Low-order model-based feedforward for high-speed jitter-free tray indexing applications

Lightweight stages are becoming the new trend in industrial high performance motion systems. In many front-end semiconductor equipments, feedforward control is widely used to improve tracking accuracy of motion systems. On the other hand, in most back-end semiconductor applications, the low frequency disturbance is more significant and it needs to be compensated effectively in order for the feedforward controller to achieve good performance. In this paper, a novel feedforward controller and a 3-DOF control structure with disturbance observer are proposed to reduce tracking error of flexible motion systems. Experiments on tray conveying and indexing tasks are conducted to show the effectiveness of the proposed solution.