Kinematic and dynamic analyses of the multi-actuated mechanical press with parallel topology

Abstract

This article proposes a new type of multi-actuated mechanical press with parallel topology to develop high stamping capacity. Four active limbs actuated by servomotor deliver forces and motions to moving platform, and the passive limbs are driven by moving platform to push or pull the ram. This four-input-single-output system realizes multiple actuations without causing being over-constrained. Due to infinite number of solutions for the inverse kinematics, selection of actuation schemes for given ram trajectories is more crucial. Further, the principle of virtual work is used in the inverse dynamic problem. By choosing the pose variables of moving platform as generalized coordinates to describe the manipulator system, the linear form of dynamic models is derived. A typical deep-drawing process with nominal 25,000 kN capacity and 1200 mm stroke is simulated, and the required driving torques are computed. These performance analyses provide a basis to the design of the control law or the estimation of servomotor parameters for the mechanical press.