Synchronous and contouring control for gantry-type feed drive systems

This paper presents a controller design to reduce consumed energy for gantry-type feed drive systems which consist of two linear actuators placed in parallel and one linear actuator placed perpendicular to the two parallel actuators. Synchronous controller design has been widely studied for two parallel actuators because positional (synchronous) error between them causes not only control performance deterioration but also significant mechanical damage to the feed drive system. Although the existing synchronous controller design aims to reduce the synchronous error, this paper first presents a new design that is effective to reduce consumed electric energy while maintaining the synchronous control performance. Contouring controller for multi-axis feed drives is also widely studied thus far, which aims to reduce contouring error in machining and coordinate measurement. This paper next presents a combined synchronous and contouring controller that aims to reduce consumed electric energy while maintaining the contouring control performance in gantry-type feed drive systems. Experimental results show the effectiveness of the proposed controller by which consumed electric energy is reduced by about 7%.