The Project involves development of a servo mechanical press mainly involves programmable actuator and control technology, punching linkage design, and ram motion design technology.
For current designs, servomotors are normally used as programmable actuators.
To develop heavy-duty programmable mechanical presses at relatively low cost, a new design is proposed and being developed in our laboratory to achieve higher tonnage by using more than one servomotor to drive the 1-DOF punching linkage [.
This new scheme is called redundant actuation, or composite actuator. It provides an optional solution to heavy-duty actuation at a relatively low cost or at a higher power than single servo motor available.
To combine two or more programmable actuators into a composite actuator, a 2-DOF or multi-DOF parallel mechanism is a feasible solution from a mechanical point of view ), similar to a yoke used between a pair of or more oxen to allow them to pull a load. In , several schemes of redundant actuation were proposed based on parallel mechanisms ).
Apparently, a composite actuator should be able to act as one servomotor of large capability in terms of nominal torque, nominal power, nominal speed, and efficiency. To function as one servomotor, the mechanism to combine the programmable actuators should be of high efficiency, of high mechanical advantage and of high structural stiffness.
It is obvious that a composite actuator can accommadate a slim un-synchronization of individual servomotors and even fault-tolerant of individual servomotors’ disorder.
Therefore, a slight difference between the motions of the two servomotors is permitted by the mechanical structure of the servo press to let the ram move freely.