Unified observer design for continuous-time linear systems under structured disturbances
摘要
This paper addresses observer design for continuous-time linear systems affected by unknown disturbances. A unified framework is developed for asymptotic estimation of a prescribed linear transformation of the state using input–output measurements only. The analysis covers finite-duration perturbations, exponentially decaying disturbances, and disturbances constrained within bounded polytopic sets. For each scenario, explicit algebraic conditions guaranteeing convergence of the estimation error are derived. A derivative-based observer structure is introduced to achieve exact disturbance decoupling under polytopic constraints. The proposed approach provides constructive gain selection procedures applicable to both full-state and functional observers without reliance on optimization techniques. Numerical simulations illustrate the theoretical results.