This paper proposes an analytical solution for a 5-DOF manipulator to follow a given trajectory while keeping the orientation of one axis in the end-effector frame. The forward kinematics and inverse kinematics for a ...This paper proposes an analytical solution for a 5-DOF manipulator to follow a given trajectory while keeping the orientation of one axis in the end-effector frame. The forward kinematics and inverse kinematics for a 5-DOF manipulator are analyzed systemically. The singular problem is discussed after the forward kinematics is provided. For any given reachable position and orientation of the end-effector, the derived inverse kinematics will provide an accurate solution. In other words, there exists no singular problem for the 5-DOF manipulator, which has wide application areas such as welding, spraying, and painting. Experiment results verify the effectiveness of the methods developed in this paper.展开更多
The trajectory tracking control for a 6-DOF robot manipulator with multiple inputs and outputs,non-linearity and strong coupling is studied.Firstly,a dynamical model for the 6-DOF robot manipulator is designed.From th...The trajectory tracking control for a 6-DOF robot manipulator with multiple inputs and outputs,non-linearity and strong coupling is studied.Firstly,a dynamical model for the 6-DOF robot manipulator is designed.From the view point of practical engineering,considering the model uncertainties and external disturbances,the robot manipulator is divided into 6 independent joint subsystems,and a linear active disturbance rejection controller(LADRC)is developed to track trajectory for each subsystem respectively.LADRC has few parameters that are easy to be adjusted in engineering.Linear expansion state observer(LESO)as the uncertainty observer is able to estimate the general uncertainties effectively.Eventually,the validity and robustness of the proposed method adopted in 6-DOF robot manipulator are demonstrated via numerical simulations and 6-DOF robot manipulator experiments,which is of practical value in engineering application.展开更多
Probe manipulators are a versatile addition to typical plasma edge diagnostics.Equipped with material samples they allow for detailed investigation of plasma–wall interaction processes,such as material erosion,deposi...Probe manipulators are a versatile addition to typical plasma edge diagnostics.Equipped with material samples they allow for detailed investigation of plasma–wall interaction processes,such as material erosion,deposition or impurity transport pathways.When combined with electrical probes,a study of scrape-off layer and plasma edge density,temperature and flow profiles as well as magnetic topologies is possible.A mid-plane manipulator is already in operation on Wendelstein 7-X.A system in the divertor region is currently under development.In the present paper we discuss the critical issue of heat and power loads,power redistribution and experimental access to the complex magnetic topology of Wendelstein 7-X.All the aforementioned aspects are of relevance for the design and operation of a probe manipulator in a device like Wendelstein?7-X.A focus is put on the topological region that is accessible for the different coil current configurations at Wendelstein 7-X and the power load on the manipulator with respect to the resulting different magnetic configurations.Qualitative analysis of power loads on plasma-facing components is performed using a numerical tracer particle diffusion tool provided via the Wendelstein 7-X Webservices.展开更多
In order to solve the problems of too large mass,too complex structure and poor flexibility of the 6 DOF manipulator,the topological optimization theory based on variable density method is applied to the 6-DOF manipul...In order to solve the problems of too large mass,too complex structure and poor flexibility of the 6 DOF manipulator,the topological optimization theory based on variable density method is applied to the 6-DOF manipulator,the topology optimization of the main structural components of the manipulator is carried out with the help of the finite element software ANSYS,and the optimized structure is simplified according to the density distribution of the units and the requirements of manufacturability.the results are compared and analysed by static mechanics.It shows that the whole mass of the 6-DOF manipulator is reduced by 47.23%without changing the original mechanical properties after topological optimization,and the optimized model can meet the requirements of manufacturability,the optimization effect is signifcant,which can be used as a reference for the structure optimization of the 6-DOF manipulator.展开更多
Seven-degree-of-freedom redundant manipulators with link offset have many advantages,including obvious geometric significance and suitability for configuration control.Their configuration is similar to that of the exp...Seven-degree-of-freedom redundant manipulators with link offset have many advantages,including obvious geometric significance and suitability for configuration control.Their configuration is similar to that of the experimental module manipulator(EMM)in the Chinese Space Station Remote Manipulator System.However,finding the analytical solution of an EMM on the basis of arm angle parameterization is difficult.This study proposes a high-precision,semi-analytical inverse method for EMMs.Firstly,the analytical inverse kinematic solution is established based on joint angle parameterization.Secondly,the analytical inverse kinematic solution for a non-offset spherical-roll-spherical(SRS)redundant manipulator is derived based on arm angle parameterization.The approximate solution of the EMM is calculated in accordance with the relationship between the joint angles of the EMM and the SRS manipulator.Thirdly,the error is corrected using a numerical method through the analytical inverse solution based on joint angle parameterization.After selecting the stride and termination condition,the precise inverse solution is computed for the EMM based on arm angle parameterization.Lastly,case solutions confirm that this method has high precision,and the arm angle parameterization method is superior to the joint angle parameterization method in terms of parameter selection.展开更多
An analytic inverse kinematic solution is presented for a 7-DOF(degree of freedom)redundant space manipulator.The proposed method can obtain all the feasible solutions in the global joint space,which are denoted by a ...An analytic inverse kinematic solution is presented for a 7-DOF(degree of freedom)redundant space manipulator.The proposed method can obtain all the feasible solutions in the global joint space,which are denoted by a joint angle parameter.Meanwhile,both the singularity problem and the joint limits are considered in detail.Besides,an optimization approach is provided to get one near optimal inverse kinematic solution from all the feasible solutions.The proposed method can reduce effectively the computational complexity,so that it can be applied online.Finally,the method’s validity is shown by kinematic simulations.展开更多
A novel hybrid perfusion manipulator(HPM)with five degrees of freedom(DOFs)is introduced by combining the 5PUS-PRPU(P,R,U and S represent prismatic,revolute,universal and spherical joint,respectively)parallel mechanis...A novel hybrid perfusion manipulator(HPM)with five degrees of freedom(DOFs)is introduced by combining the 5PUS-PRPU(P,R,U and S represent prismatic,revolute,universal and spherical joint,respectively)parallel mechanism with the 5PRR reconfigurable base to enhance the perfusion efficiency of the large-scale spherical honeycomb thermal protection layer.This study mainly presents the dimensional synthesis of the proposed HPM.First,the inverse kinematics,including the analytic expression of the rotation angles of the U joint in the PUS limb,is obtained,and mobility analysis is conducted based on screw theory.The Jacobian matrix of 5PUS-PRPU is also determined with screw theory and used for the establishment of the objective function.Second,a global and comprehensive objective function(GCOF)is proposed to represent the Jacobian matrix’s condition number.With the genetic algorithm,dimensional synthesis is conducted by minimizing GCOF subject to the given variable constraints.The values of the designed variables corresponding to different configurations of the reconfigurable base are then obtained.Lastly,the optimal structure parameters of the proposed 5-DOF HPM are determined.Results show that the HPM with the optimized parameters has an enlarged orientation workspace,and the maximum angle of the reconfigurable base is decreased,which is conducive to improving the overall stiffness of HPM.展开更多
基金This work was supported by the National High Technology Research and Development Program of China (No. 2002AA422160)the National Key Fundamental Research and Development Project of China (973, No.2002CB312200)
文摘This paper proposes an analytical solution for a 5-DOF manipulator to follow a given trajectory while keeping the orientation of one axis in the end-effector frame. The forward kinematics and inverse kinematics for a 5-DOF manipulator are analyzed systemically. The singular problem is discussed after the forward kinematics is provided. For any given reachable position and orientation of the end-effector, the derived inverse kinematics will provide an accurate solution. In other words, there exists no singular problem for the 5-DOF manipulator, which has wide application areas such as welding, spraying, and painting. Experiment results verify the effectiveness of the methods developed in this paper.
基金Supported by the National Natural Science Foundation of China(No.11672290)
文摘The trajectory tracking control for a 6-DOF robot manipulator with multiple inputs and outputs,non-linearity and strong coupling is studied.Firstly,a dynamical model for the 6-DOF robot manipulator is designed.From the view point of practical engineering,considering the model uncertainties and external disturbances,the robot manipulator is divided into 6 independent joint subsystems,and a linear active disturbance rejection controller(LADRC)is developed to track trajectory for each subsystem respectively.LADRC has few parameters that are easy to be adjusted in engineering.Linear expansion state observer(LESO)as the uncertainty observer is able to estimate the general uncertainties effectively.Eventually,the validity and robustness of the proposed method adopted in 6-DOF robot manipulator are demonstrated via numerical simulations and 6-DOF robot manipulator experiments,which is of practical value in engineering application.
基金funding from the Euratom research and training programme 2014–2018 under grant agreement no.633053
文摘Probe manipulators are a versatile addition to typical plasma edge diagnostics.Equipped with material samples they allow for detailed investigation of plasma–wall interaction processes,such as material erosion,deposition or impurity transport pathways.When combined with electrical probes,a study of scrape-off layer and plasma edge density,temperature and flow profiles as well as magnetic topologies is possible.A mid-plane manipulator is already in operation on Wendelstein 7-X.A system in the divertor region is currently under development.In the present paper we discuss the critical issue of heat and power loads,power redistribution and experimental access to the complex magnetic topology of Wendelstein 7-X.All the aforementioned aspects are of relevance for the design and operation of a probe manipulator in a device like Wendelstein?7-X.A focus is put on the topological region that is accessible for the different coil current configurations at Wendelstein 7-X and the power load on the manipulator with respect to the resulting different magnetic configurations.Qualitative analysis of power loads on plasma-facing components is performed using a numerical tracer particle diffusion tool provided via the Wendelstein 7-X Webservices.
基金supported in part by China intelligent robot project of firm-universities cooperative R&D under Grant No.2021JQR021the Anhui Provincial Teaching Demonstration Course Project under Grant No.2020SJJXSFK0330+9 种基金the demonstration experiment training center project of Anhui Polytechnic University under Grant No.2020sysx02the Overseas Visiting and Research Project for Outstanding Young Backbone Talents in Universities of Anhui Province under Grant No.gxgwfx2019041the Innovation Project for Returned Overseas Students in Anhui Province under Grant No.2020LCX013Key Research and Development Projects of Anhui Province under Grant No.202004b11020006Scientific Research Foundation of Anhui Polytechnic University under Grant No.2020YQQ010Anhui Polytechnic University Research Initiation Fund for Introducing Talents under Grant No.2019YQQ004Anhui Polytechnic University Research Project under Grant No.Xjky019201905Industrial Collaborative Innovation Fund of Anhui Polytechnic University and Jiujiang District under Grant No.2021cyxtb9Open Project of Anhui Provincial Engineering Laboratory on Information Fusion and Control of Intelligent Robot under Grant No.IFCIR2020001Open project of Key Laboratory of industrial equipment quality big data Ministry of industry and information technology under Grant No.2021-IEQBD-05.
文摘In order to solve the problems of too large mass,too complex structure and poor flexibility of the 6 DOF manipulator,the topological optimization theory based on variable density method is applied to the 6-DOF manipulator,the topology optimization of the main structural components of the manipulator is carried out with the help of the finite element software ANSYS,and the optimized structure is simplified according to the density distribution of the units and the requirements of manufacturability.the results are compared and analysed by static mechanics.It shows that the whole mass of the 6-DOF manipulator is reduced by 47.23%without changing the original mechanical properties after topological optimization,and the optimized model can meet the requirements of manufacturability,the optimization effect is signifcant,which can be used as a reference for the structure optimization of the 6-DOF manipulator.
基金This work was supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.51521003)the Major Research Plan of National Natural Science Foundation of China(Grant No.91848202).
文摘Seven-degree-of-freedom redundant manipulators with link offset have many advantages,including obvious geometric significance and suitability for configuration control.Their configuration is similar to that of the experimental module manipulator(EMM)in the Chinese Space Station Remote Manipulator System.However,finding the analytical solution of an EMM on the basis of arm angle parameterization is difficult.This study proposes a high-precision,semi-analytical inverse method for EMMs.Firstly,the analytical inverse kinematic solution is established based on joint angle parameterization.Secondly,the analytical inverse kinematic solution for a non-offset spherical-roll-spherical(SRS)redundant manipulator is derived based on arm angle parameterization.The approximate solution of the EMM is calculated in accordance with the relationship between the joint angles of the EMM and the SRS manipulator.Thirdly,the error is corrected using a numerical method through the analytical inverse solution based on joint angle parameterization.After selecting the stride and termination condition,the precise inverse solution is computed for the EMM based on arm angle parameterization.Lastly,case solutions confirm that this method has high precision,and the arm angle parameterization method is superior to the joint angle parameterization method in terms of parameter selection.
基金the National 863 Program of China(2012AA041403)the National Natural Science Foundation of China(61305107)
文摘An analytic inverse kinematic solution is presented for a 7-DOF(degree of freedom)redundant space manipulator.The proposed method can obtain all the feasible solutions in the global joint space,which are denoted by a joint angle parameter.Meanwhile,both the singularity problem and the joint limits are considered in detail.Besides,an optimization approach is provided to get one near optimal inverse kinematic solution from all the feasible solutions.The proposed method can reduce effectively the computational complexity,so that it can be applied online.Finally,the method’s validity is shown by kinematic simulations.
基金support provided by the Fundamental Research Funds for Central Universities,China(Grant No.2018JBZ007)the China Scholarship Council(Grant No.201807090006)the National Natural Science Foundation of China(Grant No.51675037).
文摘A novel hybrid perfusion manipulator(HPM)with five degrees of freedom(DOFs)is introduced by combining the 5PUS-PRPU(P,R,U and S represent prismatic,revolute,universal and spherical joint,respectively)parallel mechanism with the 5PRR reconfigurable base to enhance the perfusion efficiency of the large-scale spherical honeycomb thermal protection layer.This study mainly presents the dimensional synthesis of the proposed HPM.First,the inverse kinematics,including the analytic expression of the rotation angles of the U joint in the PUS limb,is obtained,and mobility analysis is conducted based on screw theory.The Jacobian matrix of 5PUS-PRPU is also determined with screw theory and used for the establishment of the objective function.Second,a global and comprehensive objective function(GCOF)is proposed to represent the Jacobian matrix’s condition number.With the genetic algorithm,dimensional synthesis is conducted by minimizing GCOF subject to the given variable constraints.The values of the designed variables corresponding to different configurations of the reconfigurable base are then obtained.Lastly,the optimal structure parameters of the proposed 5-DOF HPM are determined.Results show that the HPM with the optimized parameters has an enlarged orientation workspace,and the maximum angle of the reconfigurable base is decreased,which is conducive to improving the overall stiffness of HPM.
