基于滑模控制的剖面跟踪制导律

针对高超声速飞行器滑翔段的高精度制导问题，考虑复杂多约束条件以及干扰和不确定因素的影响，设计了一种基于全局积分滑模控制的剖面跟踪制导方法。首先，将多重约束转化为阻力加速度-速度（D-V）平面内的再入走廊；然后，以终端精度和总吸热量为性能指标，采用分段函数的形式优化设计出一条标准D-V剖面；再基于简化的动力学模型，推导得到关于阻力加速度微分和速度的二阶非线性模型；最后，基于滑模控制理论，设计全局积分滑模面和指数趋近律，获得控制量幅值大小，并结合侧向方位误差走廊确定控制量符号，从而实现对标准剖面的有效跟踪。采用CAV-H滑翔再入模型进行数值仿真，分析验证了提出的基于滑模控制的剖面跟踪制导律具有较好的跟踪性能和精度。

Profile tracking guidance law based on sliding mode control

A profile tracking guidance method based on global integrated sliding mode control is designed for the high precision guidance of the hypersonic vehicle gliding phase considering the influence of complex multi-constraint conditions and interference and uncertainty factors. First, the multiple constraints are transformed into the reentry corridor in the drag acceleration velocity (D-V) plane. A standard D-V profile is then optimized and designed in the form of subsection function with the terminal precision and total heat absorption as performance indexes. Moreover, based on the simplified dynamic model, the second order nonlinear model of drag acceleration differential and velocity is derived. Finally, based on the sliding mode control theory, the global integral sliding mode surface and exponential approach law are designed to obtain the amplitude of the control quantity, and the symbol of the control quantity is determined by combining with the lateral azimuth error corridor, so as to realize the effective tracking of the standard profile. The CAV-H glide reentry model is used for numerical simulation, and it is verified that the proposed profile tracking guidance law based on sliding mode control has desirable tracking performance and accuracy.