Walking is the most basic and essential part of the activities of daily living. To enable the elderly and non-ambulatory gait-impaired patients, the repetitive practice of this task, a novel gait training robot(GTR) w...Walking is the most basic and essential part of the activities of daily living. To enable the elderly and non-ambulatory gait-impaired patients, the repetitive practice of this task, a novel gait training robot(GTR) was designed followed the end-effector principle, and an active partial body weight support(PBWS) system was introduced to facilitate successful gait training. For successful establishment of a walking gait on the GTR with PBWS, the motion laws of the GTR were planned to enable the phase distribution relationships of the cycle step, and the center of gravity(COG) trajectory of the human body during gait training on the GTR was measured. A coordinated control strategy was proposed based on the impedance control principle. A robotic prototype was developed as a platform for evaluating the design concepts and control strategies. Preliminary gait training with a healthy subject was implemented by the robotic-assisted gait training system and the experimental results are encouraging.展开更多
The paper proposes a conference control model between a web server and a telecom application server,referred to as the Conference Directed Graph(CDG) ,and describes an asynchronous communication mechanism between them...The paper proposes a conference control model between a web server and a telecom application server,referred to as the Conference Directed Graph(CDG) ,and describes an asynchronous communication mechanism between them. The Corba Interface Definition Language(IDL) interfaces are defined,and a message sequence chart is illustrated. This web conference control model provides conference users with a new approach to manage and control a conference and the participants. The performance of the system prototype is analyzed and verified in the 863 project named "The Multi-media and Mobile Services Enabled Soft-switch System".展开更多
With the rapid development of the global economy,more and more attention has been paid to the energy conservation of construction machinery.The hydraulic system is the key component of construction machinery,and impro...With the rapid development of the global economy,more and more attention has been paid to the energy conservation of construction machinery.The hydraulic system is the key component of construction machinery,and improving its energy utilization rate has become an important means to achieve energy conservation.In conventional valve-controlled or pump-controlled hydraulic systems of construction machinery,controllability and energy-saving performance typically cannot be considered at the same time.The pump-valve coordinated system combines the energy-saving characteristics of the pump-controlled system and the high-precision and high-frequency response of the valve-controlled system,which has the potential to become a primary research direction of electro-hydraulic systems.This review summarizes the recent research progress in energy-saving technologies based on pump-valve coordinated systems.Particularly,we discuss the structures of hydraulic systems in different categories of construction machinery,various control methods of the electro-hydraulic system,novel hydraulic hybrid energy regeneration systems,and key components.In addition,future directions and challenges of the pump-valve coordinated systems are described,such as independent metering system(IMS),common pressure rail(CPR),and hybrid power source(HPS).展开更多
This paper considers the problem of optimal multi-objective trajectory design for autonomous rendezvous. Total velocity cost and relative state robustness of close-looped control are selected as the objective function...This paper considers the problem of optimal multi-objective trajectory design for autonomous rendezvous. Total velocity cost and relative state robustness of close-looped control are selected as the objective functions. Based on relative dynamics equations, the state equations and measurement equations for angles-only relative navigation between spacecraffs are set forth. According to the method of linear covariance analysis, the close-looped control covariance of the true relative state from the reference relative state is analyzed, and the objective functions of relative state robustness are formulated. Considering the total velocity cost and the relative state robustness, the multi-objective optimization algorithm of NSGA-II is employed to solve this multi-impulsive rendezvous problem. Lastly, the validity of the objective functions and the covariance results are demonstrated through 1 00 times Monte Carlo simulation.展开更多
基金Project(61175128) supported by the National Natural Science Foundation of ChinaProject(2008AA040203) supported by the National High Technology Research and Development Program of China
文摘Walking is the most basic and essential part of the activities of daily living. To enable the elderly and non-ambulatory gait-impaired patients, the repetitive practice of this task, a novel gait training robot(GTR) was designed followed the end-effector principle, and an active partial body weight support(PBWS) system was introduced to facilitate successful gait training. For successful establishment of a walking gait on the GTR with PBWS, the motion laws of the GTR were planned to enable the phase distribution relationships of the cycle step, and the center of gravity(COG) trajectory of the human body during gait training on the GTR was measured. A coordinated control strategy was proposed based on the impedance control principle. A robotic prototype was developed as a platform for evaluating the design concepts and control strategies. Preliminary gait training with a healthy subject was implemented by the robotic-assisted gait training system and the experimental results are encouraging.
基金the National High-Tech Research and De-velopment Plan of China (No.2001AA121021)the Na-tional Research Foundation for the Doctoral Program of Higher Education of China (No.20020013004)+2 种基金the Na-tional Grand Fundamental Research 973 Program of China (No.2003CB314806)the National Natural Science Foundation for Distinguished Young Scholars of China (No.60125101)the Cheung Kong Scholar’s Program and the Promotion Project for Creative Teams of the Ministry of Education (Networking Theory and Tech-nology in Telecommunication) (No.IRT0410).
文摘The paper proposes a conference control model between a web server and a telecom application server,referred to as the Conference Directed Graph(CDG) ,and describes an asynchronous communication mechanism between them. The Corba Interface Definition Language(IDL) interfaces are defined,and a message sequence chart is illustrated. This web conference control model provides conference users with a new approach to manage and control a conference and the participants. The performance of the system prototype is analyzed and verified in the 863 project named "The Multi-media and Mobile Services Enabled Soft-switch System".
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LR19E050002)the National Key R&D Program of China(No.2019YFB2004604)+2 种基金the National Natural Science Foundation of China(Nos.51821093 and 51708493)the Key R&D Program of Zhejiang Province(Nos.2018C01020 and 2018C01060)the Youth Funds of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.SKLoFP_QN_1804),China。
文摘With the rapid development of the global economy,more and more attention has been paid to the energy conservation of construction machinery.The hydraulic system is the key component of construction machinery,and improving its energy utilization rate has become an important means to achieve energy conservation.In conventional valve-controlled or pump-controlled hydraulic systems of construction machinery,controllability and energy-saving performance typically cannot be considered at the same time.The pump-valve coordinated system combines the energy-saving characteristics of the pump-controlled system and the high-precision and high-frequency response of the valve-controlled system,which has the potential to become a primary research direction of electro-hydraulic systems.This review summarizes the recent research progress in energy-saving technologies based on pump-valve coordinated systems.Particularly,we discuss the structures of hydraulic systems in different categories of construction machinery,various control methods of the electro-hydraulic system,novel hydraulic hybrid energy regeneration systems,and key components.In addition,future directions and challenges of the pump-valve coordinated systems are described,such as independent metering system(IMS),common pressure rail(CPR),and hybrid power source(HPS).
基金supported by the National Natural Science Foundation of China (Grant No. 10902101)
文摘This paper considers the problem of optimal multi-objective trajectory design for autonomous rendezvous. Total velocity cost and relative state robustness of close-looped control are selected as the objective functions. Based on relative dynamics equations, the state equations and measurement equations for angles-only relative navigation between spacecraffs are set forth. According to the method of linear covariance analysis, the close-looped control covariance of the true relative state from the reference relative state is analyzed, and the objective functions of relative state robustness are formulated. Considering the total velocity cost and the relative state robustness, the multi-objective optimization algorithm of NSGA-II is employed to solve this multi-impulsive rendezvous problem. Lastly, the validity of the objective functions and the covariance results are demonstrated through 1 00 times Monte Carlo simulation.
