Space robotics has been used extensively in complex space missions. Rigid-manipulator space robots may suffer from rigid-body collisions with targets. This collision is likely to cause damage to the space robot and th...Space robotics has been used extensively in complex space missions. Rigid-manipulator space robots may suffer from rigid-body collisions with targets. This collision is likely to cause damage to the space robot and the target. To overcome such a problem, a novel ContinuumManipulator Space Robot(CMSR) for performing on-orbit servicing missions is proposed in this paper. Compared with rigid-manipulator space robots, CMSRs are able to perform compliant operations and avoid rigid-body collisions with a target. The CMSR consists of two kinds of flexible components, including solar arrays and continuum manipulators. The elastic vibrations of these flexible components disturb the position and attitude of CMSRs. The beating phenomenon introduced by the energy transfer among these flexible components can cause damage to solar arrays.The complicated dynamic coupling poses enormous challenges in dynamic modeling and vibration analysis. The dynamic model for CMSRs is derived and the mechanism of the beating phenomenon is analyzed in this paper. Simulation results show that an obvious beating phenomenon occurs and the amplitude of the solar arrays increases significantly when the natural frequencies of two kinds of flexible components are close. A method is provided to avoid the beating phenomenon.展开更多
Continuum manipulators have important applications in the human–machine interaction fields.The kinematics,dynamics,and control issues of the continuum manipulators are rather different from a conventional rigid-link ...Continuum manipulators have important applications in the human–machine interaction fields.The kinematics,dynamics,and control issues of the continuum manipulators are rather different from a conventional rigid-link manipulator.By the aid of Lie groups theory and exponential coordinate representations,the kinematics of the continuum manipulators with piecewise constant curvatures and actuated by tendons is investigated in this paper.On the basis of differential kinematics analysis,the complete Jacobian of the continuum manipulators is derived analytically,and then a new motion planning approach,named as“dynamic coordination method”is presented for the multisegments continuum manipulators,which is a class of superredundant manipulators.The novel motion planning approach is featured by some appealing properties,and the feasibility of the modeling and the motion planning method is demonstrated by some numerical simulations.展开更多
Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured environment.However,their deformability and compliance can deviate...Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured environment.However,their deformability and compliance can deviate distal tip under uncertain external interactions.To address this challenge,a novel tension-based control scheme has been proposed to modulate the stiffness of a tendon-driven CM,reducing the tip position errors caused by uncertain external forces.To minimize the tip position error,a virtual spring is positioned between the deviated and the desired tip positions.The proposed algorithm corrects the manipulator deviated tip position,improving tension distribution and stiffness profile,resulting in higher stiffness and better performance.The corresponding task space stiffness and condition numbers are also computed under different cases,indicating the effectiveness of the tension control scheme in modulating the manipulator's stiffness.Experimental validation conducted on an in-house developed prototype confirms the practical feasibility of the proposed approach.展开更多
The traditionally articulated manipulator had a single control method,and the limited motion trajectory space was unsuitable for working in an unstructured environment.This paper introduces a control method and optimi...The traditionally articulated manipulator had a single control method,and the limited motion trajectory space was unsuitable for working in an unstructured environment.This paper introduces a control method and optimization for a multijoint manipulator Inspired by snakes'curling and stretching motions.First,we analyze the manipulator’s connection mode and motion planning and propose a new motion method.In addition,we calculated the relevant positions and angles and subdivided the motion of some joints based on the principle of the meta-heuristic algorithm.Ultimately,the manipulator in this mode has a larger workspace and more flexible motion trajectories.The experimental results are consistent with the theoretical analysis,which further proves the feasibility and scalability of the scheme.展开更多
We propose a novel approach to generate and manipulate topological Floquet bound states in the continuum(BICs)via a class of systems constructed by coupling two identical periodically driven one-dimensional Su-Schrief...We propose a novel approach to generate and manipulate topological Floquet bound states in the continuum(BICs)via a class of systems constructed by coupling two identical periodically driven one-dimensional Su-Schrieffer-Heeger chains.The formation of topological Floquet BICs can be adjusted only by tuning the driving amplitude or frequency,regardless of whether the static system has BICs or not.The interchain bias can only change the localization property of topological Floquet BICs,and a bigger bias can lead to transforming topological Floquet BICs into bound states out of the continuum(BOCs).But it does not change the topological properties of these topological Floquet states.Based on the repulsion effect of edge states,we propose to detect occurrence of topological Floquet BICs and transition point between topological Floquet BICs and BOCs using quantum walk.Our work provided a convenient and realistic approach for the experimental realization and manipulation of BICs in a single-particle quantum system.展开更多
Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerody...Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerodynamic parameters of the airplane model are studied. In detail, a static model of the wire-driven parallel suspension is analyzed, a mathematical model for describ- ing the aerodynamic loads exerted on the scale model is constructed and a calculation method for obtaining the aerodynamic parameters of the model by measuring the tension of wires is presented. Moreover, the measurement system for wire tension and its corresponding data acquisition system are designed and built. Thereafter, the wire-driven parallel suspension system is placed in an open return circuit low-speed wind tunnel for wind tunnel tests to acquire data of each wire tension when the airplane model is at different attitudes and different wind speeds. A group of curves about the parameters for aerodynamic load exerted on the airplane model are obtained at different wind speeds after the acquired data are analyzed. The research results validate the feasibility of using a wire-driven parallel manipulator as the suspension system for low-speed wind ttmnel tests.展开更多
Magnetic continuum robots(MCRs)have garnered substantial attention as a new class of flexible robotic systems capable of navigating complex and confined spaces with remarkable dexterity.By combining continuous,deforma...Magnetic continuum robots(MCRs)have garnered substantial attention as a new class of flexible robotic systems capable of navigating complex and confined spaces with remarkable dexterity.By combining continuous,deformable structures with remotely applied magnetic fields,MCRs achieve contactless,remote manipulation,making them well‐suited for medical ap-plications.This review introduces recent advances in MCR research,focusing on design principles,structural configurations,and control strategies.Various MCR designs and structures,including those integrated with permanent magnets,magnetic matter,ferromagnetic sphere,and micro coil,are discussed.Furthermore,different magnetic actuation platforms are intro-duced,and the level of MCR automation is classified based on control strategies.Key intelligent manipulation capabilities of MCRs,including navigation,delivery,printing,grasping,imaging,and sensing are explored.Finally,future development pri-orities and directions are identified to provide insights for advancing intelligent robotic systems.展开更多
By combining the investigation of the biomechanics and behavior of elephant trunk in the performance of a wide range of dexterous manipulations,a novel approach in the design and kinematics modeling of a fruit harvest...By combining the investigation of the biomechanics and behavior of elephant trunk in the performance of a wide range of dexterous manipulations,a novel approach in the design and kinematics modeling of a fruit harvesting continuum manipulator was proposed.By comparing the structure of two different species of elephant trunk,a new continuum structure which matched the key features of elephant trunk was designed.Based on analysis of the underlying elephant trunk’s grasping mode,a novel kinematics model was proposed.Contrast to traditional robot kinematics which focused on end effector’s position and posture,the proposed continuum manipulator kinematics focus on the center of manipulator’s position and posture,which is more effective when trunk robot realizing grasp and establishes the foundation for its application.Finally,three typical grasping experiments were implemented.The experiment results showed that the manipulator could conduct wrap/pinch manipulations effectively for both small objects and bigger ones.展开更多
Continuum manipulators have been applied in different surgical scenarios due to their dexterity and multi-DoF(degree of freedom)design compactness.To improve surgery safety,it is preferable to enable active compliance...Continuum manipulators have been applied in different surgical scenarios due to their dexterity and multi-DoF(degree of freedom)design compactness.To improve surgery safety,it is preferable to enable active compliance and force sensing abilities for a continuum manipulator.Existing works on active compliance and force sensing often rely on force sensors at the proximal or the distal ends,which inevitably increases the system complexity.In this paper,a shape reconstruction algorithm,a compliant motion controller,and a force estimation method are proposed successively based on the manipulator's tip pose via visual feedback.Four support vector regression(SVR)trainers are constructed and trained to compensate for the actuation residues,which are the differences between the actual actuation lengths outputs at the actuators and the ideal actuation lengths calculated from the estimated shape using the kinematics model,under no-load condition.Then,a compliant motion controller and a force estimation method are realized based on the current actuation residues,compared with the actuation residues under the no-load condition.In this way,no additional sensors are needed as an endoscopic camera is often available in a laparoscopic or endoscopic surgical system.The experiments were conducted on aφ3 mm-continuum manipulator to demonstrate the effectiveness of the proposed algorithms.展开更多
Polarization singularities beyond the bound states in the continuums(BICs)have garnered significant interest due to their potential for light manipulation.The conservation of topological charge has proven crucial in v...Polarization singularities beyond the bound states in the continuums(BICs)have garnered significant interest due to their potential for light manipulation.The conservation of topological charge has proven crucial in various photonic systems,and it guides the behavior of these singularities,including the generation and annihilation of BICs.This work theoretically reveals the simultaneous generation of two distinct polarization singularity types,which include off-Γaccidental BICs and Dirac-type band degeneracy points.The generation is driven by a quadratic degeneracy of symmetry-protected BICs in a photonic crystal slab.It should be noted that this is achieved through continuously tuning a geometric parameter without breaking symmetry.Importantly,the generation of both singularity types can be explained by the topological charge conservation law.This adherence ensures the stability of these singularities and allows for continuous tuning of their positions in momentum space by continuously tuning a geometric parameter while preserving symmetry.This study presents a novel framework for synthesizing and manipulating complex polarization states by combining polarization singularities from both BICs and band degeneracies and holds promise for application in other wave systems beyond photonics.展开更多
基金supported by the National Natural Science Foundation of China(Nos.91748203,11922203,11772074)。
文摘Space robotics has been used extensively in complex space missions. Rigid-manipulator space robots may suffer from rigid-body collisions with targets. This collision is likely to cause damage to the space robot and the target. To overcome such a problem, a novel ContinuumManipulator Space Robot(CMSR) for performing on-orbit servicing missions is proposed in this paper. Compared with rigid-manipulator space robots, CMSRs are able to perform compliant operations and avoid rigid-body collisions with a target. The CMSR consists of two kinds of flexible components, including solar arrays and continuum manipulators. The elastic vibrations of these flexible components disturb the position and attitude of CMSRs. The beating phenomenon introduced by the energy transfer among these flexible components can cause damage to solar arrays.The complicated dynamic coupling poses enormous challenges in dynamic modeling and vibration analysis. The dynamic model for CMSRs is derived and the mechanism of the beating phenomenon is analyzed in this paper. Simulation results show that an obvious beating phenomenon occurs and the amplitude of the solar arrays increases significantly when the natural frequencies of two kinds of flexible components are close. A method is provided to avoid the beating phenomenon.
基金supported by the National Key R&D Program of China under Grant 2019YFB1309603the Natural Science Foundation of China under Grants 51775002 and 11702294+2 种基金the Natural Science Foundation of Beijing under Grants L172001,4204097,3172009,and 3194047the Joint Program of Beijing Municipal Foundation and Education Commission under Grant KZ202010009015the Scientific Research Foundation of North China University of Technology.
文摘Continuum manipulators have important applications in the human–machine interaction fields.The kinematics,dynamics,and control issues of the continuum manipulators are rather different from a conventional rigid-link manipulator.By the aid of Lie groups theory and exponential coordinate representations,the kinematics of the continuum manipulators with piecewise constant curvatures and actuated by tendons is investigated in this paper.On the basis of differential kinematics analysis,the complete Jacobian of the continuum manipulators is derived analytically,and then a new motion planning approach,named as“dynamic coordination method”is presented for the multisegments continuum manipulators,which is a class of superredundant manipulators.The novel motion planning approach is featured by some appealing properties,and the feasibility of the modeling and the motion planning method is demonstrated by some numerical simulations.
文摘Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured environment.However,their deformability and compliance can deviate distal tip under uncertain external interactions.To address this challenge,a novel tension-based control scheme has been proposed to modulate the stiffness of a tendon-driven CM,reducing the tip position errors caused by uncertain external forces.To minimize the tip position error,a virtual spring is positioned between the deviated and the desired tip positions.The proposed algorithm corrects the manipulator deviated tip position,improving tension distribution and stiffness profile,resulting in higher stiffness and better performance.The corresponding task space stiffness and condition numbers are also computed under different cases,indicating the effectiveness of the tension control scheme in modulating the manipulator's stiffness.Experimental validation conducted on an in-house developed prototype confirms the practical feasibility of the proposed approach.
基金funded by the National Natural Science Foundation of China under Grant 51875531“Pioneer”and“Leading Goose”R&D Program of Zhejiang under Grant 2022C02057.
文摘The traditionally articulated manipulator had a single control method,and the limited motion trajectory space was unsuitable for working in an unstructured environment.This paper introduces a control method and optimization for a multijoint manipulator Inspired by snakes'curling and stretching motions.First,we analyze the manipulator’s connection mode and motion planning and propose a new motion method.In addition,we calculated the relevant positions and angles and subdivided the motion of some joints based on the principle of the meta-heuristic algorithm.Ultimately,the manipulator in this mode has a larger workspace and more flexible motion trajectories.The experimental results are consistent with the theoretical analysis,which further proves the feasibility and scalability of the scheme.
基金supported by the National Natural Science Foundation of China(Grant Nos.12175315 and 12205385)。
文摘We propose a novel approach to generate and manipulate topological Floquet bound states in the continuum(BICs)via a class of systems constructed by coupling two identical periodically driven one-dimensional Su-Schrieffer-Heeger chains.The formation of topological Floquet BICs can be adjusted only by tuning the driving amplitude or frequency,regardless of whether the static system has BICs or not.The interchain bias can only change the localization property of topological Floquet BICs,and a bigger bias can lead to transforming topological Floquet BICs into bound states out of the continuum(BOCs).But it does not change the topological properties of these topological Floquet states.Based on the repulsion effect of edge states,we propose to detect occurrence of topological Floquet BICs and transition point between topological Floquet BICs and BOCs using quantum walk.Our work provided a convenient and realistic approach for the experimental realization and manipulation of BICs in a single-particle quantum system.
基金National Natural Science Foundation of China (50475099)
文摘Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerodynamic parameters of the airplane model are studied. In detail, a static model of the wire-driven parallel suspension is analyzed, a mathematical model for describ- ing the aerodynamic loads exerted on the scale model is constructed and a calculation method for obtaining the aerodynamic parameters of the model by measuring the tension of wires is presented. Moreover, the measurement system for wire tension and its corresponding data acquisition system are designed and built. Thereafter, the wire-driven parallel suspension system is placed in an open return circuit low-speed wind tunnel for wind tunnel tests to acquire data of each wire tension when the airplane model is at different attitudes and different wind speeds. A group of curves about the parameters for aerodynamic load exerted on the airplane model are obtained at different wind speeds after the acquired data are analyzed. The research results validate the feasibility of using a wire-driven parallel manipulator as the suspension system for low-speed wind ttmnel tests.
基金support from the National Natural Science Foundation of China(No.52205590)the Natural Science Foundation of Jiangsu Province(No.BK20220834)+2 种基金the Start‐up Research Fund of Southeast University(No.RF1028623098)the Taihu Lake Innovation Fund for the School of Future Technology of Southeast Universityin part by SIAT‐CUHK Joint Laboratory of Robotics and Intelligent Systems.
文摘Magnetic continuum robots(MCRs)have garnered substantial attention as a new class of flexible robotic systems capable of navigating complex and confined spaces with remarkable dexterity.By combining continuous,deformable structures with remotely applied magnetic fields,MCRs achieve contactless,remote manipulation,making them well‐suited for medical ap-plications.This review introduces recent advances in MCR research,focusing on design principles,structural configurations,and control strategies.Various MCR designs and structures,including those integrated with permanent magnets,magnetic matter,ferromagnetic sphere,and micro coil,are discussed.Furthermore,different magnetic actuation platforms are intro-duced,and the level of MCR automation is classified based on control strategies.Key intelligent manipulation capabilities of MCRs,including navigation,delivery,printing,grasping,imaging,and sensing are explored.Finally,future development pri-orities and directions are identified to provide insights for advancing intelligent robotic systems.
基金supported by National Natural Science Foundation of China(Grant No.51075363)Zhejiang Provincial Natural Science Foundation of China(Grant No.LY12E05022).
文摘By combining the investigation of the biomechanics and behavior of elephant trunk in the performance of a wide range of dexterous manipulations,a novel approach in the design and kinematics modeling of a fruit harvesting continuum manipulator was proposed.By comparing the structure of two different species of elephant trunk,a new continuum structure which matched the key features of elephant trunk was designed.Based on analysis of the underlying elephant trunk’s grasping mode,a novel kinematics model was proposed.Contrast to traditional robot kinematics which focused on end effector’s position and posture,the proposed continuum manipulator kinematics focus on the center of manipulator’s position and posture,which is more effective when trunk robot realizing grasp and establishes the foundation for its application.Finally,three typical grasping experiments were implemented.The experiment results showed that the manipulator could conduct wrap/pinch manipulations effectively for both small objects and bigger ones.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB4700900)the National Natural Science Foundation of China(Grant No.51722507)。
文摘Continuum manipulators have been applied in different surgical scenarios due to their dexterity and multi-DoF(degree of freedom)design compactness.To improve surgery safety,it is preferable to enable active compliance and force sensing abilities for a continuum manipulator.Existing works on active compliance and force sensing often rely on force sensors at the proximal or the distal ends,which inevitably increases the system complexity.In this paper,a shape reconstruction algorithm,a compliant motion controller,and a force estimation method are proposed successively based on the manipulator's tip pose via visual feedback.Four support vector regression(SVR)trainers are constructed and trained to compensate for the actuation residues,which are the differences between the actual actuation lengths outputs at the actuators and the ideal actuation lengths calculated from the estimated shape using the kinematics model,under no-load condition.Then,a compliant motion controller and a force estimation method are realized based on the current actuation residues,compared with the actuation residues under the no-load condition.In this way,no additional sensors are needed as an endoscopic camera is often available in a laparoscopic or endoscopic surgical system.The experiments were conducted on aφ3 mm-continuum manipulator to demonstrate the effectiveness of the proposed algorithms.
基金supported by the National Natural Science Foundation of China(Nos.11974259 and 12274241)。
文摘Polarization singularities beyond the bound states in the continuums(BICs)have garnered significant interest due to their potential for light manipulation.The conservation of topological charge has proven crucial in various photonic systems,and it guides the behavior of these singularities,including the generation and annihilation of BICs.This work theoretically reveals the simultaneous generation of two distinct polarization singularity types,which include off-Γaccidental BICs and Dirac-type band degeneracy points.The generation is driven by a quadratic degeneracy of symmetry-protected BICs in a photonic crystal slab.It should be noted that this is achieved through continuously tuning a geometric parameter without breaking symmetry.Importantly,the generation of both singularity types can be explained by the topological charge conservation law.This adherence ensures the stability of these singularities and allows for continuous tuning of their positions in momentum space by continuously tuning a geometric parameter while preserving symmetry.This study presents a novel framework for synthesizing and manipulating complex polarization states by combining polarization singularities from both BICs and band degeneracies and holds promise for application in other wave systems beyond photonics.
