A method is proposed for synthesizing output feedback controllers for nonlinear Lur' e systems . The problem of designing an output dynamic controller for uncertain-free systems and systems subject to multiplicati...A method is proposed for synthesizing output feedback controllers for nonlinear Lur' e systems . The problem of designing an output dynamic controller for uncertain-free systems and systems subject to multiplicative norm-bounded perturbations in the linear part were proposed respectively. The procedure is based on the use of the absolute stability, through the circle criterion, and a linear matrix inequalities (LAI) formulation. The controller existence conditions are given in terms of existence of suitable solutions to a set of parameter-dependent LMIs.展开更多
A frequency-domain-based sufficient condition is derived to guarantee the globally asymptotic stability of the simplest Takagi-Sugeno （T-S） fuzzy control system by using the circle criterion. The analysis is perform...A frequency-domain-based sufficient condition is derived to guarantee the globally asymptotic stability of the simplest Takagi-Sugeno （T-S） fuzzy control system by using the circle criterion. The analysis is performed in the frequency domain, and hence the condition is of great significance when the frequency-response method, which is widely used in the linear control theory and practice, is employed to synthesize the simplest T-S fuzzy controller. Besides, this sufficient condition is featured by a graphical interpretation, which makes the condition straightforward to be used. Comparisons are drawn between the performance of the simplest T-S fuzzy controller and that of the linear compensator. Two numerical examples are presented to demonstrate how this sufficient condition can be applied to both stable and unstable plants.展开更多
In this paper,the method of Information Synthesis of Seismogenic System(ISSS)has been used to describe and evaluate the evolution process of self-organization of seismcgenic system in the Capital circle.Through the sy...In this paper,the method of Information Synthesis of Seismogenic System(ISSS)has been used to describe and evaluate the evolution process of self-organization of seismcgenic system in the Capital circle.Through the synthesis of precursory information,the criterion and possible index which characterize the transition of the seismogenic system from steady-state to unsteady-state and then towards the attractor cif a new steady-state have been investigated.The result shows that the synthesis of comprehensive precursor)deformation anomalies of the seismogenic large system(fault-network in the Capital circle),the information synthesis of precursory anomalies of sub-system(a few main fault zones in the Capital circle),and the unweighted or weighted synthesis of anomalous frequencies recognized by the dynamic grey-box method can all raise remarkably the reliability and distinctness of precursory information associated with the Datong Ms 6.1 earthquake.It has provided a criterion and index for evaluation and展开更多
This paper deals with the design of a nonlinear observer for sensorless induction motor control. Based upon the circle criterion approach, a nonlinear observer is designed to estimate pertinent but unmeasurable state ...This paper deals with the design of a nonlinear observer for sensorless induction motor control. Based upon the circle criterion approach, a nonlinear observer is designed to estimate pertinent but unmeasurable state variables of the considered induction machine for sensorless control purpose. The observer gain matrices are computed as a solution of linear matrix inequalities(LMI) that ensure the stability conditions of the state observer error dynamics in the sense of Lyapunov concepts. Measured and estimated state variables can be exploited to perform a state feedback control of the machine system. The simulation results are presented to illustrate the effectiveness of the proposed approach for nonlinear observer design.展开更多
基金Foundation items: the National Natural Science Foundation of China (10272001) the National Key Basic Research Special Foundation of China (G1998020302)
文摘A method is proposed for synthesizing output feedback controllers for nonlinear Lur' e systems . The problem of designing an output dynamic controller for uncertain-free systems and systems subject to multiplicative norm-bounded perturbations in the linear part were proposed respectively. The procedure is based on the use of the absolute stability, through the circle criterion, and a linear matrix inequalities (LAI) formulation. The controller existence conditions are given in terms of existence of suitable solutions to a set of parameter-dependent LMIs.
文摘A frequency-domain-based sufficient condition is derived to guarantee the globally asymptotic stability of the simplest Takagi-Sugeno （T-S） fuzzy control system by using the circle criterion. The analysis is performed in the frequency domain, and hence the condition is of great significance when the frequency-response method, which is widely used in the linear control theory and practice, is employed to synthesize the simplest T-S fuzzy controller. Besides, this sufficient condition is featured by a graphical interpretation, which makes the condition straightforward to be used. Comparisons are drawn between the performance of the simplest T-S fuzzy controller and that of the linear compensator. Two numerical examples are presented to demonstrate how this sufficient condition can be applied to both stable and unstable plants.
文摘In this paper,the method of Information Synthesis of Seismogenic System(ISSS)has been used to describe and evaluate the evolution process of self-organization of seismcgenic system in the Capital circle.Through the synthesis of precursory information,the criterion and possible index which characterize the transition of the seismogenic system from steady-state to unsteady-state and then towards the attractor cif a new steady-state have been investigated.The result shows that the synthesis of comprehensive precursor)deformation anomalies of the seismogenic large system(fault-network in the Capital circle),the information synthesis of precursory anomalies of sub-system(a few main fault zones in the Capital circle),and the unweighted or weighted synthesis of anomalous frequencies recognized by the dynamic grey-box method can all raise remarkably the reliability and distinctness of precursory information associated with the Datong Ms 6.1 earthquake.It has provided a criterion and index for evaluation and
文摘This paper deals with the design of a nonlinear observer for sensorless induction motor control. Based upon the circle criterion approach, a nonlinear observer is designed to estimate pertinent but unmeasurable state variables of the considered induction machine for sensorless control purpose. The observer gain matrices are computed as a solution of linear matrix inequalities(LMI) that ensure the stability conditions of the state observer error dynamics in the sense of Lyapunov concepts. Measured and estimated state variables can be exploited to perform a state feedback control of the machine system. The simulation results are presented to illustrate the effectiveness of the proposed approach for nonlinear observer design.
