弹道导弹制导计算中扰动引力的快速赋值

A Gravity Anomaly Rapid Calculation Method in Ballistic Missile Guidance

主动段扰动引力是引起弹道导弹制导方法误差的主要因素。因此,要提高导弹的制导精度,就必须能够在弹上实时计算扰动引力。但现有方法在计算快速性和存储量之间无法得到有效协调。为此,把广义延拓逼近思想引入有限元逼近方法中,将插值单元周围节点的信息也包含到单元内一点扰动引力的计算当中,建立了一种新的数学模型。对所选发射空域,在发射坐标系中进行了直角坐标划分。计算结果表明,这种方法能够更加精确地逼近弹道导弹主动段的扰动引力,在600 km×250 km×6 km的主动段飞行区域内,只需要保存60个节点数据,就能使由逼近误差导致的落点偏差小于10 m,是一般有限元逼近方法精度的4倍以上。

Gravity anomaly is the primary factor in guidance method error. So it is necessary to calculate gravity anomaly real-time on the missile. But it isn＇ t easy to get the balance between the fleet computation and the data memory using current methods. This paper improves the finite element method by introducing the generalized extension approximate idea, and puts forward a new model, in which the information of the vertex of the surrounding element is used to interpolate the gravity anomaly of trajectory points in current element. In this paper, the element partition of selected launch area is implemented in the launch reference frame. Experiment results indicate that this method can get the more accurate result of the gravity anomaly, and keep the fall point warp within 10 meters with 60 vertex data, in a launch area whose airspace is 600 kilometers by 250 kilometers by 6 kilometers. And the precision of it is more than four times of the finite element method.