基于量测飞行参数的螺旋运动稳定性研究

为研究旋转弹飞行时的螺旋运动稳定性,以弹体坐标系下的螺旋角运动数学模型为基础,提出一种基于量测飞行参数的稳定性分析方法,推导了螺旋角运动的局部动态稳定条件.通过对某制导弹药飞行数据的仿真和分析发现:螺旋角及其变化率呈正弦曲线型周期变化,弹体在局部动态稳定时呈现出极限环形式的螺旋运动,而在局部动态不稳定时呈现出幅值增大形式的螺旋运动.结果表明,以解算出的螺旋角及其变化率为控制系统的参考依据,利用前半周期变换率的反信号,校正后半周期的螺旋角,结果显示可以将平均螺旋张角减小17.3%.

Stability Study of Spiral Motion Based on Calculated Flight Data

To investigate the stability of spiral motion of spinning munitions in flight, a novel analytic method based on flight data is proposed. A mathematical model of spiral motion was established in body coordinate system. The partial dynamic stability condition of spiral angular movement was derived. It could be found by simulation and analysis of flight data that the spiral angles and their changing rates change periodically over time. The spiral motion of the body presents as the form of limit cycles when the body state is in partial dynamic stability, while, in partial dynamic instability, it presents the pattern of extending cycles. The spiral angles and their changing rates could be utilized to design a control loop. One possible control manner is that the opposite changing rate data of first half cycle could be used to improve spiral angle of late half cycle. As a result, the average spiral angle could be reduced by 17.3%.