高超声速飞行器楔面激波的光线偏折校正模型

天文定姿是飞行器实现高精度自主导航的重要技术手段之一。高超声速飞行器在飞行过程中会产生激波，造成光线偏折，影响星敏感器的观测和天文定姿导航的性能。现代高超声速飞行器多采用乘波体设计，其载荷舱部分可简化为楔面结构。论文聚焦高超声速飞行器上楔面激波，基于空气动力学理论，给出了高超声速楔面激波结构参数的解析计算方法，以及激波对光线偏折影响的量化测算模型。提出了一种利用解析计算结果控制光线偏折的校正模型，讨论了激波角测量误差在该模型中的传播，证明了激波角测量误差与其引起的校正效果偏差其呈负线性相关。仿真试验表明，在高度20 km、马赫数5-8的条件下，楔面上方形成稳定的激波结构，对入射光线造成的偏折可达6.8"；解析计算方法获得的激波角参数与试验结果误差在0.1"以内。这意味着运用该模型来校正光线偏折的误差可以控制在激波角观测误差的量级，可以显著提升观测精度。

Beam deflection correction model of wedge-shaped shock waves over hypersonic vehicles

Celestial attitude determination is one of the important technical means for high precision autonomous navigation of aircraft. Shock waves are generated along the surfaces of hypersonic vehicles, which cause beam deflection, affect the observation of star trackers and celestial navigation performances of these vehicles. Most modern hypersonic vehicles adopt the wave-rider design, and the payload bay can be simplified into a wedge plane structure. The shock waves over hypersonic vehicles with wedge-shaped upper surfaces were analyzed. Based on aero-optical theories an analytical calculation method of the structure parameters of the wedge shock wave and a quantitative calculation model of the impact of the shock wave on the deflection of light were given. A correction model was proposed to control the deflection of beam by using the analytical calculation results. The propagation of shock angle measurement error in this model was discussed, and it was proved that the shock angle measurement error was negatively linear correlated with the correction effect deviation caused by it. The simulation results show that under the condition of altitude 20 km and Mach number 5-8, a stable shock wave structure is formed above the wedge surface, and the deflection of incident beam can be up to 6.8 arcseconds. The error between the shock angle parameters obtained by the analytical calculation method and the test results is within 0.1 arcseconds. This means that the error of beam deflection correction by using this model can be controlled at the order of the shock angle measurement error, and the observation accuracy can be significantly improved.