Trajectory Optimization Of Low-thrust And Multi-objection For Deep Spacecraft

Trajectory design and optimization is anterior and important in the deep space mission. Anexcellent orbit design project can not only save the cost, enlarge the task outcomes, but also reducerisk and improve the success rate. In the deep space exploration, the multi-task based onmulti-objective and the continuous low-thrust technique based on electric propulsion have asuperiority of high efficiency and high payload rate. In this paper, combined both of them and kept tothe trajectory technological frontier and the future demand of Chinese space exploration activities, thedeep space trajectory optimization is researched systematically. The main research contents are asfollows:Firstly, the problem description and mathematical models of deep space trajectory optimizationare built up. The problem description includes the initial conditions, boundary conditions andperformance index of deep space trajectory optimization. The mathematical models include thedefinition of orbital coordinate system, the two-body and multi-body dynamics equations of celestialbody and spacecraft and the orbit data of celestial body.Then, two kinds of trajectory combinational optimization algorithms are researched formulti-objective and low-thrust deep spacecraft. The combinational algorithms are mainly used globaloptimization and local optimization. The Near-Earth Asteroids exploration project is chosen to selectthe asteroids sequence with dynamic programming method and optimize the low-thrust trajectory withconjugate gradient method. And the particle swarm optimization and genetic algorithm are combinedto optimal the deep spacecraft trajectory which is given in the third national deep space trajectoryoptimization competitions. The simulation results show that the combinational optimizationalgorithms are of high precision and strong portability, and can bring good performance index.Finally, the error analysis of the deep space trajectory design is researched, which are based ontwo-body and multi-body dynamics model. To get the accuracy error, the contrast experiments havethe same initial conditions and algorithm. The results show that two-body dynamics model in deepspace exploration trajectory optimization has a huge error which is accumulated with time increasing.