Modeling and orbit control for stratospheric satellite

According to the characteristics of the stratospheric satellite tether, consider the tether\´s own gravity and flexibility, build the model of the tether by using piecewise analysis and iterative calculation method. Then, combined with the overpressure balloon and the pneumatic sail, establish a meridional motion model of the "balloon-tether-pneumatic sail" flexible multi-body flight system. Based on the fuzzy control method, according to the deviation of the north and south direction\´s expectations position and actual position of the balloon, design the control system of the pneumatic sail by using the self-tuning fuzzy PID control method. Simulation results have shown that the pneumatic sail using this method can achieve the meridional orbit steady control of the stratospheric satellite in both steady wind field and unsteady wind field.