Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,lead...Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,leading to greater waste of communication resources.In response to this problem,a distributed cooperative control strategy triggered by an adaptive event is proposed.By introducing an adaptive event triggering mechanism in the distributed controller,the triggering parameters are dynamically adjusted so that the distributed controller can communicate only at a certain time,the communication pressure is reduced,and the DC bus voltage deviation is effectively reduced,at the same time,the accuracy of power distribution is improved.The MATLAB/Simulink modeling and simulation results prove the correctness and effectiveness of the proposed control strategy.展开更多
The problem of having an identical speed when dealing with multiple motors always exists in the industry.There are several methods to address the problem,but all the methodologies have two common drawbacks.Firstly,the...The problem of having an identical speed when dealing with multiple motors always exists in the industry.There are several methods to address the problem,but all the methodologies have two common drawbacks.Firstly,the control design requires continuous information on the desired speed and the actual speed of motors;secondly,it is sometimes difficult to directly measure the speed variables.In the proposed study,both of these drawbacks are addressed by designing an observer-based event-triggered networked multi-agent system.The proposed method uses the leader following consensus approach with a centralized event triggering control design so that whenever a follower's speed diverges from that of the leader,an event is triggered,which communicates and resets all the agents to the leader's speed.Moreover,an observer is designed such that the ith agent uses its jth neighbor agent and observer speed information to estimate the leader's speed.The stability of the proposed design is formulated by Lyapunov stability,while the simulation results endorse the design concepts and energy saving.展开更多
In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and ...In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and redefined by sorting the message into three types: control message, status message and alann message. Event triggered mode is added to the communication way of CAN bus, and the communication control strategy of the vehicle is made. It is proved that CAN bus load rate of control system is reduced after optimization, and the real-time performance of communication is improved effectively.展开更多
This paper aims to solve the finite-time trajectory tracking problem of underactuated surface ships under the influence of dynamic uncertainty,unknown external time-varying interference and limited communication resou...This paper aims to solve the finite-time trajectory tracking problem of underactuated surface ships under the influence of dynamic uncertainty,unknown external time-varying interference and limited communication resources.An event-triggered robust adaptive finite-time trajectory tracking control method for underactuated ships is designed by combining the existing trajectory tracking control methods and engineering needs in actual navigation.It can obviously improve the tracking accuracy of the ship,and complete the tracking task safely and efficiently.This scheme transforms the composite uncertain vector synthesized by uncertain parameters and external disturbances into a linear parameterized form.Next,considering the limitation of communication resources,a relative threshold event triggering mechanism is introduced to further extend the triggering time interval on the basis of the fixed threshold triggering scheme.Then,an event-triggered robust adaptive finite-time trajectory tracking control scheme is designed for underactuated ships,and a rigorous stability proof is provided through Lyapunov stability theory.Simulation experiment is carried out in MATLAB and the results show that the finite-time trajectory tracking control scheme proposed in this paper can effectively solve the problems of dynamic uncertainty.unknown time-varying external interference and limitation of communication resources.This paper can provide theoretical support for the autonomous navigation of intelligent ships.展开更多
Event extraction is an important research point in information extraction, which includes two important sub-tasks of event type recognition and event argument recognition. This paper describes a method based on automa...Event extraction is an important research point in information extraction, which includes two important sub-tasks of event type recognition and event argument recognition. This paper describes a method based on automatic expansion of the event triggers for event type recognition. The event triggers are first extended through a thesaurus to enable the extraction of the candidate events and their candidate types. Then, a binary classification method is used to recognize the candidate event types. This method effectively improves the unbalanced data problem in training models and the data sparseness problem with a small corpus. Evaluations on the ACE2005 dataset give a final F-score of 61.24%, which outperforms traditional methods based on pure machine learning.展开更多
Accurate prediction of the motion state of the connected vehicles,especially the preceding vehicle(PV),would effectively improve the decision-making and path planning of intelligent vehicles.The evolution of vehicle-t...Accurate prediction of the motion state of the connected vehicles,especially the preceding vehicle(PV),would effectively improve the decision-making and path planning of intelligent vehicles.The evolution of vehicle-tovehicle(V2V)communication technology makes it possible to exchange data between vehicles.However,since V2V communication has a transmission interval,which will result in the host vehicle not receiving information from the PV within the time interval.Furthermore,V2V communication is a time-triggered system that may occupy more communication bandwidth than required.On the other hand,traditional estimation methods of the PV state based on individual models are usually not applicable to a wide range of driving conditions.To address these issues,an event-triggered unscented Kalman filter(ETUKF)is first employed to estimate the PV state to strike a balance between estimation accuracy and communication cost.Then,an interactive multi-model(IMM)approach is combined with ETUKF to form IMMETUKF to further improve the estimation accuracy and applicability.Finally,simulation experiments under different driving conditions are implemented to verify the effectiveness of IMMETUKF.The test results indicated that the IMMETUKF has high estimation accuracy even when the communication rate is reduced to 14.84%and the proposed algorithm is highly adaptable to different driving conditions.展开更多
基金funded by the Natural Science Foundation of Shaanxi Province,Grant No.2021GY-135the Scientific Research Project of Yan’an University,Grant No.YDQ2018-07.
文摘Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,leading to greater waste of communication resources.In response to this problem,a distributed cooperative control strategy triggered by an adaptive event is proposed.By introducing an adaptive event triggering mechanism in the distributed controller,the triggering parameters are dynamically adjusted so that the distributed controller can communicate only at a certain time,the communication pressure is reduced,and the DC bus voltage deviation is effectively reduced,at the same time,the accuracy of power distribution is improved.The MATLAB/Simulink modeling and simulation results prove the correctness and effectiveness of the proposed control strategy.
基金This work is supported by the National Natural Science Foundation of China under grant 61273114the Innovation Program of Shanghai Municipal Education Commission under grant 14ZZ087,the Pujiang Talent Plan of Shanghai City,China under grant 14PJ1403800the International Corporation Project of Shanghai Science and Technology Commission under grants 14510722500,15220710400.
文摘The problem of having an identical speed when dealing with multiple motors always exists in the industry.There are several methods to address the problem,but all the methodologies have two common drawbacks.Firstly,the control design requires continuous information on the desired speed and the actual speed of motors;secondly,it is sometimes difficult to directly measure the speed variables.In the proposed study,both of these drawbacks are addressed by designing an observer-based event-triggered networked multi-agent system.The proposed method uses the leader following consensus approach with a centralized event triggering control design so that whenever a follower's speed diverges from that of the leader,an event is triggered,which communicates and resets all the agents to the leader's speed.Moreover,an observer is designed such that the ith agent uses its jth neighbor agent and observer speed information to estimate the leader's speed.The stability of the proposed design is formulated by Lyapunov stability,while the simulation results endorse the design concepts and energy saving.
文摘In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and redefined by sorting the message into three types: control message, status message and alann message. Event triggered mode is added to the communication way of CAN bus, and the communication control strategy of the vehicle is made. It is proved that CAN bus load rate of control system is reduced after optimization, and the real-time performance of communication is improved effectively.
基金National Natural Science Foundation of China(Grant No.51911540478)Shandong Pr ovincial Key Research and Development Plan(Grant No.2019JZZY020712)+3 种基金Shandong Provincial Graduate Education and Teaching Reform Research Project(Grant No.SDYJG19217)Shandong Jiaotong University Doctoral Research and Entrepr eneurship Fund and Shandong Jiaotong University Climbing Research and Innovation Team Plan(Grant No.SDJTUC1802)Shandong Provincial Natural Science Foundation(Grant No.ZR2022ME087)Shandong Intelligent Transportation Key Labor atory(under preparation).
文摘This paper aims to solve the finite-time trajectory tracking problem of underactuated surface ships under the influence of dynamic uncertainty,unknown external time-varying interference and limited communication resources.An event-triggered robust adaptive finite-time trajectory tracking control method for underactuated ships is designed by combining the existing trajectory tracking control methods and engineering needs in actual navigation.It can obviously improve the tracking accuracy of the ship,and complete the tracking task safely and efficiently.This scheme transforms the composite uncertain vector synthesized by uncertain parameters and external disturbances into a linear parameterized form.Next,considering the limitation of communication resources,a relative threshold event triggering mechanism is introduced to further extend the triggering time interval on the basis of the fixed threshold triggering scheme.Then,an event-triggered robust adaptive finite-time trajectory tracking control scheme is designed for underactuated ships,and a rigorous stability proof is provided through Lyapunov stability theory.Simulation experiment is carried out in MATLAB and the results show that the finite-time trajectory tracking control scheme proposed in this paper can effectively solve the problems of dynamic uncertainty.unknown time-varying external interference and limitation of communication resources.This paper can provide theoretical support for the autonomous navigation of intelligent ships.
基金Supported by the National Natural Science Foundation of China(Nos. 60975055 and 60803093)the National High-Tech Research and Development (863) Program of China (No.2008AA01Z144)
文摘Event extraction is an important research point in information extraction, which includes two important sub-tasks of event type recognition and event argument recognition. This paper describes a method based on automatic expansion of the event triggers for event type recognition. The event triggers are first extended through a thesaurus to enable the extraction of the candidate events and their candidate types. Then, a binary classification method is used to recognize the candidate event types. This method effectively improves the unbalanced data problem in training models and the data sparseness problem with a small corpus. Evaluations on the ACE2005 dataset give a final F-score of 61.24%, which outperforms traditional methods based on pure machine learning.
基金This work was supported in part by A*ST AR,Singapore,under Grant A2084c0156the SUG-NAP,Nanyang Technological University,under Grant M4082268.050.
文摘Accurate prediction of the motion state of the connected vehicles,especially the preceding vehicle(PV),would effectively improve the decision-making and path planning of intelligent vehicles.The evolution of vehicle-tovehicle(V2V)communication technology makes it possible to exchange data between vehicles.However,since V2V communication has a transmission interval,which will result in the host vehicle not receiving information from the PV within the time interval.Furthermore,V2V communication is a time-triggered system that may occupy more communication bandwidth than required.On the other hand,traditional estimation methods of the PV state based on individual models are usually not applicable to a wide range of driving conditions.To address these issues,an event-triggered unscented Kalman filter(ETUKF)is first employed to estimate the PV state to strike a balance between estimation accuracy and communication cost.Then,an interactive multi-model(IMM)approach is combined with ETUKF to form IMMETUKF to further improve the estimation accuracy and applicability.Finally,simulation experiments under different driving conditions are implemented to verify the effectiveness of IMMETUKF.The test results indicated that the IMMETUKF has high estimation accuracy even when the communication rate is reduced to 14.84%and the proposed algorithm is highly adaptable to different driving conditions.