This paper presents an investigation on the target-guided coordinated control(TACC)of unmanned surface vehicles(USVs).In the scenario of tracking non-cooperative targets,the status information of the target can only b...This paper presents an investigation on the target-guided coordinated control(TACC)of unmanned surface vehicles(USVs).In the scenario of tracking non-cooperative targets,the status information of the target can only be obtained by some USVs.In order to achieve semi-encirclement tracking of noncooperative targets under maritime security conditions,a fixed-time tracking control method based on dynamic surface control(DSC)is proposed in this paper.Firstly,a novel TACC architecture with decoupled kinematic control law and decoupled kinetic control law was designed to reduce the complexity of control system design.Secondly,the proposed DSC-based target-guided kinematic control law including tracking points pre-allocation strategy and sigmoid artificial potential functions(SigAPFs)can avoid collisions during tracking process and optimize kinematic control output.Finally,a fixed-time TACC system was proposed to achieve fast convergence of kinematic and kinetics errors.The effectiveness of the proposed TACC approach in improving target tracking safety and reducing control output chattering was verified by simulation comparison results.展开更多
The formation maintenance of multiple unmanned aerial vehicles(UAVs)based on proximity behavior is explored in this study.Individual decision-making is conducted according to the expected UAV formation structure and t...The formation maintenance of multiple unmanned aerial vehicles(UAVs)based on proximity behavior is explored in this study.Individual decision-making is conducted according to the expected UAV formation structure and the position,velocity,and attitude information of other UAVs in the azimuth area.This resolves problems wherein nodes are necessarily strongly connected and communication is strictly consistent under the traditional distributed formation control method.An adaptive distributed formation flight strategy is established for multiple UAVs by exploiting proximity behavior observations,which remedies the poor flexibility in distributed formation.This technique ensures consistent position and attitude among UAVs.In the proposed method,the azimuth area relative to the UAV itself is established to capture the state information of proximal UAVs.The dependency degree factor is introduced to state update equation based on proximity behavior.Finally,the formation position,speed,and attitude errors are used to form an adaptive dynamic adjustment strategy.Simulations are conducted to demonstrate the effectiveness and robustness of the theoretical results,thus validating the effectiveness of the proposed method.展开更多
Based on the idea of backstepping design, distributedcoordinated tracking problems under directed topology are discussedfor multiple Euler-Lagrange （EL） systems. The dynamicleader case is considered. First, with the...Based on the idea of backstepping design, distributedcoordinated tracking problems under directed topology are discussedfor multiple Euler-Lagrange （EL） systems. The dynamicleader case is considered. First, with the parameter-linearity property,a distributed coordinated adaptive control scheme is proposedfor EL systems in the presence of parametric uncertainties.Then, subject to nonlinear uncertainties and external disturbances,an improved adaptive control algorithm is developed by usingneural-network （NN） approximation of nonlinear functions. Bothproposed algorithms can make tracking errors for each followerultimately bounded. The closed-loop systems are investigated byusing the combination of graph theory, Lyapunov theory, and BarbalatLemma. Numerical examples and comparisons with othermethods are provided to show the effectiveness of the proposedcontrol strategies.展开更多
Remote control process system with distributed time-delay has attracted much attention in different fields.In this paper,non-linear remote control of a single tank process system with wireless network is considered.To...Remote control process system with distributed time-delay has attracted much attention in different fields.In this paper,non-linear remote control of a single tank process system with wireless network is considered.To deal with the distributed time-delay in a large-scale plant,the time-delay compensation controller based on DCS devices is designed by using operator theory and particle filter.Distributed control system(DCS)device is developed to monitor and control from the central monitoring room to each process.The particle filter is a probabilistic method to estimate unobservable information from observable information.First,remote control system and experimental equipment are introduced.Second,control system based on an operator theory is designed.Then,process system with distributed time-delay using particle filter is carried out.Finally,the actual experiment is conducted by using the proposed time-delay compensation controller.When estimating with the proposed method,the result is close to the case in which the distributed time-delay does not exist.The effectiveness of the proposed control system is confirmed by experiment results.展开更多
The chattering characteristic of sliding mode control isanalyzed when it is applied in distributed control systems （DCSs）.For a DCS with random time delay and packet dropout, a discreteswitching system model with ti...The chattering characteristic of sliding mode control isanalyzed when it is applied in distributed control systems （DCSs）.For a DCS with random time delay and packet dropout, a discreteswitching system model with time varying sampling period isconstructed based on the time delay system method. The reachinglaw based sliding mode controller is applied in the proposedsystem. The exponential stability condition in the form of linearmatrix inequality is figured out based on the multi-Lyaponov functionmethod. Then, the chattering characteristic is analyzed for theswitching system, and a chattering region related with time varyingsampling period and external disturbance is proposed. Finally, numericalexamples are given to illustrate the validity of the analysisresult.展开更多
In this paper,the distributed fuzzy fault-tolerant tracking consensus problem of leader-follower multi-agent systems(MASs)is studied.The objective system includes actuator faults,mismatched parameter uncertainties,non...In this paper,the distributed fuzzy fault-tolerant tracking consensus problem of leader-follower multi-agent systems(MASs)is studied.The objective system includes actuator faults,mismatched parameter uncertainties,nonlinear functions,and exogenous disturbances under switching communication topologies.To solve this problem,a distributed fuzzy fault-tolerant controller is proposed for each follower by adaptive mechanisms to track the state of the leader.Furthermore,the fuzzy logic system is utilized to approximate the unknown nonlinear dynamics.An error estimator is introduced between the mismatched parameter matrix and the input matrix.Then,a selective adaptive law with relative state information is adopted and applied.When calculating the Lyapunov function’s derivative,the coupling terms related to consensus error and mismatched parameter uncertainties can be eliminated.Finally,a numerical simulation is given to validate the effectiveness of the proposed protocol.展开更多
The problem of distributed coordinated tracking control for networked Euler-Lagrange systems without velocity measurements is investigated. Under the condition that only a portion of the followers have access to the l...The problem of distributed coordinated tracking control for networked Euler-Lagrange systems without velocity measurements is investigated. Under the condition that only a portion of the followers have access to the leader, sliding mode estimators are developed to estimate the states of the dynamic leader in finite time. To cope with the absence of velocity measurements, the distributed observers which only use position information are designed. Based on the outputs of the estimators and observers, distributed tracking control laws are proposed such that all the fol- lowers with parameter uncertainties can track the dynamic leader under a directed graph containing a spanning tree. It is shown that the distributed observer-controller guarantees asymptotical stability of the closed-loop system. Numerical simulations are worked out to illustrate the effectiveness of the control laws.展开更多
The consensus problem of the distributed attitude synchronization in the spacecraft formation flying is considered.Firstly,the attitude dynamics of a rigid body spacecraft is described by modified Rodriguez parameters...The consensus problem of the distributed attitude synchronization in the spacecraft formation flying is considered.Firstly,the attitude dynamics of a rigid body spacecraft is described by modified Rodriguez parameters（MRPs）.Then global stable distributed cooperative attitude control laws are proposed for different cases.In the first case,the control law guarantees the state consensus during the attitude synchronization.In the second case,the control law ensures both the attitudes synchronizing to a desired constant attitude and the angular velocities converging at zero.In the third case,an attitude consensus control law with bounded control input is proposed.Finally,the effectiveness and validity of the control laws are demonstrated by simulations of six rigid bodies formation flying.展开更多
This paper proposes a distributed event-triggered control(ETC)framework to address cooperative target fencing challenges in UAV swarm.The proposed architecture eliminates the reliance on preset formation parameters wh...This paper proposes a distributed event-triggered control(ETC)framework to address cooperative target fencing challenges in UAV swarm.The proposed architecture eliminates the reliance on preset formation parameters while achieving multi-objective cooperative control for target fencing,network connectivity preservation,collision avoidance,and communication efficiency optimization.Firstly,a differential state observer is constructed to obtain the target's unmeasurable states.Secondly,leveraging swarm selforganization principles,a geometric-constraint-free distributed fencing controller is designed by integrating potential field methods with consensus theory.The controller dynamically adjusts inter-UAV distances via single potential function,enabling coordinated optimization of persistent network connectivity and collision-free motion during target fencing.Thirdly,a dual-threshold ETC mechanism based on velocity consensus deviation and fencing error is proposed,which can be triggered based on task features to dynamically adjust the communication frequency,significantly reduce the communication burden and exclude Zeno behavior.Theoretical analysis demonstrates the stability of closed-loop systems.Multi-scenario simulations show that the proposed method can achieve robust fencing under target maneuverability,partial UAV failures,and communication disturbances.展开更多
This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is ...This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is destroyed by diverse time-delays which include communication time-delay and self time-delay. Based on the generalized Nyquist stability criterion and the Gerschgorin disk theorem, some sufficient conditions for the consensus of multi-agent systems are obtained. And we give the expression of the weighted average consensus value for our consensus protocol. Finally, numerical examples are presented to illustrate the theoretical results.展开更多
In recent years,with the continuous development of multi-agent technology represented by unmanned aerial vehicle(UAV)swarm,consensus control has become a hot spot in academic research.In this paper,we put forward a di...In recent years,with the continuous development of multi-agent technology represented by unmanned aerial vehicle(UAV)swarm,consensus control has become a hot spot in academic research.In this paper,we put forward a discrete-time consensus protocol and obtain the necessary and sufficient conditions for the second-order consensus of the second-order multi-agent system with a fixed structure under the condition of no saturation input.The theoretical derivation verifies that the two eigenvalues of the Laplacian of the communication network matrix and the sampling period have an important effect on achieving consensus.Then we construct and verify sufficient conditions to achieve consensus under the condition of input saturation constraints.The results show that consensus can be achieved if velocity,position gain,and sampling period satisfy a set of inequalities related to the eigenvalues of the Laplacian matrix.Finally,the accuracy and validity of the theoretical results are proved by numerical simulations.展开更多
Aiming at the group of autonomous agents consisting of multiple leader agents and multiple follower ones,a flocking behavior method with multiple leaders and a global trajectory was proposed.In this flocking method,th...Aiming at the group of autonomous agents consisting of multiple leader agents and multiple follower ones,a flocking behavior method with multiple leaders and a global trajectory was proposed.In this flocking method,the group leaders can attain the information of the global trajectory,while each follower can communicate with its neighbors and corresponding leader but does not have global knowledge.Being to a distributed control method,the proposed method firstly sets a movable imaginary point on the global trajectory to ensure that the center and average velocity of the leader agents satisfy the constraints of the global trajectory.Secondly,a two-stage strategy was proposed to make the whole group satisfy the constraints of the global trajectory.Moreover,the distance between the center of the group and the desired trajectory was analyzed in detail according to the number ratio of the followers to the leaders.In this way,on one hand,the agents of the group emerge a basic flocking behavior; on the other hand,the center of the group satisfies the constraints of global trajectory.Simulation results demonstrate the effectiveness of the proposed method.展开更多
A new method to design a quantum controller which directly controls the probability density function（PDF） of quantum systems is proposed.Based on the quantum model from the PDF perspective,two specific control algor...A new method to design a quantum controller which directly controls the probability density function（PDF） of quantum systems is proposed.Based on the quantum model from the PDF perspective,two specific control algorithms are proposed with uniform and non-uniform fields,respectively.Then a detailed control algorithm with convergence analysis is given for the small error case.By appropriately estimating the selected Lyapunov function,more accurate control effect is achieved.The proposed scheme provides a constructive method to find appropriate parameters for controller design.展开更多
This problem is a nonlinear control system with variable-domain distributed parameter. In this paper, the numerical simulation of the dynamic functions has been carried out by transforming this problem to a fixed-dom...This problem is a nonlinear control system with variable-domain distributed parameter. In this paper, the numerical simulation of the dynamic functions has been carried out by transforming this problem to a fixed-domain initial-boundary value problem, and the numerical results are obtained: (1) Thedistribution of temperature rises, the ablation amount and velocity of the thermal shield vary with the time; (2) The maximum ablating velocity, the time of the ablation beginning and ending related to thetranspiration quantity. This method succeeds in overcoming the difficulty brought up by variable domain.On the other hand, the critical transpiration quantity for the surface to start ablating, the maximum ablating velocity and time of the ablation ending are obtained theoretically.展开更多
文摘This paper presents an investigation on the target-guided coordinated control(TACC)of unmanned surface vehicles(USVs).In the scenario of tracking non-cooperative targets,the status information of the target can only be obtained by some USVs.In order to achieve semi-encirclement tracking of noncooperative targets under maritime security conditions,a fixed-time tracking control method based on dynamic surface control(DSC)is proposed in this paper.Firstly,a novel TACC architecture with decoupled kinematic control law and decoupled kinetic control law was designed to reduce the complexity of control system design.Secondly,the proposed DSC-based target-guided kinematic control law including tracking points pre-allocation strategy and sigmoid artificial potential functions(SigAPFs)can avoid collisions during tracking process and optimize kinematic control output.Finally,a fixed-time TACC system was proposed to achieve fast convergence of kinematic and kinetics errors.The effectiveness of the proposed TACC approach in improving target tracking safety and reducing control output chattering was verified by simulation comparison results.
文摘The formation maintenance of multiple unmanned aerial vehicles(UAVs)based on proximity behavior is explored in this study.Individual decision-making is conducted according to the expected UAV formation structure and the position,velocity,and attitude information of other UAVs in the azimuth area.This resolves problems wherein nodes are necessarily strongly connected and communication is strictly consistent under the traditional distributed formation control method.An adaptive distributed formation flight strategy is established for multiple UAVs by exploiting proximity behavior observations,which remedies the poor flexibility in distributed formation.This technique ensures consistent position and attitude among UAVs.In the proposed method,the azimuth area relative to the UAV itself is established to capture the state information of proximal UAVs.The dependency degree factor is introduced to state update equation based on proximity behavior.Finally,the formation position,speed,and attitude errors are used to form an adaptive dynamic adjustment strategy.Simulations are conducted to demonstrate the effectiveness and robustness of the theoretical results,thus validating the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(6130400561174200)the Research Fund for the Doctoral Program of Higher Education of China(20102302110031)
文摘Based on the idea of backstepping design, distributedcoordinated tracking problems under directed topology are discussedfor multiple Euler-Lagrange （EL） systems. The dynamicleader case is considered. First, with the parameter-linearity property,a distributed coordinated adaptive control scheme is proposedfor EL systems in the presence of parametric uncertainties.Then, subject to nonlinear uncertainties and external disturbances,an improved adaptive control algorithm is developed by usingneural-network （NN） approximation of nonlinear functions. Bothproposed algorithms can make tracking errors for each followerultimately bounded. The closed-loop systems are investigated byusing the combination of graph theory, Lyapunov theory, and BarbalatLemma. Numerical examples and comparisons with othermethods are provided to show the effectiveness of the proposedcontrol strategies.
基金Project(K117K06225)supported by JSPS KAKENHI,Japan
文摘Remote control process system with distributed time-delay has attracted much attention in different fields.In this paper,non-linear remote control of a single tank process system with wireless network is considered.To deal with the distributed time-delay in a large-scale plant,the time-delay compensation controller based on DCS devices is designed by using operator theory and particle filter.Distributed control system(DCS)device is developed to monitor and control from the central monitoring room to each process.The particle filter is a probabilistic method to estimate unobservable information from observable information.First,remote control system and experimental equipment are introduced.Second,control system based on an operator theory is designed.Then,process system with distributed time-delay using particle filter is carried out.Finally,the actual experiment is conducted by using the proposed time-delay compensation controller.When estimating with the proposed method,the result is close to the case in which the distributed time-delay does not exist.The effectiveness of the proposed control system is confirmed by experiment results.
基金supported by the National Natural Science Fundation of China(5147618751506221)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(2015JQ51792015JM5207)
文摘The chattering characteristic of sliding mode control isanalyzed when it is applied in distributed control systems （DCSs）.For a DCS with random time delay and packet dropout, a discreteswitching system model with time varying sampling period isconstructed based on the time delay system method. The reachinglaw based sliding mode controller is applied in the proposedsystem. The exponential stability condition in the form of linearmatrix inequality is figured out based on the multi-Lyaponov functionmethod. Then, the chattering characteristic is analyzed for theswitching system, and a chattering region related with time varyingsampling period and external disturbance is proposed. Finally, numericalexamples are given to illustrate the validity of the analysisresult.
基金This work was supported by Tianjin Natural Science Foundation of China(20JCYBJC01060,20JCQNJC01450)the National Natural Science Foundation of China(61973175)Tianjin Postgraduate Scientific Research and Innovation Project(2020YJSZXB03,2020YJSZXB12).
文摘In this paper,the distributed fuzzy fault-tolerant tracking consensus problem of leader-follower multi-agent systems(MASs)is studied.The objective system includes actuator faults,mismatched parameter uncertainties,nonlinear functions,and exogenous disturbances under switching communication topologies.To solve this problem,a distributed fuzzy fault-tolerant controller is proposed for each follower by adaptive mechanisms to track the state of the leader.Furthermore,the fuzzy logic system is utilized to approximate the unknown nonlinear dynamics.An error estimator is introduced between the mismatched parameter matrix and the input matrix.Then,a selective adaptive law with relative state information is adopted and applied.When calculating the Lyapunov function’s derivative,the coupling terms related to consensus error and mismatched parameter uncertainties can be eliminated.Finally,a numerical simulation is given to validate the effectiveness of the proposed protocol.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(61321002)the Projects of Major International(Regional)Joint Research Program(61120106010)+5 种基金the National Natural Science Foundation of China(61175112)the Beijing Education Committee Cooperation Building Foundation Projectthe Program for Changjiang Scholars and Innovative Research Team in University(IRT1208)the Changjiang Scholars Programthe Science and Technology Project of Education Department of Fujian Province(JA12370)the Beijing Outstanding Ph.D.Program Mentor Grant(20131000704)
文摘The problem of distributed coordinated tracking control for networked Euler-Lagrange systems without velocity measurements is investigated. Under the condition that only a portion of the followers have access to the leader, sliding mode estimators are developed to estimate the states of the dynamic leader in finite time. To cope with the absence of velocity measurements, the distributed observers which only use position information are designed. Based on the outputs of the estimators and observers, distributed tracking control laws are proposed such that all the fol- lowers with parameter uncertainties can track the dynamic leader under a directed graph containing a spanning tree. It is shown that the distributed observer-controller guarantees asymptotical stability of the closed-loop system. Numerical simulations are worked out to illustrate the effectiveness of the control laws.
基金supported by the National Science Foundation of China (6097406260972119)the Chinese Ministry of Science and Intergovernmental Cooperation Project(2009DFA12870)
文摘The consensus problem of the distributed attitude synchronization in the spacecraft formation flying is considered.Firstly,the attitude dynamics of a rigid body spacecraft is described by modified Rodriguez parameters（MRPs）.Then global stable distributed cooperative attitude control laws are proposed for different cases.In the first case,the control law guarantees the state consensus during the attitude synchronization.In the second case,the control law ensures both the attitudes synchronizing to a desired constant attitude and the angular velocities converging at zero.In the third case,an attitude consensus control law with bounded control input is proposed.Finally,the effectiveness and validity of the control laws are demonstrated by simulations of six rigid bodies formation flying.
文摘This paper proposes a distributed event-triggered control(ETC)framework to address cooperative target fencing challenges in UAV swarm.The proposed architecture eliminates the reliance on preset formation parameters while achieving multi-objective cooperative control for target fencing,network connectivity preservation,collision avoidance,and communication efficiency optimization.Firstly,a differential state observer is constructed to obtain the target's unmeasurable states.Secondly,leveraging swarm selforganization principles,a geometric-constraint-free distributed fencing controller is designed by integrating potential field methods with consensus theory.The controller dynamically adjusts inter-UAV distances via single potential function,enabling coordinated optimization of persistent network connectivity and collision-free motion during target fencing.Thirdly,a dual-threshold ETC mechanism based on velocity consensus deviation and fencing error is proposed,which can be triggered based on task features to dynamically adjust the communication frequency,significantly reduce the communication burden and exclude Zeno behavior.Theoretical analysis demonstrates the stability of closed-loop systems.Multi-scenario simulations show that the proposed method can achieve robust fencing under target maneuverability,partial UAV failures,and communication disturbances.
基金supported by the National Natural Science Foundation of China(6127312661363002+3 种基金61374104)the Natural Science Foundation of Guangdong Province(10251064101000008S2012010009675)the Fundamental Research Funds for the Central Universities(2012ZM0059)
文摘This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is destroyed by diverse time-delays which include communication time-delay and self time-delay. Based on the generalized Nyquist stability criterion and the Gerschgorin disk theorem, some sufficient conditions for the consensus of multi-agent systems are obtained. And we give the expression of the weighted average consensus value for our consensus protocol. Finally, numerical examples are presented to illustrate the theoretical results.
基金supported by the National Natural Science Foundation of China(61703427).
文摘In recent years,with the continuous development of multi-agent technology represented by unmanned aerial vehicle(UAV)swarm,consensus control has become a hot spot in academic research.In this paper,we put forward a discrete-time consensus protocol and obtain the necessary and sufficient conditions for the second-order consensus of the second-order multi-agent system with a fixed structure under the condition of no saturation input.The theoretical derivation verifies that the two eigenvalues of the Laplacian of the communication network matrix and the sampling period have an important effect on achieving consensus.Then we construct and verify sufficient conditions to achieve consensus under the condition of input saturation constraints.The results show that consensus can be achieved if velocity,position gain,and sampling period satisfy a set of inequalities related to the eigenvalues of the Laplacian matrix.Finally,the accuracy and validity of the theoretical results are proved by numerical simulations.
基金Projects(61170160,61202338)supported by the National Natural Science Foundation of China
文摘Aiming at the group of autonomous agents consisting of multiple leader agents and multiple follower ones,a flocking behavior method with multiple leaders and a global trajectory was proposed.In this flocking method,the group leaders can attain the information of the global trajectory,while each follower can communicate with its neighbors and corresponding leader but does not have global knowledge.Being to a distributed control method,the proposed method firstly sets a movable imaginary point on the global trajectory to ensure that the center and average velocity of the leader agents satisfy the constraints of the global trajectory.Secondly,a two-stage strategy was proposed to make the whole group satisfy the constraints of the global trajectory.Moreover,the distance between the center of the group and the desired trajectory was analyzed in detail according to the number ratio of the followers to the leaders.In this way,on one hand,the agents of the group emerge a basic flocking behavior; on the other hand,the center of the group satisfies the constraints of global trajectory.Simulation results demonstrate the effectiveness of the proposed method.
基金supported by the National Natural Science Founda-tion of China (6077400160736021+6 种基金6072106260703083)the National Basic Research Program of China (973 Program) (2009CB320603)the National High Technology Research and Development Program of China (863 Program) (2008AA042602)the "111" Project of China(B07031)the Fundamental Research Funds for the Central Universities (2010QNA5014)the Zhejiang Innovation Program for Graduates(YK2009009)
文摘A new method to design a quantum controller which directly controls the probability density function（PDF） of quantum systems is proposed.Based on the quantum model from the PDF perspective,two specific control algorithms are proposed with uniform and non-uniform fields,respectively.Then a detailed control algorithm with convergence analysis is given for the small error case.By appropriately estimating the selected Lyapunov function,more accurate control effect is achieved.The proposed scheme provides a constructive method to find appropriate parameters for controller design.
文摘This problem is a nonlinear control system with variable-domain distributed parameter. In this paper, the numerical simulation of the dynamic functions has been carried out by transforming this problem to a fixed-domain initial-boundary value problem, and the numerical results are obtained: (1) Thedistribution of temperature rises, the ablation amount and velocity of the thermal shield vary with the time; (2) The maximum ablating velocity, the time of the ablation beginning and ending related to thetranspiration quantity. This method succeeds in overcoming the difficulty brought up by variable domain.On the other hand, the critical transpiration quantity for the surface to start ablating, the maximum ablating velocity and time of the ablation ending are obtained theoretically.
