Switched LPV Observer for Joint State and Delay Estimation: Application to a DC Motor-Propeller

In this paper we propose a switched linear parameter-varying (LPV) observer for single-input single-output (SISO) linear time-invariant (LTI) systems with an internal and unknown time-varying input delay. The observer estimates the unknown states and input delay using only the measured output and the known input. A switching component ensures feasible observer gain design under mild input and delay conditions, guaranteeing a bounded estimation error even when the input derivative is close to zero and observability is lost. This overcomes a limitation in previous approaches for delay estimation. The practical performance of the observer is demonstrated through experimental results obtained from its application to a physical DC motor-propeller system.