In the realm of advanced manufacturing and energy technologies, a team of researchers from the University of Sheffield, including Zezhi Tang, Christopher Passmore, Andrew I Campbell, Jonathan Howse, J Anthony Rossiter, Stephen Ebbens, and George Panoutsos, has developed a novel control system to enhance the precision of roll-to-roll slot die coating processes. This technique is crucial for producing high-quality films used in lithium-ion batteries, solar cells, and optical films, among other applications.
Roll-to-roll slot die coating is a manufacturing process where a thin film is applied onto a moving substrate, such as a plastic or metal foil. The quality of the coated film depends on maintaining precise control over parameters like pump rate, substrate velocity, and coating gap. However, these parameters are often disrupted by disturbances in process conditions, leading to inconsistencies in the film’s characteristics.
To address this challenge, the researchers utilized a disturbance observer (DO) to detect and mitigate disturbances within the system. The DO can identify disturbances that occur in the same or different channels as the control signal. Once detected, a generalized compensator is implemented to counteract these disturbances, thereby enhancing the system’s ability to suppress uncertainties.
The researchers integrated the disturbance rejection system with an output tracking controller. This combination allows the coating system to maintain the desired film thickness under varying input conditions and disturbances. The effectiveness of this approach was validated using a test rig equipped with a camera system. The camera system facilitated the development of a data-driven model of the dynamic process, represented by state-space equations. Simulation results demonstrated the effectiveness of the disturbance observer-based output tracking control (DOBOTC) system, providing a robust solution for maintaining precise control over the coating process.
This research, published in the journal IEEE Transactions on Control Systems Technology, offers practical applications for the energy sector, particularly in the manufacturing of lithium-ion batteries and solar cells. By improving the consistency and quality of the coated films, this technology can enhance the performance and reliability of energy storage and conversion devices. The DOBOTC system’s ability to handle generalized disturbances makes it a valuable tool for optimizing manufacturing processes in the energy industry.
This article is based on research available at arXiv.