Design of active disturbances rejection control law of low altitude sea-skimming tow target

To solve the problems that the modeling error and the internal and external disturbances of the low altitude sea-skimming tow target are great, an altitude control scheme based on the active disturbance rejection control technique is proposed. The contradiction of over-control and rapidity is harmonized by arranging the transient process, and the feedback of differential signal is achieved by track differentiator extracting the differential error signal. A nonlinear feedback method is used to improve the control efficiency avoid using integrator. Finally, the un-modeled dynamics and unknown disturbances in the system are estimated and compensated by the extended-state observer. The simulation results show that the control system has good dynamic capability, stable precision and strong robustness when being imported several kinds of disturbances.