Disturbance Observer-Based Optimal Tracking Control for Slot Coating Process with Mismatched Input Disturbances

Slot coating is a widely used technique in various manufacturing processes. The efficiency of the process mostly depends on the precise control of diverse inputs such as pump rate and gap. However, this method can be sensitive to minor disturbances in process conditions, which can disrupt the uniformity of the film thickness. To overcome the challenge, through the implementation of the generalized disturbance observer and compensator, the impact of disturbances can be attenuated in the output channel. In addition, by combining with an output tracking controller, the proposed composite architecture effectively compensates the disturbances while guaranteeing the tracking of the specified film thickness across a wide range of situations. The simulation results were illustrated to showcase the effectiveness of the disturbance observer-based optimal tracking control (DOBOTC) system.