This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter...This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter-satellite distance of space-based laser interferometers are first modeled.Subject to the delayed communication behaviors,a new delay-dependent attitude-orbit coordinated controller is designed.Moreover,by reconstructing the less conservative Lyapunov-Krasovskii functional and free-weight matrices,sufficient criteria are derived to ensure the exponential stability of the closed-loop relative translation and attitude error system.Finally,a simulation example is employed to illustrate the numerical validity of the proposed controller for in-orbit detection missions.展开更多
This paper analyzes the fuzzy variable structure control algorithms for delay systems and describes the compensation mechanism of the integral factor to the effect of the delay. Based on the linearized model of the co...This paper analyzes the fuzzy variable structure control algorithms for delay systems and describes the compensation mechanism of the integral factor to the effect of the delay. Based on the linearized model of the congestion-avoidance flow-control mode of transmission control protocol (TCP), we present delay control algorithms for active queue management (AQM) and discuss the parameter tuning of the algorithms. The NS (network simulator) simulation results show that the proposed control scheme for the nonlinear TCP/AQM model has good performance and robustness with respect to the uncertainties of the round-trip time (RTT) and the number of active TCP sessions. Compared to other similar schemes, our algorithms perform better in terms of packet loss ratio, throughput and butter fluctuation.展开更多
The properties and the design of PWM systems are discussed. The relations among the orifice areas of the valves, initial times and the rate of piston areas are deduced. Also a PWM system is designed and some experimen...The properties and the design of PWM systems are discussed. The relations among the orifice areas of the valves, initial times and the rate of piston areas are deduced. Also a PWM system is designed and some experiments are done. The experiment results agree with those of theory analyses. It can be shown that the relations are correct and the conclusion of theory analyses is reasonable.展开更多
An extended robust model predictive control approach for input constrained discrete uncertain nonlinear systems with time-delay based on a class of uncertain T-S fuzzy models that satisfy sector bound condition is pre...An extended robust model predictive control approach for input constrained discrete uncertain nonlinear systems with time-delay based on a class of uncertain T-S fuzzy models that satisfy sector bound condition is presented. In this approach, the minimization problem of the “worst-case” objective function is converted into the linear objective minimization problem in- volving linear matrix inequalities (LMIs) constraints. The state feedback control law is obtained by solving convex optimization of a set of LMIs. Sufficient condition for stability and a new upper bound on robust performance index are given for these kinds of uncertain fuzzy systems with state time-delay. Simulation results of CSTR process show that the proposed robust predictive control approach is effective and feasible.展开更多
For the first-order integrating processes with long delay, the disturbance observer-based 2DoF control scheme is analyzed in detail with regard to the control input limitation. After that, a simple anti-windup scheme,...For the first-order integrating processes with long delay, the disturbance observer-based 2DoF control scheme is analyzed in detail with regard to the control input limitation. After that, a simple anti-windup scheme, without an additional parameter, is proposed to compensate for the adverse effects of the input saturation. The proposed method can properly keep the control signal saturated for an optimum length of time without discarding the control energy. The simulation results show that the control input saturation can dramatically degrade the closed loop system performance. Under the nonfinal and model uncertainty cases, the controller with anti-windup strategy will obtain fast and smooth responses. Furthermore, the simulation results illustrate that the proposed anti-windup scheme may achieve good performance for the high order integrating processes with long delay.展开更多
In this paper, the robust fault detection filter (RFDF) design problems are studied for nonlinear time-delay systems with unknown inputs. First, a reference residual model is introduced to formulate the RFDF design pr...In this paper, the robust fault detection filter (RFDF) design problems are studied for nonlinear time-delay systems with unknown inputs. First, a reference residual model is introduced to formulate the RFDF design problem as an H∞ model-matching problem. Then appropriate input/output selection matrices are introduced to extend a performance index to the time-delay systems in time domain. The reference residual model designed according to the performance index is an optimal residual generator, which takes into account the robustness against disturbances and sensitivity to faults simultaneously. Applying robust H∞ optimization control technique, the existence conditions of the RFDF for nonlinear time-delay systems with unknown inputs are presented in terms of linear matrix inequality (LMI) formulation, independently of time delay. An illustrative design example is used to demonstrate the validity and applicability of the proposed approach.展开更多
Taking into consideration the disadvantage of Balanced Scorecard(BSC)not being able to reflect time delay,nonlinear problems of causal relationship and being lack of effective simulation,we combined it with the charac...Taking into consideration the disadvantage of Balanced Scorecard(BSC)not being able to reflect time delay,nonlinear problems of causal relationship and being lack of effective simulation,we combined it with the characteristics of the System Dynamics(SD).Basing on the background of manufacturing enterprises,through SD integrating with the BSC we established a new performance evaluation method-SD-BSC method to overcome the disadvantage of BSC.A performance evaluation model of SD-BSC is provided and the simulation results are analyzed which show different production policies will lead to different customer's satisfaction degrees.The SD-BSC dynamic performance evaluation method can reflect dynamic,complex causal feedback relationship and time delay,so it compensates for the disadvantage of traditional financial performance evaluation method,and at the same time makes the BSC perfect.展开更多
As one of Qo S(Quality of Service) metrics, delay is critical important to delay sensitive applications, such as interactive video, network game and online surgery. In this paper, we exploit SDN(Software Defined Netwo...As one of Qo S(Quality of Service) metrics, delay is critical important to delay sensitive applications, such as interactive video, network game and online surgery. In this paper, we exploit SDN(Software Defined Networking) advantages to solve delay Qo S problem. Our work mainly focuses on SDN based queuing delay estimation with real traffic and end-to-end delay control. First, we propose a queuing estimation model and extended it for end-to-end delay of the whole path. It is proved to be feasible and accurate with experimental results in SDN environment. Second, in order to demonstrate the use of our proposed model, we also implement an end-to-end delay control application in SDN. It fulfills specific delay Qo S requirements by dynamically switching flows to a suitable queue based on estimation results and delay requirements.展开更多
Based on a nonlinear state predictor (NSP) and a strong tracking filter (STF), a sensor fault tolerant generic model control (FTGMC) approach for a class of nonlinear time-delay processes is proposed. First, the NSP i...Based on a nonlinear state predictor (NSP) and a strong tracking filter (STF), a sensor fault tolerant generic model control (FTGMC) approach for a class of nonlinear time-delay processes is proposed. First, the NSP is introduced, and it is used to extend the conventional generic model control (GMC) to nonlinear processes with large input time-delay. Then the STF is adopted to estimate process states and sensor bias, the estimated sensor bias is used to drive a fault detection logic. When a sensor fault is detected, the estimated process states by the STF will be used to construct the process output to form a 'soft sensor', which is then used by the NSP (instead of the real outputs) to provide state predictors. These procedures constitute an active fault tolerant control scheme. Finally, simulation results of a three-tank-system demonstrate the effectiveness of the proposed approach.展开更多
A robust model predictive control (MPC) algorithm for discrete time linear systems with time-delay (RPC-TDS) subjected to constrained input control is presented, where the polytopic uncertainties exist in state matric...A robust model predictive control (MPC) algorithm for discrete time linear systems with time-delay (RPC-TDS) subjected to constrained input control is presented, where the polytopic uncertainties exist in state matrices and input matrices. In the algorithm the standard optimization of quadratic objective function has been transformed into optimization of sum of N+1 upper bounds of the quadratic objective function with respect to N control moves and a state feedback control law, where N is the control horizon. The feasibility of the optimization problem guarantees that the algorithm is robustly stable. The simulation results verify the effectiveness of the proposed algorithm.展开更多
The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was contin...The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was continuous-time one, and the control input was discrete-time one. By using an input delay approach and a sector bound method, the network induced delays, quantization parameter and sampling intervals were presented in one framework in the case of the state and the control input by quantized in a logarithmic form. A novel Lyapunov function with discontinuity, which took full advantages of the NCS characteristic information, was exploited. In addition, it was shown that Lyapunov function decreased at the jump instants. Furthermore, the Leibniz-Newton formula and free-weighting matrix methods were used to obtain the guaranteed cost controller design conditions which were dependent on the NCS characteristic information. A numerical example was used to illustrate the effectiveness of the proposed methods.展开更多
This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique...This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization criteria.The restriction that the control widthhas to be larger than the time delay is removed.This leads to a larger application scope for our method.Moreover, notranscendental equation is involved in the obtained result, which reduces the computational burden.Two examples aregiven to validate the theoretical results.展开更多
A finite horizon predictive control algorithm, which applies a saturated feedback control law as its local control law, is presented for nonlinear systems with time-delay subject to input constraints. In the algorithm...A finite horizon predictive control algorithm, which applies a saturated feedback control law as its local control law, is presented for nonlinear systems with time-delay subject to input constraints. In the algorithm, N free control moves, a saturated local control law and the terminal weighting matrices are solved by a minimization problem based on linear matrix inequality （LMI） constraints online. Compared with the algorithm with a nonsaturated local law, the presented algorithm improves the performances of the closed-loop systems such as feasibility and optimality. This model predictive control （MPC） algorithm is applied to an industrial continuous stirred tank reactor （CSTR） with explicit input constraint. The simulation results demonstrate that the presented algorithm is effective.展开更多
Decentralized H_∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition w...Decentralized H_∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition which makes the closed-loop system decentralized asymptotically stable with H_∞ performance was derived based on Lyapunov stability theorem. This condition is expressed as the solvability problem of linear matrix inequalities. The method overcomes the limitations of the existing algebraic Riccati equation method. Finally, a numerical example was given to demonstrate the design procedure for the decentralized H_∞ state feedback controller.展开更多
A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary l...A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary loop had two controllers and the primary loop had two controllers.The two secondary loop controllers were designed using IMC technique.They were decoupled completely and could be adjusted independently,which avoided the undesirable influence on performance of the primary controllers.The main controller in the primary loop was devised as a PID using the method of minimum sensitivity,which could guarantee not only the nominal performance but also the robust stability of the system.A setpoint filter was added in the primary loop to improve the tracking performance.All the controllers of the two closed-loops were designed analytically,and could be adjusted and optimized by single parameter respectively.Simulations were carried out on three various processes with time delay,and the results show that the proposed method can provide a better performance of both set-point tracking and disturbance rejection and robustness against parameters perturbation.展开更多
The study of controlling high-current proton beam halo-chaos has become a key concerned issue for manyimportant applications. In this paper, time-delayed feedback control method is proposed for beam halo-chaos. Partic...The study of controlling high-current proton beam halo-chaos has become a key concerned issue for manyimportant applications. In this paper, time-delayed feedback control method is proposed for beam halo-chaos. Particle incell simulation results show that the method is very effective and has some advantages for high-current beam experimentsand engineering.展开更多
This paper presents the containment analysis and design of heterogeneous linear multi-agent systems(MAS)with time-delay under the output regulation.The leaders are treated as exosystems and an modified output regulati...This paper presents the containment analysis and design of heterogeneous linear multi-agent systems(MAS)with time-delay under the output regulation.The leaders are treated as exosystems and an modified output regulation error is designed,which can deal with more than one leader in containment control,then the containment problem will be turned into an output regulation problem.A novel analysis framework of the output regulation is proposed to design a dynamic state feedback control law for containment error and distributed observer when the agents cannot receive external system signal,which guarantees the convergence of all follower agents to the dynamic convex hull spanned by the leaders.The system stability for time-delay containment is proved by the output regulation method instead of the Lyapunov method.Finally,a numerical example is given to illustrate the validity of the theoretical results.展开更多
基金supported by the Na⁃tional Key R&D Program of China(No.2022YFC2204800)the Graduate Student Independent Exploration and Innovation Program of Central South University(No.2024ZZTS 0767).
文摘This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter-satellite distance of space-based laser interferometers are first modeled.Subject to the delayed communication behaviors,a new delay-dependent attitude-orbit coordinated controller is designed.Moreover,by reconstructing the less conservative Lyapunov-Krasovskii functional and free-weight matrices,sufficient criteria are derived to ensure the exponential stability of the closed-loop relative translation and attitude error system.Finally,a simulation example is employed to illustrate the numerical validity of the proposed controller for in-orbit detection missions.
文摘This paper analyzes the fuzzy variable structure control algorithms for delay systems and describes the compensation mechanism of the integral factor to the effect of the delay. Based on the linearized model of the congestion-avoidance flow-control mode of transmission control protocol (TCP), we present delay control algorithms for active queue management (AQM) and discuss the parameter tuning of the algorithms. The NS (network simulator) simulation results show that the proposed control scheme for the nonlinear TCP/AQM model has good performance and robustness with respect to the uncertainties of the round-trip time (RTT) and the number of active TCP sessions. Compared to other similar schemes, our algorithms perform better in terms of packet loss ratio, throughput and butter fluctuation.
文摘The properties and the design of PWM systems are discussed. The relations among the orifice areas of the valves, initial times and the rate of piston areas are deduced. Also a PWM system is designed and some experiments are done. The experiment results agree with those of theory analyses. It can be shown that the relations are correct and the conclusion of theory analyses is reasonable.
基金Project (No. 60421002) supported by the National Natural ScienceFoundation of China
文摘An extended robust model predictive control approach for input constrained discrete uncertain nonlinear systems with time-delay based on a class of uncertain T-S fuzzy models that satisfy sector bound condition is presented. In this approach, the minimization problem of the “worst-case” objective function is converted into the linear objective minimization problem in- volving linear matrix inequalities (LMIs) constraints. The state feedback control law is obtained by solving convex optimization of a set of LMIs. Sufficient condition for stability and a new upper bound on robust performance index are given for these kinds of uncertain fuzzy systems with state time-delay. Simulation results of CSTR process show that the proposed robust predictive control approach is effective and feasible.
文摘For the first-order integrating processes with long delay, the disturbance observer-based 2DoF control scheme is analyzed in detail with regard to the control input limitation. After that, a simple anti-windup scheme, without an additional parameter, is proposed to compensate for the adverse effects of the input saturation. The proposed method can properly keep the control signal saturated for an optimum length of time without discarding the control energy. The simulation results show that the control input saturation can dramatically degrade the closed loop system performance. Under the nonfinal and model uncertainty cases, the controller with anti-windup strategy will obtain fast and smooth responses. Furthermore, the simulation results illustrate that the proposed anti-windup scheme may achieve good performance for the high order integrating processes with long delay.
基金Project (No. 60574081) supported by the National Natural ScienceFoundation of China
文摘In this paper, the robust fault detection filter (RFDF) design problems are studied for nonlinear time-delay systems with unknown inputs. First, a reference residual model is introduced to formulate the RFDF design problem as an H∞ model-matching problem. Then appropriate input/output selection matrices are introduced to extend a performance index to the time-delay systems in time domain. The reference residual model designed according to the performance index is an optimal residual generator, which takes into account the robustness against disturbances and sensitivity to faults simultaneously. Applying robust H∞ optimization control technique, the existence conditions of the RFDF for nonlinear time-delay systems with unknown inputs are presented in terms of linear matrix inequality (LMI) formulation, independently of time delay. An illustrative design example is used to demonstrate the validity and applicability of the proposed approach.
基金Sponsored by the Key Science Research Project of Abroad Scholars of Heilongjiang Province(Grant No.1055HZ029).
文摘Taking into consideration the disadvantage of Balanced Scorecard(BSC)not being able to reflect time delay,nonlinear problems of causal relationship and being lack of effective simulation,we combined it with the characteristics of the System Dynamics(SD).Basing on the background of manufacturing enterprises,through SD integrating with the BSC we established a new performance evaluation method-SD-BSC method to overcome the disadvantage of BSC.A performance evaluation model of SD-BSC is provided and the simulation results are analyzed which show different production policies will lead to different customer's satisfaction degrees.The SD-BSC dynamic performance evaluation method can reflect dynamic,complex causal feedback relationship and time delay,so it compensates for the disadvantage of traditional financial performance evaluation method,and at the same time makes the BSC perfect.
基金supported by the project of 111 Intelligence Introduction for Innovation at Communication University of ChinaNSFC under grant No.61371191,No.61472389 and No.61201236ETH Zurich for the valuable discussion about H2020 MAMI project related to TCP modeling in this work
文摘As one of Qo S(Quality of Service) metrics, delay is critical important to delay sensitive applications, such as interactive video, network game and online surgery. In this paper, we exploit SDN(Software Defined Networking) advantages to solve delay Qo S problem. Our work mainly focuses on SDN based queuing delay estimation with real traffic and end-to-end delay control. First, we propose a queuing estimation model and extended it for end-to-end delay of the whole path. It is proved to be feasible and accurate with experimental results in SDN environment. Second, in order to demonstrate the use of our proposed model, we also implement an end-to-end delay control application in SDN. It fulfills specific delay Qo S requirements by dynamically switching flows to a suitable queue based on estimation results and delay requirements.
基金Supported by the National Natural Science Foundation of China (No. 60025307, No. 60234010) the National 863 Project(No. 2001AA413130,2002AA412420)+1 种基金 Research Fund for the Doctoral Program of Higher Education (No. 20020003063) the National 973 Program
文摘Based on a nonlinear state predictor (NSP) and a strong tracking filter (STF), a sensor fault tolerant generic model control (FTGMC) approach for a class of nonlinear time-delay processes is proposed. First, the NSP is introduced, and it is used to extend the conventional generic model control (GMC) to nonlinear processes with large input time-delay. Then the STF is adopted to estimate process states and sensor bias, the estimated sensor bias is used to drive a fault detection logic. When a sensor fault is detected, the estimated process states by the STF will be used to construct the process output to form a 'soft sensor', which is then used by the NSP (instead of the real outputs) to provide state predictors. These procedures constitute an active fault tolerant control scheme. Finally, simulation results of a three-tank-system demonstrate the effectiveness of the proposed approach.
基金The project is supported by the National High Technology Research and Development (863) Programof China (2002AA412010)
文摘A robust model predictive control (MPC) algorithm for discrete time linear systems with time-delay (RPC-TDS) subjected to constrained input control is presented, where the polytopic uncertainties exist in state matrices and input matrices. In the algorithm the standard optimization of quadratic objective function has been transformed into optimization of sum of N+1 upper bounds of the quadratic objective function with respect to N control moves and a state feedback control law, where N is the control horizon. The feasibility of the optimization problem guarantees that the algorithm is robustly stable. The simulation results verify the effectiveness of the proposed algorithm.
基金Project(61104106) supported by the National Natural Science Foundation of ChinaProject(201202156) supported by the Natural Science Foundation of Liaoning Province,ChinaProject(LJQ2012100) supported by Program for Liaoning Excellent Talents in University(LNET)
文摘The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was continuous-time one, and the control input was discrete-time one. By using an input delay approach and a sector bound method, the network induced delays, quantization parameter and sampling intervals were presented in one framework in the case of the state and the control input by quantized in a logarithmic form. A novel Lyapunov function with discontinuity, which took full advantages of the NCS characteristic information, was exploited. In addition, it was shown that Lyapunov function decreased at the jump instants. Furthermore, the Leibniz-Newton formula and free-weighting matrix methods were used to obtain the guaranteed cost controller design conditions which were dependent on the NCS characteristic information. A numerical example was used to illustrate the effectiveness of the proposed methods.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60774039,60974024,and 61074089CityU Research Enhancement Fund 9360127,CityU SRG 7002355
文摘This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization criteria.The restriction that the control widthhas to be larger than the time delay is removed.This leads to a larger application scope for our method.Moreover, notranscendental equation is involved in the obtained result, which reduces the computational burden.Two examples aregiven to validate the theoretical results.
基金Supported by the National High Technology Research and Development Program of China(2004AA412050)
文摘A finite horizon predictive control algorithm, which applies a saturated feedback control law as its local control law, is presented for nonlinear systems with time-delay subject to input constraints. In the algorithm, N free control moves, a saturated local control law and the terminal weighting matrices are solved by a minimization problem based on linear matrix inequality （LMI） constraints online. Compared with the algorithm with a nonsaturated local law, the presented algorithm improves the performances of the closed-loop systems such as feasibility and optimality. This model predictive control （MPC） algorithm is applied to an industrial continuous stirred tank reactor （CSTR） with explicit input constraint. The simulation results demonstrate that the presented algorithm is effective.
文摘Decentralized H_∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition which makes the closed-loop system decentralized asymptotically stable with H_∞ performance was derived based on Lyapunov stability theorem. This condition is expressed as the solvability problem of linear matrix inequalities. The method overcomes the limitations of the existing algebraic Riccati equation method. Finally, a numerical example was given to demonstrate the design procedure for the decentralized H_∞ state feedback controller.
基金Project(J11LG02) supported by the Science and Technology Funds of Education Department of Shandong Province,China
文摘A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary loop had two controllers and the primary loop had two controllers.The two secondary loop controllers were designed using IMC technique.They were decoupled completely and could be adjusted independently,which avoided the undesirable influence on performance of the primary controllers.The main controller in the primary loop was devised as a PID using the method of minimum sensitivity,which could guarantee not only the nominal performance but also the robust stability of the system.A setpoint filter was added in the primary loop to improve the tracking performance.All the controllers of the two closed-loops were designed analytically,and could be adjusted and optimized by single parameter respectively.Simulations were carried out on three various processes with time delay,and the results show that the proposed method can provide a better performance of both set-point tracking and disturbance rejection and robustness against parameters perturbation.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10247005,70071047,and 19875080
文摘The study of controlling high-current proton beam halo-chaos has become a key concerned issue for manyimportant applications. In this paper, time-delayed feedback control method is proposed for beam halo-chaos. Particle incell simulation results show that the method is very effective and has some advantages for high-current beam experimentsand engineering.
基金National Key Research and Development Plan of China(No.2017YFB1201003-020)National Natural Science Foundation of China(Nos.61663020,61661027)。
文摘This paper presents the containment analysis and design of heterogeneous linear multi-agent systems(MAS)with time-delay under the output regulation.The leaders are treated as exosystems and an modified output regulation error is designed,which can deal with more than one leader in containment control,then the containment problem will be turned into an output regulation problem.A novel analysis framework of the output regulation is proposed to design a dynamic state feedback control law for containment error and distributed observer when the agents cannot receive external system signal,which guarantees the convergence of all follower agents to the dynamic convex hull spanned by the leaders.The system stability for time-delay containment is proved by the output regulation method instead of the Lyapunov method.Finally,a numerical example is given to illustrate the validity of the theoretical results.
