This paper investigates stability problem of DC micro-grid under disturbance.Tracking control based on the sampled H∞controller is designed for solving such problem.First,it sets up the model of the DC micro-grid wit...This paper investigates stability problem of DC micro-grid under disturbance.Tracking control based on the sampled H∞controller is designed for solving such problem.First,it sets up the model of the DC micro-grid with the energy storage unit.Next,it presents the model for the closed-loop control system and the design method for the sampled state feedback controller.Then,it gives the sampled H∞performance analysis by considering the sampled quantisation error as an external disturbance term of the system.It derives one sufficient condition for stabilisation of the DC micro-grid based on linear matrix inequalities and Lyapunov theory.Finally,simulations verify the validity of our results.展开更多
The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was ope...The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was operated at high-speed in the flux-weakening mode with the fixed-point DSP. The investigation showed that this was due to the on-line compensation of the winding resistance voltage drop and quantisation errors associated with the fixed-point architecture of the DSP. A simple look-up table scheme is proposed to eliminate the oscillation and to achieve extended flux-weakening capability.展开更多
From a holistic perspective of a physical space of any given size1, it is invariably necessary to consider its energy content, since no physical means exists of making a physical space completely devoid of energy. Suc...From a holistic perspective of a physical space of any given size1, it is invariably necessary to consider its energy content, since no physical means exists of making a physical space completely devoid of energy. Such a space would therefore only be a fictive “geometric space”—that can be intellectually conceived and treated according to the rules of the appropriate geometry—although not existing in reality in the cosmos. Cosmic space always contains energy in one form or another, limited by the space under consideration. Therefore, each space possesses an energy density—no matter how low, which never becomes zero. Because of the mass-energy equivalence relationship , cosmic space also possesses a mass equivalent and is therefore “materialistic” in nature. If this is considered in association with Einstein’s space-time, what is obtained instead is an “energy-time”, i.e. an energy effect, which is based on Planck’s action quantum h. Under this condition, a close relationship would appear to exist between the General Theory of Relativity and Quantum Physics. Furthermore, it will be shown that the physical conditions of space are such that a natural quantisation of space and time exists, thus obviating the need for any artificial or arbitrary quantisation.展开更多
This paper is primarily devoted to the distributed consensus tracking control for heterogeneous nonlinear multi-agent systems(MASs)with a directed communication topology.Taking the considered heterogeneous nonlinear M...This paper is primarily devoted to the distributed consensus tracking control for heterogeneous nonlinear multi-agent systems(MASs)with a directed communication topology.Taking the considered heterogeneous nonlinear MASs own unknown nonlinear term and quantised input signals,the adaptive radial basis function neural networks(RBFNNs)-based approximator is utilised to tackle these interesting challenges.Next,considering the boundness of disturbances,the upper bound of time-varying disturbance is utilised in the controller design.Then,a distributed dynamic compensator is developed to complete coordination task,which only requires to exchange output information via the communication network.In addition,the compensator transforms the adaptive output consensus problem into asymptotic tracking problem,without needing extra stability conditions.Finally,by means of the Lyapunov stability theory,the satisfying result of the consensus error converging to zero asymptotically can be obtained.Through simulations,the effectiveness of the developed protocol is illustrated.展开更多
This paper addresses the ultimate boundedness control problem for a class of networked nonlinear systems with the round-robin(RR)protocol and uniform quantisation.The communication between sensor nodes and the control...This paper addresses the ultimate boundedness control problem for a class of networked nonlinear systems with the round-robin(RR)protocol and uniform quantisation.The communication between sensor nodes and the controller is implemented via a constrained communication channel.The quantised output of the system is transmitted to the remote controller through a communication channel subject to a transmission delay.For the purpose of alleviating possible data collision,the well-known RR communication protocol is deployed to schedule the data transmissions.On the other hand,the uniform quantisation effects of the network are characterised by a round function(i.e.the nearest integer function).The purpose of the addressed problem is to design an observer-based controller for the networked nonlinear systems such that,in the presence of RR protocol and uniform quantisation effects,the closed-loop system is ultimately bounded.The controller is designed based on mean square stability analysis and Lyapunov-like method.A set of sufficient conditions for the ultimate boundedness of the closed-loop system are established and,on the basis of which,the desired controller gains are obtained by solving a set of linear matrix inequalities.The effectiveness of the proposed method is verified by numerical examples.展开更多
基金The work was supported by the Natural Science Foundation of China[grant numbers 61673188,61603212,61761130081 and 61876097]the Foundation for Innovative Research Groups of Hubei Province of China[grant number 2017CFA005]+1 种基金the Fundamental Research Funds for the Central Universities of HUST[grant number 2018KFYXKJC051]the Research Funds for Hubei Key Laboratory of Applied Mathematics(Hubei University).
文摘This paper investigates stability problem of DC micro-grid under disturbance.Tracking control based on the sampled H∞controller is designed for solving such problem.First,it sets up the model of the DC micro-grid with the energy storage unit.Next,it presents the model for the closed-loop control system and the design method for the sampled state feedback controller.Then,it gives the sampled H∞performance analysis by considering the sampled quantisation error as an external disturbance term of the system.It derives one sufficient condition for stabilisation of the DC micro-grid based on linear matrix inequalities and Lyapunov theory.Finally,simulations verify the validity of our results.
文摘The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was operated at high-speed in the flux-weakening mode with the fixed-point DSP. The investigation showed that this was due to the on-line compensation of the winding resistance voltage drop and quantisation errors associated with the fixed-point architecture of the DSP. A simple look-up table scheme is proposed to eliminate the oscillation and to achieve extended flux-weakening capability.
文摘From a holistic perspective of a physical space of any given size1, it is invariably necessary to consider its energy content, since no physical means exists of making a physical space completely devoid of energy. Such a space would therefore only be a fictive “geometric space”—that can be intellectually conceived and treated according to the rules of the appropriate geometry—although not existing in reality in the cosmos. Cosmic space always contains energy in one form or another, limited by the space under consideration. Therefore, each space possesses an energy density—no matter how low, which never becomes zero. Because of the mass-energy equivalence relationship , cosmic space also possesses a mass equivalent and is therefore “materialistic” in nature. If this is considered in association with Einstein’s space-time, what is obtained instead is an “energy-time”, i.e. an energy effect, which is based on Planck’s action quantum h. Under this condition, a close relationship would appear to exist between the General Theory of Relativity and Quantum Physics. Furthermore, it will be shown that the physical conditions of space are such that a natural quantisation of space and time exists, thus obviating the need for any artificial or arbitrary quantisation.
基金funded by the National Science Foundation of China(Grant Nos.62373176 and 61973146),the Applied Basic Research Program of Liaoning Province(No.2022JH2/101300276),and the Key Project of the Educational Department of Liaoning Province(Grant No.JYTZD2023084).
文摘This paper is primarily devoted to the distributed consensus tracking control for heterogeneous nonlinear multi-agent systems(MASs)with a directed communication topology.Taking the considered heterogeneous nonlinear MASs own unknown nonlinear term and quantised input signals,the adaptive radial basis function neural networks(RBFNNs)-based approximator is utilised to tackle these interesting challenges.Next,considering the boundness of disturbances,the upper bound of time-varying disturbance is utilised in the controller design.Then,a distributed dynamic compensator is developed to complete coordination task,which only requires to exchange output information via the communication network.In addition,the compensator transforms the adaptive output consensus problem into asymptotic tracking problem,without needing extra stability conditions.Finally,by means of the Lyapunov stability theory,the satisfying result of the consensus error converging to zero asymptotically can be obtained.Through simulations,the effectiveness of the developed protocol is illustrated.
基金supported in part by the National Natural Science Foundation of China under Grants 62173079 and U1808205the Science and Technology Program of Gansu Province under Grant 21ZD4GA028.
文摘This paper addresses the ultimate boundedness control problem for a class of networked nonlinear systems with the round-robin(RR)protocol and uniform quantisation.The communication between sensor nodes and the controller is implemented via a constrained communication channel.The quantised output of the system is transmitted to the remote controller through a communication channel subject to a transmission delay.For the purpose of alleviating possible data collision,the well-known RR communication protocol is deployed to schedule the data transmissions.On the other hand,the uniform quantisation effects of the network are characterised by a round function(i.e.the nearest integer function).The purpose of the addressed problem is to design an observer-based controller for the networked nonlinear systems such that,in the presence of RR protocol and uniform quantisation effects,the closed-loop system is ultimately bounded.The controller is designed based on mean square stability analysis and Lyapunov-like method.A set of sufficient conditions for the ultimate boundedness of the closed-loop system are established and,on the basis of which,the desired controller gains are obtained by solving a set of linear matrix inequalities.The effectiveness of the proposed method is verified by numerical examples.
