Kinematic design of a PKM-type composite actuator

Nowadays one development trend of machines is to grow bigger and bigger in size and hence larger actuators are required. To develop a larger servo mechanical press, a composite actuator scheme is proposed to combine two or more programmable actuators to act as one actuator through a two- or multi- degree of freedom (dof) parallel kinematic mechanism (PKM). In this paper, the performance indices for the compositie actuator are proposed to describe the mechanical adavantages of a general mechanism. The kinematic model is built based on Assur's Group method. The dimensional design are introduced to make the composite actuator having a nearly constant mechanical advantage. Based on the discussions, a pending patent is applied for a new servo mechanical press developed in the laboratory.