A direct-drive SCARA robot for wafer&ceramic-substrate handling based on visual servoing

Abstract

In this paper, a 4-DOF (Degrees of Freedom) direct-drive SCARA (Selective Compliant Assembly Robot Arm) robot is designed for wafer&ceramic-substrate handing purpose. In order to improve the flexibility of the whole wafer&ceramic-substrate handling system, we abandon the traditional aligner which can only achieve accurate positioning of the wafer and for ceramic-substrate is powerless, but introduce the visual servoing control strategy to excellent achieve the purpose of rapid and accurate aligning of the wafer&ceramic-substrate. In view of the structural characteristics of SCARA robot, we adopted the XY/Z-Partitioned IBVS scheme, which realized the control decoupling of x-, y-axis and z-axis. The reliability of visual servoing control strategy is verified by simulation and the physical prototype of the SCARA robot. Performance meets with the requirements in the wafer&ceramic-substrate handling process.