Path following of a stratospheric satellite by the aid of wind currents

Path-following controller of a stratospheric satellite is designed under circumstances of wind currents utilization, parameter uncertainty, input value errors, and external disturbances. In order to reduce the energy consumption of the stratospheric satellite, the stratospheric east (west) wind currents are utilized by the stratospheric satellite to track the desired path. To utilize the wind currents, an air balloon as well as altitude control model are designed. Fuzzy disturbances observers are presented to estimate uncertainties and external disturbances. Input values are quantized by logarithmic quantizers. Rigorous stability analysis proves that path-following errors of the stratospheric satellite can be reduced to zero, and all closed-loop signals are uniformly bounded regardless of uncertainties and disturbances. Simulation results show that the stratospheric satellite can track the desired path well and the proposed control strategy can reduce the energy consumption of the stratospheric satellite effectively.