The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the...The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is analyzed.According to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and posture.Under the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible rope.The trajectoy of the lifting system considering the deformation of flexible rope.The results show that the mass and elasticity of the flexible rope can not be neglected.Meanwhile,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation method.The research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。展开更多
As humans and robots work closer together than ever,anthropomorphic robotic arms with intuitive human-robot interaction interfaces have drawn massive attention to improving the quality of robot-assisted manipulation.I...As humans and robots work closer together than ever,anthropomorphic robotic arms with intuitive human-robot interaction interfaces have drawn massive attention to improving the quality of robot-assisted manipulation.In pursuit of this,we designed a dedicated 7-degrees-of-freedom(DoF)anthropomorphic robotic arm having three compact differential joints and a head-mounted gaze tracker enabling head-pose-tracked 3D gaze estimation.Moreover,two key challenges were addressed to achieve accurate robot-assisted manipulation of the object indicated by the direction of human gaze.First,a novel predictive pupil feature was proposed for 3D gaze estimation.Differing from most existing features subjected to the common paraxial approximation assumption,the proposed novel predictive pupil feature considered the light refraction at two corneal surfaces with a more realistic eye model,significantly improving the 3D gaze estimation accuracy when the eyeball rotates at large angles.Second,a novel optimization-based approach was developed to efficiently compensate for the posture errors of the designed 7-DoF anthropomorphic robotic arm for accurate manipulation.Compared with the existing Jacobian-based or optimization-based approaches with nominal joint values as iteration initial,the proposed approach computed the optimal iteration initial and realized faster convergence for real-time posture error compensation.With the posture error compensation in real time and 3D gaze estimated accurately,the human can command accurate robot-assisted manipulation using his eyes intuitively.The proposed system was successfully tested on five healthy subjects.展开更多
基金the National Natural Science Foundation of China(No.51965032)the Natural Science Foundation of Gansu Province of China(No.22JR5RA319)+1 种基金the Science and Technology Foundation of Gansu Province of China(No.21YF5WA060)the Excellent Doctoral Student Foundation of Gansu Province of China(No.23JRRA842).
文摘The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is analyzed.According to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and posture.Under the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible rope.The trajectoy of the lifting system considering the deformation of flexible rope.The results show that the mass and elasticity of the flexible rope can not be neglected.Meanwhile,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation method.The research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。
基金supported by the National Natural Science Foundation of China(Grant Nos.52027806,52435005,92248304,52075191).
文摘As humans and robots work closer together than ever,anthropomorphic robotic arms with intuitive human-robot interaction interfaces have drawn massive attention to improving the quality of robot-assisted manipulation.In pursuit of this,we designed a dedicated 7-degrees-of-freedom(DoF)anthropomorphic robotic arm having three compact differential joints and a head-mounted gaze tracker enabling head-pose-tracked 3D gaze estimation.Moreover,two key challenges were addressed to achieve accurate robot-assisted manipulation of the object indicated by the direction of human gaze.First,a novel predictive pupil feature was proposed for 3D gaze estimation.Differing from most existing features subjected to the common paraxial approximation assumption,the proposed novel predictive pupil feature considered the light refraction at two corneal surfaces with a more realistic eye model,significantly improving the 3D gaze estimation accuracy when the eyeball rotates at large angles.Second,a novel optimization-based approach was developed to efficiently compensate for the posture errors of the designed 7-DoF anthropomorphic robotic arm for accurate manipulation.Compared with the existing Jacobian-based or optimization-based approaches with nominal joint values as iteration initial,the proposed approach computed the optimal iteration initial and realized faster convergence for real-time posture error compensation.With the posture error compensation in real time and 3D gaze estimated accurately,the human can command accurate robot-assisted manipulation using his eyes intuitively.The proposed system was successfully tested on five healthy subjects.
