A novel disturbance observer using adaptive observation and time delay estimation in discrete time systems

In the note, a novel disturbance observer capable of both abrupt disturbances and general disturbance having bounded bandwidth is proposed. Initiated from an adaptive disturbance observation, we enhanced the estimation property to cope with abrupt disturbance and bounded bandwidth disturbances. The generalized form of disturbance observer is derived on the state space. To estimate the abrupt disturbance efficiently, time delay estimation is combined with adaptive estimation method. In addition, for a class of linear systems, its potential applicability will be demonstrated by a numerical simulation.