Research On Dynamics, Singular And Precision Of Parallel Manipulator

Sine 1978, Professor Hunt firstly proposed that The Stewart platform is used as robotic architecture, which is a six-degree-of-freedom mechanism with two bodies connected together by six extensible legs. Parallel manipulators have being causing scholastic's attentions around the world and becoming a newly hot research topic of robotic, which has the potentially features of their structures: high rigidity, high accuracy, large load-carrying capacity, and rapid speed over serial manipulators.Mechanical theory of parallel manipulators which structures are quite complex and have many inherent characters is a branch of multi-dof, multi-closed loop structure system. Through researching the topic, it's of responsibility to master parallel and develop new prototype. In the present work, the dynamics theory, singular and precision of 3-6 Stewart platform will be discussed. The detail problems are followed.Based on the screw theory, the dynamics problem was discussed in twist-shape relations, so as to the open serial and closed chains analysis. It made relationship between wrench and twist on the virtual work principle; It founded dynamic formulation by Klein principle. It did dynamic analysis of three-shaft parallel manipulator on platform; The velocity and acceleration of parallel manipulator was held and the relations of velocity and acceleration were found between platform and different driving legs for dynamic analysis of parallel manipulator; The derivation of dynamic formulation for parallel manipulator by the screw theory and the principle of virtual work was gained; The functions of mass, moment of inertia, velocity of platform and driving legs for the dynamic model were discussed.The parallel manipulator possesses singular configuration where the manipulator was uncontrolled when Jacobin determinant is zero at the points in the path. Base on the screw theory and kinematics' theory, the singularity loci and distribution characteristics for...