Robust Predictor Feedback Input Delay Compensation with Application to Daylight Harvesting Control

This paper presents a multi-variable predictor feedback controller for a static, multi-input multi-output, daylight harvesting system affected by an uncertain input delay and unknown external disturbances. To this end, a predictor feedback control scheme is incorporated into a stabilizing feedback controller used in the absence of delay. The issues rising from delay estimation errors are discussed and heuristic stability and robustness analysis based on the root locus method is presented that facilitates the complicated task of controller design and tuning in presence of delay mismatch. The proposed analysis can be applied to systems of any order with time delay, regardless of their open-loop stability characteristics. Simulation results are presented to verify the effectiveness of the proposed analysis method and control scheme.