The enhanced time delay observer for nonlinear systems

In this paper, we will propose an improved version of the time delay observer (TDO) that solves two problems inherent in TDO, viz., a steady state reconstruction error, and a restriction in selecting gains. By introducing a low pass filter and a state associated with it, we have obtained the enhanced time delay observer (ETDO). This observer turns out to have neither steady state reconstruction error nor any restriction in selecting gains, thereby solving the problems.