A Robust Sliding Mode Observer for Dynamic Positioning System

Nonlinear Passive Observer for Motion Estimation in Multi-Axis Precision Motion Control

“…Several recent efforts have used passivity to demonstrate robustness and the global exponential stability of nonlinear observers. Yang et al [27] presented a robust nonlinear observer for a ship positioning system based on a sliding mode that estimates the lowfrequency position and velocity of a vessel from noisy position measurements. Xie et al [28] introduced a nonlinear passive observer to filter high-frequency disturbances on a measured position and heading of a ship, as well as to estimate the vessel's velocity.…”