Performance output tracking and disturbance rejection for an Euler–Bernoulli beam equation with unmatched boundary disturbance

This paper considers performance output tracking and disturbance rejection for a boundary controlled one-dimensional Euler–Bernoulli beam equation suffered unknown external bounded disturbance. By first proposing a disturbance estimator and then based on this disturbance estimator, we construct a servomechanism to track the reference signal and reject the external disturbance. Four control objectives are achieved: a) the output is exponentially tracking the reference signal; b) the disturbance is rejected; c) all the states of internal-loops are bounded; d) when the disturbance and reference are disconnected, the closed-loop is exponentially stable. Finally, the state of the system is shown to be exponentially tracking the reference state.