Advanced Synchronization Control of a Dual-Linear-Motor-Driven Gantry With Rotational Dynamics

Dual-linear-motor-driven gantry systems have been widely used in high-speed or heavy payload precision motion systems. Due to the unique physical properties such as mechanical coupling, the precise synchronization control of such kinds of systems is crucial to achieve good tracking and smooth operation performance. However, the existing synchronization schemes usually focus on the pure motion synchronization only and, thus, have certain inherent performance limitations. In this paper, an accurate multi-input multi-output mathematical model of a dual-driven gantry is presented first, where the complete planar motions of the crossbeam include the traditional linear motion along the guide rails and the previously ignored rotational motion around the mass center. With the better understanding of the mechanical coupling and the internal forces caused by the rotational dynamics, an advanced synchronization control scheme by directly taking into account the additive rotational dynamics is presented, which not only synchronizes the motions of two parallel motors but also regulates the internal forces. In the proposed scheme, the adaptive robust control algorithm is also applied to obtain a guaranteed robust performance in the presence of both parametric uncertainties and uncertain nonlinearities. Comparative experiments with previous control schemes are carried out to show the better synchronization performance and verify the effectiveness of the proposed method.