With the continuous development of modern science and technology,robot mechanisms are used in various industries.Structurally,robot mechanisms can be divided into series mechanisms,parallel mechanisms,and series-parallel hybrid mechanisms.Because of the characteristics of high rigidity,large bearing capacity and high precision,the parallel mechanism has obvious advantages compared with the series mechanism,and has received increasing attention.In this paper,a class of spatial 3-RRC parallel mechanisms with three axes parallel to each branch as the research object is analyzed,kinematics for it is analysed including degree of freedom(DOF),position,singularity,and workspace.Finally,based on the results of theoretical analysis,a workspace analysis software for spatial 3-RRC parallel mechanism was developed using Visual Basic.First,parameterize the structure of the spatial 3-RRC parallel mechanism,use the the mobility principel based on reciprocal screw and the modified Kutzbach-GrĂ¼bler formula to analyze the DOF of the mechanism and make a full-cycle discrimination;Introduce new constraints on the mobile platform of spatial 3-RRC parallel mechanism and verify whether the DOF of the mechanism changes to determine the singularity.Secondly,the position equation was established through geometric knowledge,use CAD(Computer Aided Design)software to carry out graphical calculation of forward and inverse solutions;Based on the sufficient and necessary conditions of the inverse position solution,the maximum workspace of the 3-RRC parallel mechanism under geometrical constraints is the intersection of three hollow cylinders,and the workespace can also be drawn;Finally,verify the correctness of the forward and inverse position solutions and the workespace by CAD software.Finally,the workspace analysis software for spatial 3-RRC parallel mechanism was developed,design the software interface based on the functions to be implemented,determine the corresponding code of the controls in the software interface,and finally complete the software development to facilitate the design and optimization of spatial 3-RRC parallel mechanism. |