Modeling and Synchronization Control of a Dual Drive Industrial Gantry Stage

Dual drive gantry mechanisms, in which two actuators are physically connected through a crossbeam to provide a joint thrust for higher acceleration, are widely used in high-speed or heavy payload precision motion control applications. Synchronizing motions of the two actuators and avoiding excessive internal forces are both essential to the smooth operation of these systems. This paper presents a novel synchronization control scheme with thrust allocation that achieves not only better motion synchronization of the two actuators but also simultaneous regulation of internal forces. With decreased internal forces, lesser wear in sliding parts, lower energy consumption, and higher performances can be achieved for dual drive gantry stages. In contrast, existing synchronization control approaches mainly focus on pure motion compensation and synchronization of the two actuators only. Due to the near-rigid physical coupling between the two actuators, excessive internal forces or the “pull and drag” phenomena could still exhibit under existing approaches even when their motions are quite well synchronized. Comparative experimental results are also obtained to show the superiority of the proposed synchronization controller over existing ones in practical applications.