Control structure design for sheet forming processes

The control structure design for paper-making processes is addressed. The r ecycle structure in the process is identified first and the zero gain proce ss characteristic is derived from material. balances. A new control structu re is proposed to overcome the zero gain behavior. This leads to a decouple d CD/MD control formulation as opposed to the traditional singular CD contr ol problem. Practical issues such as desired actuator positions, consistenc y measurement problems and actuator interaction are addressed and remedial actions are also proposed. Simulation results show that the proposed contro l structure demonstrates good control performance and exhibits robustness t o modeling errors. More importantly, the improvement is achieved by the con trol structure redesign.