Servo drives introduce improved synchronization of large presses with robots

Productivity of press lines for the automotive industry can be increased by 10-30% by the introduction of servo drives. Highest productivity is however only obtained by optimally synchronizing presses and loading/unloading equipment (robots). This paper proposes synchronization algorithms which are designed for low-power servo-press drives, in which acceleration and deceleration of the press takes a significant part of the cycle. Deceleration at the end of the cycle is started at a point already taking into account at what moment the loader will have completed its work. During deceleration, the moment at which to re-accelerate for the next cycle is re-calculated based on an actual prediction of loader motion. In a practical implementation, the proposed algorithms for press control are implemented in a robot controller, the same controller which controls the loader robot.