Kinematics and dynamics of a 6 degree-of-freedom fully parallel manipulator with elastic joints

This paper deals with the kinematics and dynamics analysis of a 6 degree-of-freedom RTS fully parallel manipulator with elastic joints. The elastic joints are used to realize highly precise operation. Rotary input is applied to drive six groups of four-bar linkages in this system. Two displacement equations and velocity analysis of the active links and elastic joints are firstly addressed. The angular-velocity of the elastic joints in the motional state are described. In order to investigate the effect of the elastic moment in the dynamic analysis, the elastic bending and the torsional deformation of the elastic joints are presented by only using the vector operation. The standard dynamics formulation including the equivalent torque of the elastic moment with the generalized input is established by virtue of the principle of virtual work and the Lagrange’s method. A study through simulation is provided for a trajectory given in the task-space. Because of employing the kinematic influence coefficients, the dynamic modeling does become simply and the dynamics can readily be formulated in the simulation.