Rehabilitation robots can reproduce the rehabilitation movements of therapists by designed rehabilitation robot control methods to achieve the goal of training the patients’motion abilities.This paper proposes an imp...Rehabilitation robots can reproduce the rehabilitation movements of therapists by designed rehabilitation robot control methods to achieve the goal of training the patients’motion abilities.This paper proposes an impedance sliding-mode control method based on stiffness-scheduled law for the rehabilitation robot,which can be applied to rehabilitation training with both active and passive modes.A free-model-based sliding-mode control strategy is developed to avoid model dependence and reduce the system uncertainty caused by limb shaking.Additionally,the stiffness scheduling rule automatically regulates the impedance parameter of the rehabilitation robot based on the force exerted by the patient on the robot such that the rehabilitation training caters to the patient’s health condition.The proposed method is compared with the fixed stiffness and variable stiffness impedance methods,and the superiority of the proposed method is proved.Rehabilitation training experiments on an actual rehabilitation robot are provided to demonstrate the feasibility and stability of the proposed method.展开更多
The realization of Majorana zero modes in condensed matter have been attracting enormous interests from fundamental science such as topological quantum computation.Recently iron based superconductors were identified a...The realization of Majorana zero modes in condensed matter have been attracting enormous interests from fundamental science such as topological quantum computation.Recently iron based superconductors were identified as a high-temperature platform for realizing topological superconductivity and Majorana modes.As unconventional superconductors,one of the most important characteristics of them is that they are in the vicinity of magnetic states due to the strong Hund’s coupling in iron atoms.Here we propose that the line defects with missing Te/Se anions in Fe(Se,Te)superconductors provide the realization of intrinsic antiferromagnetic(AFM)chains with Rashba spin-orbit coupling.Against conventional wisdom,Majorana zero modes(MZMs)can be robustly generated at these AFM chain ends.These results can consistently explain the recent experimental observation of zero-energy end states in line defects of monolayer Fe(Te,Se)/SrTiO_(3) by scanning tunneling microscopy(STM)measurements.Our research not only demonstrates an unprecedented interplay among native line defect,emergent magnetism and topological superconductivity but also explores a high-temperature platform for Majorana fermions.展开更多
基金supported by the National Natural Science Foundation of China under grants 62373051 and U22A2048.
文摘Rehabilitation robots can reproduce the rehabilitation movements of therapists by designed rehabilitation robot control methods to achieve the goal of training the patients’motion abilities.This paper proposes an impedance sliding-mode control method based on stiffness-scheduled law for the rehabilitation robot,which can be applied to rehabilitation training with both active and passive modes.A free-model-based sliding-mode control strategy is developed to avoid model dependence and reduce the system uncertainty caused by limb shaking.Additionally,the stiffness scheduling rule automatically regulates the impedance parameter of the rehabilitation robot based on the force exerted by the patient on the robot such that the rehabilitation training caters to the patient’s health condition.The proposed method is compared with the fixed stiffness and variable stiffness impedance methods,and the superiority of the proposed method is proved.Rehabilitation training experiments on an actual rehabilitation robot are provided to demonstrate the feasibility and stability of the proposed method.
基金funding provided by Shanghai Jiao Tong Universitysupported by the National Natural Science Foundation of China(grant no.12047503)+2 种基金supported by the Ministry of Science and Technology(grant no.2022YFA1403901)the National Natural Science Foundation of China(grant no.NSFC-11888101)the New Cornerstone Foundation.
文摘The realization of Majorana zero modes in condensed matter have been attracting enormous interests from fundamental science such as topological quantum computation.Recently iron based superconductors were identified as a high-temperature platform for realizing topological superconductivity and Majorana modes.As unconventional superconductors,one of the most important characteristics of them is that they are in the vicinity of magnetic states due to the strong Hund’s coupling in iron atoms.Here we propose that the line defects with missing Te/Se anions in Fe(Se,Te)superconductors provide the realization of intrinsic antiferromagnetic(AFM)chains with Rashba spin-orbit coupling.Against conventional wisdom,Majorana zero modes(MZMs)can be robustly generated at these AFM chain ends.These results can consistently explain the recent experimental observation of zero-energy end states in line defects of monolayer Fe(Te,Se)/SrTiO_(3) by scanning tunneling microscopy(STM)measurements.Our research not only demonstrates an unprecedented interplay among native line defect,emergent magnetism and topological superconductivity but also explores a high-temperature platform for Majorana fermions.
