Capability Analysis of Linear Extended State Observer Under Model Mismatch for LADRC control

The Linear Extended State Observer (LESO) with model mismatch for Linear Active Disturbance Rejection Control (LADRC) is investigated in this paper, which is different from the existed results that only consider the unknown disturbances. Not only the uncertain disturbances in system are considered, but the model mismatch between the observer and the actual system is also considered. In Bounded-Input Bounded-Output stability scheme, the observer is analyzed in the time domain, and the observer error under a certain degree model mismatch is given. It is proved that for LESO, the observer error caused by the model mismatch is bounded and related to the bandwidth (w 0 ), and the error caused by model mismatch can be decreased by increasing bandwidth of the observer.