This paper deals with the problem of delay-dependent stability and stabilization for networked control systems(NCSs)with multiple time-delays.In view of multi-input and multi-output(MIMO)NCSs with many independent sen...This paper deals with the problem of delay-dependent stability and stabilization for networked control systems(NCSs)with multiple time-delays.In view of multi-input and multi-output(MIMO)NCSs with many independent sensors and actuators,a continuous time model with distributed time-delays is proposed.Utilizing the Lyapunov stability theory combined with linear matrix inequalities(LMIs)techniques,some new delay-dependent stability criteria for NCSs in terms of generalized Lyapunov matrix equation and LMIs are derived.Stabilizing controller via state feedback is formulated by solving a set of LMIs.Compared with the reported methods,the proposed methods give a less conservative delay bound and more general results.Numerical example and simulation show that the methods are less conservative and more effective.展开更多
In this paper,delay-dependent robust stability for a class of uncertain networked control systems(NCSs)with multiple state time-delays is investigated.Modeling of multi-input and multi-output(MIMO)NCSs with networkind...In this paper,delay-dependent robust stability for a class of uncertain networked control systems(NCSs)with multiple state time-delays is investigated.Modeling of multi-input and multi-output(MIMO)NCSs with networkinduced delays and uncertainties through new methods are proposed.Some new stability criteria in terms of LMIs are derived by using Lyapunov stability theory combined with linear matrix inequalities(LMIs)techniques.We analyze the delay-dependent asymptotic stability and obtain maximum allowable delay bound(MADB)for the NCSs with the proposed methods.Compared with the reported results,the proposed results obtain a much less conservative MADB which are more general.Numerical example and simulation is used to illustrate the effectiveness of the proposed methods.展开更多
Considering the stochastic delay problems existing in networked control systems, a new control mode is proposed for networked control systems whose delay is longer than a sampling period. Under the control mode, the m...Considering the stochastic delay problems existing in networked control systems, a new control mode is proposed for networked control systems whose delay is longer than a sampling period. Under the control mode, the mathematical model of such a system is established. A stochastic stabilization condition for the system is given. The maximum delay can be derived from the stabilization condition.展开更多
This letter presents the principles of Coded Orthogonal Frequency Division Multiplexing (COFDM) system and focuses on the effect of the Guard Interval (GI) on the systemperformance. The role of the GI parameter period...This letter presents the principles of Coded Orthogonal Frequency Division Multiplexing (COFDM) system and focuses on the effect of the Guard Interval (GI) on the systemperformance. The role of the GI parameter period to solve the problem of interferences that occur at the receiver is discussed. A new COFDM concept with a Variable GI (VGI) is proposed in order to improve the Bit Error Rate (BER) performance in the presence of multipaths with variable delays. A series of simulations have been carried out on the BER performance as a function of GI, maximum delay spread, and Signal-to-Noise Ratio (SNR), with QPSK as modulation scheme over multipath fading and Additive White Gaussian Noise (AWGN). The results show that the optimum values of the GI parameter approximately equal to the maximum delay spread, and the proposed system with VGI provides a better performance compared with the fixed length GI.展开更多
Based on bounded network-induced time-delay, the networked control system is modeled as a linear time-variant singular system. Using the Lyapunov theory and the linear matrix inequality approach, the criteria for dela...Based on bounded network-induced time-delay, the networked control system is modeled as a linear time-variant singular system. Using the Lyapunov theory and the linear matrix inequality approach, the criteria for delay-independent stability and delay-dependent stability of singular networked control systems are derived and transformed to a feasibility problem of linear matrix inequality formulation, which can be solved by the Matlab LMI toolbox, and the feasible solutions provide the maximum allowable delay bound that makes the system stable. A numerical example is provided, which shows that the analysis method is valid and the stability criteria are feasible.展开更多
Provided the results of a research conducted to investigate the relationships between the empirical vibration attenuation equation of Peak Particle Velocity （PPV） and the Scaled Charge （SC） through testing the bla...Provided the results of a research conducted to investigate the relationships between the empirical vibration attenuation equation of Peak Particle Velocity （PPV） and the Scaled Charge （SC） through testing the blasting-induced vibrations on the spot of Wanshishan tunnel based on 96 vibration recordings. It is found that the maximum charge amount per delay in Wanshishan tunnel excavating is determined by the buildings on the surface and the constructed tunnel nearby. Considering that the repeated blast loading in tunnel blasting caused accumulative effects of damage on buildings, comfortable threshold damage limits of PPV to maintain buildings safety was given. Dynamic Stress Ratio （DSR） was adopted to study the stability of constructed tunnel on the action of blasting induced vibrations. The method to determine specific maximum charge amount per delay in Wanshishan tunnel excavation was given. It is proved that the findings in this study are very effective to control the negative effects of blasting-induced vibrations on buildings on the surface and constructed tunnel nearby.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.60275013).
文摘This paper deals with the problem of delay-dependent stability and stabilization for networked control systems(NCSs)with multiple time-delays.In view of multi-input and multi-output(MIMO)NCSs with many independent sensors and actuators,a continuous time model with distributed time-delays is proposed.Utilizing the Lyapunov stability theory combined with linear matrix inequalities(LMIs)techniques,some new delay-dependent stability criteria for NCSs in terms of generalized Lyapunov matrix equation and LMIs are derived.Stabilizing controller via state feedback is formulated by solving a set of LMIs.Compared with the reported methods,the proposed methods give a less conservative delay bound and more general results.Numerical example and simulation show that the methods are less conservative and more effective.
基金the National Natural Science Foundation of China(No.60275013).
文摘In this paper,delay-dependent robust stability for a class of uncertain networked control systems(NCSs)with multiple state time-delays is investigated.Modeling of multi-input and multi-output(MIMO)NCSs with networkinduced delays and uncertainties through new methods are proposed.Some new stability criteria in terms of LMIs are derived by using Lyapunov stability theory combined with linear matrix inequalities(LMIs)techniques.We analyze the delay-dependent asymptotic stability and obtain maximum allowable delay bound(MADB)for the NCSs with the proposed methods.Compared with the reported results,the proposed results obtain a much less conservative MADB which are more general.Numerical example and simulation is used to illustrate the effectiveness of the proposed methods.
基金This project was supported by the National Natural Science Foundation of China (60274014, 60574088).
文摘Considering the stochastic delay problems existing in networked control systems, a new control mode is proposed for networked control systems whose delay is longer than a sampling period. Under the control mode, the mathematical model of such a system is established. A stochastic stabilization condition for the system is given. The maximum delay can be derived from the stabilization condition.
文摘This letter presents the principles of Coded Orthogonal Frequency Division Multiplexing (COFDM) system and focuses on the effect of the Guard Interval (GI) on the systemperformance. The role of the GI parameter period to solve the problem of interferences that occur at the receiver is discussed. A new COFDM concept with a Variable GI (VGI) is proposed in order to improve the Bit Error Rate (BER) performance in the presence of multipaths with variable delays. A series of simulations have been carried out on the BER performance as a function of GI, maximum delay spread, and Signal-to-Noise Ratio (SNR), with QPSK as modulation scheme over multipath fading and Additive White Gaussian Noise (AWGN). The results show that the optimum values of the GI parameter approximately equal to the maximum delay spread, and the proposed system with VGI provides a better performance compared with the fixed length GI.
基金the National Natural Science Foundation of China (60574011)the National Natural Science Foundation of Liaoning Province (2050770).
文摘Based on bounded network-induced time-delay, the networked control system is modeled as a linear time-variant singular system. Using the Lyapunov theory and the linear matrix inequality approach, the criteria for delay-independent stability and delay-dependent stability of singular networked control systems are derived and transformed to a feasibility problem of linear matrix inequality formulation, which can be solved by the Matlab LMI toolbox, and the feasible solutions provide the maximum allowable delay bound that makes the system stable. A numerical example is provided, which shows that the analysis method is valid and the stability criteria are feasible.
基金Supported by the National Natural Science Foundation of China（50974059）
文摘Provided the results of a research conducted to investigate the relationships between the empirical vibration attenuation equation of Peak Particle Velocity （PPV） and the Scaled Charge （SC） through testing the blasting-induced vibrations on the spot of Wanshishan tunnel based on 96 vibration recordings. It is found that the maximum charge amount per delay in Wanshishan tunnel excavating is determined by the buildings on the surface and the constructed tunnel nearby. Considering that the repeated blast loading in tunnel blasting caused accumulative effects of damage on buildings, comfortable threshold damage limits of PPV to maintain buildings safety was given. Dynamic Stress Ratio （DSR） was adopted to study the stability of constructed tunnel on the action of blasting induced vibrations. The method to determine specific maximum charge amount per delay in Wanshishan tunnel excavation was given. It is proved that the findings in this study are very effective to control the negative effects of blasting-induced vibrations on buildings on the surface and constructed tunnel nearby.
