一种基于引力场线性化的制导方法

A New Guidance Method Using Linearized Gravitational Field

文章针对航天器连续推力轨道机动过程中各种摄动误差的修正问题,提出了最优补偿系数的引力场线性化闭环制导方法。按照力的性质可将摄动力分为保守摄动力和非保守摄动力。通过对保守摄动力进行简化,给出了力的线性表达式,在此基础上基于引力场线性化方法,将惯性系下航天器受摄运动方程转化为线性形式,推导出了以摄动引起的位置偏差为反馈量的闭环制导加速度的表达式。之后考虑非保守摄动力(也即大气阻力),通过引入补偿系数,并利用遗传算法对补偿系数进行优化,得到修正的闭环制导加速度表达式。文中所提的制导方法可用于各种空间轨道机动过程中摄动误差的修正,以交会为例进行了仿真,结果表明修正后的轨道能够很好地跟踪理想轨道,且交会精度高。

Aiming at correcting various types of perturbation errors induced during the orbital maneuver of a continuous thrust spacecraft,we propose a closed-loop guidance method for linearizing its gravitational field with optimal compensation coefficients.Generally,there are two kinds of perturbation： conservative perturbation and non-conservative perturbation.Sections 1 and 2 of the full paper explain our method mentioned in the title,which we believe is new.Their core consists of：（1） we simplify the conservative perturbation and give its linear expressions;then we linearize the equations of motion of the perturbed spacecraft in its inertial frame and deduce the expressions of closed-loop guidance acceleration,which is the feedback of position errors due to perturbation;（2） we take the non-conservative perturbation,namely atmospheric drag,into consideration and use the genetic algorithm to optimize the compensation coefficient k,thus obtaining the modified closed-loop guidance acceleration expressions.Section 3 gives a numerical example of rendezvous;the simulation results,presented in Figs 2 through 8,and their analysis show preliminarily that the orbit of the tracking spacecraft,which is modified with our new method,can well track the ideal orbit of the target spacecraft with good rendezvous accuracy.Our new guidance method can be used for modifying the perturbation errors during various types of orbital maneuver.