探空火箭定时定点入轨的一种制导控制规律

针对特定探测天体,给出了特殊用途的探空火箭与其实现空间交会的时刻与地点的计算方法.根据特定天体的运行轨道,发射前算出标称交会飞行轨道,装订在箭载计算机内.火箭发射后,利用箭载惯性导航系统确定自身当前的位置与速度,比对标称飞行轨道参数得出飞行偏差,通过控制火箭推力偏斜调整飞行轨道,使探空火箭在交会时刻到达交会点,并在交会时刻相对与惯性空间的速度为0.定义了研究所用的各种坐标系,建立了火箭飞行动力学方程.研究了标称飞行轨道最优交会点选取,交会时间与发射时间计算等问题.给出了发射后动力飞行段的制导控制规律,核心思想是将控制信号分解为时间控制、当地水平面上的海拔高度控制、南北控制与东西控制,通过设置偏置量减小关机后轨道摄动因素引起的漂移.利用计算机数值仿真验证了这种制导控制规律的可行性.

Trajectory control logic of space exploration rocket required to arrive given site with zero speed at given time

The special space exploration rocket is launched to rendezvous with the celestial body flying around earth, the absolute velocity of rocket should be zero at rendezvous time in order to satisfy the observe requirement. The ideal rendezvous orbit was designed before launch based on the orbit of the celestial body and launch site. The orbit parameters were loaded to onboard computer of rocket. After launch, the inertial navigation system was used to measure the rocket position and velocity, the thruster fire direction was adjusted try to eliminate the flight orbit errors. The several coordinated was defined and rocket orbit dynamical equation was created. The ideal rendezvous time, launch time and rendezvous point in space were studied. The trajectory control logic given during the thruster force is available. The error signal is decomposed into time error, altitude error, north-south error and east-west error in local horizontal frame. Position and velocity shift can be set to reduce the orbit drift caused by perturbation. The feasibility of control logic is verified by computer numerical simulation.