Improved successive approximation control for formation flying at libration points of solar-earth system

In deep space exploration, the libration points (especially L2 point) of solar-earth system is a re-search hotspot in recent years. Space station and telescope can be arranged at this point, and it does not need too much kinetic energy. Therefore, it is of great significance to arrange flight formation on the libration point of solar-earth for scientific research. However, the flight keeping control technology of flight formation on the solar-earth libration points (also called Lagrange points) is one of the key problems to be solved urgently. Based on the nonlinear dynamic model of formation flying, the improved successive approximation algorithm is used to achieve formation keeping con-trol. Compared with the control algorithm based on orbital elements, this control algorithm has the advantages of high control accuracy and short control time in formation keeping control of solar-earth libration points. The disadvantage is that the calculation is complicated. But, with the devel-opment of computer technology, the computational load is gradually increasing, and there will be more extensive application value in the future. Finally, the error and control simulations of the formation flying of the spacecraft with the libration points of the solar-earth system are carried out for two days. The simulation results show that the method can quickly achieve the requirements of high-precision control.