Goal oriented( GO) methodology is a kind of success oriented system reliability analysis method and has been used widely.The repairable system with dual input closed-loop feedback link( DICLFL) considering shutdown co...Goal oriented( GO) methodology is a kind of success oriented system reliability analysis method and has been used widely.The repairable system with dual input closed-loop feedback link( DICLFL) considering shutdown correlation didn't make reliability analysis accurately based on existing GO methodology. So, a reliability analysis method used to deal with DICLFL considering shutdown correlation is provided based on GO methodology.Firstly, a new operator, which is used to describe DICLFL considering shutdown correlation,whose number is 1,is created and named as Type 9C operator. And then,the formulas of type 9C operator are derived based on Markov process theory. Finally,the new method presented in this paper is adopted to conduct the reliability analysis of an electro-hydraulic servo speed control system. The analysis result is compared with those of Monte Carlo simulation and fault tree analysis( FTA). The comparison results show that this new reliability analysis method based on GO methodology is feasible and meaningful for reliability analysis of repairable systems with DICLFL considering shutdown correlation.Meantime,it will be useful for more other applications.展开更多
The control law design for a near-space hypersonic vehicle(NHV)is highly challenging due to its inherent nonlinearity,plant uncertainties and sensitivity to disturbances.This paper presents a novel functional link net...The control law design for a near-space hypersonic vehicle(NHV)is highly challenging due to its inherent nonlinearity,plant uncertainties and sensitivity to disturbances.This paper presents a novel functional link network(FLN)control method for an NHV with dynamical thrust and parameter uncertainties.The approach devises a new partially-feedback-functional-link-network(PFFLN)adaptive law and combines it with the nonlinear generalized predictive control(NGPC)algorithm.The PFFLN is employed for approximating uncertainties in flight.Its weights are online tuned based on Lyapunov stability theorem for the first time.The learning process does not need any offline training phase.Additionally,a robust controller with an adaptive gain is designed to offset the approximation error.Finally,simulation results show a satisfactory performance for the NHV attitude tracking,and also illustrate the controller's robustness.展开更多
This paper presents a novel adaptive nonlinear model predictive control design for trajectory tracking of flexible-link manipulators consisting of feedback linearization, linear model predictive control, and unscented...This paper presents a novel adaptive nonlinear model predictive control design for trajectory tracking of flexible-link manipulators consisting of feedback linearization, linear model predictive control, and unscented Kalman filtering. Reducing the nonlinear system to a linear system by feedback linearization simplifies the optimization problem of the model predictive controller significantly, which, however, is no longer linear in the presence of parameter uncertainties and can potentially lead to an undesired dynamical behaviour. An unscented Kalman filter is used to approximate the dynamics of the prediction model by an online parameter estimation, which leads to an adaptation of the optimization problem in each time step and thus to a better prediction and an improved input action. Finally, a detailed fuzzy-arithmetic analysis is performed in order to quantify the effect of the uncertainties on the control structure and to derive robustness assessments. The control structure is applied to a serial manipulator with two flexible links containing uncertain model parameters and acting in three-dimensional space.展开更多
Aims: The aim of the study is to investigate if the new method of auditory and visual biofeedback as Upper Limb Exercise may improve praxis skills alone without any traditional physical therapy treatment or not and wi...Aims: The aim of the study is to investigate if the new method of auditory and visual biofeedback as Upper Limb Exercise may improve praxis skills alone without any traditional physical therapy treatment or not and within three successive months of treatment in children with hemiplegic cerebral palsy. Methods: A 6-year-old hemiplegic cerebral palsied child was treated with Upper-Limb Exerciser as one of augmented visual and auditory feedback devices. Sensory Integration and Praxis test was used to measure a child’s ability to integrate sensory input for perception, motor planning, and spatial actions in;Space Visualization, Figure-Ground Perception, Standing and Walking Balance, Design Copying, Postural Praxis, Bilateral Motor Coordination, Constructional Praxis, Postrotary Nystagmus, Motor Accuracy, Sequencing Praxis, Oral Praxis, Manual Form Perception, Kinesthesia, Finger Identification, Graphethesia, Localization of Tactile Stimuli, and Praxis on Verbal Command. Results: The results revealed improvement of the major standard score for each of the 17 subtests of Sensory Integration and Praxis Test when compared after three successive treatment. Conclusion: The using upper limb exerciser as one method of augmented visual and auditory feedback can be used as one of the physical and occupational therapy programs aiming to improve praxis skills in hemiplegic cerebral palsied children.展开更多
基金Technical Basis Projects of China's MIIT(Nos.ZQ092012B003,2012090003)
文摘Goal oriented( GO) methodology is a kind of success oriented system reliability analysis method and has been used widely.The repairable system with dual input closed-loop feedback link( DICLFL) considering shutdown correlation didn't make reliability analysis accurately based on existing GO methodology. So, a reliability analysis method used to deal with DICLFL considering shutdown correlation is provided based on GO methodology.Firstly, a new operator, which is used to describe DICLFL considering shutdown correlation,whose number is 1,is created and named as Type 9C operator. And then,the formulas of type 9C operator are derived based on Markov process theory. Finally,the new method presented in this paper is adopted to conduct the reliability analysis of an electro-hydraulic servo speed control system. The analysis result is compared with those of Monte Carlo simulation and fault tree analysis( FTA). The comparison results show that this new reliability analysis method based on GO methodology is feasible and meaningful for reliability analysis of repairable systems with DICLFL considering shutdown correlation.Meantime,it will be useful for more other applications.
基金supported by the National Natural Science Foundation of China(9071602860974106)
文摘The control law design for a near-space hypersonic vehicle(NHV)is highly challenging due to its inherent nonlinearity,plant uncertainties and sensitivity to disturbances.This paper presents a novel functional link network(FLN)control method for an NHV with dynamical thrust and parameter uncertainties.The approach devises a new partially-feedback-functional-link-network(PFFLN)adaptive law and combines it with the nonlinear generalized predictive control(NGPC)algorithm.The PFFLN is employed for approximating uncertainties in flight.Its weights are online tuned based on Lyapunov stability theorem for the first time.The learning process does not need any offline training phase.Additionally,a robust controller with an adaptive gain is designed to offset the approximation error.Finally,simulation results show a satisfactory performance for the NHV attitude tracking,and also illustrate the controller's robustness.
文摘This paper presents a novel adaptive nonlinear model predictive control design for trajectory tracking of flexible-link manipulators consisting of feedback linearization, linear model predictive control, and unscented Kalman filtering. Reducing the nonlinear system to a linear system by feedback linearization simplifies the optimization problem of the model predictive controller significantly, which, however, is no longer linear in the presence of parameter uncertainties and can potentially lead to an undesired dynamical behaviour. An unscented Kalman filter is used to approximate the dynamics of the prediction model by an online parameter estimation, which leads to an adaptation of the optimization problem in each time step and thus to a better prediction and an improved input action. Finally, a detailed fuzzy-arithmetic analysis is performed in order to quantify the effect of the uncertainties on the control structure and to derive robustness assessments. The control structure is applied to a serial manipulator with two flexible links containing uncertain model parameters and acting in three-dimensional space.
文摘Aims: The aim of the study is to investigate if the new method of auditory and visual biofeedback as Upper Limb Exercise may improve praxis skills alone without any traditional physical therapy treatment or not and within three successive months of treatment in children with hemiplegic cerebral palsy. Methods: A 6-year-old hemiplegic cerebral palsied child was treated with Upper-Limb Exerciser as one of augmented visual and auditory feedback devices. Sensory Integration and Praxis test was used to measure a child’s ability to integrate sensory input for perception, motor planning, and spatial actions in;Space Visualization, Figure-Ground Perception, Standing and Walking Balance, Design Copying, Postural Praxis, Bilateral Motor Coordination, Constructional Praxis, Postrotary Nystagmus, Motor Accuracy, Sequencing Praxis, Oral Praxis, Manual Form Perception, Kinesthesia, Finger Identification, Graphethesia, Localization of Tactile Stimuli, and Praxis on Verbal Command. Results: The results revealed improvement of the major standard score for each of the 17 subtests of Sensory Integration and Praxis Test when compared after three successive treatment. Conclusion: The using upper limb exerciser as one method of augmented visual and auditory feedback can be used as one of the physical and occupational therapy programs aiming to improve praxis skills in hemiplegic cerebral palsied children.
