Dear Editor,In this letter,a constrained networked predictive control strategy is proposed for the optimal control problem of complex nonlinear highorder fully actuated(HOFA)systems with noises.The method can effectiv...Dear Editor,In this letter,a constrained networked predictive control strategy is proposed for the optimal control problem of complex nonlinear highorder fully actuated(HOFA)systems with noises.The method can effectively deal with nonlinearities,constraints,and noises in the system,optimize the performance metric,and present an upper bound on the stable output of the system.展开更多
Dear Editor,The attacker is always going to intrude covertly networked control systems(NCSs)by dynamically changing false data injection attacks(FDIAs)strategy,while the defender try their best to resist attacks by de...Dear Editor,The attacker is always going to intrude covertly networked control systems(NCSs)by dynamically changing false data injection attacks(FDIAs)strategy,while the defender try their best to resist attacks by designing defense strategy on the basis of identifying attack strategy,maintaining stable operation of NCSs.To solve this attack-defense game problem,this letter investigates optimal secure control of NCSs under FDIAs.First,for the alterations of energy caused by false data,a novel attack-defense game model is constructed,which considers the changes of energy caused by the actions of the defender and attacker in the forward and feedback channels.展开更多
This paper investigates the problem of optimal secure control for networked control systems under hybrid attacks.A control strategy based on the Stackelberg game framework is proposed,which differs from conventional m...This paper investigates the problem of optimal secure control for networked control systems under hybrid attacks.A control strategy based on the Stackelberg game framework is proposed,which differs from conventional methods by considering both denial-of-service(DoS)and false data injection(FDI)attacks simultaneously.Additionally,the stability conditions for the system under these hybrid attacks are established.It is technically challenging to design the control strategy by predicting attacker actions based on Stcakelberg game to ensure the system stability under hybrid attacks.Another technical difficulty lies in establishing the conditions for mean-square asymptotic stability due to the complexity of the attack scenarios Finally,simulations on an unstable batch reactor system under hybrid attacks demonstrate the effectiveness of the proposed strategy.展开更多
The Internet of Things(IoT)technology provides data acquisition,transmission,and analysis to control rehabilitation robots,encompassing sensor data from the robots as well as lidar signals for trajectory planning(desi...The Internet of Things(IoT)technology provides data acquisition,transmission,and analysis to control rehabilitation robots,encompassing sensor data from the robots as well as lidar signals for trajectory planning(desired trajectory).In IoT rehabilitation robot systems,managing nonvanishing uncertainties and input quantization is crucial for precise and reliable control performance.These challenges can cause instability and reduced effectiveness,particularly in adaptive networked control.This paper investigates networked control with guaranteed performance for IoT rehabilitation robots under nonvanishing uncertainties and input quantization.First,input quantization is managed via a quantization-aware control design,ensur stability and minimizing tracking errors,even with discrete control inputs,to avoid chattering.Second,the method handles nonvanishing uncertainties by adjusting control parameters via real-time neural network adaptation,maintaining consistent performance despite persistent disturbances.Third,the control scheme guarantees the desired tracking performance within a specified time,with all signals in the closed-loop system remaining uniformly bounded,offering a robust,reliable solution for IoT rehabilitation robot control.The simulation verifies the benefits and efficacy of the proposed control strategy.展开更多
The proliferation of distributed and renewable energy resources introduces additional operational challenges to power distribution systems.Transactive energy management,which allows networked neighborhood communities ...The proliferation of distributed and renewable energy resources introduces additional operational challenges to power distribution systems.Transactive energy management,which allows networked neighborhood communities and houses to trade energy,is expected to be developed as an effective method for accommodating additional uncertainties and security mandates pertaining to distributed energy resources.This paper proposes and analyzes a two-layer transactive energy market in which houses in networked neighborhood community microgrids will trade energy in respective market layers.This paper studies the blockchain applications to satisfy socioeconomic and technological concerns of secure transactive energy management in a two-level power distribution system.The numerical results for practical networked microgrids located at IllinoisTech−Bronzeville in Chicago illustrate the validity of the proposed blockchain-based transactive energy management for devising a distributed,scalable,efficient,and cybersecured power grid operation.The conclusion of the paper summarizes the prospects for blockchain applications to transactive energy management in power distribution systems.展开更多
Dear Editor,This letter addresses the robust predefined-time control challenge for leaderless optimal formation in networked mobile vehicle(NMV)systems.The aim is to minimize a composite global cost function derived f...Dear Editor,This letter addresses the robust predefined-time control challenge for leaderless optimal formation in networked mobile vehicle(NMV)systems.The aim is to minimize a composite global cost function derived from individual strongly convex functions of each agent,considering both input disturbances and network communication constraints.A novel predefined-time optimal formation control(PTOFC)algorithm is presented,ensuring agent state convergence to optimal formation positions within an adjustable settling time.Through the integration of an integral sliding mode technique,disturbances are effectively countered.A representative numerical example highlights the effectiveness and robustness of the developed approach.展开更多
Dear Editor,This letter focuses on the distributed cooperative regulation problem for a class of networked re-entrant manufacturing systems(RMSs).The networked system is structured with a three-tier architecture:the p...Dear Editor,This letter focuses on the distributed cooperative regulation problem for a class of networked re-entrant manufacturing systems(RMSs).The networked system is structured with a three-tier architecture:the production line,the manufacturing layer and the workshop layer.The dynamics of re-entrant production lines are governed by hyperbolic partial differential equations(PDEs)based on the law of mass conservation.展开更多
To handle input and output time delays that commonly exist in many networked control systems(NCSs), a new robust continuous sliding mode control(CSMC) scheme is proposed for the output tracking in uncertain single inp...To handle input and output time delays that commonly exist in many networked control systems(NCSs), a new robust continuous sliding mode control(CSMC) scheme is proposed for the output tracking in uncertain single input-single-output(SISO) networked control systems. This scheme consists of three consecutive steps. First, although the network-induced delay in those systems can be effectively handled by using Pade approximation(PA), the unmatched disturbance cames out as another difficulty in the control design. Second, to actively estimate this unmatched disturbance, a generalized proportional integral observer(GPIO) technique is utilized based on only one measured state. Third, by constructing a new sliding manifold with the aid of the estimated unmatched disturbance and states, a GPIO-based CSMC is synthesized, which is employed to cope with not only matched and unmatched disturbances, but also networkinduced delays. The stability of the entire closed-loop system under the proposed GPIO-based CSMC is detailedly analyzed.The promising tracking efficiency and feasibility of the proposed control methodology are verified through simulations and experiments on Quanser's servo module for motion control under various test conditions.展开更多
Dear Editor,This letter presents a joint probabilistic scheduling and resource allocation method(PSRA) for 5G-based wireless networked control systems(WNCSs). As a control-aware optimization method, PSRA minimizes the...Dear Editor,This letter presents a joint probabilistic scheduling and resource allocation method(PSRA) for 5G-based wireless networked control systems(WNCSs). As a control-aware optimization method, PSRA minimizes the linear quadratic Gaussian(LQG) control cost of WNCSs by optimizing the activation probability of subsystems, the number of uplink repetitions, and the durations of uplink and downlink phases. Simulation results show that PSRA achieves smaller LQG control costs than existing works.展开更多
Abstract--This paper provides a survey on modeling and theories of networked control systems （NCS）. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfectio...Abstract--This paper provides a survey on modeling and theories of networked control systems （NCS）. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfections are quantization errors, packet dropouts, variable sampling/transmission intervals, vari- able transmission delays, and communication constraints. Then follows in the second part a presentation of several theories that have been applied for controlling networked systems. These theories include： input delay system approach, Markovian system approach, switched system approach, stochastic system approach, impulsive system approach, and predictive control approach. In the last part, some advanced issues in NCS including decentral- ized and distributed NCS, cloud control system, and co-design of NCS are reviewed. Index Terms--Decentralized networked control systems （NCS）, distributed networked control systems, network constraints, net- worked control system, quantization, time delays.展开更多
Urban rail transit is an efficient and environmentally friendly mode of transport,which is an important means of transportation for passengers.From a holistic point of view,this paper constructs an urban rail transit ...Urban rail transit is an efficient and environmentally friendly mode of transport,which is an important means of transportation for passengers.From a holistic point of view,this paper constructs an urban rail transit interchange topology(URTIT)network based on the interchange relationships among lines.We investigate a unique influence propagation mechanism to explore the impact of applying new technologies on the passenger travel behavior of urban rail transit.We analyze the influence from three aspects:the influence range,the influence propagation path,and the influence intensity.Based on the Dijkstra algorithm,the influence propagation paths are found according to the shortest transfer time.The improved path-based gravity model is applied to measure the influence intensity.The case study on urban rail transit in Beijing,China is carried out.The influence propagation mechanism of a single line in the Beijing URTIT network is analyzed,considering that Beijing Subway Line S1 is equipped with magnetic levitation technology.We not only quantify the impact of technologies on passenger travel behavior of urban rail transit,but also perform the sensitivity analysis.To avoid randomness,the influence propagation mechanisms of all lines are explored in this paper.The research results correspond to the situation in reality,which can provide certain references for urban rail transit operation and planning.展开更多
In social and ecological systems,individual migration behavior and peer pressure are crucial factors influencing decision-making and cooperative behavior.However,how migration regulates the evolution of cooperation an...In social and ecological systems,individual migration behavior and peer pressure are crucial factors influencing decision-making and cooperative behavior.However,how migration regulates the evolution of cooperation and the specific role of peer pressure in this process remain to be further investigated.To address this,this study develops a model that incorporates migration mechanisms and peer pressure within the framework of the networked prisoner’s dilemma game.Specifically,we modify the population structure and introduce a migration strategy based on payoff maximization,enabling individuals to dynamically adjust their positions according to the local environment.The model also considers the impact of peer pressure on individual decision-making and introduces heterogeneity in individuals’sensitivity to pressure,thereby systematically examining the role of both factors in the evolution of cooperative behavior.Based on this framework,we further compare our model with a scenario in which no migration mechanism is present to evaluate its impact on cooperative dynamics.The results reveal that the migration mechanism significantly promotes the evolution of cooperative behavior.Under this mechanism,higher individual sensitivity leads to an increased level of cooperation,and stronger peer pressure intensity more effectively enhances the promotion of cooperation.Additionally,the influence of population structure on cooperation frequency cannot be overlooked.An increase in vacant nodes provides cooperators with greater buffering space and more migration opportunities,making cooperative behavior more stable and facilitating its propagation within the system.These findings suggest that appropriately regulating individual mobility and reinforcing peer pressure constraints can enhance the stability and propagation of cooperative behavior,providing significant theoretical support for social governance,organizational management,and group collaboration.展开更多
For the past decades,networked control systems(NCSs),as an interdisciplinary subject,have been one of the main research highlights and many fruitful results from different aspects have been achieved.With these growing...For the past decades,networked control systems(NCSs),as an interdisciplinary subject,have been one of the main research highlights and many fruitful results from different aspects have been achieved.With these growing research trends,it is significant to consolidate the latest knowledge and information to keep up with the research needs.In this paper,the results of different aspects of NCSs,such as quantization,estimation,fault detection and networked predictive control,are summarized.In addition,with the development of cloud technique,cloud control systems are proposed for the further development of NCSs.展开更多
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
A control scheme that integrates control technology with communication technology to solve the delay problem is introduced for a class of networked control systems: Networked Half-Link Systems (NHLS). Concretely, we u...A control scheme that integrates control technology with communication technology to solve the delay problem is introduced for a class of networked control systems: Networked Half-Link Systems (NHLS). Concretely, we use the master-slave clock synchronization technology to evaluate the delays online, and then the LQ optimal control based on delays is adopted to stabilize the controlled plant. During the clock synchronization process, the error of evaluated delays is inevitably induced from the clock synchronization error, which will deteriorate the system performances, and even make system unstable in certain cases. Hence, the discussions about the clock error, and the related control analysis and design are also developed. Specifically, we present the sufficient conditions of controller parameters that guarantee the system stability, and a controller design method based on the error of delays is addressed thereafter. The experiments based on a CANbus platform are fulfilled, and the experimental results verify the previous analytic results finally.展开更多
To deal with a lack of semantic interoperability of traditional knowledge retrieval approaches, a semantic-based networked manufacturing （NM） knowledge retrieval architecture is proposed, which offers a series of to...To deal with a lack of semantic interoperability of traditional knowledge retrieval approaches, a semantic-based networked manufacturing （NM） knowledge retrieval architecture is proposed, which offers a series of tools for supporting the sharing of knowledge and promoting NM collaboration. A 5-tuple based semantic information retrieval model is proposed, which includes the interoperation on the semantic layer, and a test process is given for this model. The recall ratio and the precision ratio of manufacturing knowledge retrieval are proved to be greatly improved by evaluation. Thus, a practical and reliable approach based on the semantic web is provided for solving the correlated concrete problems in regional networked manufacturing.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
The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is...The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.展开更多
This book is greatly appreciated for its collection of various innovative activities which could be applied in different levels of technology-savvy classrooms.It is regarded as guidance to show paths for language educ...This book is greatly appreciated for its collection of various innovative activities which could be applied in different levels of technology-savvy classrooms.It is regarded as guidance to show paths for language educators to teach in digital age,although most of the teachers today are digital immigrants who "have become fascinated by and adopted many,or most aspects of the new technology are,and always will be compared to them"(Prensky,2001).They have to attempt to equip themselves with the knowledge of new media,which aims to provide the current students with their needs to become fully literate in this digital age.However,when the Internet began to arrive in schools,it was embraced by educators already seasoned in the challenges of change.展开更多
Two significant issues in Internet-based networked control systems （ INCSs）, transport performance of different protocols and security breach from Internet side, are investigated. First, for improving the performanc...Two significant issues in Internet-based networked control systems （ INCSs）, transport performance of different protocols and security breach from Internet side, are investigated. First, for improving the performance of data transmission, user datagram protocol （UDP） is adopted as the main stand for controllers and plants using INCSs. Second, a dual-channel secure transmission scheme （DCSTS）based on data transmission characteristics of INCSs is proposed, in which a raw UDP channel and a secure TCP （transmission control protocol） connection making use of SSL/TLS （secure sockets layer/transport layer security） are included. Further, a networked control protocol （NCP） at application layer for supporting DCSTS between the controllers and plants in INCSs is designed, and it also aims at providing a universal communication mechanism for interoperability of devices among the networked control laboratories in Beijing Institute of Technology of China, Central South University of China and Tokyo University of Technology of Japan. By means of a networked single-degree-of-free- dom robot arm, an INCS under the new protocol and security environment is created. Compared with systems such as IPSec or SSL/TLS, which may cause more than 91% network throughput deduction, the new DCSTS protocol may yield results ten times better, being just 5.67%.展开更多
基金supported in part by the National Natural Science Foundation of China(62173255,62188101)Shenzhen Key Laboratory of Control Theory and Intelligent Systems(ZDSYS20220330161800001)
文摘Dear Editor,In this letter,a constrained networked predictive control strategy is proposed for the optimal control problem of complex nonlinear highorder fully actuated(HOFA)systems with noises.The method can effectively deal with nonlinearities,constraints,and noises in the system,optimize the performance metric,and present an upper bound on the stable output of the system.
基金supported in part by the National Science Foundation of China(62373240,62273224,U24A20259).
文摘Dear Editor,The attacker is always going to intrude covertly networked control systems(NCSs)by dynamically changing false data injection attacks(FDIAs)strategy,while the defender try their best to resist attacks by designing defense strategy on the basis of identifying attack strategy,maintaining stable operation of NCSs.To solve this attack-defense game problem,this letter investigates optimal secure control of NCSs under FDIAs.First,for the alterations of energy caused by false data,a novel attack-defense game model is constructed,which considers the changes of energy caused by the actions of the defender and attacker in the forward and feedback channels.
基金supported in part by Shanghai Rising-Star Program,China under grant 22QA1409400in part by National Natural Science Foundation of China under grant 62473287 and 62088101in part by Shanghai Municipal Science and Technology Major Project under grant 2021SHZDZX0100.
文摘This paper investigates the problem of optimal secure control for networked control systems under hybrid attacks.A control strategy based on the Stackelberg game framework is proposed,which differs from conventional methods by considering both denial-of-service(DoS)and false data injection(FDI)attacks simultaneously.Additionally,the stability conditions for the system under these hybrid attacks are established.It is technically challenging to design the control strategy by predicting attacker actions based on Stcakelberg game to ensure the system stability under hybrid attacks.Another technical difficulty lies in establishing the conditions for mean-square asymptotic stability due to the complexity of the attack scenarios Finally,simulations on an unstable batch reactor system under hybrid attacks demonstrate the effectiveness of the proposed strategy.
基金supported in part by the National Natural Science Foundation of China under Grant 62302475in part by the Research Funds of Centre for Leading Medicine and Advanced Technologies of IHM under Grant 2023IHM01081 and 2023IHM01085+1 种基金in part by the Hefei Municipal Natural Science Foundation under Grant 202328partly by the Anhui Science and Technology Innovation Tackling Plan Project under Grant 202423k09020044。
文摘The Internet of Things(IoT)technology provides data acquisition,transmission,and analysis to control rehabilitation robots,encompassing sensor data from the robots as well as lidar signals for trajectory planning(desired trajectory).In IoT rehabilitation robot systems,managing nonvanishing uncertainties and input quantization is crucial for precise and reliable control performance.These challenges can cause instability and reduced effectiveness,particularly in adaptive networked control.This paper investigates networked control with guaranteed performance for IoT rehabilitation robots under nonvanishing uncertainties and input quantization.First,input quantization is managed via a quantization-aware control design,ensur stability and minimizing tracking errors,even with discrete control inputs,to avoid chattering.Second,the method handles nonvanishing uncertainties by adjusting control parameters via real-time neural network adaptation,maintaining consistent performance despite persistent disturbances.Third,the control scheme guarantees the desired tracking performance within a specified time,with all signals in the closed-loop system remaining uniformly bounded,offering a robust,reliable solution for IoT rehabilitation robot control.The simulation verifies the benefits and efficacy of the proposed control strategy.
基金funded in part by Grant No.RG-15-135-43 from the Deanship of Scientific Research(DSR)at King Abdulaziz University in Saudi Arabia.
文摘The proliferation of distributed and renewable energy resources introduces additional operational challenges to power distribution systems.Transactive energy management,which allows networked neighborhood communities and houses to trade energy,is expected to be developed as an effective method for accommodating additional uncertainties and security mandates pertaining to distributed energy resources.This paper proposes and analyzes a two-layer transactive energy market in which houses in networked neighborhood community microgrids will trade energy in respective market layers.This paper studies the blockchain applications to satisfy socioeconomic and technological concerns of secure transactive energy management in a two-level power distribution system.The numerical results for practical networked microgrids located at IllinoisTech−Bronzeville in Chicago illustrate the validity of the proposed blockchain-based transactive energy management for devising a distributed,scalable,efficient,and cybersecured power grid operation.The conclusion of the paper summarizes the prospects for blockchain applications to transactive energy management in power distribution systems.
基金supported by the National Natural Science Foundation of China(62373162,U24A20268,624B2055)the Shenzhen Science and Technology Program(JCYJ 20240813114007010)the Knowledge Innovation Program of Wuhan-Basic Research(2023010201010100).
文摘Dear Editor,This letter addresses the robust predefined-time control challenge for leaderless optimal formation in networked mobile vehicle(NMV)systems.The aim is to minimize a composite global cost function derived from individual strongly convex functions of each agent,considering both input disturbances and network communication constraints.A novel predefined-time optimal formation control(PTOFC)algorithm is presented,ensuring agent state convergence to optimal formation positions within an adjustable settling time.Through the integration of an integral sliding mode technique,disturbances are effectively countered.A representative numerical example highlights the effectiveness and robustness of the developed approach.
文摘Dear Editor,This letter focuses on the distributed cooperative regulation problem for a class of networked re-entrant manufacturing systems(RMSs).The networked system is structured with a three-tier architecture:the production line,the manufacturing layer and the workshop layer.The dynamics of re-entrant production lines are governed by hyperbolic partial differential equations(PDEs)based on the law of mass conservation.
基金supported in part by the Australian Research Council Discovery Project(DP190101557)
文摘To handle input and output time delays that commonly exist in many networked control systems(NCSs), a new robust continuous sliding mode control(CSMC) scheme is proposed for the output tracking in uncertain single input-single-output(SISO) networked control systems. This scheme consists of three consecutive steps. First, although the network-induced delay in those systems can be effectively handled by using Pade approximation(PA), the unmatched disturbance cames out as another difficulty in the control design. Second, to actively estimate this unmatched disturbance, a generalized proportional integral observer(GPIO) technique is utilized based on only one measured state. Third, by constructing a new sliding manifold with the aid of the estimated unmatched disturbance and states, a GPIO-based CSMC is synthesized, which is employed to cope with not only matched and unmatched disturbances, but also networkinduced delays. The stability of the entire closed-loop system under the proposed GPIO-based CSMC is detailedly analyzed.The promising tracking efficiency and feasibility of the proposed control methodology are verified through simulations and experiments on Quanser's servo module for motion control under various test conditions.
基金supported by the Liaoning Revitalization Talents Program(XLYC2203148)
文摘Dear Editor,This letter presents a joint probabilistic scheduling and resource allocation method(PSRA) for 5G-based wireless networked control systems(WNCSs). As a control-aware optimization method, PSRA minimizes the linear quadratic Gaussian(LQG) control cost of WNCSs by optimizing the activation probability of subsystems, the number of uplink repetitions, and the durations of uplink and downlink phases. Simulation results show that PSRA achieves smaller LQG control costs than existing works.
基金supported by the Deanship of Scientific Research(DSR) at KFUPM through Research Project(IN141048)
文摘Abstract--This paper provides a survey on modeling and theories of networked control systems （NCS）. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfections are quantization errors, packet dropouts, variable sampling/transmission intervals, vari- able transmission delays, and communication constraints. Then follows in the second part a presentation of several theories that have been applied for controlling networked systems. These theories include： input delay system approach, Markovian system approach, switched system approach, stochastic system approach, impulsive system approach, and predictive control approach. In the last part, some advanced issues in NCS including decentral- ized and distributed NCS, cloud control system, and co-design of NCS are reviewed. Index Terms--Decentralized networked control systems （NCS）, distributed networked control systems, network constraints, net- worked control system, quantization, time delays.
基金supported by the Beijing Natural Science Foundation(Grant No.L231009)National Natural Science Foundation of China(Grant No.72288101)Fundamental Research Funds for the Central Universities(Grant No.2022JBZY017)。
文摘Urban rail transit is an efficient and environmentally friendly mode of transport,which is an important means of transportation for passengers.From a holistic point of view,this paper constructs an urban rail transit interchange topology(URTIT)network based on the interchange relationships among lines.We investigate a unique influence propagation mechanism to explore the impact of applying new technologies on the passenger travel behavior of urban rail transit.We analyze the influence from three aspects:the influence range,the influence propagation path,and the influence intensity.Based on the Dijkstra algorithm,the influence propagation paths are found according to the shortest transfer time.The improved path-based gravity model is applied to measure the influence intensity.The case study on urban rail transit in Beijing,China is carried out.The influence propagation mechanism of a single line in the Beijing URTIT network is analyzed,considering that Beijing Subway Line S1 is equipped with magnetic levitation technology.We not only quantify the impact of technologies on passenger travel behavior of urban rail transit,but also perform the sensitivity analysis.To avoid randomness,the influence propagation mechanisms of all lines are explored in this paper.The research results correspond to the situation in reality,which can provide certain references for urban rail transit operation and planning.
基金supported in part by the National Natural Science Foundation of China(Grant No.72031009)Major Project of the National Social Science Foundation of China(Grant No.20&ZD058).
文摘In social and ecological systems,individual migration behavior and peer pressure are crucial factors influencing decision-making and cooperative behavior.However,how migration regulates the evolution of cooperation and the specific role of peer pressure in this process remain to be further investigated.To address this,this study develops a model that incorporates migration mechanisms and peer pressure within the framework of the networked prisoner’s dilemma game.Specifically,we modify the population structure and introduce a migration strategy based on payoff maximization,enabling individuals to dynamically adjust their positions according to the local environment.The model also considers the impact of peer pressure on individual decision-making and introduces heterogeneity in individuals’sensitivity to pressure,thereby systematically examining the role of both factors in the evolution of cooperative behavior.Based on this framework,we further compare our model with a scenario in which no migration mechanism is present to evaluate its impact on cooperative dynamics.The results reveal that the migration mechanism significantly promotes the evolution of cooperative behavior.Under this mechanism,higher individual sensitivity leads to an increased level of cooperation,and stronger peer pressure intensity more effectively enhances the promotion of cooperation.Additionally,the influence of population structure on cooperation frequency cannot be overlooked.An increase in vacant nodes provides cooperators with greater buffering space and more migration opportunities,making cooperative behavior more stable and facilitating its propagation within the system.These findings suggest that appropriately regulating individual mobility and reinforcing peer pressure constraints can enhance the stability and propagation of cooperative behavior,providing significant theoretical support for social governance,organizational management,and group collaboration.
基金supported by National Basic Research Program of China(973 Program)(No.2012CB720000)National Natural Science Foundation of China(Nos.61225015 and 60974011)+3 种基金Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.61321002)Beijing Municipal Natural Science Foundation(Nos.4102053 and 4101001)Beijing Natural Science Foundation(Nos.4132042)Beijing Higher Education Young Elite Teacher Project(No.YETP1212)
文摘For the past decades,networked control systems(NCSs),as an interdisciplinary subject,have been one of the main research highlights and many fruitful results from different aspects have been achieved.With these growing research trends,it is significant to consolidate the latest knowledge and information to keep up with the research needs.In this paper,the results of different aspects of NCSs,such as quantization,estimation,fault detection and networked predictive control,are summarized.In addition,with the development of cloud technique,cloud control systems are proposed for the further development of NCSs.
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.
文摘A control scheme that integrates control technology with communication technology to solve the delay problem is introduced for a class of networked control systems: Networked Half-Link Systems (NHLS). Concretely, we use the master-slave clock synchronization technology to evaluate the delays online, and then the LQ optimal control based on delays is adopted to stabilize the controlled plant. During the clock synchronization process, the error of evaluated delays is inevitably induced from the clock synchronization error, which will deteriorate the system performances, and even make system unstable in certain cases. Hence, the discussions about the clock error, and the related control analysis and design are also developed. Specifically, we present the sufficient conditions of controller parameters that guarantee the system stability, and a controller design method based on the error of delays is addressed thereafter. The experiments based on a CANbus platform are fulfilled, and the experimental results verify the previous analytic results finally.
基金The National High Technology Research and Devel-opment Program of China (863Program) (No2003AA1Z2560,2002AA414060)the Key Science and Technology Program of Shaanxi Province (No2006K04-G10)
文摘To deal with a lack of semantic interoperability of traditional knowledge retrieval approaches, a semantic-based networked manufacturing （NM） knowledge retrieval architecture is proposed, which offers a series of tools for supporting the sharing of knowledge and promoting NM collaboration. A 5-tuple based semantic information retrieval model is proposed, which includes the interoperation on the semantic layer, and a test process is given for this model. The recall ratio and the precision ratio of manufacturing knowledge retrieval are proved to be greatly improved by evaluation. Thus, a practical and reliable approach based on the semantic web is provided for solving the correlated concrete problems in regional networked manufacturing.
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.
文摘The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.
文摘This book is greatly appreciated for its collection of various innovative activities which could be applied in different levels of technology-savvy classrooms.It is regarded as guidance to show paths for language educators to teach in digital age,although most of the teachers today are digital immigrants who "have become fascinated by and adopted many,or most aspects of the new technology are,and always will be compared to them"(Prensky,2001).They have to attempt to equip themselves with the knowledge of new media,which aims to provide the current students with their needs to become fully literate in this digital age.However,when the Internet began to arrive in schools,it was embraced by educators already seasoned in the challenges of change.
文摘Two significant issues in Internet-based networked control systems （ INCSs）, transport performance of different protocols and security breach from Internet side, are investigated. First, for improving the performance of data transmission, user datagram protocol （UDP） is adopted as the main stand for controllers and plants using INCSs. Second, a dual-channel secure transmission scheme （DCSTS）based on data transmission characteristics of INCSs is proposed, in which a raw UDP channel and a secure TCP （transmission control protocol） connection making use of SSL/TLS （secure sockets layer/transport layer security） are included. Further, a networked control protocol （NCP） at application layer for supporting DCSTS between the controllers and plants in INCSs is designed, and it also aims at providing a universal communication mechanism for interoperability of devices among the networked control laboratories in Beijing Institute of Technology of China, Central South University of China and Tokyo University of Technology of Japan. By means of a networked single-degree-of-free- dom robot arm, an INCS under the new protocol and security environment is created. Compared with systems such as IPSec or SSL/TLS, which may cause more than 91% network throughput deduction, the new DCSTS protocol may yield results ten times better, being just 5.67%.
