Performance analysis and kinematic design of the 3-PUU pure translational parallel mechanism with vertical guide-ways are investigated. Two novel performance indices, the critical slider stroke and the main section ar...Performance analysis and kinematic design of the 3-PUU pure translational parallel mechanism with vertical guide-ways are investigated. Two novel performance indices, the critical slider stroke and the main section area of workspace, are defined; The expressions of two other indices, i.e. the global dexterity and global force transfer ratio are revised based on the main section of workspace. Using these indices, performance changes versus the varieties of dimensional parameters of mechanism are investigated in detail and the graphic descriptions of change tendencies of the performance indices are illustrated. By means of these obtained graphic descriptions, kinematic parameters for the 3-PUU pure translational parallel mechanism with better characteristics can be directly acquired.展开更多
Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators（more than three design parameters）, such as Stewart ma...Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators（more than three design parameters）, such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace（SUW）, primary kinematic performance indices of the Stewart manipulator involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.展开更多
As the structures of multiarm robots are serially arranged,the packaging and transportation of these robots are often inconvenient.The ability of these robots to operate objects must also be improved.Addressing this i...As the structures of multiarm robots are serially arranged,the packaging and transportation of these robots are often inconvenient.The ability of these robots to operate objects must also be improved.Addressing this issue,this paper presents a type of multiarm robot that can be adequately folded into a designed area.The robot can achieve different operation modes by combining different arms and objects.First,deployable kinematic chains(DKCs)are designed,which can be folded into a designated area and be used as an arm structure in the multiarm robot mechanism.The strategy of a platform for storing DKCs is proposed.Based on the restrictions in the storage area and the characteristics of parallel mechanisms,a class of DKCs,called base assembly library,is obtained.Subsequently,an assembly method for the synthesis of the multiarm robot mechanism is proposed,which can be formed by the connection of a multiarm robot mechanism with an operation object based on a parallel mechanism structure.The formed parallel mechanism can achieve a reconfigurable characteristic when different DKCs connect to the operation object.Using this method,two types of multiarm robot mechanisms with four DKCs that can switch operation modes to perform different tasks through autonomous combination and release operation is proposed.The obtained mechanisms have observable advantages when compared with the traditional mechanisms,including optimizing the occupied volume during transportation and using parallel mechanism theory to analyze the switching of operation modes.展开更多
This paper addresses geometry design of a new kind of 2-DOF parallel manipulator actuated horizontally by linear actua- tors. The first step of the optimum design involves developing a non-dimensional structure of the...This paper addresses geometry design of a new kind of 2-DOF parallel manipulator actuated horizontally by linear actua- tors. The first step of the optimum design involves developing a non-dimensional structure of the planar 2-DOF parallel manipulator. The global conditioning index, global velocity index, global stiffness index and global payload index of the 2-DOF parallel manipu- lators are investigated, and the geometrical parameters without dimension are determined with respect to the specification on per- formances. Finally, based on the optimum non-dimensional result, the optimum dimensional parameters are achieved which is suit- able for the desired workspace. The optimum methodology of this paper is convenient and can be extended to other parallel mecha-展开更多
To promote the pose accuracy performance of a spatial parallel kinematic Mechanism( PKM) in service,a workshop oriented tolerance synthesis method based on design of experiment( DOE) is proposed,which involves two con...To promote the pose accuracy performance of a spatial parallel kinematic Mechanism( PKM) in service,a workshop oriented tolerance synthesis method based on design of experiment( DOE) is proposed,which involves two consecutive stages. In the first stage of DOE,the tolerance factor sensitivities are obtained according to initial tolerance settings with the consideration of the current manufacturing capacity,and the second stage of DOE makes use of them to produce multiple tolerance allocations which can adapt to current manufacturing capacity. A tolerance synthesis procedure is developed and integrated in tolerance design system for PKM. Comparing the results with peer method,the validity and practicability of this method is verified.展开更多
Robot-assisted technology has been increasingly employed in the therapy of post stroke patients to deliver high-quality treatment and alleviate therapists5 burden.This paper introduces a novel parallel end traction ap...Robot-assisted technology has been increasingly employed in the therapy of post stroke patients to deliver high-quality treatment and alleviate therapists5 burden.This paper introduces a novel parallel end traction apparatus(PETA)to supplement equipment selection.Considering the appearance and performance of the PETA,two types of special five-bar linkage mechanisms are selected as the potential configurations of the actuation execution unit because of their compact arrangement and parallel structure.Kinematic analysis of each mechanism,i.e.,position solutions and Jacobian matrix,is carried out.Subsequently,a comparative study between the two mechanisms is conducted.In the established source of nondimensional parameter synthesis,the singularity,maximum continuous workspace,and performance variation trends are analyzed.Based on the evaluation results,the final scheme with determined configuration and corresponding near-optimized non-dimensional parameters is obtained.Then,a prototype is constructed.By adding a lockable translational degree of freedom in the vertical direction,the PETA can provide 2D planar exercise and 3D spatial exercise.Finally,a control system is developed for passive exercise mode based on the derived inverse position solution,and preliminary experiments are performed to verify the applicability of the PETA.展开更多
基金This project is supported by National Natural Science Foundation of China (No.60275031)Municipal Key Lab Open Fund of Beijing, China (No.KP01-072200384).
文摘Performance analysis and kinematic design of the 3-PUU pure translational parallel mechanism with vertical guide-ways are investigated. Two novel performance indices, the critical slider stroke and the main section area of workspace, are defined; The expressions of two other indices, i.e. the global dexterity and global force transfer ratio are revised based on the main section of workspace. Using these indices, performance changes versus the varieties of dimensional parameters of mechanism are investigated in detail and the graphic descriptions of change tendencies of the performance indices are illustrated. By means of these obtained graphic descriptions, kinematic parameters for the 3-PUU pure translational parallel mechanism with better characteristics can be directly acquired.
基金Supported by National Natural Science Foundation of China(Grant Nos.51205224,51475252)National Outstanding Youth Science Foundation of China(Grant No.51225503)
文摘Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators（more than three design parameters）, such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace（SUW）, primary kinematic performance indices of the Stewart manipulator involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.
基金Supported by National Natural Science Foundation of China(Grant No.51875033)the Fundamental Research Funds for the Central Universities(Grant No.2018JBM051)program of China Scholarships Council(Grant No.CSC201907090037).
文摘As the structures of multiarm robots are serially arranged,the packaging and transportation of these robots are often inconvenient.The ability of these robots to operate objects must also be improved.Addressing this issue,this paper presents a type of multiarm robot that can be adequately folded into a designed area.The robot can achieve different operation modes by combining different arms and objects.First,deployable kinematic chains(DKCs)are designed,which can be folded into a designated area and be used as an arm structure in the multiarm robot mechanism.The strategy of a platform for storing DKCs is proposed.Based on the restrictions in the storage area and the characteristics of parallel mechanisms,a class of DKCs,called base assembly library,is obtained.Subsequently,an assembly method for the synthesis of the multiarm robot mechanism is proposed,which can be formed by the connection of a multiarm robot mechanism with an operation object based on a parallel mechanism structure.The formed parallel mechanism can achieve a reconfigurable characteristic when different DKCs connect to the operation object.Using this method,two types of multiarm robot mechanisms with four DKCs that can switch operation modes to perform different tasks through autonomous combination and release operation is proposed.The obtained mechanisms have observable advantages when compared with the traditional mechanisms,including optimizing the occupied volume during transportation and using parallel mechanism theory to analyze the switching of operation modes.
文摘This paper addresses geometry design of a new kind of 2-DOF parallel manipulator actuated horizontally by linear actua- tors. The first step of the optimum design involves developing a non-dimensional structure of the planar 2-DOF parallel manipulator. The global conditioning index, global velocity index, global stiffness index and global payload index of the 2-DOF parallel manipu- lators are investigated, and the geometrical parameters without dimension are determined with respect to the specification on per- formances. Finally, based on the optimum non-dimensional result, the optimum dimensional parameters are achieved which is suit- able for the desired workspace. The optimum methodology of this paper is convenient and can be extended to other parallel mecha-
基金Sponsored by the National Defense Basic Scientific Research Program(Grant No.A0320110019)the Shanghai Science and Technology Innovation Action Plan(Grant No.11DZ1120800)
文摘To promote the pose accuracy performance of a spatial parallel kinematic Mechanism( PKM) in service,a workshop oriented tolerance synthesis method based on design of experiment( DOE) is proposed,which involves two consecutive stages. In the first stage of DOE,the tolerance factor sensitivities are obtained according to initial tolerance settings with the consideration of the current manufacturing capacity,and the second stage of DOE makes use of them to produce multiple tolerance allocations which can adapt to current manufacturing capacity. A tolerance synthesis procedure is developed and integrated in tolerance design system for PKM. Comparing the results with peer method,the validity and practicability of this method is verified.
基金The authors thank Henan Huibo Medical Co.,Ltd.for several useful suggestions on this apparatus.Additionally,this research is funded in part by Beijing Natural Science Foundation(Grant No.3204036)in part by the National Key R&D Program of China(Grant Nos.2018YFB1307004 and 2020YFC2004200)+1 种基金in part by the National Natural Science Foundation of China(Grant No.61903011)in part by the General Program of Science and Technology Development Project of the Beijing Municipal Education Commission(Grant No.KM202010005021).
文摘Robot-assisted technology has been increasingly employed in the therapy of post stroke patients to deliver high-quality treatment and alleviate therapists5 burden.This paper introduces a novel parallel end traction apparatus(PETA)to supplement equipment selection.Considering the appearance and performance of the PETA,two types of special five-bar linkage mechanisms are selected as the potential configurations of the actuation execution unit because of their compact arrangement and parallel structure.Kinematic analysis of each mechanism,i.e.,position solutions and Jacobian matrix,is carried out.Subsequently,a comparative study between the two mechanisms is conducted.In the established source of nondimensional parameter synthesis,the singularity,maximum continuous workspace,and performance variation trends are analyzed.Based on the evaluation results,the final scheme with determined configuration and corresponding near-optimized non-dimensional parameters is obtained.Then,a prototype is constructed.By adding a lockable translational degree of freedom in the vertical direction,the PETA can provide 2D planar exercise and 3D spatial exercise.Finally,a control system is developed for passive exercise mode based on the derived inverse position solution,and preliminary experiments are performed to verify the applicability of the PETA.
