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
Dear Editor,This letter presents an improved repetitive controller(IRC) that uses a complex-coefficient filter to enhance the tracking performance of a system for periodic signals. Compared with the low-pass filter us...Dear Editor,This letter presents an improved repetitive controller(IRC) that uses a complex-coefficient filter to enhance the tracking performance of a system for periodic signals. Compared with the low-pass filter used in the conventional repetitive controller(CRC), the complex-coefficient filter causes less change in the phase and amplitude of a signal at the frequencies of the periodic signal, especially at the fundamental frequency, when the two filters have the same cutofffrequency.展开更多
It’s possible for malicious operators to seize hold of electrical control systems, for instance, the engine control unit of driverless vehicles, from various vectors, e.g. autonomic control system, remote vehicle acc...It’s possible for malicious operators to seize hold of electrical control systems, for instance, the engine control unit of driverless vehicles, from various vectors, e.g. autonomic control system, remote vehicle access, or human drivers. To mitigate potential risks, this paper provides the inauguration study by proposing a theoretical framework in the physical, human and cyber triad. Its goal is to, at each time point, detect adversary control behaviors and protect control systems against malicious operations via integrating a variety of methods. This paper only proposes a theoretical framework which tries to indicate possible threats. With the support of the framework, the security system can lightly reduce the risk. The development and implementation of the system are out of scope.展开更多
In view of the deficiencies in aspects such as failure rate requirements and analysis assumptions of advisory circular,this paper investigates the sources of high safety requirements,and the top-down design method for...In view of the deficiencies in aspects such as failure rate requirements and analysis assumptions of advisory circular,this paper investigates the sources of high safety requirements,and the top-down design method for the flight control system life cycle.Correspondingly,measures are proposed,including enhancing the safety target value to 10^(−10)per flight hour and implementing development assurance.In view of the shortcomings of mainstream aircraft flight control systems,such as weak backup capability and complex fault reconfiguration logic,improvements have been made to the system’s operating modes,control channel allocation,and common mode failure mitigation schemes based on the existing flight control architecture.The flight control design trends and philosophies have been analyzed.A flight control system architecture scheme is proposed,which includes three operating modes and multi-level voters/monitors,three main control channels,and a backup system independent of the main control system,which has been confirmed through functional modeling simulations.The proposed method plays an important role in the architecture design of safety-critical flight control system.展开更多
Addressing issues such as the disconnect between theory and practice and low student engagement in control system education,this paper uses the course“The Working Process of Open-Loop Control Systems”as a case study...Addressing issues such as the disconnect between theory and practice and low student engagement in control system education,this paper uses the course“The Working Process of Open-Loop Control Systems”as a case study to explore the integration of AI technology with the“project-guided and task-driven”teaching model.By constructing a four-dimensional teaching framework of“situation-task-activity-evaluation,”AI tools are embedded in project practices such as the construction of a mechanical timed flower watering device and the optimization of a digital timed flower watering device,achieving precision,interactivity,and personalization in the teaching process.Teaching practice demonstrates that this model significantly enhances students’technical awareness,materialization capabilities,and engineering thinking,providing a reference for the teaching reform of technical courses in high school education.展开更多
Antarctic telescopes,especially those located at Dome A,face significant reliability challenges owing to the extremely harsh working environment,among which the reliability of the control system is critical in ensurin...Antarctic telescopes,especially those located at Dome A,face significant reliability challenges owing to the extremely harsh working environment,among which the reliability of the control system is critical in ensuring stable operation.This paper describes various factors affecting the reliability of Antarctic telescopes,as well as the challenges of reliability improvement.Combined with the development of Antarctic telescopes and the experience of Antarctic scientific expeditions,we introduce,in detail,the optimization strategy for reliability enhancement,including the hardware layer,software layer,modular design to facilitate maintenance,and reliability management.The current status of the Antarctic Survey Telescope(AST3)is also briefly introduced,along with future development plans.We aim to provide ideas for the reliability design of Antarctic telescopes and provide technical support for the development of future Antarctic telescopes.展开更多
Aiming at the problems of poor adaptability and insufficient fault prediction of traditional mechanical automation control systems in complex working conditions,a mechanical automation control system based on artifici...Aiming at the problems of poor adaptability and insufficient fault prediction of traditional mechanical automation control systems in complex working conditions,a mechanical automation control system based on artificial intelligence is designed.This design integrates expert control,fuzzy control,and neural network control technologies,and builds a hierarchical distributed architecture.Fault warning adopts threshold judgment and dynamic time warping pattern recognition technologies,and state monitoring realizes accurate analysis through multi-source data fusion and Kalman filtering algorithm.Practical applications show that this system can reduce the equipment failure rate by more than 30%.With the help of intelligent scheduling optimization,it can significantly improve production efficiency and reduce energy consumption,providing a reliable technical solution and practical path for the intelligent upgrade of the mechanical automation field.展开更多
Aquila Optimizer(AO)is a recently proposed population-based optimization technique inspired by Aquila’s behavior in catching prey.AO is applied in various applications and its numerous variants were proposed in the l...Aquila Optimizer(AO)is a recently proposed population-based optimization technique inspired by Aquila’s behavior in catching prey.AO is applied in various applications and its numerous variants were proposed in the literature.However,chaos theory has not been extensively investigated in AO.Moreover,it is still not applied in the parameter estimation of electro-hydraulic systems.In this work,ten well-defined chaotic maps were integrated into a narrowed exploitation of AO for the development of a robust chaotic optimization technique.An extensive investigation of twenty-three mathematical benchmarks and ten IEEE Congress on Evolutionary Computation(CEC)functions shows that chaotic Aquila optimization techniques perform better than the baseline technique.The investigation is further conducted on parameter estimation of an electro-hydraulic control system,which is performed on various noise levels and shows that the proposed chaotic AO with Piecewise map(CAO6)achieves the best fitness values of and at noise levels and respectively.Friedman test 2.873E-05,1.014E-04,8.728E-031.300E-03,1.300E-02,1.300E-01,for repeated measures,computational analysis,and Taguchi test reflect the superiority of CAO6 against the state of the arts,demonstrating its potential for addressing various engineering optimization problems.However,the sensitivity to parameter tuning may limit its direct application to complex optimization scenarios.展开更多
With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling an...With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft,addressing the challenges associated with mode switching.First,we analyze the functional architecture and operational characteristics of multi-mode EHA,and sumarize the operating modes and implementation methods.Based on the EHA system architecture,we then develop a theoretical mathematical model and a simulation model.Using the simulation model,we analyze the performance of the EHA during normal operation.Finally,the performance of the EHA during mode switching under various functional switching scenarios is investigated.The results indicate that the EHA meets the performance requirements in terms of accuracy,bandwidth,and load capacity.Additionally,the hydraulic cylinder operates smoothly during the EHA mode switching,and the response time for switching between different modes is less than the specified threshold.These findings validate the system performance of multi-mode EHA,which helps to improve the reliability of EHA and the safety of aircraft flight control systems.展开更多
With the acceleration of urbanization and the increasing number of high-rise buildings,elevators,as key equipment for vertical transportation,have attracted significant attention regarding the safety,reliability,and e...With the acceleration of urbanization and the increasing number of high-rise buildings,elevators,as key equipment for vertical transportation,have attracted significant attention regarding the safety,reliability,and efficiency of their operation.This design develops a four-floor elevator control system based on S7-200PLC.It realizes the following functions:the second and third floors support both upward and downward request functions(with corresponding indicator lights turning on),the first floor only supports the upward request function,and the fourth floor only supports the downward request function.Meanwhile,the elevator automatically opens its door after arriving at each floor and closes the door automatically 6 seconds later.The design aims to achieve precise control and efficient operation of the elevator.展开更多
Micro/nanorobots have exhibited excellent application potential in the biomedical field,such as drug delivery,minimally invasive surgery,and bio-sensing.Furthermore,in order to achieve practical application,it is esse...Micro/nanorobots have exhibited excellent application potential in the biomedical field,such as drug delivery,minimally invasive surgery,and bio-sensing.Furthermore,in order to achieve practical application,it is essential for swimming micro/nanorobots to navigate towards specific targets or adjust their speed and morphology in complete environments.The navigation of swimming micro/nanorobots with temporal and spatial precision is critical for fulfilling the demand of applications.Here,we introduced a fully integrated wearable control system for micro/nanorobots navigation and manipulation,which is composed of a multifunctional sensor array,an artificial intelligence(AI)planner,and a magnetic field generator.The sensor array could perceive real-time changes in gestures,wrist rotation,and acoustic signals.AI planner based on machine learning offers adaptive path planning in response to dynamically changing signals to generate magnetic fields for the on-demand manipulation of micro/nanorobots.Such a novel,feasible control strategy was validated in the biological experiment in which cancer cells were targeted and killed by photothermal therapy using micro/nanorobots and integrated control platform.This wearable control system could play a crucial role in future intelligent medical applications and could be easily reconfigured toward other medical robots’control.展开更多
With the integration of informatization and intelligence into the Communication-Based Train Control(CBTC)systems,the system is facing an increasing number of information security threats.As an important method of char...With the integration of informatization and intelligence into the Communication-Based Train Control(CBTC)systems,the system is facing an increasing number of information security threats.As an important method of characterizing the system security status,the security situation assessment is used to analyze the system security situation.However,existing situation assessment methods fail to integrate the coupling relationship between the physical layer and the information layer of the CBTC systems,and cannot dynamically characterize the real-time security situation changes under cyber attacks.In this paper,a hierarchical security situation assessment approach is proposed to address the security challenges of CBTC systems,which can perceive cyber attacks,quantify the security situation,and characterize the security situation changes under cyber attacks.Specifically,for the physical layer ofCBTC systems,the impact of cyber attacks is evaluated with the train punctuality rate and train departure interval indicators.For the information layer of CBTC systems,the system vulnerabilities and system threats are selected as static level indicators,and the critical network characteristics are selected as dynamic level indicators to quantify the real-time security situation.Finally,the comprehensive security situation assessment value of the CBTC systems is obtained by integrating the physical and information layer indicators.Simulation results illustrate that the proposed approach can dynamically characterize the real-time security situation of CBTC systems,enhancing the ability to perceive and assess information security risks.展开更多
Compared to other energy sources,nuclear reactors offer several advantages as a spacecraft power source,including compact size,high power density,and long operating life.These qualities make nuclear power an ideal ene...Compared to other energy sources,nuclear reactors offer several advantages as a spacecraft power source,including compact size,high power density,and long operating life.These qualities make nuclear power an ideal energy source for future deep space exploration.A whole system model of the space nuclear reactor consisting of the reactor neutron kinetics,reactivity control,reactor heat transfer,heat exchanger,and thermoelectric converter was developed.In addition,an electrical power control system was designed based on the developed dynamic model.The GRS method was used to quantitatively calculate the uncertainty of coupling parameters of the neutronics,thermal-hydraulics,and control system for the space reactor.The Spearman correlation coefficient was applied in the sensitivity analysis of system input parameters to output parameters.The calculation results showed that the uncertainty of the output parameters caused by coupling parameters had the most considerable variation,with a relative standard deviation<2.01%.Effective delayed neutron fraction was most sensitive to electrical power.To obtain optimal control performance,the non-dominated sorting genetic algorithm method was employed to optimize the controller parameters based on the uncertainty quantification calculation.Two typical transient simulations were conducted to test the adaptive ability of the optimized controller in the uncertainty dynamic system,including 100%full power(FP)to 90%FP step load reduction transient and 5%FP/min linear variable load transient.The results showed that,considering the influence of system uncertainty,the optimized controller could improve the response speed and load following accuracy of electrical power control,in which the effectiveness and superiority have been verified.展开更多
This paper presents a thermophysical study approach for a pure environmental control system(ECS),incorporating the geometric dimensions of heat exchangers,ram air duct,and air cycle machine(ACM)blades of the Sabreline...This paper presents a thermophysical study approach for a pure environmental control system(ECS),incorporating the geometric dimensions of heat exchangers,ram air duct,and air cycle machine(ACM)blades of the Sabreliner’s environmental control system.Real flight scenarios are simulated by considering flight input variables such as altitude,aircraft speed,compression ratio of the air cycle machine,and the mass flow rate of bleed air.The study evaluates the coefficient of performance(COP)of the environmental control system,the heat exchanger efficiencies,and the work distribution of the air cycle machine based on five flight scenarios,with a particular focus on considering the effects of humidity on environmental control system performance.The results demonstrate that at cruising altitude(11,000 m),air humidity conditions allow an increase in the COP of around 9.28%compared to dry conditions.Conversely,on land,humidity conditions reduce the performance by 4.26%compared to dry conditions.It was also found that the effects of humidity at high aircraft speeds become negligible.In general terms,the humidity conditions in the air proved to have positive effects on the environmental control system’s performance but negative effects on the heat exchanger efficiencies,reducing them by 0.22%.Additionally,land conditions reflect significant improvements in performance when the compression ratio of the air cycle machine is varied.Furthermore,in the work distribution of the air cycle machine,humidity conditions were demonstrated to consume 2.91%less work fromthe turbine compared to dry conditions.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
In the production processes of modern industry,accurate assessment of the system’s health state and traceability non-optimal factors are key to ensuring“safe,stable,long-term,full load and optimal”operation of the ...In the production processes of modern industry,accurate assessment of the system’s health state and traceability non-optimal factors are key to ensuring“safe,stable,long-term,full load and optimal”operation of the production process.The benzene-to-ethylene ratio control system is a complex system based on anMPC-PID doublelayer architecture.Taking into consideration the interaction between levels,coupling between loops and conditions of incomplete operation data,this paper proposes a health assessment method for the dual-layer control system by comprehensively utilizing deep learning technology.Firstly,according to the results of the pre-assessment of the system layers and loops bymultivariate statisticalmethods,seven characteristic parameters that have a significant impact on the health state of the system are identified.Next,aiming at the problem of incomplete assessment data set due to the uneven distribution of actual system operating health state,the original unbalanced dataset is augmented using aWasserstein generative adversarial network with gradient penalty term,and a complete dataset is obtained to characterise all the health states of the system.On this basis,a new deep learning-based health assessment framework for the benzeneto-ethylene ratio control system is constructed based on traditionalmultivariate statistical assessment.This framework can overcome the shortcomings of the linear weighted fusion related to the coupling and nonlinearity of the subsystem health state at different layers,and reduce the dependence of the prior knowledge.Furthermore,by introducing a dynamic attention mechanism(AM)into the convolutional neural network(CNN),the assessment model integrating both assessment and traceability is constructed,which can achieve the health assessment and trace the non-optimal factors of the complex control systems with the double-layer architecture.Finally,the effectiveness and superiority of the proposed method have been verified by the benzene-ethylene ratio control system of the alkylation process unit in a styrene plant.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
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
With the gradual development of smart power plants and large-scale centralized control,there is a need to exchange a large number of signals between different DCS systems and between DCS and PLC systems.Different cont...With the gradual development of smart power plants and large-scale centralized control,there is a need to exchange a large number of signals between different DCS systems and between DCS and PLC systems.Different control systems have different brands and cannot communicate directly via networks.Moreover,due to network security concerns,the main control of unit units and the auxiliary control system of the entire plant cannot communicate directly via networks either.The commonly adopted methods for signal exchange between control systems are hardwiring and 485 communications.Both have obvious drawbacks,where hardwiring requires a large number of channels and cable laying;485 configuration is difficult,not easy to maintain,and faults are hard to locate.This paper studies how to strike a balance between the two,using a minimal amount of hardwiring to transmit a large number of signals,which is safe,reliable,cost-effective,and can be maintained by any control personnel without network security risks.展开更多
This phenomenological qualitative study explored the lived experiences of employees at Maryland's Historically Black Colleges and Universities(HBCUs)concerning internal control systems through the theoretical lens...This phenomenological qualitative study explored the lived experiences of employees at Maryland's Historically Black Colleges and Universities(HBCUs)concerning internal control systems through the theoretical lenses of the COSO framework and employee engagement theory.Using semi-structured interviews with faculty and staff who had worked at the institution for more than three years,the research investigated how employees perceive leadership tone,risk assessment processes,policy implementation,communication channels,and evaluation mechanisms related to internal controls.The study revealed five major themes that characterize employee experiences with internal control systems at this HBCU.Leadership communication was found to be hierarchical but inclusive,though marked by inconsistent communication of ethical values and significant resource constraints affecting implementation.Risk management practices were predominantly reactive rather than proactive,with limited systematic risk assessment processes that focused more on academic risks than operational vulnerabilities.Policy implementation was characterized by unclear separation of duties,substantial workload imbalances,and limited resources that compromised effective control activities.Communication challenges emerged as a critical weakness,with participants describing information sharing as inconsistent,unclear,and selective,compounded by significant technology obstacles in accessing necessary information.The evaluation and improvement processes were found to be limited and primarily driven by external accreditation requirements rather than systematic internal monitoring,resulting in reactive responses to issues rather than proactive enhancement.The findings contribute to the limited research on internal control systems within HBCUs by providing phenomenological insights into how structural constraints including funding limitations,unclear role delineation,and reactive management approaches create barriers to implementing robust internal control systems.Despite institutional commitment to inclusive leadership and student success,the study reveals that addressing these challenges requires not only increased resources but also structural changes to workload distribution,communication practices,and a shift toward more proactive risk management and monitoring procedures.The research provides evidence-based insights for HBCU administrators seeking to strengthen internal control implementation while maintaining institutional mission and cultural values.展开更多
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 the National Natural Science Foundation of China(61873348,6230 3266,62273200)JSPS(Japan Society for the Promotion of Science) KAKENHI(22H03998,23K25252)
文摘Dear Editor,This letter presents an improved repetitive controller(IRC) that uses a complex-coefficient filter to enhance the tracking performance of a system for periodic signals. Compared with the low-pass filter used in the conventional repetitive controller(CRC), the complex-coefficient filter causes less change in the phase and amplitude of a signal at the frequencies of the periodic signal, especially at the fundamental frequency, when the two filters have the same cutofffrequency.
文摘It’s possible for malicious operators to seize hold of electrical control systems, for instance, the engine control unit of driverless vehicles, from various vectors, e.g. autonomic control system, remote vehicle access, or human drivers. To mitigate potential risks, this paper provides the inauguration study by proposing a theoretical framework in the physical, human and cyber triad. Its goal is to, at each time point, detect adversary control behaviors and protect control systems against malicious operations via integrating a variety of methods. This paper only proposes a theoretical framework which tries to indicate possible threats. With the support of the framework, the security system can lightly reduce the risk. The development and implementation of the system are out of scope.
文摘In view of the deficiencies in aspects such as failure rate requirements and analysis assumptions of advisory circular,this paper investigates the sources of high safety requirements,and the top-down design method for the flight control system life cycle.Correspondingly,measures are proposed,including enhancing the safety target value to 10^(−10)per flight hour and implementing development assurance.In view of the shortcomings of mainstream aircraft flight control systems,such as weak backup capability and complex fault reconfiguration logic,improvements have been made to the system’s operating modes,control channel allocation,and common mode failure mitigation schemes based on the existing flight control architecture.The flight control design trends and philosophies have been analyzed.A flight control system architecture scheme is proposed,which includes three operating modes and multi-level voters/monitors,three main control channels,and a backup system independent of the main control system,which has been confirmed through functional modeling simulations.The proposed method plays an important role in the architecture design of safety-critical flight control system.
文摘Addressing issues such as the disconnect between theory and practice and low student engagement in control system education,this paper uses the course“The Working Process of Open-Loop Control Systems”as a case study to explore the integration of AI technology with the“project-guided and task-driven”teaching model.By constructing a four-dimensional teaching framework of“situation-task-activity-evaluation,”AI tools are embedded in project practices such as the construction of a mechanical timed flower watering device and the optimization of a digital timed flower watering device,achieving precision,interactivity,and personalization in the teaching process.Teaching practice demonstrates that this model significantly enhances students’technical awareness,materialization capabilities,and engineering thinking,providing a reference for the teaching reform of technical courses in high school education.
基金supported by the National Natural Science Foundation of China (12303089, 11973065)the Jiangsu Funding Program for Excellent Postdoctoral Talent (2022ZB449)the Polar Research Institute of China (PRIC) for their support and help with the Antarctic telescope project
文摘Antarctic telescopes,especially those located at Dome A,face significant reliability challenges owing to the extremely harsh working environment,among which the reliability of the control system is critical in ensuring stable operation.This paper describes various factors affecting the reliability of Antarctic telescopes,as well as the challenges of reliability improvement.Combined with the development of Antarctic telescopes and the experience of Antarctic scientific expeditions,we introduce,in detail,the optimization strategy for reliability enhancement,including the hardware layer,software layer,modular design to facilitate maintenance,and reliability management.The current status of the Antarctic Survey Telescope(AST3)is also briefly introduced,along with future development plans.We aim to provide ideas for the reliability design of Antarctic telescopes and provide technical support for the development of future Antarctic telescopes.
文摘Aiming at the problems of poor adaptability and insufficient fault prediction of traditional mechanical automation control systems in complex working conditions,a mechanical automation control system based on artificial intelligence is designed.This design integrates expert control,fuzzy control,and neural network control technologies,and builds a hierarchical distributed architecture.Fault warning adopts threshold judgment and dynamic time warping pattern recognition technologies,and state monitoring realizes accurate analysis through multi-source data fusion and Kalman filtering algorithm.Practical applications show that this system can reduce the equipment failure rate by more than 30%.With the help of intelligent scheduling optimization,it can significantly improve production efficiency and reduce energy consumption,providing a reliable technical solution and practical path for the intelligent upgrade of the mechanical automation field.
基金funded by Taif University,Saudi Arabia,Project No.(TU-DSPP-2024-52).
文摘Aquila Optimizer(AO)is a recently proposed population-based optimization technique inspired by Aquila’s behavior in catching prey.AO is applied in various applications and its numerous variants were proposed in the literature.However,chaos theory has not been extensively investigated in AO.Moreover,it is still not applied in the parameter estimation of electro-hydraulic systems.In this work,ten well-defined chaotic maps were integrated into a narrowed exploitation of AO for the development of a robust chaotic optimization technique.An extensive investigation of twenty-three mathematical benchmarks and ten IEEE Congress on Evolutionary Computation(CEC)functions shows that chaotic Aquila optimization techniques perform better than the baseline technique.The investigation is further conducted on parameter estimation of an electro-hydraulic control system,which is performed on various noise levels and shows that the proposed chaotic AO with Piecewise map(CAO6)achieves the best fitness values of and at noise levels and respectively.Friedman test 2.873E-05,1.014E-04,8.728E-031.300E-03,1.300E-02,1.300E-01,for repeated measures,computational analysis,and Taguchi test reflect the superiority of CAO6 against the state of the arts,demonstrating its potential for addressing various engineering optimization problems.However,the sensitivity to parameter tuning may limit its direct application to complex optimization scenarios.
基金supported by the Chinese Civil Aircraft Project(No.MJ-2017-S49).
文摘With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft,addressing the challenges associated with mode switching.First,we analyze the functional architecture and operational characteristics of multi-mode EHA,and sumarize the operating modes and implementation methods.Based on the EHA system architecture,we then develop a theoretical mathematical model and a simulation model.Using the simulation model,we analyze the performance of the EHA during normal operation.Finally,the performance of the EHA during mode switching under various functional switching scenarios is investigated.The results indicate that the EHA meets the performance requirements in terms of accuracy,bandwidth,and load capacity.Additionally,the hydraulic cylinder operates smoothly during the EHA mode switching,and the response time for switching between different modes is less than the specified threshold.These findings validate the system performance of multi-mode EHA,which helps to improve the reliability of EHA and the safety of aircraft flight control systems.
基金College Students’Innovation and Entrepreneurship Training Program of Jinzhong University。
文摘With the acceleration of urbanization and the increasing number of high-rise buildings,elevators,as key equipment for vertical transportation,have attracted significant attention regarding the safety,reliability,and efficiency of their operation.This design develops a four-floor elevator control system based on S7-200PLC.It realizes the following functions:the second and third floors support both upward and downward request functions(with corresponding indicator lights turning on),the first floor only supports the upward request function,and the fourth floor only supports the downward request function.Meanwhile,the elevator automatically opens its door after arriving at each floor and closes the door automatically 6 seconds later.The design aims to achieve precise control and efficient operation of the elevator.
基金supported by the National Key Research and Development Program(2022YFB4701700)National Excellent Youth Science Fund Project of the National Natural Science Foundation of China(52322502)+6 种基金the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(52025054)National Natural Science Foundation of China(52175009),Postdoctoral Fellowship Program of CPSF(GZC20232498)Postdoctoral Innovative Talents in Shandong Province(SDBX2023011)China Postdoctoral Science Foundation Grant(2023M733341)Key R&D Program of Shandong Province,China(2021ZLGX04)National Heilongjiang Providence Nature Science Foundation of China(YQ2022E022)Fundamental Research Funds for the Central Universities。
文摘Micro/nanorobots have exhibited excellent application potential in the biomedical field,such as drug delivery,minimally invasive surgery,and bio-sensing.Furthermore,in order to achieve practical application,it is essential for swimming micro/nanorobots to navigate towards specific targets or adjust their speed and morphology in complete environments.The navigation of swimming micro/nanorobots with temporal and spatial precision is critical for fulfilling the demand of applications.Here,we introduced a fully integrated wearable control system for micro/nanorobots navigation and manipulation,which is composed of a multifunctional sensor array,an artificial intelligence(AI)planner,and a magnetic field generator.The sensor array could perceive real-time changes in gestures,wrist rotation,and acoustic signals.AI planner based on machine learning offers adaptive path planning in response to dynamically changing signals to generate magnetic fields for the on-demand manipulation of micro/nanorobots.Such a novel,feasible control strategy was validated in the biological experiment in which cancer cells were targeted and killed by photothermal therapy using micro/nanorobots and integrated control platform.This wearable control system could play a crucial role in future intelligent medical applications and could be easily reconfigured toward other medical robots’control.
基金supported in part by the project of the State Key Laboratory of Advanced Rail Autonomous Operation(RAO2023ZZ004)in part by the Beijing Natural Science Foundation-Fengtai Rail Transit Frontier Research Joint Fund(L211002)+2 种基金in part by the Foundation of China State Railway Group Corporation Limited under Grant L2021G003in part by the Scientific and Technical Research Fund of China Academy of Railway Sciences Corporation Limited under Grant 2021YJ094in part by the Project I23L00200 and Project I24F00010.
文摘With the integration of informatization and intelligence into the Communication-Based Train Control(CBTC)systems,the system is facing an increasing number of information security threats.As an important method of characterizing the system security status,the security situation assessment is used to analyze the system security situation.However,existing situation assessment methods fail to integrate the coupling relationship between the physical layer and the information layer of the CBTC systems,and cannot dynamically characterize the real-time security situation changes under cyber attacks.In this paper,a hierarchical security situation assessment approach is proposed to address the security challenges of CBTC systems,which can perceive cyber attacks,quantify the security situation,and characterize the security situation changes under cyber attacks.Specifically,for the physical layer ofCBTC systems,the impact of cyber attacks is evaluated with the train punctuality rate and train departure interval indicators.For the information layer of CBTC systems,the system vulnerabilities and system threats are selected as static level indicators,and the critical network characteristics are selected as dynamic level indicators to quantify the real-time security situation.Finally,the comprehensive security situation assessment value of the CBTC systems is obtained by integrating the physical and information layer indicators.Simulation results illustrate that the proposed approach can dynamically characterize the real-time security situation of CBTC systems,enhancing the ability to perceive and assess information security risks.
基金supported by the National Natural Science Foundation of China(12305185)Natural Science Foundation of Hunan Province,China(No.2023JJ50122)+1 种基金International Cooperative Research Project of the Ministry of Education,China(No.HZKY20220355)Scientific Research Foundation of the Education Department of Hunan Province,China(No.22A0307).
文摘Compared to other energy sources,nuclear reactors offer several advantages as a spacecraft power source,including compact size,high power density,and long operating life.These qualities make nuclear power an ideal energy source for future deep space exploration.A whole system model of the space nuclear reactor consisting of the reactor neutron kinetics,reactivity control,reactor heat transfer,heat exchanger,and thermoelectric converter was developed.In addition,an electrical power control system was designed based on the developed dynamic model.The GRS method was used to quantitatively calculate the uncertainty of coupling parameters of the neutronics,thermal-hydraulics,and control system for the space reactor.The Spearman correlation coefficient was applied in the sensitivity analysis of system input parameters to output parameters.The calculation results showed that the uncertainty of the output parameters caused by coupling parameters had the most considerable variation,with a relative standard deviation<2.01%.Effective delayed neutron fraction was most sensitive to electrical power.To obtain optimal control performance,the non-dominated sorting genetic algorithm method was employed to optimize the controller parameters based on the uncertainty quantification calculation.Two typical transient simulations were conducted to test the adaptive ability of the optimized controller in the uncertainty dynamic system,including 100%full power(FP)to 90%FP step load reduction transient and 5%FP/min linear variable load transient.The results showed that,considering the influence of system uncertainty,the optimized controller could improve the response speed and load following accuracy of electrical power control,in which the effectiveness and superiority have been verified.
文摘This paper presents a thermophysical study approach for a pure environmental control system(ECS),incorporating the geometric dimensions of heat exchangers,ram air duct,and air cycle machine(ACM)blades of the Sabreliner’s environmental control system.Real flight scenarios are simulated by considering flight input variables such as altitude,aircraft speed,compression ratio of the air cycle machine,and the mass flow rate of bleed air.The study evaluates the coefficient of performance(COP)of the environmental control system,the heat exchanger efficiencies,and the work distribution of the air cycle machine based on five flight scenarios,with a particular focus on considering the effects of humidity on environmental control system performance.The results demonstrate that at cruising altitude(11,000 m),air humidity conditions allow an increase in the COP of around 9.28%compared to dry conditions.Conversely,on land,humidity conditions reduce the performance by 4.26%compared to dry conditions.It was also found that the effects of humidity at high aircraft speeds become negligible.In general terms,the humidity conditions in the air proved to have positive effects on the environmental control system’s performance but negative effects on the heat exchanger efficiencies,reducing them by 0.22%.Additionally,land conditions reflect significant improvements in performance when the compression ratio of the air cycle machine is varied.Furthermore,in the work distribution of the air cycle machine,humidity conditions were demonstrated to consume 2.91%less work fromthe turbine compared to dry conditions.
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 National Science Foundation of China(62263020)the Key Project of Natural Science Foundation of Gansu Province(25JRRA061)+1 种基金the Key R&D Program of Gansu Province(23YFGA0061)the Scientific Research Initiation Fund of Lanzhou University of Technology(061602).
文摘In the production processes of modern industry,accurate assessment of the system’s health state and traceability non-optimal factors are key to ensuring“safe,stable,long-term,full load and optimal”operation of the production process.The benzene-to-ethylene ratio control system is a complex system based on anMPC-PID doublelayer architecture.Taking into consideration the interaction between levels,coupling between loops and conditions of incomplete operation data,this paper proposes a health assessment method for the dual-layer control system by comprehensively utilizing deep learning technology.Firstly,according to the results of the pre-assessment of the system layers and loops bymultivariate statisticalmethods,seven characteristic parameters that have a significant impact on the health state of the system are identified.Next,aiming at the problem of incomplete assessment data set due to the uneven distribution of actual system operating health state,the original unbalanced dataset is augmented using aWasserstein generative adversarial network with gradient penalty term,and a complete dataset is obtained to characterise all the health states of the system.On this basis,a new deep learning-based health assessment framework for the benzeneto-ethylene ratio control system is constructed based on traditionalmultivariate statistical assessment.This framework can overcome the shortcomings of the linear weighted fusion related to the coupling and nonlinearity of the subsystem health state at different layers,and reduce the dependence of the prior knowledge.Furthermore,by introducing a dynamic attention mechanism(AM)into the convolutional neural network(CNN),the assessment model integrating both assessment and traceability is constructed,which can achieve the health assessment and trace the non-optimal factors of the complex control systems with the double-layer architecture.Finally,the effectiveness and superiority of the proposed method have been verified by the benzene-ethylene ratio control system of the alkylation process unit in a styrene plant.
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 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.
文摘With the gradual development of smart power plants and large-scale centralized control,there is a need to exchange a large number of signals between different DCS systems and between DCS and PLC systems.Different control systems have different brands and cannot communicate directly via networks.Moreover,due to network security concerns,the main control of unit units and the auxiliary control system of the entire plant cannot communicate directly via networks either.The commonly adopted methods for signal exchange between control systems are hardwiring and 485 communications.Both have obvious drawbacks,where hardwiring requires a large number of channels and cable laying;485 configuration is difficult,not easy to maintain,and faults are hard to locate.This paper studies how to strike a balance between the two,using a minimal amount of hardwiring to transmit a large number of signals,which is safe,reliable,cost-effective,and can be maintained by any control personnel without network security risks.
文摘This phenomenological qualitative study explored the lived experiences of employees at Maryland's Historically Black Colleges and Universities(HBCUs)concerning internal control systems through the theoretical lenses of the COSO framework and employee engagement theory.Using semi-structured interviews with faculty and staff who had worked at the institution for more than three years,the research investigated how employees perceive leadership tone,risk assessment processes,policy implementation,communication channels,and evaluation mechanisms related to internal controls.The study revealed five major themes that characterize employee experiences with internal control systems at this HBCU.Leadership communication was found to be hierarchical but inclusive,though marked by inconsistent communication of ethical values and significant resource constraints affecting implementation.Risk management practices were predominantly reactive rather than proactive,with limited systematic risk assessment processes that focused more on academic risks than operational vulnerabilities.Policy implementation was characterized by unclear separation of duties,substantial workload imbalances,and limited resources that compromised effective control activities.Communication challenges emerged as a critical weakness,with participants describing information sharing as inconsistent,unclear,and selective,compounded by significant technology obstacles in accessing necessary information.The evaluation and improvement processes were found to be limited and primarily driven by external accreditation requirements rather than systematic internal monitoring,resulting in reactive responses to issues rather than proactive enhancement.The findings contribute to the limited research on internal control systems within HBCUs by providing phenomenological insights into how structural constraints including funding limitations,unclear role delineation,and reactive management approaches create barriers to implementing robust internal control systems.Despite institutional commitment to inclusive leadership and student success,the study reveals that addressing these challenges requires not only increased resources but also structural changes to workload distribution,communication practices,and a shift toward more proactive risk management and monitoring procedures.The research provides evidence-based insights for HBCU administrators seeking to strengthen internal control implementation while maintaining institutional mission and cultural values.
