On The Design of a Novel Finite-Time Nonlinear Extended State Observer for Class of Nonlinear Systems with Mismatch Disturbances and Uncertainties
For control engineers, this work offers an incremental improvement to ESO by reducing peaking, but the results are only simulated on a single motor example.
The paper proposes a finite-time nonlinear extended state observer (NLESO) for active disturbance rejection control of nonlinear systems with mismatch disturbances and uncertainties. The NLESO reduces peaking compared to linear ESO, and simulations on a PMDC motor demonstrate its effectiveness.
In this paper, a novel finite - time Nonlinear Extended State Observer (NLESO) is proposed and employed in Active Disturbance Rejection Control (ADRC) to stabilize a nonlinear system against system's uncertainties and discontinuous disturbances using output feedback technique. The first task was to aggregate the uncertainties, disturbances, and any other undesired nonlinearities in the system into a single term called the "generalized disturbance". Consequently, the ESO estimates the generalized disturbance and cancel it from the input channel in an online fashion. A peaking phenomenon that existed in Linear ESO (LESO) has been reduced significantly by adopting a saturation - like nonlinear function in the proposed Nonlinear ESO (NLESO). Stability analysis of the NLEO is studied using finite - time Lyapunov theory, and the comparisons are presented over simulations on Permanent Magnet DC (PMDC) motor to confirm the effectiveness of the proposed observer concerning LESO.