This study presents an adaptive one-step ahead state predictor for a class of uncertain non-linear systems including power electronic
systems such as power converters and motor drives. The proposed predictor is designed using an adaptive proportional–integral
observer design method with σ-modification so that it robustly estimates the real state without steady-state estimation errors. The
simulation and experiment results demonstrate that the proposed method effectively predicts the one-step ahead state in the
presence of parameter variations.