Adaptive Wavelet Tracking Control of Dual-Linear-Motor-Driven Gantry Stage With Suppression of Crossbeam Rotation

Dual-linear-motor-driven gantry stages (DLMDGS) are crucial components of high-end manufacturing equipment, known for their ability to achieve high-precision control at high-speeds. However, the traditional model-based control method has almost reached its limits in terms of improving control performance. In this paper, a novel approach is proposed to improve control performance by considering the rotation suppression of the crossbeam, which reduces the coupling dynamics between the two motion directions. To achieve high tracking performance, a high precision robust control scheme is developed based on the wavelet series approximation method. Through detailed analysis of the forces applied to the stage and approximation of the unknown dynamics, an on-line adaptive feed-forward compensation law is designed to enhance tracking precision and inhibit the rotation of the crossbeam. The stability of the system under the proposed control scheme is demonstrated through the Lyapunov method. Moreover, comparative tests are conducted on a real system to validate the effectiveness of our proposed method.