An exponential observer with delay-dependent gain for a class of nonlinear systems with time-varying measurement delay

This paper presents a state observer for drift observable nonlinear systems when output measurements are affected by a known and bounded time varying delay. The proposed observer is an improvement over our previous work in [15] and it includes a delay-dependent gain to attain exponential convergence to zero of the estimation error. The result is illustrated through an application to nonlinear systems with sampled measurements.