The optical storage microgrid system composed of power electronic converters is a small inertia system.Load switching and power supply intermittent will affect the stability of the direct current(DC)bus voltage.Aiming...The optical storage microgrid system composed of power electronic converters is a small inertia system.Load switching and power supply intermittent will affect the stability of the direct current(DC)bus voltage.Aiming at this problem,a virtual inertia optimal control strategy applied to optical storage microgrid is proposed.Firstly,a small signal model of the system is established to theoretically analyze the influence of virtual inertia and damping coefficient on DC bus voltage and to obtain the constraint range of virtual inertia and damping coefficient;Secondly,aiming at the defect that the Sailfish optimization algorithm is easy to premature maturity,a Sailfish optimization algorithm based on the leak-proof net and the cross-mutation propagation mechanism is proposed;Finally,the virtual inertia and damping coefficient of the system are optimized by the improved Sailfish algorithm to obtain the best control parameters.The simulation results in Matlab/Simulink show that the virtual inertia control optimized by the improved Sailfish algorithm improves the system inertia as well as the dynamic response and robustness of the DC bus voltage.展开更多
According to these characteristics of the movement of the special platform servo,a new improved grey predictive PID control algorithm was proposed based on the grey predictive PID,and then the algorithm was simulated ...According to these characteristics of the movement of the special platform servo,a new improved grey predictive PID control algorithm was proposed based on the grey predictive PID,and then the algorithm was simulated by MATLAB.As a result that it can improve the response speed and stability of the system,and meet the demand of the system.展开更多
Energy conservation and congestion control are widely researched topics in Wireless Sensor Networks in recent years. The main objective is to develop a model to find the optimized path on the basis of distance between...Energy conservation and congestion control are widely researched topics in Wireless Sensor Networks in recent years. The main objective is to develop a model to find the optimized path on the basis of distance between source and destination and the residual energy of the node. This paper shows an implementation of nature inspired improved Bat Algorithm to control congestion in Wireless Sensor Networks at transport layer. The Algorithm has been applied on the fitness function to obtain an optimum solution. Simulation results have shown improvement in parameters like network lifetime and throughput as compared with CODA (Congestion Detection and Avoidance), PSO (Particle Swarm Optimization) algorithm and ACO (Ant Colony Optimization).展开更多
The fluctuation of active power output of wind farm has many negative impacts on large-scale wind power integration into power grid. In this paper, flywheel energy storage system (FESS) was connected to AC side of the...The fluctuation of active power output of wind farm has many negative impacts on large-scale wind power integration into power grid. In this paper, flywheel energy storage system (FESS) was connected to AC side of the doubly-fed induction generator (DFIG) wind farm to realize smooth control of wind power output. Based on improved wind power prediction algorithm and wind speed-power curve modeling, a new smooth control strategy with the FESS was proposed. The requirement of power system dispatch for wind power prediction and flywheel rotor speed limit were taken into consideration during the process. While smoothing the wind power fluctuation, FESS can track short-term planned output of wind farm. It was demonstrated by quantitative analysis of simulation results that the proposed control strategy can smooth the active power fluctuation of wind farm effectively and thereby improve power quality of the power grid.展开更多
With the rapid development of software technology, software vulnerability has become a major threat to computer security. The timely detection and repair of potential vulnerabilities in software, are of great signific...With the rapid development of software technology, software vulnerability has become a major threat to computer security. The timely detection and repair of potential vulnerabilities in software, are of great significance in reducing system crashes and maintaining system security and integrity. This paper focuses on detecting three common types of vulnerabilities: Unused_Variable, Use_of_Uninitialized_Variable, and Use_After_ Free. We propose a method for software vulnerability detection based on an improved control flow graph(ICFG) and several predicates of vulnerability properties for each type of vulnerability. We also define a set of grammar rules for analyzing and deriving the three mentioned types of vulnerabilities, and design three vulnerability detection algorithms to guide the process of vulnerability detection. In addition, we conduct cases studies of the three mentioned types of vulnerabilities with real vulnerability program segments from Common Weakness Enumeration(CWE). The results of the studies show that the proposed method can detect the vulnerability in the tested program segments. Finally, we conduct manual analysis and experiments on detecting the three types of vulnerability program segments(30 examples for each type) from CWE, to compare the vulnerability detection effectiveness of the proposed method with that of the existing detection tool Cpp Check. The results show that the proposed method performs better. In summary, the method proposed in this paper has certain feasibility and effectiveness in detecting the three mentioned types of vulnerabilities, and it will also have guiding significance for the detection of other common vulnerabilities.展开更多
In this paper,a novel robust control allocation method for a control system with uncertain param-eters is proposed based on the algorithms of maximum–minimum and improved fish swarm.Based on the algorithm of maximum...In this paper,a novel robust control allocation method for a control system with uncertain param-eters is proposed based on the algorithms of maximum–minimum and improved fish swarm.Based on the algorithm of maximum–minimum,the control allocation problem with an uncer-tain allocation matrix is transformed into the definite control allocation problem;then by using an improved fish swarm algorithm,the resultant control allocation problem is solved.Finally,the simulation results show that the proposed robust control allocation method has better robust-ness to system modelling uncertainty and possesses stronger anti-interference ability than the existing control allocation methods.展开更多
The generation of electricity based on renewable energy sources,parti-cularly Photovoltaic(PV)system has been greatly increased and it is simply insti-gated for both domestic and commercial uses.The power generated fr...The generation of electricity based on renewable energy sources,parti-cularly Photovoltaic(PV)system has been greatly increased and it is simply insti-gated for both domestic and commercial uses.The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power.An improved interleaved Single-ended Primary Inductor-Converter(SEPIC)converter is employed in proposed work to extricate most of power from renewable source.This proposed converter minimizes ripples,reduces electromagnetic interference due tofilter elements and the contin-uous input current improves the power output of PV panel.A Crow Search Algo-rithm(CSA)based Proportional Integral(PI)controller is utilized for controlling the converter switches effectively by optimizing the parameters of PI controller.The optimized PI controller reduces ripples present in Direct Current(DC)vol-tage,maintains constant voltage at proposed converter output and reduces over-shoots with minimum settling and rise time.This voltage is given to single phase grid via 1�Voltage Source Inverter(VSI).The command pulses of 1�VSI are produced by simple PI controller.The response of the proposed converter is thus improved with less input current.After implementing CSA based PI the efficiency of proposed converter obtained is 96%and the Total Harmonic Distor-tion(THD)is found to be 2:4%.The dynamics and closed loop operation is designed and modeled using MATLAB Simulink tool and its behavior is performed.展开更多
In order to improve the control effect of the bearing, this article studies the temperature control technology to improve the genetic algorithm, at the same time, analyze temperature simulation of bearing based on fuz...In order to improve the control effect of the bearing, this article studies the temperature control technology to improve the genetic algorithm, at the same time, analyze temperature simulation of bearing based on fuzzy PID control technology and improved genetic algorithm, the simulation results show that, the control method has good robustness based on Improved Genetic Algorithm. It can monitor a plurality of beating temperature, provides a new method for the detection and prevention of bearing fault.展开更多
In this paper,a Novel Compliant Actuator(NCA)-driven Upper-Limb Exoskeleton(ULE)with force controllable,impact resistance,and back drivability is designed to ensure the safety of the subject during Human-Robot Interac...In this paper,a Novel Compliant Actuator(NCA)-driven Upper-Limb Exoskeleton(ULE)with force controllable,impact resistance,and back drivability is designed to ensure the safety of the subject during Human-Robot Interaction(HRI)processing.Based on the designed NCA-driven ULE,this paper constructs a Model Predictive Control Scheme(MPCS)for force trajectory tracking,which minimises future tracking errors by solving an optimal control problem with inequality constraints.In addition,an Error-Accumulation Improved Newton Algorithm(EAINA)is proposed to solve the MPCS for suppressing various noises and external disturbances.The proposed EAINA is theoretically proved to have small steady state for noise conditions and stability of the EAINA using Lyapunov method.Finally,experimental results verify that the proposed MPCS solved by the EAINA in the NCA-driven ULE achieves robustness,fast convergence,strong tolerance and stability for trajectory rehabilitation task.展开更多
基金the National Natural Science Foundation of China(52177184)。
文摘The optical storage microgrid system composed of power electronic converters is a small inertia system.Load switching and power supply intermittent will affect the stability of the direct current(DC)bus voltage.Aiming at this problem,a virtual inertia optimal control strategy applied to optical storage microgrid is proposed.Firstly,a small signal model of the system is established to theoretically analyze the influence of virtual inertia and damping coefficient on DC bus voltage and to obtain the constraint range of virtual inertia and damping coefficient;Secondly,aiming at the defect that the Sailfish optimization algorithm is easy to premature maturity,a Sailfish optimization algorithm based on the leak-proof net and the cross-mutation propagation mechanism is proposed;Finally,the virtual inertia and damping coefficient of the system are optimized by the improved Sailfish algorithm to obtain the best control parameters.The simulation results in Matlab/Simulink show that the virtual inertia control optimized by the improved Sailfish algorithm improves the system inertia as well as the dynamic response and robustness of the DC bus voltage.
基金supported by the Chongqing Scientific and Technological Innovating Program under grant CSTC2008AC1014
文摘According to these characteristics of the movement of the special platform servo,a new improved grey predictive PID control algorithm was proposed based on the grey predictive PID,and then the algorithm was simulated by MATLAB.As a result that it can improve the response speed and stability of the system,and meet the demand of the system.
文摘Energy conservation and congestion control are widely researched topics in Wireless Sensor Networks in recent years. The main objective is to develop a model to find the optimized path on the basis of distance between source and destination and the residual energy of the node. This paper shows an implementation of nature inspired improved Bat Algorithm to control congestion in Wireless Sensor Networks at transport layer. The Algorithm has been applied on the fitness function to obtain an optimum solution. Simulation results have shown improvement in parameters like network lifetime and throughput as compared with CODA (Congestion Detection and Avoidance), PSO (Particle Swarm Optimization) algorithm and ACO (Ant Colony Optimization).
文摘The fluctuation of active power output of wind farm has many negative impacts on large-scale wind power integration into power grid. In this paper, flywheel energy storage system (FESS) was connected to AC side of the doubly-fed induction generator (DFIG) wind farm to realize smooth control of wind power output. Based on improved wind power prediction algorithm and wind speed-power curve modeling, a new smooth control strategy with the FESS was proposed. The requirement of power system dispatch for wind power prediction and flywheel rotor speed limit were taken into consideration during the process. While smoothing the wind power fluctuation, FESS can track short-term planned output of wind farm. It was demonstrated by quantitative analysis of simulation results that the proposed control strategy can smooth the active power fluctuation of wind farm effectively and thereby improve power quality of the power grid.
基金Supported by the National Natural Science Foundation of China(61202110 and 61502205)the Project of Jiangsu Provincial Six Talent Peaks(XYDXXJS-016)
文摘With the rapid development of software technology, software vulnerability has become a major threat to computer security. The timely detection and repair of potential vulnerabilities in software, are of great significance in reducing system crashes and maintaining system security and integrity. This paper focuses on detecting three common types of vulnerabilities: Unused_Variable, Use_of_Uninitialized_Variable, and Use_After_ Free. We propose a method for software vulnerability detection based on an improved control flow graph(ICFG) and several predicates of vulnerability properties for each type of vulnerability. We also define a set of grammar rules for analyzing and deriving the three mentioned types of vulnerabilities, and design three vulnerability detection algorithms to guide the process of vulnerability detection. In addition, we conduct cases studies of the three mentioned types of vulnerabilities with real vulnerability program segments from Common Weakness Enumeration(CWE). The results of the studies show that the proposed method can detect the vulnerability in the tested program segments. Finally, we conduct manual analysis and experiments on detecting the three types of vulnerability program segments(30 examples for each type) from CWE, to compare the vulnerability detection effectiveness of the proposed method with that of the existing detection tool Cpp Check. The results show that the proposed method performs better. In summary, the method proposed in this paper has certain feasibility and effectiveness in detecting the three mentioned types of vulnerabilities, and it will also have guiding significance for the detection of other common vulnerabilities.
基金supported by the National Natural Science Foundation of China(61973253 and 62176214)。
文摘In this paper,a novel robust control allocation method for a control system with uncertain param-eters is proposed based on the algorithms of maximum–minimum and improved fish swarm.Based on the algorithm of maximum–minimum,the control allocation problem with an uncer-tain allocation matrix is transformed into the definite control allocation problem;then by using an improved fish swarm algorithm,the resultant control allocation problem is solved.Finally,the simulation results show that the proposed robust control allocation method has better robust-ness to system modelling uncertainty and possesses stronger anti-interference ability than the existing control allocation methods.
文摘The generation of electricity based on renewable energy sources,parti-cularly Photovoltaic(PV)system has been greatly increased and it is simply insti-gated for both domestic and commercial uses.The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power.An improved interleaved Single-ended Primary Inductor-Converter(SEPIC)converter is employed in proposed work to extricate most of power from renewable source.This proposed converter minimizes ripples,reduces electromagnetic interference due tofilter elements and the contin-uous input current improves the power output of PV panel.A Crow Search Algo-rithm(CSA)based Proportional Integral(PI)controller is utilized for controlling the converter switches effectively by optimizing the parameters of PI controller.The optimized PI controller reduces ripples present in Direct Current(DC)vol-tage,maintains constant voltage at proposed converter output and reduces over-shoots with minimum settling and rise time.This voltage is given to single phase grid via 1�Voltage Source Inverter(VSI).The command pulses of 1�VSI are produced by simple PI controller.The response of the proposed converter is thus improved with less input current.After implementing CSA based PI the efficiency of proposed converter obtained is 96%and the Total Harmonic Distor-tion(THD)is found to be 2:4%.The dynamics and closed loop operation is designed and modeled using MATLAB Simulink tool and its behavior is performed.
文摘In order to improve the control effect of the bearing, this article studies the temperature control technology to improve the genetic algorithm, at the same time, analyze temperature simulation of bearing based on fuzzy PID control technology and improved genetic algorithm, the simulation results show that, the control method has good robustness based on Improved Genetic Algorithm. It can monitor a plurality of beating temperature, provides a new method for the detection and prevention of bearing fault.
基金supported by the National Natural Science Foundation of China(Nos.62373065,61873304,62173048,and 62106023)the Key Science and Technology Projects of Jilin Province,China(No.20230204081YY).
文摘In this paper,a Novel Compliant Actuator(NCA)-driven Upper-Limb Exoskeleton(ULE)with force controllable,impact resistance,and back drivability is designed to ensure the safety of the subject during Human-Robot Interaction(HRI)processing.Based on the designed NCA-driven ULE,this paper constructs a Model Predictive Control Scheme(MPCS)for force trajectory tracking,which minimises future tracking errors by solving an optimal control problem with inequality constraints.In addition,an Error-Accumulation Improved Newton Algorithm(EAINA)is proposed to solve the MPCS for suppressing various noises and external disturbances.The proposed EAINA is theoretically proved to have small steady state for noise conditions and stability of the EAINA using Lyapunov method.Finally,experimental results verify that the proposed MPCS solved by the EAINA in the NCA-driven ULE achieves robustness,fast convergence,strong tolerance and stability for trajectory rehabilitation task.
