火星探测捕获的误差传播分析

Error propagation analysis of capture for Mars exploration

火星探测捕获的误差传播是设计任务方案时需考虑的重要问题。针对3种不同的捕获策略:推力沿速度反方向、推力方向固定和匀速转动,基于协方差分析描述函数技术(covariance analysis describing equation technique,CADET)法建立了轨道状态均值和均方差的传播方程,误差源包括初始状态误差、模型误差、执行误差等。仿真整个捕获过程,利用CADET方法分析单一误差和综合误差对每种捕获策略入轨精度的影响,以蒙特卡罗法为基准评估其准确性。结果表明,CADET法能够高精度地计算不同的误差传播,且速度快,具有一定的工程实用性,可为我国未来火星探测任务的轨道捕获段实施方案提供参考。

Error propagation analysis of capture for Mars exploration is an important issue to be considered, which has a direct impact on the success of the task. In terms of three different capture strategies,considering many sources of error such as the initial state error,model error,execution error,propagation equations of states, mean and standard deviation value are established with the covariance analysis describing equation tech-nique （CADET）. When simulating the whole capture process, considering one simulation error each time and combined errors at last, and results of CADET are compared with Monte Carlo method. The simulation result shows that the CADET can yield high-precision results along with lower computation cost, demonstrating its better engineering application value,which can serve as a reference for the implementation plan of orbit captu-ring phase of Chinese incoming Mars exploration.