Inverse dynamics and simulation of a 3-DOF spatial parallel manipulator

Recently the parallel manipulators with less DOF have attracted the researchers, but works on their dynamics are relative few. In this paper, an inverse dynamic formulation is presented by the Newton-Euler approach for a spatial parallel manipulator, which has two translational degrees of freedom and one rotational degree of freedom. The inverse kinematics analysis is firstly performed in closed form. Then the force and moment equilibrium equations for the manipulator are presented. According to the kinematic constraints of the legs and the platform, some joint constraint forces are eliminated and an algorithm to solve the actuator forces is given. In addition, ADAMS is used to perform the kinematic and dynamic simulation for the manipulator. The simulation results are compared to those derived from algebraic formulae and the comparison shows the validity of the mathematical model.