一种 6-DOF 小行星着陆轨迹序列凸优化方法

Aiming at the multi-constraint trajectory optimization problem of 6-degrees-of-freedom（6-DOF）dynamic asteroid landing，an optimization algorithm of asteroid landing trajectory based on sequence convex optimization is proposed. Firstly，the polyhedron gravity field，a suitable approach for describing the gravitational field of irregular-shaped asteroid，is adopted to calculate the gravitational field of the asteroid，which can be used to describe the gravitational field of the asteroid of any shape，and the calculation accuracy is higher than that of the spherical harmonic gravity field and the particle group gravity field. In order to solve the problem of optimal fuel consumption during asteroid landing under convex constraints，the initial non-convex continuous-time optimization problem is transformed into convex sub-problem，namely the second-order cone programming problem（SOCP），by linearizing and discretization of the dynamics model and constraints. Virtual control terms and trust domains are then introduced to enhance the robustness of the algorithm. The effectiveness of the proposed algorithm is demonstrated by the simulation of landing on an irregular-shaped asteroid，and the results meet all the constraints，achieving the goals of high-precision landing and optimal fuel consumption.