Control structure design for sheet forming processes

The control structure design for paper-making processes is addressed. The recycle structure in the process is identified first and the zero gain process characteristic is derived from material. balances. A new control structure is proposed to overcome the zero gain behavior. This leads to a decoupled CD/MD control formulation as opposed to the traditional singular CD control problem. Practical issues such as desired actuator positions, consistency measurement problems and actuator interaction are addressed and remedial actions are also proposed. Simulation results show that the proposed control structure demonstrates good control performance and exhibits robustness to modeling errors. More importantly, the improvement is achieved by the control structure redesign.