Improved Fractional-Order Extended State Observer-Based Hypersonic Vehicle Active Disturbance Rejection Control

In this work, a novel fractional-order extended state observer (FOESO)-based linear active disturbance rejection control (LADRC) method is firstly proposed for a hypersonic vehicle (HV) to address the measurement noise problem. The uncertainty and external disturbance of an HV was discussed and addressed by the active disturbance rejection control and many different control methods in recent decades. However, the research of an HV with measurement noise is insufficient. For the LADRC, the anti-noise ability is highly dependent on the bandwidth of the extended state observer (ESO). Meanwhile, the control performance of the LADRC is relevant to the bandwidth. The FOESO is presented, aiming to address the tradeoff of the control performance or noise suppression. The FOESO-based LADRC (FOESO-LADRC) introduces fractional calculus. It can enhance the anti-noise ability with little influence on the control performance. The simulation results show that the FOESO-LADRC has a significant improvement in the noise suppression. In addition, compared with the LADRC, it obtains a better solution to address the tradeoff between the bandwidth and noise impact.