Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recover...Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recovery outcome of motor dysfunction patients after stroke.Rehabilitation robots mainly have been developed along this direction to satisfy requirements of recovery therapy,or focused on one or more of the above three points.Therefore,rehabilitation robot based on neuro-machine interaction has been proposed for the paralyzed limb training of post-stroke patient,which utilizes motor related EEG,UCSDI(Ultrasound Current Source Density Imaging),EMG for the robot control and feeds back the multi-sensory interaction information such as visual,auditory,force,haptic sensation to the patient simultaneously.This neuro-controlled and perceptual rehabilitation robot will bring great benefits to post-stroke patients.In order to develop such a kind of rehabilitation robot,some key technologies,such as non-invasive precise measurement and decoding of neural signals,realistic sensation feedback,coordinated control for both the rehabilitation robot and the patient,need to be solved.In this paper,some fundamental problems in developing and optimizing such a kind of rehabilitation robot based on neuro-machine interaction are proposed and discussed.展开更多
Quantum metrology provides a fundamental limit on the precision of multi-parameter estimation,called the Heisenberg limit,which has been achieved in noiseless quantum systems.However,for systems subject to noises,it i...Quantum metrology provides a fundamental limit on the precision of multi-parameter estimation,called the Heisenberg limit,which has been achieved in noiseless quantum systems.However,for systems subject to noises,it is hard to achieve this limit since noises are inclined to destroy quantum coherence and entanglement.In this paper,a combined control scheme with feedback and quantum error correction(QEC)is proposed to achieve the Heisenberg limit in the presence of spontaneous emission,where the feedback control is used to protect a stabilizer code space containing an optimal probe state and an additional control is applied to eliminate the measurement incompatibility among three parameters.Although an ancilla system is necessary for the preparation of the optimal probe state,our scheme does not require the ancilla system to be noiseless.In addition,the control scheme in this paper has a low-dimensional code space.For the three components of a magnetic field,it can achieve the highest estimation precision with only a 2-dimensional code space,while at least a4-dimensional code space is required in the common optimal error correction protocols.展开更多
This paper deals with the leader-following consensus problem for a class of second-order nonlinear multi-agent systems by output feedback.The communication topology is characterized by a Markovian switching graph.Firs...This paper deals with the leader-following consensus problem for a class of second-order nonlinear multi-agent systems by output feedback.The communication topology is characterized by a Markovian switching graph.Firstly,an input-driven observer is introduced to estimate the consensus error of each follower agent.Then,a cooperative nonlinear control law is constructed using the relative output information between neighboring agents by employing the backstepping methodology,which achievesleader-following consensusin mean square sense.Compared with the existing results,the nonlinear functions are required to satisfy polynomial growth condition rather than globally Lipschitz growth or Lipschitz-like growth condition.A numerical example is given to illustrate the theoretical results.展开更多
This paper focuses on the connectivity-preserving consensus of nonlinear switched multi-agent systems with predefined accuracy.Accordingly,a unified error transformation is adopted to preserve the initial interaction ...This paper focuses on the connectivity-preserving consensus of nonlinear switched multi-agent systems with predefined accuracy.Accordingly,a unified error transformation is adopted to preserve the initial interaction pattern determined by agents’limited communication ranges and initial states.Meanwhile,the so-called congelation of variables method is used to handle the unknown aperiodically time-varying parameters,which are fast-varying in an unknown compact set with only their radii known a priori.In addition,a series of continuously differentiable functions are incorporated into the Lyapunov function to design the controller.Based on Lyapunov stability theory,the proposed control algorithm guarantees that the consensus errors converge with a predefined accuracy,whereas most existing connectivity-preserving results can only ensure uniform ultimate boundedness.Simultaneously,all closed-loop signals remain bounded.Finally,two simulations are provided to validate the effectiveness of the proposed control protocol.展开更多
基金supported by the National Natural Science Foundation of China ( Grant no. 61272379, 61325018)the Technique Support Project of Jiangsu Province ( Grantno. BE2014132)
文摘Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recovery outcome of motor dysfunction patients after stroke.Rehabilitation robots mainly have been developed along this direction to satisfy requirements of recovery therapy,or focused on one or more of the above three points.Therefore,rehabilitation robot based on neuro-machine interaction has been proposed for the paralyzed limb training of post-stroke patient,which utilizes motor related EEG,UCSDI(Ultrasound Current Source Density Imaging),EMG for the robot control and feeds back the multi-sensory interaction information such as visual,auditory,force,haptic sensation to the patient simultaneously.This neuro-controlled and perceptual rehabilitation robot will bring great benefits to post-stroke patients.In order to develop such a kind of rehabilitation robot,some key technologies,such as non-invasive precise measurement and decoding of neural signals,realistic sensation feedback,coordinated control for both the rehabilitation robot and the patient,need to be solved.In this paper,some fundamental problems in developing and optimizing such a kind of rehabilitation robot based on neuro-machine interaction are proposed and discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.61873251)。
文摘Quantum metrology provides a fundamental limit on the precision of multi-parameter estimation,called the Heisenberg limit,which has been achieved in noiseless quantum systems.However,for systems subject to noises,it is hard to achieve this limit since noises are inclined to destroy quantum coherence and entanglement.In this paper,a combined control scheme with feedback and quantum error correction(QEC)is proposed to achieve the Heisenberg limit in the presence of spontaneous emission,where the feedback control is used to protect a stabilizer code space containing an optimal probe state and an additional control is applied to eliminate the measurement incompatibility among three parameters.Although an ancilla system is necessary for the preparation of the optimal probe state,our scheme does not require the ancilla system to be noiseless.In addition,the control scheme in this paper has a low-dimensional code space.For the three components of a magnetic field,it can achieve the highest estimation precision with only a 2-dimensional code space,while at least a4-dimensional code space is required in the common optimal error correction protocols.
基金supported by Science and Technology Commission of Shanghai Municipality(No.20dz1207000).
文摘This paper deals with the leader-following consensus problem for a class of second-order nonlinear multi-agent systems by output feedback.The communication topology is characterized by a Markovian switching graph.Firstly,an input-driven observer is introduced to estimate the consensus error of each follower agent.Then,a cooperative nonlinear control law is constructed using the relative output information between neighboring agents by employing the backstepping methodology,which achievesleader-following consensusin mean square sense.Compared with the existing results,the nonlinear functions are required to satisfy polynomial growth condition rather than globally Lipschitz growth or Lipschitz-like growth condition.A numerical example is given to illustrate the theoretical results.
基金supported by the National Natural Science Foundation of China(Grant No.61673014)。
文摘This paper focuses on the connectivity-preserving consensus of nonlinear switched multi-agent systems with predefined accuracy.Accordingly,a unified error transformation is adopted to preserve the initial interaction pattern determined by agents’limited communication ranges and initial states.Meanwhile,the so-called congelation of variables method is used to handle the unknown aperiodically time-varying parameters,which are fast-varying in an unknown compact set with only their radii known a priori.In addition,a series of continuously differentiable functions are incorporated into the Lyapunov function to design the controller.Based on Lyapunov stability theory,the proposed control algorithm guarantees that the consensus errors converge with a predefined accuracy,whereas most existing connectivity-preserving results can only ensure uniform ultimate boundedness.Simultaneously,all closed-loop signals remain bounded.Finally,two simulations are provided to validate the effectiveness of the proposed control protocol.
