基于变结构理论的中制导律设计方法研究

对于采用复合制导的空地导弹,中末制导交接班问题是影响命中概率的关键因素。针对这一问题,采用变结构理论设计中制导律。首先建立滑模面,保证滑模面上速度矢量与视线重合,且零化视线角速率,然后设计到达函数,使到达条件得到满足,可以保证交班时刻导弹可靠捕获目标,并为末制导提供最优初始条件。建立了导弹六自由度数学模型和目标捕获模型,进行全系统数字仿真,实验结果表明：在中末制导交接时刻,弹目视线与导弹速度矢量基本重合,误差为0.12°,视线角速度为-0.02°/s,在±20°视场下满足捕获需求,并且为末制导提供最优初始条件。该方法可以满足中末制导交接班要求,具有较强鲁棒性,且中制导段弹道平滑,需用过载小。

Research on the midcourse guidance law based on variable structure theory

For air-ground missile using composite guided method, the problem of seeker handing-off is a key factor affecting the hitting probability. To solve this problem, the variable structure theory is used to design the midcourse guidance law. Firstly, the sliding surface is established, on the sliding surface, the missile velocity vector coincides with the line of sight, moreover, the line-of-sight rate is zero on the sliding surface. Then, the arrival function is designed to meet the arrival conditions. By doing this, we can ensure that the missile can capture the target at the handover moment, and we can also provide optimal initial conditions for the terminal guidance. The six degree-of-freedom missile simulation model and the target capturing model is established and used to test and verify the design result. As the simulation results shown, the missile velocity vector almost coincides with the line of sight at the handover moment, with a angle error of 0.12°, the line-of-sight angle rate is -0.02°/s. We can see that the ±20°filed-of-view meets the requirement of capturing and we can also provide optimal initial conditions for the terminal guidance by using this midcourse guidance law. This method can meet the requirement of handing-off, the simulation results also show its good dynamic performance and strong robustness.