed H2/H∞performance index in normal case and fault cases.The new enhanced LMI representations provide additional degrees of freedom to solve the non-convex optimization problem,and reduce the conservativeness of the controller design.Simulation results of the aero-data model in a research environment(ADMIRE)model show the advantages of the enhanced LMI approach.
基金This work was supported by the National Natural Science Foundation of China （Nos. 61633014, 61573220, 61573221） and the Fundamental Research Funds of Shandong University （No. 201 7JC009）.
文摘This paper is concerned with the mixed H2/H∞ control with linear continuous time system and time delay. To deal with this, we presents a Stackelberg strategy by treating the control input and the disturbance as leader and follower, respectively. The leader＇s control strategy minimizes the cost function which is in H2 norm and the follower＇s control strategy maximizes the cost function which is in H∞ norm. The main technique of this paper is deal with the noncausal relationship of the variables caused by time delay in the control input by introducing two costates to capture the future information and one state to capture the past information. Through theory analyzing, the Stackelberg strategy exists uniquely. Moreover, with the assistance of the extended state space expression, the explicit expression of the strategy is obtained.
基金supported by the National Basic Research Program of China (973 Program)(No.2016YFA0100400)the National Natural Science Foundation of China(No.81773009)
文摘Autophagy is an evolutionarily conserved lysosome-mediated catabolic process（Klionsky,2007）.Autophagy is believed to be essential for cell survival,especially when cells were exposed to stresses,such as nutrient starvation.
文摘This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncertain system in terms of linear matrix inequalities (LMIs). A solution to the robust H2 estimation problem is then derived in terms of two LMIs. As compared to the existing results, our result on robust H2 estimation is more general. In addition, explicit search of appropriate scaling parameters is not needed as the optimization is convex in the scaling parameters. The LMI approach is also extended to solve the robust H2 control problem which has been difficult for the traditional Riccati equation approach since no separation principle has been known for uncertain systems. The design approach is demonstrated through a simple example.
基金This work was supported by the Science Foundation of Education Commission of Hubei Province(No.D200613002)the Doctoral Pre-ResearchFoundation of Three Gorges University.
文摘This paper presents an improved method for H-two control with regional stability constraints for the closedloop system. The controller is given by the convex combination of a set of fixed gains. Both continuous and discrete-time systems in a known polytopic domain are investigated. New LMI-based sufficient conditions for the existence of parameterdependent Lyapunov functions are proposed. Numerical examples are given to show the proposed conditions provide useful and less conservative results for the problems of H-two control with regional stability constraints.
