Internal Model Control with Distributed-Delay-Compensator to Attenuate Multi-Harmonic Periodic Disturbance of Time-Delay System

A distributed-delay based compensator for the Internal Model Control scheme is introduced as an alternative to the repetitive control structure to attenuate periodic disturbance with multiple harmonics. Besides the periodic signal attenuation, the scheme is derived to compensate an input time-delay of the controlled system. Next, the performance requirements on the spectral, frequency, and time domain characteristics are used for an optimization-based design. The task is to minimize the ${{\mathcal{H}}_{\infty} }$ norm of the weighted sensitivity, while the spectral and structural properties comply with the constraints. The proposed design is tested on a model of a hot rolling process, which motivates the research. Numerical analysis and simulation-based verification complete the presentation.