扰动引力对高超声速跳跃-滑翔弹道的影响分析

Influence of Disturbing Gravity on Hypersonic Skipping-Gliding Trajectory

在临近空间长时间超声速滑翔的导弹,扰动引力对弹道的影响不可忽略。考虑地球扁率及自转的影响,建立了助推-滑翔导弹跳跃-滑翔段三自由度弹道模型;通过球谐函数计算扰动引力,针对起始飞行高度与速度固定的跳跃滑翔弹道,分析了不同阶次扰动引力的变化趋势以及所产生的落点偏差;同时在固定阶次扰动引力下,分别分析了扰动引力对不同射向角、不同起始飞行高度跳跃-滑翔弹道落点精度的影响。仿真结果表明,扰动引力影响不同射向角跳跃-滑翔弹道所产生的落点偏差最大超过4900 m,偏差随着弹道起始高度的降低而减小,当扰动引力计算阶次超过360阶时落点偏差趋于一致,计算结果具有可靠性。因此在实际作战背景下,必须考虑扰动引力对临近空间跳跃-滑翔导弹命中精度的影响,在满足作战条件的前提下可以采用降低跳跃-滑翔弹道起始飞行高度的方式来减小扰动引力对落点精度的影响。

The influences of disturbing gravity on trajectory can’t be ignored when the missile is gliding at supersonic speed in near space. A three degree-of-freedom trajectory model was established considering the earth’s flattening factor and rotation. The disturbing gravity is calculated by using the spherical harmonic function method, and the variation tendency of the disturbing gravity and the landing point deviation under different-order coefficient are analyzed for the skipping-gliding trajectories with fixed-initial flight height and speed. At the same time, under the fixed-order disturbing gravity, the influence of disturbing gravity on the accuracy of the landing point under different shooting angles and different initial flying heights of skippinggliding trajectory is analyzed respectively. The simulation results show that: 1) The maximum deviation of the drop point caused by the disturbing gravity under different shooting angles of skipping-gliding trajectory is more than 4900 meters, and the deviation decreases with the reduction of the initial height of the ballistic trajectory;and 2) When the order of the disturbing gravity exceeds 360, the drop point deviation tends to be consistent, and the calculation results are reliable. Therefore, under the actual combat background , it is necessary to consider the influence of disturbing gravity on the hitting precision of the missile. Under the condition of meeting the operational requirements, it is possible to reduce the initial height of the skippinggliding trajectory to reduce the impact of the disturbing gravity on the precision of the landing point.