This article deals with the use of an interdisciplinary approach to modelling and creation of a complex technical system of different physical nature in relation to the kinematics of cutting and shaping. The professor...This article deals with the use of an interdisciplinary approach to modelling and creation of a complex technical system of different physical nature in relation to the kinematics of cutting and shaping. The professor of the National Technical University of Ukraine, Kuznetcov Iu. N., proposed the approach based on generalization of knowledge, methodological basis of which is the theory of evolution of the systems and methods of genetic analysis and synthesis. For generalization of the knowledge in the fundamental sciences is based on the principles of a limited number of elementary generic structures with the introduction of the gene concept. The modelling and synthesis of kinematic cutting schemes are providing the efficiency and viability of genetic and morphological approach. The material point, which can interact with other ma-terial points in space and time, simulating anthropogenic system of different origin, is introduced as a material object.展开更多
Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction system.However,the joint position tracking perfor...Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction system.However,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure control.This method ensures the tracking error converges in a finite time,even when the system faces uncertainties.The method also preserves the passivity of the system.Moreover,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity signals.This observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation channels.In particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot interaction.The effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.展开更多
The aim of this study was to investigate the effect of weight cutting and 18 hours rehydration in wrestlers＇ techniques performance. Methods： twenty-five men elite wrestlers participated in study, they randomly are ...The aim of this study was to investigate the effect of weight cutting and 18 hours rehydration in wrestlers＇ techniques performance. Methods： twenty-five men elite wrestlers participated in study, they randomly are divided into： group A （age of 18.38 ± 1.32 years, height 1.70 ± 0.04 m, weight 71.11± 11.80 kg） and group B （age of 21.00±2.08 years, height 1.75 ± 0.04 m, weight 76.25 ±12.55 kg）. Body composition, biomechanical analysis were measure before dehydration, after weight cutting and after 18 hours rehydration. All subjects were dehydrated 3.5% of their body weight. Group A lost body weight in sauna and group B dehydrated according to active method. Single takedown technique＇s biomechanical parameters are measured in six points of body （both side）. Three dimensional motion analysis and Skillspector software （version 1.3.2） is used to calculated fight and left shoulder, pelvis, and knee linear velocity, left/right trunk, thigh segment angular velocity, and position. Reflective body markers attached all of the subjects＇ joints, and we used hero 3 camera @ 15 fps/1440 p. Results with repeated measure and independent T-test showed that biomechanical characteristics decrease significantly after weight cutting （P 〈 0.05）. Compare groups showed that dehydration by sauna have significantly more negative effect than active method. 18-hour rehydration period is not sufficient for recovery.展开更多
文摘This article deals with the use of an interdisciplinary approach to modelling and creation of a complex technical system of different physical nature in relation to the kinematics of cutting and shaping. The professor of the National Technical University of Ukraine, Kuznetcov Iu. N., proposed the approach based on generalization of knowledge, methodological basis of which is the theory of evolution of the systems and methods of genetic analysis and synthesis. For generalization of the knowledge in the fundamental sciences is based on the principles of a limited number of elementary generic structures with the introduction of the gene concept. The modelling and synthesis of kinematic cutting schemes are providing the efficiency and viability of genetic and morphological approach. The material point, which can interact with other ma-terial points in space and time, simulating anthropogenic system of different origin, is introduced as a material object.
基金supported by the National Natural Science Foundation of China(Grant Nos.91648112,52375506)。
文摘Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction system.However,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure control.This method ensures the tracking error converges in a finite time,even when the system faces uncertainties.The method also preserves the passivity of the system.Moreover,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity signals.This observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation channels.In particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot interaction.The effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.
文摘The aim of this study was to investigate the effect of weight cutting and 18 hours rehydration in wrestlers＇ techniques performance. Methods： twenty-five men elite wrestlers participated in study, they randomly are divided into： group A （age of 18.38 ± 1.32 years, height 1.70 ± 0.04 m, weight 71.11± 11.80 kg） and group B （age of 21.00±2.08 years, height 1.75 ± 0.04 m, weight 76.25 ±12.55 kg）. Body composition, biomechanical analysis were measure before dehydration, after weight cutting and after 18 hours rehydration. All subjects were dehydrated 3.5% of their body weight. Group A lost body weight in sauna and group B dehydrated according to active method. Single takedown technique＇s biomechanical parameters are measured in six points of body （both side）. Three dimensional motion analysis and Skillspector software （version 1.3.2） is used to calculated fight and left shoulder, pelvis, and knee linear velocity, left/right trunk, thigh segment angular velocity, and position. Reflective body markers attached all of the subjects＇ joints, and we used hero 3 camera @ 15 fps/1440 p. Results with repeated measure and independent T-test showed that biomechanical characteristics decrease significantly after weight cutting （P 〈 0.05）. Compare groups showed that dehydration by sauna have significantly more negative effect than active method. 18-hour rehydration period is not sufficient for recovery.
