Trajectory planning of a new mechanical press with controllable mechanism

This paper presents the trajectory planning on a new metal forming press with controllable mechanism presented in our former study. The new press consists of a large constant speed motor and a servomotor to drive a two degree-of-freedom planar parallel mechanism. And the new design has a number of advantages: it is flexible (i.e., its ram motion is programmable) and it is inexpensive to build and to operate. This paper focuses on the trajectory planning. First, the inverse kinematics is presented, which gives the relationship between the ram travel and the angular motion, speed and acceleration of the two motors. Next, the trajectory planning is investigated based on polynomial interpolation and optimization. A simulation Study is also made to illustrate the method.